|Publication number||US3653741 A|
|Publication date||Apr 4, 1972|
|Filing date||Feb 16, 1970|
|Priority date||Feb 16, 1970|
|Publication number||US 3653741 A, US 3653741A, US-A-3653741, US3653741 A, US3653741A|
|Inventors||Alvin M Marks|
|Original Assignee||Alvin M Marks|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (7), Referenced by (296), Classifications (7)|
|External Links: USPTO, USPTO Assignment, Espacenet|
United States Patent Marks  ELECTRO-OPTICAL DIPOLAR MATERIAL  Inventor: Alvin M. Marks, 166-25 Ninth Avenue,
Whitestone, NY. 11357  Filed: Feb. 16, 1970  Appl.No.: 11,696
Related U.S. Application Data  Continuation-in-part of Ser. No. 378,836, June 29,
1964, Pat. No. 3,512,876.
DIPOLE PARTICLES PARALLEL T0 sum-A E U/VPDLAR/ZED L/Gur ANDOM V/gRA TIONS REFLECIED LIGHT POLAR/ZED NOIZIZONTALLY [451 Apr. 4, 1972 3,205,775 /1965 Marks ..350/147 X 3,350,982 11/1967 Marks.... ..350/152 X 3,353,895 ll/1967 Emerson... ..350/147 X 3,443,854 5/1969 Weiss ..350/147 3,536,373 10/1970 Bird et al. ..350/147 Primary Examiner-David Schonberg Assistant Examiner-Paul R. Miller Atlorney-Philip D. Amins  ABSTRACT An article of manufacture is provided as a matrix having dispersed substantially uniformly therethrough a plurality of electro-optically responsive dipole particles selected from the group consisting of electrically conductive and semi-conductive material and dichroic crystals, the matrix being a transparent medium capable of being in the fluid state during the initial orientation of the dipoles, whereby the dipoles are capable of rotation to a desired preferred orientation upon the application of a force field, the medium being thereafter solidified. A method of applying the force field is disclosed.
26 Claims, 13 Drawing Figures TEAL/SMITH?!) LIGHT IZE IV THE POLARIZATION FFFECTY 0F DIPOLE 542 775255 OIPIENTEU /N 7' ll! PLANE of 77/5 SURFACE.
PATENTEDAPR 41972 3,653,741
SHEET 1 OF 5 X DIRECTION OF ELECTRIC VECTUR OF LIGHT: POLARIZATION AMPL r005 pawns/Wad") &
A L ma VELENGTH (coma) THE THREE FUNDAMENTAL A RIB TE OF LIGHT ARE 2 AMPLITUDE, WA VELENG'I'H, WAVELENGTH 4ND POLAR/Z4 T/ON FIG. I
POLAR GRAPH 0 RELATIVE RESPONSE VERSUS ANGLE OFA D/POLE 7'04 CONSTANT SIGN 4 INTENSI 7').
Q 11 35 Q cos u; [a l Y I 90 /ao ANGLE POLAR/ZA T/QN 0105c T/ON INVENTOR. DIPOLE ANTENNA 41 1 MARKS RElAT/VE Reva/vs: OFA DI OLE Awe-m4 mesa: poue/zn r/o/v 0025c mu ;0. I
FIG. 3 ATI'DR/VE S PATENTED PR 4 m2 SHEET 2 OF 5 LIGHT HALF WAVE DI OLE WITH I. CENTRAL LOAD RESISTOR 2. DISTRIBUTED RESISTANCE SHOW/N6 HALF WA VE DIPOLE WITH CHARACfER/ST/C LOAD QES/STOR TUNED T0 ABSORB MAX/MUM POWER.
FIG-4 PHYS/CA1. CR S 5 SECTION A floo A NA EFFEcr/ve A .50 cnoss sear/01v n/cwsss A254 AZ/B suowlm mar rue EFFECTIVE c2055 SECTION OFAN 5 ANTENNA MAYBE MANY 77,4155 ms PHYSICAL cm sear/01v,- uv 77115 case msx. POWER IS fwwveusa FROM mv EFFECflV' c1205: SECTION mm ms SMALLER ACTLML cross SECTION or THE ANTENNAE.
A woven/mm INVENTOR J41 w/v M. MARKS A rron/vsrs s/mwnva ms RELA m1: POWE'R nesoeaso on RRAOMTD vexzsu:
mamas/var Fae m/cK A/VD EKJENTED R 1 72 3,653,741
SHEET 3 0F 5 DIPOLES NORMAL SUI/"A C E 7 PARTICLES AL/GIVED NORMAL TO THE SURFACE COAT/N6 l5 TRANSPARENT.
TBMIQVITTEO L/GH T DIPDL E POLAR/ZED PARTICLES YER T/CALL Y PAMLLEL T0 SURFA CE UNPOLA RIZED Ll GUT RANDOM V/BRA TIONS REFLECTED LIGHT FULAR/ZED HORlZ0/VTALLY 8 syows THE POLARIZATION EFFECTS OF DIPOLE MRWCZES ORIENTED IN 77/: PLANE OF THE SURFACE.
DIPOL E 5 WI T H RANDOM DIRECT/0N mow M6 DPO s HAVING .4 xzwvao/w INVENTOR- FIG. 9 4 5442 PXJENTED 4 1973 SHEET [1F 5 INCIDENT LIGHT fiuwwm) PULSE Y APPL IED EL EC TR/C Z w. m P
FIELD FLU/O O12 PLASTIC LAYER WHICH HAROE'NS SUPPORT 01 ARIZED ZANSMITTED RAY AZUMINUM FLARE POLAR/ZED FIGBA INVENTOR. AL WM 1% MAQKS This application is a continuation-in-part of U.S. application Ser. No. 378,836, filed June 29, 1964, in the name ofAlvin M. Marks, now U.S. Pat. No. 3,572,876.
This invention relates to conducting dipole polarizers and articles, products, devices, and the like, produced therefrom having preferred optical properties, the conducting dipoles being advantageously formed of metals, non-metals, or semiconductive materials capable of forming whiskers by vapor deposition or capable of forming submicron rod-like shapes by using metallurgical melting and controlled freezing techniques, growth from a vapor, or other known techniques. The dipoles are suspended in a transparent layer of material capable of being congealed or hardened after the dipoles have been oriented in the desired direction.
RELATED APPLICATION In related application Ser. No. 378,836, now U.S. Pat. No. 3,512,876 methods and apparatus are disclosed for controlling light and related forms of electromagnetic radiation using dipole particles suspension in transparent media. By employing an external electrical or magnetic field, the optical properties of the media can be varied by orienting and disorienting the dipolar particles in suspension in accordance with the field applied, the media being a fluid in which Brownian movement aids in randomizing the dipole particles upon removal of the external field. In its broad aspects, the related application provides a light-controlling device comprising in combination a fluid suspending medium and a plurality of minute dipole particles rotatably carried in the medium, the particles advantageously having a long dimension of the order of about )t/2n and at least one other dimension preferably not exceeding about 1 n (where A is the wavelength of light and n is the index of refraction of the suspending medium). The disposition of the particles in the medium is controlled by applying an electric, magnetic or mechanical shear force field to the suspension. One example of a light-controlling device is an electro-optical shutter. The related application goes into great detail in the technical aspects of dipole particles, which disclosure is wholly incorporated into this application by reference.
BACKGROUND OF THE INVENTION In the prior art, it is known to produce metal polarizers by the reduction of metal salts in stretched polymers, such as cellulose hydrate, gelatin, polyvinyl alcohol, and the like. The metals so reduced form aggregates within the interstices of the polymer. Such aggregates are usually relatively uncontrolled as to length and diameter. Since most polymers have disordered regions, irregularly shaped metal deposits were often formed which detracted from the transmittance and polarization characteristics. The polymers employed, were capable of swelling or dissolving in water, and were generally sensitive to ambient atmospheric conditions.
Elongated silver particles having a maximum ratio of three to one in the form of ellipsoid of silver, have been produced in glass by strong stretching. For a given mass per unit area of absorbent material, the absorption obtained by such particles is greater than that of an ordinary colorant, such as cobalt dissolved in the glass, by a factor of about 3,000 to one.
The prior art methods of stretching to deform particles do not enable control of particle ratio of length/width, nor do they result in optimum length/width ratios required for strong polarization.
Another polarizer described in the prior art consists of minute wires or conductors on a glass surface or within a glass structure. However, no practical means for the production of such structures have been disclosed. Very long thin conductors are not as efficient for producing a high degree of polarization and transmittance in a specific wavelength range. The dipoles herein disclosed may be fabricated by incorporation into a suitable stable polymer or a glass melt and aligned by mechanical shear forces, or an electric or magnetic field. It
would be desirable to have a dipole particle which is inert and which will resist degradation during use in the ambient environment.
OBJECTS OF THE INVENTION It is an object of the invention to provide conductive and semi-conductive dipole particles which are substantially inert to the ambient environment and which resist degradation.
Another object is to provide as an article of manufacture a transparent material, such as a solid material made of glass or transparent plastic, characterized by a dispersion of microscopic, inert, dipole particles oriented to confer light polarizing properties on the material.
A further object is to provide a solid transparent substrate having a transparent coating thereon containing a dispersion of submicron, inert, conductive, dipole particles having a preferred orientation, whereby to provide predetermined optical properties to the coated substrate.
A still further object is to provide a composition of matter for optical use, said composition comprising a suspending medium containing a plurality of dipole particles, the medium being one capable of being converted to the fluid or soft state to enable orientation of the particles and capable of being solidified to permanently fix the position of oriented dipole particles.
The invention also provides as an object a method of producing dipole particles of relatively controlled sizes.
These and other objects will more clearly appear when taken in conjunction with the disclosure and with the accompanying figures of the drawing which are summarized as follows:
IN THE DRAWING FIG. 1 illustrates the three fundamental attributes of light;
FIG. 2 is a polar graph showing relative response versus the angle of a dipole to a constant signal intensity;
FIG. 3 shows the relative response of a dipole antenna versus polarization direction;
FIG. 4 depicts a half-wave dipole with a characteristic load resistor tuned to absorb maximum power;
FIG. 5 illustrates diagrammatically the effective cross section of a dipole antenna as compared to the actual physical cross section;
FIG. 6 is a graph showing the relative power absorbed or reradiated as a function of the wavelength of light for thick and thin half-wave dipoles;
FIG. 7 depicts a transparent substrate, e.g. glass or plastic, having a transparent coating, e.g. of plastic, in which dipoles are dispersed and oriented normal to the surface of the coat- FIG. 8 is similar to FIG. 7 except that the dipole particles are oriented parallel to the surface to provide polarization effects, whether the coated article is a lens, a coated windshield for automobiles, coated sheet material, and so forth; and FIG. 8A shows flake orientation;
FIG. 9 is similar to FIGS. 7 and 8 except that the dipoles in the coating are randomly oriented;
FIG. 10 is a diagrammatic cross sectional view of a machine for the continuous production of polarizing film or sheet utilizing dipoles which are electrically aligned;
FIG. 11 is a detailed fragment of the electrical aligning section of the device of FIG. 10; and
FIG. 12 is a vertical cross section of a high pressure spin coating device for producing high field orientation dipole suspension coatings.
GENERAL STATEMENT OF THE INVENTION The present invention overcomes the deficiencies of the prior art by providing metal whisker dipoles or submicron rodlike dipoles of relatively inert material such as chromium, aluminum nickelide, platinum or other conducting metal; or alternatively, by utilizing semi-conductors which are advantageous for certain other characteristics, such as silicon, germanium, or zinc sulfide whiskers, and having a selected length, and length to width ranges.
These are preferentially incorporated in a readily meltable glass, thermoplastic or plastic solution, and orientated by means well known to the art, such as by the application of an electrical or magnetic field or by the application of stretching where differential shear is produced during stretch causing the parallel orientation of the particles, and subsequently solidified by cooling or evaporation of solvent.
Thus, as one broad aspect of the invention, a composition of matter is provided for optical use comprising a plurality of conductive or semi-conductive asymmetric particles (e.g. dipoles) suspended in a transparent medium which is substantially a solid at ambient temperatures but which can be melted or softened to a fluid state at an elevated temperature to form any desired shape, the particles being then oriented to a preferred direction by an electrical or magnetic field before allowing the shaped body to solidify.
Another aspect of the invention resides in an article of manufacture in the form of a polarizer comprising a layer of transparent material having a dispersion of inert conductive or semi-conductive dipole particles therein having a length of A/Zn i 50 percent, and preferably having an average diameter of at least about IOn, where n equals the index of refraction of the transparent medium, the long axis of particles being oriented in the plane of the transparent medium.
The dipole particles can be produced by various methods. Thus, metal dipoles can be produced by vapor deposition in a partial vacuum to produce metal whiskers which can be sized in a blender and the sizes separated by centrifuging or by differential settling.
Another method is to produce a eutectic of a binary alloy which, by directional freezing, produces a rod-like structure, the size of the rod-like structure being determined by the velocity of the plane of soldification and temperature gradient. After selectively dissolving away the matrix metal, the residue of rod-like material is washed and then suspended in an inert liquid for sizing in a blender, the sized material being thereafter selectively separated using differential settling or centrifuging techniques. The foregoing and other methods will be described in more detail hereinafter.
The dipole particles useful in the present invention are characterized in that they have at least one dimension large relative to at least one other dimension, that is to say, they are in the form of flakes, needles or the like. The dipole particles should haveat least one dimension equal to one-half of the wavelength of the radiation to be controlled, (normally, visible light, but in some cases, infrared, ultraviolet, microwave, or other portions of the electro-magnetic spectrum) and at least one other dimension substantially smaller than one-half of said wavelength. The magnitude of the third dimension, that is, whether the particle is a needle or a flake, depends on the requirements of the specific embodiment of the invention, as more fully discussed below.
For purposes of brevity, the term light is used throughout the present specification and claims in a generic sense and is intended to encompass not only visible light but also infrared and ultraviolet light, as well as microwave radiation in the neighboring portions of the electromagnetic spectrum.
In addition to the dimensional requirements herein disclosed, the electrical or magnetic properties of the dipolar particles, i.e. the conductivity, should be such as to facilitate orientation in an electric or magnetic field, and strong interaction with electromagnetic radiation.
The suspending medium is a fluid, non-reactive with the dipole particles, or is a substance capable of being converted to a fluid, at a temperature sufficiently low to avoid any adverse effect on the dipole particles.
It is not in all cases necessary that the suspending medium be in the liquid state during the first stage of orienting the particles. Providing the applied torque is sufiiciently strong to orient the dipole particles against a certain amount of plastic resistance of the suspending medium, it is sufficient if the suspending medium is in a highly deformable plastic state. The term fluid" as used herein should therefore be understood to encompass such a plastic or soft condition. For most applications of the present invention, the suspending medium is present as a liquid during alignment or disorientation of the dipole particles. The dipole particles must also be of such a nature that they are capable of being oriented by an applied electric, magnetic or, in certain cases, a mechanical shear force field.
Some particles have an inherent dipole moment by reason of their internal structure in which the effective center of positive charge in the molecule or crystal is spaced from the center of positive charge. Such an inherent dipolar character, if present, is effective to some degree in augmenting the tendency of the particles to orient themselves in an applied force field. Inherent dipolarity is, however, neither essential nor a major factor in determining the effectiveness of the dipole particles.
As stated hereinbefore, the preferred dimensions of the particles above referred to may be characterized by A/2n where A is the wavelength of the light to be polarized and n is the index of refraction of the medium in which the particles are suspended and oriented.
For example, if a suspension of dipole particles is to polarize light at 5,600A, and the index of refraction of the transparent suspending medium is 1.5, the optimum length for the dipole whisker is 5,600/2 1.5= (5600/3) 1,860A. The length to diameter ratio should be not less than three, and preferably greater; that is, from 10 to 100. The percentage of polarization increases with the length/width ratio, and the width of absorption or reflectance band decreases. Where dipole particles are highly conducting, such as with silver, gold or copper whiskers, the polarizer acts as a beam splitter, and the radiation is partly transmitted and partly reflected. The transmitted radiation is polarized with good image resolution. The reflected radiation, however, is scattered, and polarized in a plane at to that of the plane of polarization of the transmitted light.
A beam splitting polarizer of this type is particularly useful where polarization of intense light beam sources is required. In the case of the absorption polarizer, the temperature of the polarizing element rises perhaps to cause destruction. However, with the beam splitting polarizer, the radiation is mostly reflected and transmitted, and the temperature rise is minimized.
The most efficient sheet polarizer is that which requires the smallest number of particles per unit area to accomplish a given percent polarization. The most efficient sheet polarizer is obtained by selecting particles within a narrow size range, about the optimum A/Zn dimension. For example, for most efficient polarization in the range from 4,500A to 6,600A, dipole particles having length ranges between 1,500A to 2,200A, are selected. For a still narrower range of polarizing characteristics, then a still narrower range of dipole particle lengths is employed. For example, for a narrow frequency band which might characterize a laser, then a single length with close tolerances is employed.
Stable chemical structures are relatively rare. Most chemical structures are relatively easily deteriorated by ultraviolet, visible and infrared light, heat and chemical action.
Light is an electromagnetic wave having three fundamental attributes, which are: amplitude or intensity, wavelength or color; and polarization or the vibration direction at right angles to the ray.
These three fundamental attributes of light are shown in FIG. 1.
A half-wave dipole antenna, which is normally used for television reception, has interesting properties.
The half-wave dipole is capable of controlling all three attributes of light, by varying its length, thickness, resistivity and angular position.
The electric power absorbed from the radiation by the halfwave dipole depends upon two orientation angles of the dipole. The first angle, 6, is that between the length of the dipole and the signal path. The second angle, 45, is that between the length of the dipole and the direction of polarization of the signal.
FIG. 2 shows a polar graph of radiant power absorbed versus angle 0.
In FIG. 3, the radiation ray path is normal to the plane of the diagram, and there is shown the angle versus the power absorbed by the dipole.
A maximum response is obtained when the antenna is aligned parallel to the polarized electric vector of the radiation and at right angles to the signal path ((12 0, and 90). The antenna absorbs no power when it is placed at right angles to the polarized electric vector of the radiation; or arranged parallel to the ray path.
When adjusted for a maximum response, a half-wave or M2 antenna is then said to become resonant to the particular wavelength A.
The power absorbed by the dipole from the radiant energy may be re-radiated, or absorbed and dissipated as heat, depending on the electrical resistance of the half-wave dipole antenna.
lf power is to be absorbed from the dipole antenna and utilized in an outside electric circuit, as for example in a television set, a matched or characteristic resistance of 73 ohms must be inserted at its center of the half-wave dipole antenna, as shown in FIG. 4.
An antenna may be made of such material, thickness and length as to achieve full power absorption, or nearly total reflection.
In FIG. 4, there is also shown a half-wave (M2) antenna 2; in which the central resistor is replaced with a single rod having a distributed resistance of approximately 80 ohms, which results in the absorption of radiation in the wavelength range it.
Now, if instead of a half-wave antenna with a central resistor or an equivalent distributed resistance, a half-wave antenna of low resistance is employed, then the half-wave dipole antenna becomes reflective for the full wavelength. The radiant power may be said to be absorbed by the half-wave dipole and then re-radiated in all directions, with the intensity direction pattern shown in FIG. 2. Thus, the resistivity characteristics of the materials, together with the length and width, controls the distributed resistance of the half-wave antenna. These factors may be adjusted so that the half-wave dipole antenna has high absorptivity or high reflectivity for incident radiation of a given wavelength band.
FIG. 5 shows another very important property of the halfwave dipole antenna, the effective cross section.
FIG. 5 shows a half-wave dipole antenna having a thickness of one twenty-fifth its length. Its length is M2 and its thickness M50. The physical cross section of this half-wave dipole at right angles to the light ray is:
()\/2) (M50) A /IOO. However, it is known that the effective cross section of a half-Wave dipole antenna is much larger. The cross section from which the half-wave dipole appears to absorb power is approximately A /8. A rectangle of this size is shown in dotted lines surrounding the antenna rod, the radiant power actually funnelling into the dipole. In this example, the effective area of the antenna has been increased by a factor of A /B divided by XVIOO or 12.5 times.
Dipole antennas have been employed for the electro-magnetic spectrum all the way from long wave radio down through the television range into the microwave and millimeter wave spectrum.
Dipoles have been observed which are resonant in the range of the wavelength of visible light. Yellow light at the peak sensitivity of the human eye has a wavelength of 0.565 microns (yellow). Elongated metal rods of submicron dimensions in colloidal suspension in a transparent medium, results in myriads of light-responsive dipoles. The transparent medium keeps the dipoles in spaced relation.
The index of refraction n of a given medium may be defined as the ratio of the speed of light in free space, to the speedof light in the medium. Since the speed of light in all substances is less than in free space, n is always greater than one. The wavelength of light in a given medium is inversely proportional to the index of refraction n" ofthe medium.
Because the index of refraction of transparent media is approximately 1.5, the dimensions of a half-wave dipole must be decreased in inverse proportion; that is, for n 1.5, the actual resonant length of a half-wave dipole in such a medium becomes r) A/l .5 =A/3.
For example, in a medium having an index of refraction of 1.5, a half-wave dipole should have a length of (0.565/3) 0.188 microns (or 1880A) of yellow light for 0.565 microns wavelength (or 5650A).
The M3 dimension, of course, is correct only for n 1.5 and will vary with the index of refraction of the medium.
Another interesting property of the dipole is that the sharpness of its tuning, or the wavelength range over which it will absorb 0r reflect, depends on the ratio of the length to the thickness of the dipole, as well as on the resistivity of the dipole material.
FIG. 6 refers to the reflection or absorption of radiant energy by a half-wave antenna showing the relative power absorbed or re-radiated, versus the ratio of length to thickness of the antennae.
A. For thin dipole antenna (25/1) B. For a thick dipole antenna (10/ ll) We now come to the application of these basic concepts to light control; that is, control of all three basic attributes of light, intensity, color and polarization, by dipoles in suspensions in a transparent medium.
Pigments formed from dipolar materials are visually indestructable. The polarization, reflectivity or absorptivity characteristics of the dipole suspensions are predetermined by the appropriate selection of length, width and resistivity of the dipoles, together with their concentration and orientation.
Such a dipole suspension has the property of absorbing or reflecting specified wavelength ranges. Since a specific resonance characteristic is obtainable from the same material merely by changing its length to width ratio, very pure colors can be obtained by transmission or reflection from coatings formed from such suspensions. When oriented, the dipole suspension has strong polarizing properties.
The substances chosen to form the dipoles are preferably chemically stable materials, which remain permanently within the suspension, and which are not subject to chemical destruction by ordinary atmospheric agents or by exposure to light. However, dichroic crystalline needles, such as herapathite dipoles, may be employed as dipoles.
The dipoles may be formed of metals, such as gold, platinum, palladium, chromium, tin, or metal compounds such as Al Ni, and the like, which are known to grow submicron crystal-whiskers, under appropriate conditions, such as from the vapor phase. Semi-metals, such as carbon, silicon and germanium, are also known to form crystal-whiskers. These crystal-whiskers may then be incorporated in a fluid to form a dipole suspension.
A crystal-whisker made of a single substance of the utmost permanence, may be predetermined in its properties; a perfect black, a perfect white diffuse reflector, or having sharp absorptivity or reflectivity bands in the yellow, green, blue or other regions of the spectrum. When oriented, these result in polarizing these characteristics.
The effective cross section per particle oriented normal to the light ray and parallel to the electric vector of the light in a I medium of index of refraction n is:
/8n (I) This property is useful in calculating the number of particles required for substantially complete light absorption or reflection as follows:
Assuming no aggregation of particles, the concentration of a suspension of submicron dipolar particles per square centimeter in a medium having an index of refraction of 1.5 is determined as follows:
= 6.25 X 10 particles/cm? It is possible to obtain the interparticle spacing between dipoles oriented in the same direction, the interparticle spacing for substantially parallel dipoles being the center to center distance between the longitudinal axis of the particles taken-at right angles to each other. The interparticle spacing for substantially complete light absorption or reflection does not substantially exceed the width of the effective cross section.
The derivation of the interparticle spacing, d,,, for the polarizing case is determined where the dipoles are all parallel and disposed in the plane of the sheet. The details are disclosed in copending application (Ser. No. 378,836, filed June 29, 1964, and need not be repeated here. Simply stated, the interparticle spacing may be determined as follows:
N, the number of diples per unit volume of suspension V, volume of cube occupied by one dipole l/N,
d,,= interparticle spacing= V,,= l/N, 3
The concentration of dipole particles required to provide effective surface coverage is generally very low as will be apparent from the following:
Assuming a square cross section for the particle having a width a, the mass per particle is b= width to length ratio and 8= density in gms./cm. of the dipole.
Thus, the mass m, per dipole particle of gold for length to width ratio of 25 where 8 of gold equals 19 and b 1/25 is:
m, of gold 2 X l0 gms./particle.
The mass m, of dipoles per unit area is then determined as follows:
Thus, (it/n) b (particles/cm?) X (mass/particle) 6.25 x x 2 x 10- x 1.25 x 10- gms./cm.
As will be noted, very small concentrations of dipole particles of the order of about 2 micrograms/cm. are sufficient to provide effective surface coverage.
For a film of 10" cm.(0.4 mil) thickness, and density l gm./cm. this corresponds to a dipole concentration of only 0.125 percent of the solid film.
Because their effective cross section is much greater than the physical cross section, the dipolar particles may be very sparsely distributed in space. The dipolar particles are sufficiently far apart from each other so as to have no physical interaction. Each dipolar particle acts independently of the other.
FIG. 7 shows a film containing dipole particles with their length oriented normal to the surface. The film is transparent because the cross section particles present to the radiation is so small that substantially no light scatter and no light absorption occurs.
FIG. 8 shows a film in the XY plane in which the dipole particles are aligned in the OX direction. Light transmitted along the Z axis into the surface emerges from the other side plane polarized with the electric vector By in the ZY plane. Reflected light is plane polarized with the electric vector E I in the ZX plane. Reflected light is polarized and scattered.
FIG. 9 shows a film having dipolar particles in random orientation. Reflected light is symmetrically scattered in all directions. The transmitted light and the reflected light show no polarization. However, since the dipoles are tuned to a particular wave band, the transmitted and reflected rays are complementary in color. Consequently, in the random orientation, the dipoles act as pigments. However, these dipolar pigments are subject to control by variation of physical quantities of dimension resistivity and orientation.
As stated hereinabove, dipoles may be oriented by an electric field, a magnetic field (if the particle is magnetic, diamagnetic or paramagnetic), or by viscous shear forces in the suspending fluid. Dipole particles tend to disorient rapidly in suspending fluids of low viscosity. For low viscosity fluids obtained by heating to a fluid temperature, the disorientation of dipolar particles may occur in milliseconds. The disorientation is due to Brownian movement or the random impact of the fluid molecules on the dipole particle.
However, if the suspending fluid viscosity is high, dipole orientation will persist for a longer time, from seconds to hours. A permanent orientation of dipolar particles may be achieved in a fluid by allowing the solvent, in the case of a plastic composition, to evaporate while maintaining the orientation.
Metallurgical techniques may be employed to produce dipoles. A known eutectic method for the manufacture of metal dipoles has produced chromium rods and aluminum nickelide rods having a length/width ratio of about 100, in a range of diameters from 50A to 300A, and lengths to about 40,000A. The method involves the precipitation of one metal dissolved in another; for example, chromium precipitated from a chromium-copper melt, using a travelling temperature difierential, or directional cooling from one end of a melt. The solidification rate may vary from about 0.1 to 10 cm./sec. at a temperature gradient of about 1 to C./cm. Subsequently, the copper is dissolved in acid, leaving long thin chromium metal rods having a submicron diameter, and of various lengths. After the extraction of the metal rods, they can be further decreased in size using acid of controlled concentration. Thus, where the diameter is 500 to 1,000A, acid treatment can further decrease the diameter.
It has been found that long rods may be chopped into shorter lengths in a suitable range by the following procedure. The metal rods are suspended in an inert fluid. The fluid may comprise water, alcohol, or an ester with or without dissolved polymer. The polymer helps to suspend these particles. The suspension is placed in a high speed blender, the revolving metal blades of which cause strong shear and impact forces to occur. Most of the cut rods do not appear to be bent but appear to be cleanly sheared into shorter straight rods.
It is theorized that the particles are cut by high speed impact or possibly torn asunder by opposing turbulent shear forces. Whatever the physical explanation may be, the rod lengths varying from about 700A up to the maximum particle length are placed in suspension. The particles are then separated into size ranges by fractional centrifugation or by electrophoresis. The larger particles, in the case of centrifugation, are thrown down as the first centrifugate and then successively smaller ranges of particles are thrown down into the centrifugate. Finally, there remains only smaller particles of irregular shape of a very small length/width ratio. A suitable intermediate ratio range is selected and the process may be repeated, using a smaller viscosity fluid if required, to get a narrower range of ratios. These particles are then filtered and washed with solvent and vacuum dried.
Where glass is used as the final matrix, the selected dipole rods are then mixed with finely powdered glass frits, of a suitable composition well known in the art. This mix is melted, stirred, debubbled, and cast to form sheets. These sheets, when heated to a high viscosity, may be drawn by stretching to orient the dipolar particles. Alternatively, the sheets may be melted or softened at high temperatures to a low viscosity, and the dipole rods oriented by electrical means. To produce a light polarizing sheet, the orientation is carried out to position the dipoles parallel to the surface.
To produce a uniaxial polarizer of the type described in my US. Pats. Nos. 3,205,775 and 3,350,982, the dipole rods are oriented normal to the surface of the sheet. To obtain a wedge-shaped transmission pattern requires a combination of two sheets in which the dipole rods are oriented respectively parallel to, and normal to the surface; that is, a combination of uniaxial and linear polarizing sheets.
Various techniques known in the art of glass making may be employed. For example, continuous drawing methods may be employed using a glass melt containing dipoles, and the drawing and rolling of the glass will cause the orientation of the dipolar particles to produce polarized glass. Various selected size ranges may be employed to produce sharp absorption and reflection bands.
To polarize the entire visible spectrum, selected length ranges of dipole rods varying in length from about 1,000A to 2,500A may be employed. To produce glasses which will polarize the infrared, larger particles are employed from about 2,100A up to about 10,000A in length to polarize infrared in the range of l to 30 microns. Thus, broadly speaking, the length of the dipoles may range from 1,000A to 10,000A, the ultimate size being determined by the particular end use.
Polarizers may also be made by incorporating these dipolar rods in the same selected size ranges in polymers normally employed for polarizing materials; ie polyvinyl alcohol, polyvinyl butyral, and these subjected to mechanical elongation to orient the particles in a manner well known in the art.
Another method which may be employed advantageously is the incorporation of the particles in a polymer solution, such as a silicone polymer solution, which has a high degree of stability at an elevated temperature. This solution may be employed by flowing or spinning a coating onto a glass surface, for example, a lens, which is subjected to an electrical field just before it dries, while the dipoles are free to turn. The di ole rods may be oriented with their long axes parallel to the surface by applying an electrical field parallel to the surface or the dipoles may be oriented normal to the surface by the application of an electrical field normal to the surface.
The polymeric coating containing the dipoles is set by allowing the fluid to evaporate. The dipoles may be placed in a monomer and oriented by electrical fields while the monomer is setting. Alternatively, the monomer may be stretched when partially polymerized to orient the particles by mechanical shear forces and then finally set by completing the curing process.
As illustrative of the various methods which may be employed in producing conductive dipoles, the following examples are given:
EXAMPLE 1 Flake Dipole Suspensions To prepare metallic flakes for use as dipole particles, a layer of metal is deposited, for example, by known vacuum deposition techniques, on a film of plastic or other convenient substrate, and the substrate is subsequently dissolved, thus causing the metal film to be suspended as a flake in the solvent. The suspended film is then chopped to flakes of the desired size by using a Waring blender and the desired sizes separated by differential centrifugation.
EXAMPLE 2 Ultrathin Aluminum Flake Suspensions A novel method of preparing ultrathin aluminum flake suspensions uses aluminum flakes 1-17 microns in diameter, and 0.1 to 1 micron in thickness as the starting point. A suspension is prepared by adding 48 grams of the aluminum flake material to 300 cubic centimeters of di-isooctyl adipate. This mixture is then shaken and poured into a 500 cubic centimeter graduated cylinder and allowed to settle. Most of the aluminum flakes then settle to the bottom of the graduate. However, a small portion of the flakes remains suspended in a thin layer at the top of the graduate. This top layer then comprises ultrathin aluminum flakes, approximately 0.1 micron in thickness, which are then recovered.
Thus, by means of this flotation method, the 0.1 micron thickness flakes are separated from the thicker flakes. These ultrathin flakes may be further separated and concentrated by centrifuging.
Another way to make thin flakes of aluminum or the like is to coat a thin rubber sheet with a film of aluminum by exposing it to aluminum vapor, until a film of approximately 0.01
l fl micron thickness has been built up. This sheet is then stretched to break up the surface into flakes of aluminum. The underlying rubber sheet is next dissolved in order to place the flakes in suspension. Finally, the large flakes are eliminated, and the small flakes in the desired size range are concentrated, by centrifugation. This technique can also be employed using polyvinyl alcohol or polyvinyl chloride sheets by heating the sheets after the coating step, to facilitate their being stretched.
The resulting suspension is suited for use in those embodiments of the invention which require a suspension of dipoles in the form of flakes, for example, the Reflective-Absorptive devices, discussed in the referenced copending application.
XAMPLE 3 Needle-like Metal Dipole Suspensions diameter in the submicron range, and deposit a film of aluminum on the thread by passing the thread through a zone or chamber in which it is exposed to aluminum vapor. The thread is then wound on a spool, and sliced with a microtome. Finally, the supporting thread is dissolved in a suitable solvent,
leaving the metal coating in the form of thin aluminum strips in colloidal suspension.
EXAMPLE 4 Needle-like Metal Dipoles from Whiskers Needle-shaped metallic dipoles may be formed from a metal, such as gold, platinum, palladium, chromium, tin or the like, which are known to grow submicron-diameter crystal whiskers under appropriate conditions, usually from the vapor phase. These crystal whiskers may then be incorporated into fluid to form a dipole suspension. Such needles, if classified to a uniform length, may be made sharply selective as to the wavelengths of light affected by them. This property results from their large length-to-thickness ratio and resistivity, for reasons which are explained below. Such materials constitute a new class of pigments different in effectiveness and mode of operation from conventional pigments.
The factors controlling the growth of needle-like whisker dipoles are partial pressure and temperature of the metal vapor, temperature and nature of the deposition surface, and time of growth. Usually, the growth occurs best under vacuum, or inert gas such as helium or nitrogen, but, in some cases, as with gold, whiskers can be grown in air. Two gold sheets separated by a few millimeters and by a few degrees temperature difference, held in air at a temperature such as to generate an appreciable gold partial vapor pressure, will cause gold whisker crystals to grow normal to the surface of the cooler gold sheet. The dimensions of the whiskers are such as to fall within the size ranges herein specified. On cooling, the whiskers may be incorporated in a plastic film formed by coat ing the surface of the gold sheet, encompassing the whiskers. Upon drying, the film may be stripped away and dissolved, leaving the gold dipoles in suspension in the fluid. This process may be performed continuously using an endless belt of a material, such as stainless steel, which is initially provided with active sites for initiation of whisker growth.
Flat Crystals Flakes made from crystalline material, such as lead carbonate (pearlescence), may be grown to any desired size by methods well known to the art. These flakes have an index of refraction of about 2.4, and, when placed in a fluid having an index of refraction of about 1.5, are readily aligned by an electric field, and in the equivalent of about -20 layers almost totally reflect visible ultraviolet and near infrared radiation, when disoriented or oriented in the plane of the cell wall or sheet; while being almost completely transparent when aligned normal to the sheet surface.
Zinc vapor will deposit submicron flat crystals on a substrate, which can be dissolved away as above described, to yield a metal flake suspension having dipolar characteristics.
Graphite forms flat hexagon flakes which, when suspended in a fluid of low viscosity, show dipolar characteristics.
EXAMPLE 6 Metal Coated Preformed Dipoles Preformed rods of Boehmite (colloidal alumina) are metalcoated by vapor deposition. The Boehmite is in the form of minute crystalline rods or fibrils having a length of approximately 1,000A and a width of about 5A. In metal coating the fibrils, the Boehmite crystal rods are heated to various elevated temperatures while exposed to the metal vapor.
Another method is to coat Boehmite particles by chemical deposition. For example, Boehmite particles may be soaked in a solution of a metal halide or nitrate, such as gold chloride, gold nitrate or silver nitrate. The particles are washed to remove all but the adsorbed salt. The Boehmite powder is then heated to a temperature of about 300 C to decompose the adsorbed salt and thus produce a coating of silver or gold metal on the Boehmite.
EXAMPLE 7 Production of Dipoles from Binary Eutectics Metal fibers can be prepared by the unidirectional solidification of binary eutectic alloy. A well known example is the system Al-Al Ni. The alloy containing about 5.7 percent to 6.4 percent by weight of nickel and the balance aluminum is produced by melting together high purity aluminum (99.99 percent) and high purity nickel (99.99 percent). The melts are unidirectionally solidified using induction and resistance heating sources by maintaining a thermal gradient during cooling. Whiskers or rods of Al Ni are formed lying parallel to each other in the direction of solidification and dispersed through an aluminum matrix. By increasing the rate of cooling, the diameter of the needles or rods can be increased. The Al Ni whiskers may be extracted from the aluminum matrix by using a 3 percent solution of aqueous HCl solution. As soon as the whiskers are dislodged, they are removed rapidly from solution and are washed. The whiskers can be graded according to size by differential settling or differential centrifugation as described hereinbefore. Splat cooling may be employed by striking metal droplets against a cold surface of high heat conductivity.
Examples of other eutectic alloys are the following:
Au-Ca Au'13.2% Ca Ca Au. Au Au-Na Au-17% Na NaAu, Au Au-Sb Au-347c Sb AuSb, Au-0.64% Sb Au-Te Te-47"7 Au AuTe Au Au-Tl fl-27.7% Au T1 Au Au-U Au-12.5% U U Au, Au
' Atomic percent As will be noted, the fibers contain substantially one metal, that is, some of the compositions yield fibers which at worst contain less than 1 percent of the second metal. Of the 13 systems listed, five may yield fibers of pure or nearly pure metal in a matrix of a second pure metal, such as Ag-Bi, Ag- Pb, Al-Ga, Al-Sn and Au-Tl. There are other systems, among which is included the system Cu-Cr.
The resistivities of some of the metals are given as follows:
TABLE 2 Resistivities of Metals Resistivity Element OXIO ohm-cm. at 20 C.
Aluminum 2.62 Antimony 39.0 Cadmium 7.5 Chromium 2.6 Copper 1.69
Indium Iron 10.0
Lead 21.9 Palladium 10.8
Silver 1.62 Tantalum 13.1 Thallium 18.1 Titanium 30 Zinc 6.0
Utilizing the known resistivities of the foregoing metals, the
length to width ratios of absorbing and reflecting dipoles can be calculated using equation (57) of parent application Ser. No. 378,836 now U.S. Pat. No. 3,512,876, referred to hereinabove. These calculations are summarized in Table 3 which sets forth the length to width ratios for absorbing and reflecting dipoles utilizing specified metals.
reflecting dipole is assumed to have a distributed resistance R of 8 ohms. Values of 1.5 for n and 0.5 microns for )1 were used.
Thus, the properties of the metal dipoles can be determined beforehand, depending upon the length to width ratio and those sizes selected in accordance with the particular property desired.
IIaving graded the sizes of the metal dipoles, these can then be used to make a wide range of products. In this connection, reference is made to FIGS. 10 and 11 as illustrative of forming polarizer material in sheet form.
In FIG. 10, there is shown a supply roll 1 and a wind up roll 2 for a thin film substrate or web 3 of plastic material, such as .cellulose acetate, cellulose acetate butyrate, acrylic, vinyl film or the like, having a thickness, for example of 0.1 to 1 mm. Film 3 passes over roller 4 where it is coated by a polymer solution 5 containing dipoles. The level 6 of the polymer solution is maintained by the feed 7, from a level sensing device such as an inverted bottle (not shown). Evaporation of solvents from the coating is initially prevented by means of the shield 8. The dipole coating layer 9 shown in FIG. 11 remains liquid for a time sufficient to enable orientation of the dipole particles by an electrical field 11. An electric field parallel to the surface of the coating is maintained between a plurality of electrodes 12, 13, 14, 15, 16, etc. in the vicinity of the coating 9. To minimize the effect of the vertical component of the electric field near the electrodes, cool air may be provided in the areas and 21 by ducts 22 and 23 (FIG. 11). This decreases the temperature, and increases the viscosity, of the coating layer 9 thereby preventing the dipoles from being disoriented by the vertical field component. In a similar manner, heated air may be provided in the areas 25 and 26 by the ducts 27 and 28 to decrease the viscosity of the coating 9 where the component of the electric field is most nearly parallel to the surface of the film. This enables the dipoles 10 to be aligned parallel to the surface of the coating 9. The dipoles are fixed by passing the film 3 through the evaporation chamber 30 (FIG. 10) which is provided with the input air duct 31 and the output air duct 32 containing the evaporated solvent. The duct 31 may contain a number of sections. Section 33 may be at a low temperature to freeze the particles into alignment initially while evaporation is occurring. Section 34 may be at ambient temperature to continue the evaporation of solvent and section 35 may be at a higher temperature to evaporate the residual solvent. The film emerging from section 35 over roll 36 is dry.
If an herapathite dipolar suspension is employed, the electric field 11 is preferably AC field having a frequency of 10 to 100 kHz. at an electric field intensity of l to 20 kv./cm. The best alignment is obtained at the greatest electric field intensity which is just under the electric breakdown strength of air. Greater electric field strengths may be employed if the entire device is pressurized to several atmospheres.
With metal dipoles in a nonionic fluid, DC or low frequency AC may be employed, in the same electric field strength range.
The herapathite composition which may be employed contains submicron selected particles prepared for example as in Example I in the copending application Ser. No. 378,836 previously noted.
Metal dipole suspension may, for example, be prepared as described herein. In this connection, reference is made to a technical paper entitled Behavior of Unidirectionally Solidified Al-Al Ni Eutectic by Lemkey, Hertzberg and Ford; Transactions of the Metallurgical Society of AIME, Feb, 1965, Vol. 233, pages 334-341.
In this article, it is shown that at a growth velocity exceeding 3 cm. per hour, a spaced rod-like structure occurs initially. The spacing between the rods, and the rod diameter becomes smaller as the velocity increases. The rod spacing is proportional to the inverse square root of the growth velocity. For example, extrapolation to 300 cm. per hour shows particle separation of 0.2 microns with and diameter of about 300A.
The thermal gradient was between 25 and 37 C. per cm. A,
greater temperature gradient, which results in smaller dipole rods, may be obtained by placing the eutectic in a small diameter tube, such as a quartz tube, having an inside diameter of 1 mm.
To achieve a dipole diameter of -300A, a thermal gradient of about 300 C. per cm. may be used at a growth velocity of about 0.13 cm./sec. After the rods are grown, the matrix is then dissolved away utilizing an acid, such as dilute hydrochloric acid. The particles may be further decreased in size by washing them with a suitable acid, such as hydrochloric acid, until the optimum diameter and length has been ob tained. The dipole rods remaining undissolved are washed with water, and then with alcohol and acetone and dispersed in a solvent containing a polymer as described above.
The invention may be employed in the coating of lenses using a spin coating technique as follows with particular reference being made to FIG. 12
The object is to apply field of the order of 200 to 300 Kv./cm. across an air gap in which the coating is placed. The purpose of the device is to obtain maximum orientations and extremely large electrodichroic ratios for coatings oriented in the plane of the surface of the lens. The effect is essentially electrostatic and the currents employed would generally be in the microampere range. The electric field is preferably applied across a distance not exceeding about 7 cms. on most lens applications, an electric field of upwards of 1 million volts being contemplated for such a distance, the voltage being AC or DC. Since the gap normally required for a field of 1 million volts is about 33 cms, the electric breakdown strength must be increased by about 5 times. This may be accomplished by placing the element to be coated and aligned in a pressure tank operating at about 5 times atmospheric pressure or approximately 75 p.s.i.
In FIG. 12, a cylindric chamber 40 is provided with a cover 41 sealed by O-rings 42. A shaft 43 passes through cylindrical chamber 40 via a sealed bearing 44, the shaft being inserted into the extending end on insulated body 45. Slip rings 46 and 47 are connected through insulated bushings 48 and 49, respectively, to terminals 50 and 51.
The bushings 48 and 49 should be large enough in diameter so that the path length between the exposed conductors and the walls on the interior is greater than that which would afford a spark breakdown path under the established interior pressure conditions. Exterior atmospheric pressure conditions can be tolerated provided bushings 48 and 49 are extended sufficiently outward to provide at least a 33 cm. total gap or they may be alternatively immersed in an insulating oil bath 52. The dipole fluid 53 is poured on lens 54 held within spin holder 54A and rotated along with electrodes 55 and 56 between which the intense electric field is established. Excess fluid is thrown off and the dipoles are oriented to very nearly parallelism. Provision should be made for the evaporation of the solvent and for the provision of additional air to carry away the evaporated solvent. This may be done with an air source pipe 57 and an exit pipe 58 connected to a valve which controls the flow of air through the chamber.
The interior 59 of the chamber is desirably maintained at a pressure of at least 75 p.s.i. before the application of the voltage. When the operation is complete, the dipolar particles are aligned and evaporation has occurred to solidify coating 53. The voltage is then turned off and the rotation of shaft 43 stopped. The pressure within the chamber is released and the top 41 removed so that the coated lens can be taken out of the spin holder and another inserted.
A polarizing medium results after fluid layer shown in FIG 12 has solidified (as by cooling if the fluid is a thermoplastic or a glass). For example, the dipoles may be metal needles, such as platinum, and the medium a low melting point low viscosity glass, such as solder glass The dipole particles utilized in invention differ from those of prior art polarizers, such as Polaroid J polarization which was an oriented herapathite suspension in cellulose acetate butyrate. The dipoles of the present invention are controlled in size and shape to close tolerances, whereas those of the prior art were of random size and shape. Consequently, polarizers produced in accordance with this invention have no perceptible light scatter. Light polarizers according to this scatter was a particularly serious disadvantage of prior art polarizers which were a result of the process of manufacturing, which caused larger particles to be produced in situ.
As stated hereinbefore, semiconductors, as set forth, may be employed in the preparation of such dipoles as described.
Preparation of Submicron Herapathite Crystals To produce submicron herapathite crystals in high concentration in a low viscosity suspending fluid, which form an optically clear, non-scattering dipole particle suspension of suitable electrodichroic ratio and sensitivity, the reacting solutions should be:
The iodine is dissolved in the normal propanol by heating and shaking.
Quinine Bisulphate 32.5
For complete solution warm with agitation in a hot water This solution is then warmed to 70 C. and pressure filtered at the same temperature to remove any small undissolved crystal which would act as nuclei for crystallization.
Solutions Nos. 1 and 4 are then mixed in proportion and rapidly mixed in a container cooled by an acetone dry ice bath. The result is:
Before reaction After reaction Perercent cent Pts. Material Solids Solids Solids No. l 9 Iodine 20.0 1.8 (Quinine Bisulph c) g 4.06 3.7 5.5 lQS. 44.4
No. 91 (Nitrocellulose)... 7. 55 6.87 Nl 5 5;
While Solution No. 5 is being prepared, alkyl epoxy stearate (Celluflex-ZS), a high boiling solvent also known as a plasticizer is cooled in an ice bath to 0 C., and added in the following proportions to make a paste containing the submicron herapathite particles in suspension:
Paste P cent Pts. Material Solids solids lodoquininesulphate... 4.24 Sus- 13.0
pended SolutionNo.5 77 Nitrocellulose... ..30 16.3 Celluflex-23 23 'Celluflex-23 23.0 solution 70.7
No. 6 is then mixed with a mechanical stirrer for about 10 minutes to insure complete reaction and homogenity. After this, to remove the volatile solvents, the suspension No. 6 is placed in a rotating evacuator for about 2 hours and a paste is then obtained which is substantially free from solvents except the plasticizer and which has a resistivity of at least 30 megohm-cm.
The analysis of the paste resulting from No. 6 after the volatiles have been removed is:
No. 9 may be used directly or be centrifuged to obtain a supernatent liquid for use in an electrodichroic system.
A herapathite suspension prepared in this manner is characterized by elongated submicron crystals of herapathite, which remain in suspension without settling and which is suitable for use as a dipole particle suspension in the practice of this invention.
Chemically, herapathite is quinine trisulphate dihydroiodide tetraiodide hexahydrate, the chemical name for 4C l-LO N 31-1 80 2H1 L, 61-1 0. The molecular weight is 2,464.
Stoichiometrically herapathite contains approximately 25.8 percent of iodine which is approximately a ratio of iodine to quinine bisulphate of 1 [3.
However, I have found that the proportions can be varied from as through A. This is apparently due to herapathite being a molecular compound or a mixed crystal in which the proportion of the components may vary.
Moreoever, the HI in the compound is present in the proportion of two moles of quinine to one of H1. The heating of the iodine solution No. 1 usually sufi'ices to provide sufficient H1 as set forth in the above example. The presence of H1 in stoichiometric quantities is required to form a stable crystalline compound. An additional quantity of H] may be added to achieve the molar ratio set forth.
Generally, I have found the composition of Example A to be satisfactory, and this composition has been used in most of the tests.
As will be appreciated from the foregoing disclosure, the embodiments provided by the invention are many and varied. F or example, as one embodiment, an article of manufacture is provided comprising a matrix having dispersed substantially uniformly at least at the surface thereof a plurality of dipoles selected from the group consisting of electrically conductive and semi-conductive material, such as metal or herapathite dipoles, the matrix being a medium capable of being in the fluid state during the initial dispersion of the dipoles whereby said dipoles are capable of rotation to a desired preferred orientation upon the application of a force field. Thus, the liquid state of the matrix may be in the form of a solution that dries during the application of the force field, or the medium forming the matrix may be one which is converted to the fluid state by the application of heat, but which is capable of hardening during the application of a force field. The matrix might be a coating applied to a surface, such as a curable plastic coating; or it might be a coating applied to a transparent substrate, such as glass or a hard plastic.
The dipoles dispersed in the matrix may have an average length of about A/Zn 50 percent and an average diameter ranging up to about M n i 50 percent, A being the wavelength of light and nthe index of refraction of the matrix medium. Depending on the wavelength of the particular light striking the surface, the dipoles may range in length from about 1,000A to 10,000A.
The number of particles in a unit area of matrix medium may be determined simply by using the formula N 8n /A The interparticle spacing of the dipoles oriented in the plane of the matrix medium is generally at least about the effective cross section of the dipole divided by its average length, the effective cross section being determined by the formula: Effective cross section A /8n Another embodiment provided by the invention is a composition of matter for a light controlling device comprising a transparent suspending medium and a plurality of dipole particles selected from the group consisting of conductive and semi-conductive material suspended in the medium, the medium being one which is capable of being in a fluid state to enable the dipoles to be rotated to a preferred orientation upon the application of a non-constant force field, the medium being then capable of being solidified at ambient temperatures during the application of the force field in order to fix the particular orientation of the dipoles desired. The type of dipole particles employed may be the same as those discussed herein before.
A further embodiment is an article of manufacture in the form of a solid transparent layer of a medium having substantially uniformly dispersed therethrough said dipole particles having a preferred orientation relative to the plane of the transparent layer. The transparent layer may be a material selected from the group consisting of glass and plastic. By glass, is meant any transparent inorganic material capable of being worked into any desired shape, either by melting and shaping the glass, or by forming a coating of the glass-like material onto a transparent substrate, such as with a solution which, upon drying, leaves a glass-like coating. Similarly, by plastic, is meant any transparent organic material which is capable of being softened and shaped into any desired form or which can be employed as a solution which leaves a coating after the solution has been evaporated from a layer deposited by the solution. In any event, it is any material of the foregoing type which is capable of having a fluid state during which dipole particles dispersed through the fluid can be oriented by using a non-constant force field, which force field is maintained until it is caused to harden or cure or form a permanent layer by drying.
As another embodiment, the invention provides a polarizer comprising a solid layer of transparent medium, such as glass or plastic, having a substantially uniform dispersion therethrough of dipole particles oriented in the plane of the layer, selected from the group consisting of electrically conductive and semi-conductive particles, the particles preferably and advantageously having an average length of about A/Zn flO percent and a diameter ranging up to about A/lOniSO percent. As stated above, the dipole particles may advantageously be metallic and be spaced from each other in accordance with the preferred limitations stated hereinbefore.
The invention also provides a composite article of manufacture comprising a substrate of a transparent material having a transparent optical coating thereon, such as glass or plastic, and containing a dispersion of dipole particles similarly as described herein.
The method embodiment of the invention for producing an article of manufacture of a transparent medium having preferred optical properties resides in providing the medium, e.g. glass or plastic, in the fluid state containing a uniform dispersion of dipole particles selected from the group consisting of electrically conductive and semi-conductive material (eg metal dipoles), in forming a layer of the material in the fluid state, in subjecting the layer to the action of a force field whereby to orient said dipoles in a predetermined direction, and in maintaining the force field while allowing the layer to solidify. The solidification referred to may be the result of dry ing the fluid, allowing the fluid to harden or cure which, in the case of glass, would harden by cooling and the same is true for some plastics. However, the plastic might have a curing catalyst which causes hardening to take place while the force field is maintained.
The methods disclosed hereinabove may similarly be employed in producing a coated substrate of transparent material in which the coating may be of glass or plastic containing dipoles which is applied to the substrate in a fluid state and the dipoles similarly oriented in the plane of the coating using the non-constant force field.
A method which may be employed in efiecting the orientation of dipole particles in a transparent medium resides in providing the medium as a layer in the plastically deformable state (eg glass or plastic) containing a uniform dispersion of dipole particles, in physically stretching the layer unidirectionally so as to orient the dipoles in the plane of the layer in the direction of stretch, and then allowing the stretched layer to congeal or harden to permanently fix the oriented positions of the dipoles dispersed in the layer.
It will be understood that in polarizers made in accordance with this invention, the flakes (e.g. aluminum flakes) are oriented normal to the surface and in parallel planes as shown in FIG. 8A. The orientation shown in FIG. 8A may be obtained by momentarily applying a pulsed electric field along the Z-axis, followed immediately by a pulsed electric field along the X-axis, whereby the particles are oriented along the respective axes. The pulses are applied sufficiently rapidly, for example at a repetition rate of about 1,000 per second so that the flakes do not have a chance to disorient between successive pulses. Thus, the plane of substantially each of the flakes, when oriented, may be parallel to two of the axes. For example, the plane of substantially each of the oriented particles may be parallel to the plane of the layer, or normal thereto.
Although the present invention has been described in conjunction with preferred embodiments, it is to be understood that modifications and variations may be resorted to without departing from the spirit and scope of the invention as those skilled in the art will readily understand. Such modifications and variations are considered to be within the purview and scope of the invention and the appended claims.
What is claimed is:
1. A film, sheet or block of material comprising a matrix having dispersed substantially uniformly therethrough a plurality of electro-optically responsive dipole particles selected from the group consisting of electrically conductive and semiconductive material and dichroic crystals, said matrix comprising a medium having separate fluid and solid states'and being in the fluid state during the initial orientation of the dipoles, and said dipoles being rotatable to a predetermined desired orientation upon the application of a force field.
2. The material of claim 1, wherein the dipoles are metallic.
3. The material of claim 1, wherein the dipoles have an average length of about A/Zn i 50 percent and an average diameter ranging up to about A/ lOn 50 percent, A being the wavelength of light and n the index of refraction of the matrix medium.
4. The material of claim 3, wherein the dipoles range in length from about 1,000A to 10,000A.
5. The material of claim 4, wherein the number of particles per unit area is at least the reciprocal of the effective cross section per particle.
6. A material in accordance with claim 1, wherein said material comprises a transparent optical coating on a substrate of transparent material, said coating having said dipole particles oriented in the plane thereof, said dipole particles having an average length of about A/2n i 50 percent and an average diameter ranging up to about lOn 50%, where A is the wavelength of light and n" the index of refraction of the transparent coating.
7. The material of claim 6, wherein the substrate and the coating are selected from the group consisting of glass and plastic.
8. The material of claim 6, wherein the dipole particles are metallic.
9. The material of claim 8, wherein the dipole particles have an average length of about 1,000A to 10,000A.
10. The material of claim 9, wherein the number of particles per unit area is at least the reciprocal of the effective cross section per particle.
11. A film, sheet, or block of matter for a light-controlling device comprising a transparent suspending medium and a plurality of dipole particles selected from the group consisting of conductive and semi-conductive material, and dichroic crystals, suspended in the medium, said medium having separate fluid and solid states and being in a fluid state to enable the dipoles to be rotated to a predetermined orientation upon the application of a force field, and said medium being solidified to permanently fix the rotational position of the dipole particles.
12. The matter of claim 11, wherein the transparent suspending medium is selected from the group consisting of glass and plastic. 7
13. The matter of claim 12, wherein the dipole particles have an average length of about )\/2n 1 50 percent, and an average diameter ranging up to about A/lOn i 50 percent, A being the wavelength of light and n the index of refraction of the suspending medium.
14. The matter of claim 13, wherein the dipoles range from about 1,000A to 10,000A in length.
15. The matter of claim M, wherein the dipole particles are metallic.
16. A film, sheet or block of material comprising a solid transparent layer of a medium having substantially uniformly dispersed therethrough dipole particles selected from the group consisting of conductive and semi-conductive material, and dichroic crystals, said particles having a preferred orientation relative to the plane of the transparent layer, and wherein the dipoles have an average length of about )t/Zn 50 percent, and an average diameter ranging up to about )t/ 10n I 50 percent, A being the wavelength of light and n" the index of refraction of the transparent medium.
17. The material of claim 16, wherein the dipoles are metallic and have an average length falling within the range of about 1,000A to 10,000A.
18. The material of claim 16, wherein the umber of particles per unit area is at least the reciprocal of the effective cross section per particle.
19. A polarizer comprising a solid layer of transparent medium having a substantially uniform dispersion therethrough of dipole particles oriented in the plane of said layer selected from the group consisting of electrically conductive and semiconductive particles, and dichroic crystals, said dipole particles having an average length of about t/2n i 50 percent and an average diameter ranging up to about k/lOn 1 50 percent, where A is the wavelength of light and n" the index of refraction of the transparent material.
20. The polarizer of claim 19, wherein the transparent material is selected from the group consisting of glass and plastic.
21. The polarizer of claim 19, wherein the dipole particles are metallic.
22. The polarizer of claim 21, wherein the dipole particles have an average length of about 1,000A to 10,000A.
23. The polarizer of claim 22, wherein the number of particles per unit area is at least the reciprocal of the effective cross section per particle.
24. A polarizer comprising a layer of transparent material containing a uniform dispersion of flake particles selected from the group consisting of electrically conductive and semiconductive material, and dichroic crystals, the plane of the layer being referenced to a coordinate system having three mutually perpendicular axes described as the X-, Y- and Z- axes, and the flakes being oriented such that the plane of substantially each of the flakes is parallel to a plane formed by two of said axes.
25. The polarizer of claim 24, wherein the flakes are substantially normal to the plane of the layer.
26. The polarizer of claim 25, wherein the flakes are aluminum.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US2123901 *||Apr 3, 1936||Jul 19, 1938||Sheet Polarizer Company Inc||Light polarizing material|
|US2481621 *||May 2, 1945||Sep 13, 1949||Skiatron Corp||Light modulation by cathode-ray orientation of liquid-suspended particles|
|US3205775 *||Jun 19, 1961||Sep 14, 1965||Alvin M Marks||Light polarizing structures incorporating uniaxial and linear polarizers|
|US3350982 *||Jul 21, 1965||Nov 7, 1967||Alvin M Marks||Light polarizing structures|
|US3353895 *||Apr 16, 1962||Nov 21, 1967||Polaroid Corp||Light polarizer comprising filamentous particles on surface of transparent sheet and method of making same|
|US3443854 *||Jun 25, 1964||May 13, 1969||Siemens Ag||Dipole device for electromagnetic wave radiation in micron wavelength ranges|
|US3536373 *||Feb 12, 1968||Oct 27, 1970||Polaroid Corp||Light polarizer|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US3774988 *||Jun 21, 1971||Nov 27, 1973||Polaroid Corp||Variable light-filtering device|
|US5305143 *||Aug 9, 1991||Apr 19, 1994||Kabushiki Kaisha Toyota Chuo Kenkyusho||Inorganic thin film polarizer|
|US5835255 *||May 5, 1994||Nov 10, 1998||Etalon, Inc.||Visible spectrum modulator arrays|
|US5986796 *||Nov 5, 1996||Nov 16, 1999||Etalon Inc.||Visible spectrum modulator arrays|
|US5999315 *||Apr 25, 1997||Dec 7, 1999||Kyocera Corporation||Polarizer and a production method thereof and an optical isolator|
|US6040937 *||Jul 31, 1996||Mar 21, 2000||Etalon, Inc.||Interferometric modulation|
|US6055090 *||Jan 27, 1999||Apr 25, 2000||Etalon, Inc.||Interferometric modulation|
|US6313947||Mar 23, 1999||Nov 6, 2001||Hoya Corporation||Light polarizing glass containing copper particles and process for preparation thereof|
|US6359722 *||Oct 23, 2000||Mar 19, 2002||Minebea Co., Ltd.||Optical isolator with a compact dimension|
|US6541853 *||Sep 7, 1999||Apr 1, 2003||Silicon Graphics, Inc.||Electrically conductive path through a dielectric material|
|US6650455||Nov 13, 2001||Nov 18, 2003||Iridigm Display Corporation||Photonic mems and structures|
|US6674562||Apr 8, 1998||Jan 6, 2004||Iridigm Display Corporation||Interferometric modulation of radiation|
|US6680792||Oct 10, 2001||Jan 20, 2004||Iridigm Display Corporation||Interferometric modulation of radiation|
|US6710908||Feb 13, 2002||Mar 23, 2004||Iridigm Display Corporation||Controlling micro-electro-mechanical cavities|
|US6710921 *||Jan 15, 2002||Mar 23, 2004||Moxtek||Polarizer apparatus for producing a generally polarized beam of light|
|US6867896||Sep 28, 2001||Mar 15, 2005||Idc, Llc||Interferometric modulation of radiation|
|US6943941 *||Feb 27, 2003||Sep 13, 2005||Asml Netherlands B.V.||Stationary and dynamic radial transverse electric polarizer for high numerical aperture systems|
|US7012726||Nov 3, 2003||Mar 14, 2006||Idc, Llc||MEMS devices with unreleased thin film components|
|US7012732||Mar 1, 2005||Mar 14, 2006||Idc, Llc||Method and device for modulating light with a time-varying signal|
|US7042643||Feb 19, 2002||May 9, 2006||Idc, Llc||Interferometric modulation of radiation|
|US7060895||May 4, 2004||Jun 13, 2006||Idc, Llc||Modifying the electro-mechanical behavior of devices|
|US7110158||Aug 19, 2002||Sep 19, 2006||Idc, Llc||Photonic MEMS and structures|
|US7119945||Mar 3, 2004||Oct 10, 2006||Idc, Llc||Altering temporal response of microelectromechanical elements|
|US7123216||Oct 5, 1999||Oct 17, 2006||Idc, Llc||Photonic MEMS and structures|
|US7126738||Feb 25, 2002||Oct 24, 2006||Idc, Llc||Visible spectrum modulator arrays|
|US7128414 *||Dec 24, 2003||Oct 31, 2006||Essilor International Compagnie Cenerale D'optique||Methods for coating lenses|
|US7130104||Jun 16, 2005||Oct 31, 2006||Idc, Llc||Methods and devices for inhibiting tilting of a mirror in an interferometric modulator|
|US7138984||Jun 5, 2001||Nov 21, 2006||Idc, Llc||Directly laminated touch sensitive screen|
|US7161094||May 18, 2006||Jan 9, 2007||Idc, Llc||Modifying the electro-mechanical behavior of devices|
|US7161728||Dec 9, 2003||Jan 9, 2007||Idc, Llc||Area array modulation and lead reduction in interferometric modulators|
|US7161730||Jul 22, 2005||Jan 9, 2007||Idc, Llc||System and method for providing thermal compensation for an interferometric modulator display|
|US7164520||May 12, 2004||Jan 16, 2007||Idc, Llc||Packaging for an interferometric modulator|
|US7172915||Jan 8, 2004||Feb 6, 2007||Qualcomm Mems Technologies Co., Ltd.||Optical-interference type display panel and method for making the same|
|US7187489||Jun 1, 2006||Mar 6, 2007||Idc, Llc||Photonic MEMS and structures|
|US7193768||Mar 24, 2004||Mar 20, 2007||Qualcomm Mems Technologies, Inc.||Interference display cell|
|US7198973||Nov 13, 2003||Apr 3, 2007||Qualcomm Mems Technologies, Inc.||Method for fabricating an interference display unit|
|US7221495||Jun 24, 2003||May 22, 2007||Idc Llc||Thin film precursor stack for MEMS manufacturing|
|US7221501||Apr 15, 2005||May 22, 2007||Asml Netherlands B.V.||Stationary and dynamic radial transverse electric polarizer for high numerical aperture systems|
|US7236284||Oct 21, 2005||Jun 26, 2007||Idc, Llc||Photonic MEMS and structures|
|US7250315||Sep 14, 2004||Jul 31, 2007||Idc, Llc||Method for fabricating a structure for a microelectromechanical system (MEMS) device|
|US7256922||Jul 2, 2004||Aug 14, 2007||Idc, Llc||Interferometric modulators with thin film transistors|
|US7259449||Mar 16, 2005||Aug 21, 2007||Idc, Llc||Method and system for sealing a substrate|
|US7259865||Nov 17, 2005||Aug 21, 2007||Idc, Llc||Process control monitors for interferometric modulators|
|US7280265||May 12, 2004||Oct 9, 2007||Idc, Llc||Interferometric modulation of radiation|
|US7289256||Apr 1, 2005||Oct 30, 2007||Idc, Llc||Electrical characterization of interferometric modulators|
|US7289259||Feb 11, 2005||Oct 30, 2007||Idc, Llc||Conductive bus structure for interferometric modulator array|
|US7291921||Mar 29, 2004||Nov 6, 2007||Qualcomm Mems Technologies, Inc.||Structure of a micro electro mechanical system and the manufacturing method thereof|
|US7297471||Apr 15, 2003||Nov 20, 2007||Idc, Llc||Method for manufacturing an array of interferometric modulators|
|US7299681||Mar 25, 2005||Nov 27, 2007||Idc, Llc||Method and system for detecting leak in electronic devices|
|US7302157||Apr 1, 2005||Nov 27, 2007||Idc, Llc||System and method for multi-level brightness in interferometric modulation|
|US7304784||Jul 21, 2005||Dec 4, 2007||Idc, Llc||Reflective display device having viewable display on both sides|
|US7317568||Jul 29, 2005||Jan 8, 2008||Idc, Llc||System and method of implementation of interferometric modulators for display mirrors|
|US7321456||Apr 11, 2005||Jan 22, 2008||Idc, Llc||Method and device for corner interferometric modulation|
|US7321457||Jun 1, 2006||Jan 22, 2008||Qualcomm Incorporated||Process and structure for fabrication of MEMS device having isolated edge posts|
|US7327510||Aug 19, 2005||Feb 5, 2008||Idc, Llc||Process for modifying offset voltage characteristics of an interferometric modulator|
|US7343080||Jul 1, 2005||Mar 11, 2008||Idc, Llc||System and method of testing humidity in a sealed MEMS device|
|US7349136||May 27, 2005||Mar 25, 2008||Idc, Llc||Method and device for a display having transparent components integrated therein|
|US7349139||May 3, 2006||Mar 25, 2008||Idc, Llc||System and method of illuminating interferometric modulators using backlighting|
|US7355780||Feb 11, 2005||Apr 8, 2008||Idc, Llc||System and method of illuminating interferometric modulators using backlighting|
|US7359066||Mar 4, 2005||Apr 15, 2008||Idc, Llc||Electro-optical measurement of hysteresis in interferometric modulators|
|US7368803||Mar 25, 2005||May 6, 2008||Idc, Llc||System and method for protecting microelectromechanical systems array using back-plate with non-flat portion|
|US7369252||Nov 17, 2005||May 6, 2008||Idc, Llc||Process control monitors for interferometric modulators|
|US7369292||May 3, 2006||May 6, 2008||Qualcomm Mems Technologies, Inc.||Electrode and interconnect materials for MEMS devices|
|US7369294||Aug 20, 2005||May 6, 2008||Idc, Llc||Ornamental display device|
|US7369296||Aug 5, 2005||May 6, 2008||Idc, Llc||Device and method for modifying actuation voltage thresholds of a deformable membrane in an interferometric modulator|
|US7372613||Apr 22, 2005||May 13, 2008||Idc, Llc||Method and device for multistate interferometric light modulation|
|US7372619||May 23, 2006||May 13, 2008||Idc, Llc||Display device having a movable structure for modulating light and method thereof|
|US7373026||Jul 1, 2005||May 13, 2008||Idc, Llc||MEMS device fabricated on a pre-patterned substrate|
|US7379227||Feb 11, 2005||May 27, 2008||Idc, Llc||Method and device for modulating light|
|US7382515||Jan 18, 2006||Jun 3, 2008||Qualcomm Mems Technologies, Inc.||Silicon-rich silicon nitrides as etch stops in MEMS manufacture|
|US7385744||Jun 28, 2006||Jun 10, 2008||Qualcomm Mems Technologies, Inc.||Support structure for free-standing MEMS device and methods for forming the same|
|US7388704||Jun 30, 2006||Jun 17, 2008||Qualcomm Mems Technologies, Inc.||Determination of interferometric modulator mirror curvature and airgap variation using digital photographs|
|US7403323||Nov 17, 2005||Jul 22, 2008||Idc, Llc||Process control monitors for interferometric modulators|
|US7405861||May 2, 2005||Jul 29, 2008||Idc, Llc||Method and device for protecting interferometric modulators from electrostatic discharge|
|US7405863||Jun 1, 2006||Jul 29, 2008||Qualcomm Mems Technologies, Inc.||Patterning of mechanical layer in MEMS to reduce stresses at supports|
|US7405924||Mar 25, 2005||Jul 29, 2008||Idc, Llc||System and method for protecting microelectromechanical systems array using structurally reinforced back-plate|
|US7407284||Oct 31, 2006||Aug 5, 2008||Essilor International Compagnie Generale D'optique||Methods for coating lenses|
|US7415186||Sep 1, 2005||Aug 19, 2008||Idc, Llc||Methods for visually inspecting interferometric modulators for defects|
|US7417735||Aug 5, 2005||Aug 26, 2008||Idc, Llc||Systems and methods for measuring color and contrast in specular reflective devices|
|US7417783||Jul 1, 2005||Aug 26, 2008||Idc, Llc||Mirror and mirror layer for optical modulator and method|
|US7417784||Apr 19, 2006||Aug 26, 2008||Qualcomm Mems Technologies, Inc.||Microelectromechanical device and method utilizing a porous surface|
|US7420725||Apr 29, 2005||Sep 2, 2008||Idc, Llc||Device having a conductive light absorbing mask and method for fabricating same|
|US7420728||Mar 25, 2005||Sep 2, 2008||Idc, Llc||Methods of fabricating interferometric modulators by selectively removing a material|
|US7424198||Jan 28, 2005||Sep 9, 2008||Idc, Llc||Method and device for packaging a substrate|
|US7429334||Mar 25, 2005||Sep 30, 2008||Idc, Llc||Methods of fabricating interferometric modulators by selectively removing a material|
|US7450295||Mar 2, 2006||Nov 11, 2008||Qualcomm Mems Technologies, Inc.||Methods for producing MEMS with protective coatings using multi-component sacrificial layers|
|US7453579||Sep 9, 2005||Nov 18, 2008||Idc, Llc||Measurement of the dynamic characteristics of interferometric modulators|
|US7460246||Feb 24, 2005||Dec 2, 2008||Idc, Llc||Method and system for sensing light using interferometric elements|
|US7460291||Aug 19, 2003||Dec 2, 2008||Idc, Llc||Separable modulator|
|US7463421||Jul 28, 2005||Dec 9, 2008||Idc, Llc||Method and device for modulating light|
|US7471442||Jun 15, 2006||Dec 30, 2008||Qualcomm Mems Technologies, Inc.||Method and apparatus for low range bit depth enhancements for MEMS display architectures|
|US7476327||May 4, 2004||Jan 13, 2009||Idc, Llc||Method of manufacture for microelectromechanical devices|
|US7483197||Mar 28, 2006||Jan 27, 2009||Idc, Llc||Photonic MEMS and structures|
|US7492502||Aug 5, 2005||Feb 17, 2009||Idc, Llc||Method of fabricating a free-standing microstructure|
|US7511884||Jul 25, 2005||Mar 31, 2009||Asml Netherlands B.V.||Stationary and dynamic radial transverse electric polarizer for high numerical aperture systems|
|US7527995||May 20, 2005||May 5, 2009||Qualcomm Mems Technologies, Inc.||Method of making prestructure for MEMS systems|
|US7527996||Apr 19, 2006||May 5, 2009||Qualcomm Mems Technologies, Inc.||Non-planar surface structures and process for microelectromechanical systems|
|US7527998||Jun 30, 2006||May 5, 2009||Qualcomm Mems Technologies, Inc.||Method of manufacturing MEMS devices providing air gap control|
|US7532194||Feb 3, 2004||May 12, 2009||Idc, Llc||Driver voltage adjuster|
|US7532377||Apr 6, 2006||May 12, 2009||Idc, Llc||Movable micro-electromechanical device|
|US7534640||Jul 21, 2006||May 19, 2009||Qualcomm Mems Technologies, Inc.||Support structure for MEMS device and methods therefor|
|US7535466||Apr 1, 2005||May 19, 2009||Idc, Llc||System with server based control of client device display features|
|US7547565||May 20, 2005||Jun 16, 2009||Qualcomm Mems Technologies, Inc.||Method of manufacturing optical interference color display|
|US7547568||Feb 22, 2006||Jun 16, 2009||Qualcomm Mems Technologies, Inc.||Electrical conditioning of MEMS device and insulating layer thereof|
|US7550794||Sep 20, 2002||Jun 23, 2009||Idc, Llc||Micromechanical systems device comprising a displaceable electrode and a charge-trapping layer|
|US7550810||Feb 23, 2006||Jun 23, 2009||Qualcomm Mems Technologies, Inc.||MEMS device having a layer movable at asymmetric rates|
|US7553684||Jun 17, 2005||Jun 30, 2009||Idc, Llc||Method of fabricating interferometric devices using lift-off processing techniques|
|US7554711||Jul 24, 2006||Jun 30, 2009||Idc, Llc.||MEMS devices with stiction bumps|
|US7554714||Jun 10, 2005||Jun 30, 2009||Idc, Llc||Device and method for manipulation of thermal response in a modulator|
|US7564612||Aug 19, 2005||Jul 21, 2009||Idc, Llc||Photonic MEMS and structures|
|US7564613||Oct 9, 2007||Jul 21, 2009||Qualcomm Mems Technologies, Inc.||Microelectromechanical device and method utilizing a porous surface|
|US7566664||Aug 2, 2006||Jul 28, 2009||Qualcomm Mems Technologies, Inc.||Selective etching of MEMS using gaseous halides and reactive co-etchants|
|US7567373||Jul 26, 2005||Jul 28, 2009||Idc, Llc||System and method for micro-electromechanical operation of an interferometric modulator|
|US7570865||Jan 28, 2008||Aug 4, 2009||Idc, Llc||System and method of testing humidity in a sealed MEMS device|
|US7582952||Feb 21, 2006||Sep 1, 2009||Qualcomm Mems Technologies, Inc.||Method for providing and removing discharging interconnect for chip-on-glass output leads and structures thereof|
|US7586484||Apr 1, 2005||Sep 8, 2009||Idc, Llc||Controller and driver features for bi-stable display|
|US7616369||Mar 31, 2006||Nov 10, 2009||Idc, Llc||Film stack for manufacturing micro-electromechanical systems (MEMS) devices|
|US7618831||Nov 17, 2005||Nov 17, 2009||Idc, Llc||Method of monitoring the manufacture of interferometric modulators|
|US7623287||Apr 19, 2006||Nov 24, 2009||Qualcomm Mems Technologies, Inc.||Non-planar surface structures and process for microelectromechanical systems|
|US7623752||Jan 28, 2008||Nov 24, 2009||Idc, Llc||System and method of testing humidity in a sealed MEMS device|
|US7630114||Oct 28, 2005||Dec 8, 2009||Idc, Llc||Diffusion barrier layer for MEMS devices|
|US7630119||Aug 12, 2005||Dec 8, 2009||Qualcomm Mems Technologies, Inc.||Apparatus and method for reducing slippage between structures in an interferometric modulator|
|US7636151||Jun 15, 2006||Dec 22, 2009||Qualcomm Mems Technologies, Inc.||System and method for providing residual stress test structures|
|US7642110||Jul 30, 2007||Jan 5, 2010||Qualcomm Mems Technologies, Inc.||Method for fabricating a structure for a microelectromechanical systems (MEMS) device|
|US7643203||Apr 10, 2006||Jan 5, 2010||Qualcomm Mems Technologies, Inc.||Interferometric optical display system with broadband characteristics|
|US7649671||Jun 1, 2006||Jan 19, 2010||Qualcomm Mems Technologies, Inc.||Analog interferometric modulator device with electrostatic actuation and release|
|US7653371||Aug 30, 2005||Jan 26, 2010||Qualcomm Mems Technologies, Inc.||Selectable capacitance circuit|
|US7668415||Mar 25, 2005||Feb 23, 2010||Qualcomm Mems Technologies, Inc.||Method and device for providing electronic circuitry on a backplate|
|US7684104||Aug 22, 2005||Mar 23, 2010||Idc, Llc||MEMS using filler material and method|
|US7692839||Apr 29, 2005||Apr 6, 2010||Qualcomm Mems Technologies, Inc.||System and method of providing MEMS device with anti-stiction coating|
|US7692844||Jan 5, 2004||Apr 6, 2010||Qualcomm Mems Technologies, Inc.||Interferometric modulation of radiation|
|US7701631||Mar 7, 2005||Apr 20, 2010||Qualcomm Mems Technologies, Inc.||Device having patterned spacers for backplates and method of making the same|
|US7706044||Apr 28, 2006||Apr 27, 2010||Qualcomm Mems Technologies, Inc.||Optical interference display cell and method of making the same|
|US7706050||Mar 5, 2004||Apr 27, 2010||Qualcomm Mems Technologies, Inc.||Integrated modulator illumination|
|US7710629||Jun 3, 2005||May 4, 2010||Qualcomm Mems Technologies, Inc.||System and method for display device with reinforcing substance|
|US7710632||Feb 4, 2005||May 4, 2010||Qualcomm Mems Technologies, Inc.||Display device having an array of spatial light modulators with integrated color filters|
|US7710636||Aug 22, 2005||May 4, 2010||Qualcomm Mems Technologies, Inc.||Systems and methods using interferometric optical modulators and diffusers|
|US7711239||Apr 19, 2006||May 4, 2010||Qualcomm Mems Technologies, Inc.||Microelectromechanical device and method utilizing nanoparticles|
|US7719500||May 20, 2005||May 18, 2010||Qualcomm Mems Technologies, Inc.||Reflective display pixels arranged in non-rectangular arrays|
|US7763546||Aug 2, 2006||Jul 27, 2010||Qualcomm Mems Technologies, Inc.||Methods for reducing surface charges during the manufacture of microelectromechanical systems devices|
|US7781850||Mar 25, 2005||Aug 24, 2010||Qualcomm Mems Technologies, Inc.||Controlling electromechanical behavior of structures within a microelectromechanical systems device|
|US7794803 *||Dec 9, 2003||Sep 14, 2010||Sharp Kabushiki Kaisha||Plastic substrate and liquid crystal display having same|
|US7795061||Dec 29, 2005||Sep 14, 2010||Qualcomm Mems Technologies, Inc.||Method of creating MEMS device cavities by a non-etching process|
|US7807488||Aug 19, 2005||Oct 5, 2010||Qualcomm Mems Technologies, Inc.||Display element having filter material diffused in a substrate of the display element|
|US7808703||May 27, 2005||Oct 5, 2010||Qualcomm Mems Technologies, Inc.||System and method for implementation of interferometric modulator displays|
|US7813026||Jan 21, 2005||Oct 12, 2010||Qualcomm Mems Technologies, Inc.||System and method of reducing color shift in a display|
|US7830586||Jul 24, 2006||Nov 9, 2010||Qualcomm Mems Technologies, Inc.||Transparent thin films|
|US7835061||Jun 28, 2006||Nov 16, 2010||Qualcomm Mems Technologies, Inc.||Support structures for free-standing electromechanical devices|
|US7855824||Jan 14, 2005||Dec 21, 2010||Qualcomm Mems Technologies, Inc.||Method and system for color optimization in a display|
|US7880954||May 3, 2006||Feb 1, 2011||Qualcomm Mems Technologies, Inc.||Integrated modulator illumination|
|US7893919||Jan 21, 2005||Feb 22, 2011||Qualcomm Mems Technologies, Inc.||Display region architectures|
|US7898521||Aug 26, 2005||Mar 1, 2011||Qualcomm Mems Technologies, Inc.||Device and method for wavelength filtering|
|US7903047||Apr 17, 2006||Mar 8, 2011||Qualcomm Mems Technologies, Inc.||Mode indicator for interferometric modulator displays|
|US7907319||May 12, 2006||Mar 15, 2011||Qualcomm Mems Technologies, Inc.||Method and device for modulating light with optical compensation|
|US7911428||Aug 19, 2005||Mar 22, 2011||Qualcomm Mems Technologies, Inc.||Method and device for manipulating color in a display|
|US7916103||Apr 8, 2005||Mar 29, 2011||Qualcomm Mems Technologies, Inc.||System and method for display device with end-of-life phenomena|
|US7916980||Jan 13, 2006||Mar 29, 2011||Qualcomm Mems Technologies, Inc.||Interconnect structure for MEMS device|
|US7920135||Apr 1, 2005||Apr 5, 2011||Qualcomm Mems Technologies, Inc.||Method and system for driving a bi-stable display|
|US7928928||Mar 11, 2005||Apr 19, 2011||Qualcomm Mems Technologies, Inc.||Apparatus and method for reducing perceived color shift|
|US7936497||Jul 28, 2005||May 3, 2011||Qualcomm Mems Technologies, Inc.||MEMS device having deformable membrane characterized by mechanical persistence|
|US7961393||Jun 22, 2007||Jun 14, 2011||Moxtek, Inc.||Selectively absorptive wire-grid polarizer|
|US8004743||Apr 21, 2006||Aug 23, 2011||Qualcomm Mems Technologies, Inc.||Method and apparatus for providing brightness control in an interferometric modulator (IMOD) display|
|US8008736||Jun 3, 2005||Aug 30, 2011||Qualcomm Mems Technologies, Inc.||Analog interferometric modulator device|
|US8014059||Nov 4, 2005||Sep 6, 2011||Qualcomm Mems Technologies, Inc.||System and method for charge control in a MEMS device|
|US8027087||Sep 10, 2010||Sep 27, 2011||Moxtek, Inc.||Multilayer wire-grid polarizer with off-set wire-grid and dielectric grid|
|US8040588||Feb 25, 2008||Oct 18, 2011||Qualcomm Mems Technologies, Inc.||System and method of illuminating interferometric modulators using backlighting|
|US8045252||Feb 20, 2008||Oct 25, 2011||Qualcomm Mems Technologies, Inc.||Spatial light modulator with integrated optical compensation structure|
|US8059326||Apr 30, 2007||Nov 15, 2011||Qualcomm Mems Technologies Inc.||Display devices comprising of interferometric modulator and sensor|
|US8111445||Jan 15, 2008||Feb 7, 2012||Qualcomm Mems Technologies, Inc.||Spatial light modulator with integrated optical compensation structure|
|US8124434||Jun 10, 2005||Feb 28, 2012||Qualcomm Mems Technologies, Inc.||Method and system for packaging a display|
|US8248696||Jun 25, 2009||Aug 21, 2012||Moxtek, Inc.||Nano fractal diffuser|
|US8284474||Jan 24, 2007||Oct 9, 2012||Qualcomm Mems Technologies, Inc.||Method and system for interferometric modulation in projection or peripheral devices|
|US8362987||Apr 29, 2005||Jan 29, 2013||Qualcomm Mems Technologies, Inc.||Method and device for manipulating color in a display|
|US8394656||Jul 7, 2010||Mar 12, 2013||Qualcomm Mems Technologies, Inc.||Method of creating MEMS device cavities by a non-etching process|
|US8416487||Jan 26, 2009||Apr 9, 2013||Qualcomm Mems Technologies, Inc.||Photonic MEMS and structures|
|US8611007||Sep 2, 2011||Dec 17, 2013||Moxtek, Inc.||Fine pitch wire grid polarizer|
|US8638491||Aug 9, 2012||Jan 28, 2014||Qualcomm Mems Technologies, Inc.||Device having a conductive light absorbing mask and method for fabricating same|
|US8670171||Oct 18, 2010||Mar 11, 2014||Qualcomm Mems Technologies, Inc.||Display having an embedded microlens array|
|US8682130||Sep 13, 2011||Mar 25, 2014||Qualcomm Mems Technologies, Inc.||Method and device for packaging a substrate|
|US8735225||Mar 31, 2009||May 27, 2014||Qualcomm Mems Technologies, Inc.||Method and system for packaging MEMS devices with glass seal|
|US8798425||Nov 22, 2011||Aug 5, 2014||Qualcomm Mems Technologies, Inc.||Decoupled holographic film and diffuser|
|US8817357||Apr 8, 2011||Aug 26, 2014||Qualcomm Mems Technologies, Inc.||Mechanical layer and methods of forming the same|
|US8830557||Sep 10, 2012||Sep 9, 2014||Qualcomm Mems Technologies, Inc.||Methods of fabricating MEMS with spacers between plates and devices formed by same|
|US8848294||Oct 22, 2010||Sep 30, 2014||Qualcomm Mems Technologies, Inc.||Method and structure capable of changing color saturation|
|US8853747||Oct 14, 2010||Oct 7, 2014||Qualcomm Mems Technologies, Inc.||Method of making an electronic device with a curved backplate|
|US8872085||Sep 26, 2007||Oct 28, 2014||Qualcomm Mems Technologies, Inc.||Display device having front illuminator with turning features|
|US8873144||Mar 27, 2012||Oct 28, 2014||Moxtek, Inc.||Wire grid polarizer with multiple functionality sections|
|US8885244||Jan 18, 2013||Nov 11, 2014||Qualcomm Mems Technologies, Inc.||Display device|
|US8913320||Aug 6, 2012||Dec 16, 2014||Moxtek, Inc.||Wire grid polarizer with bordered sections|
|US8913321||Sep 27, 2012||Dec 16, 2014||Moxtek, Inc.||Fine pitch grid polarizer|
|US8922890||Mar 21, 2012||Dec 30, 2014||Moxtek, Inc.||Polarizer edge rib modification|
|US8928967||Oct 4, 2010||Jan 6, 2015||Qualcomm Mems Technologies, Inc.||Method and device for modulating light|
|US8947772||Mar 5, 2014||Feb 3, 2015||Moxtek, Inc.||Durable, inorganic, absorptive, ultra-violet, grid polarizer|
|US8963159||Apr 4, 2011||Feb 24, 2015||Qualcomm Mems Technologies, Inc.||Pixel via and methods of forming the same|
|US8964280||Jan 23, 2012||Feb 24, 2015||Qualcomm Mems Technologies, Inc.||Method of manufacturing MEMS devices providing air gap control|
|US8970939||Feb 16, 2012||Mar 3, 2015||Qualcomm Mems Technologies, Inc.||Method and device for multistate interferometric light modulation|
|US8971675||Mar 28, 2011||Mar 3, 2015||Qualcomm Mems Technologies, Inc.||Interconnect structure for MEMS device|
|US9001412||Oct 10, 2012||Apr 7, 2015||Qualcomm Mems Technologies, Inc.||Electromechanical device with optical function separated from mechanical and electrical function|
|US9019183||Sep 24, 2007||Apr 28, 2015||Qualcomm Mems Technologies, Inc.||Optical loss structure integrated in an illumination apparatus|
|US9019590||Dec 27, 2011||Apr 28, 2015||Qualcomm Mems Technologies, Inc.||Spatial light modulator with integrated optical compensation structure|
|US9025235||Feb 1, 2008||May 5, 2015||Qualcomm Mems Technologies, Inc.||Optical interference type of color display having optical diffusion layer between substrate and electrode|
|US9086564||Mar 4, 2013||Jul 21, 2015||Qualcomm Mems Technologies, Inc.||Conductive bus structure for interferometric modulator array|
|US9097885||Jan 27, 2014||Aug 4, 2015||Qualcomm Mems Technologies, Inc.||Device having a conductive light absorbing mask and method for fabricating same|
|US9110289||Jan 13, 2011||Aug 18, 2015||Qualcomm Mems Technologies, Inc.||Device for modulating light with multiple electrodes|
|US9134527||Apr 4, 2011||Sep 15, 2015||Qualcomm Mems Technologies, Inc.||Pixel via and methods of forming the same|
|US9348076||Aug 27, 2014||May 24, 2016||Moxtek, Inc.||Polarizer with variable inter-wire distance|
|US9354374||Aug 27, 2014||May 31, 2016||Moxtek, Inc.||Polarizer with wire pair over rib|
|US9523805||Sep 24, 2013||Dec 20, 2016||Moxtek, Inc.||Fine pitch wire grid polarizer|
|US20020126364 *||Feb 19, 2002||Sep 12, 2002||Iridigm Display Corporation, A Delaware Corporation||Interferometric modulation of radiation|
|US20030043157 *||Aug 19, 2002||Mar 6, 2003||Iridigm Display Corporation||Photonic MEMS and structures|
|US20040051929 *||Aug 19, 2003||Mar 18, 2004||Sampsell Jeffrey Brian||Separable modulator|
|US20040169924 *||Feb 27, 2003||Sep 2, 2004||Asml Netherlands, B.V.||Stationary and dynamic radial transverse electric polarizer for high numerical aperture systems|
|US20040209192 *||Nov 13, 2003||Oct 21, 2004||Prime View International Co., Ltd.||Method for fabricating an interference display unit|
|US20040263944 *||Jun 24, 2003||Dec 30, 2004||Miles Mark W.||Thin film precursor stack for MEMS manufacturing|
|US20050002082 *||May 12, 2004||Jan 6, 2005||Miles Mark W.||Interferometric modulation of radiation|
|US20050046948 *||Mar 24, 2004||Mar 3, 2005||Wen-Jian Lin||Interference display cell and fabrication method thereof|
|US20050122560 *||Dec 9, 2003||Jun 9, 2005||Sampsell Jeffrey B.||Area array modulation and lead reduction in interferometric modulators|
|US20050142684 *||Sep 14, 2004||Jun 30, 2005||Miles Mark W.||Method for fabricating a structure for a microelectromechanical system (MEMS) device|
|US20050146680 *||Dec 24, 2003||Jul 7, 2005||Essilor International Compagnie Generale D'optique||Methods for coating lenses|
|US20050168431 *||Feb 3, 2004||Aug 4, 2005||Clarence Chui||Driver voltage adjuster|
|US20050180008 *||Apr 15, 2005||Aug 18, 2005||Asml Netherlands B.V.||Stationary and dynamic radial transverse electric polarizer for high numerical aperture systems|
|US20050195467 *||Mar 3, 2004||Sep 8, 2005||Manish Kothari||Altering temporal response of microelectromechanical elements|
|US20050212738 *||Jan 14, 2005||Sep 29, 2005||Brian Gally||Method and system for color optimization in a display|
|US20050231790 *||Mar 1, 2005||Oct 20, 2005||Miles Mark W||Method and device for modulating light with a time-varying signal|
|US20050244949 *||Feb 11, 2005||Nov 3, 2005||Miles Mark W||Method and device for modulating light|
|US20050254115 *||May 12, 2004||Nov 17, 2005||Iridigm Display Corporation||Packaging for an interferometric modulator|
|US20050259324 *||Jul 25, 2005||Nov 24, 2005||Asml Netherlands B.V.||Stationary and dynamic radial transverse electric polarizer for high numerical aperture systems|
|US20060001942 *||Jul 2, 2004||Jan 5, 2006||Clarence Chui||Interferometric modulators with thin film transistors|
|US20060028708 *||Jul 28, 2005||Feb 9, 2006||Miles Mark W||Method and device for modulating light|
|US20060065043 *||Mar 25, 2005||Mar 30, 2006||William Cummings||Method and system for detecting leak in electronic devices|
|US20060065436 *||Mar 25, 2005||Mar 30, 2006||Brian Gally||System and method for protecting microelectromechanical systems array using back-plate with non-flat portion|
|US20060066503 *||Apr 1, 2005||Mar 30, 2006||Sampsell Jeffrey B||Controller and driver features for bi-stable display|
|US20060066504 *||Apr 1, 2005||Mar 30, 2006||Sampsell Jeffrey B||System with server based control of client device display features|
|US20060066541 *||Aug 19, 2005||Mar 30, 2006||Gally Brian J||Method and device for manipulating color in a display|
|US20060066543 *||Aug 20, 2005||Mar 30, 2006||Gally Brian J||Ornamental display device|
|US20060066557 *||Mar 18, 2005||Mar 30, 2006||Floyd Philip D||Method and device for reflective display with time sequential color illumination|
|US20060066596 *||Apr 1, 2005||Mar 30, 2006||Sampsell Jeffrey B||System and method of transmitting video data|
|US20060066600 *||Jun 3, 2005||Mar 30, 2006||Lauren Palmateer||System and method for display device with reinforcing substance|
|US20060066856 *||Aug 5, 2005||Mar 30, 2006||William Cummings||Systems and methods for measuring color and contrast in specular reflective devices|
|US20060066863 *||Mar 4, 2005||Mar 30, 2006||Cummings William J||Electro-optical measurement of hysteresis in interferometric modulators|
|US20060066864 *||Nov 17, 2005||Mar 30, 2006||William Cummings||Process control monitors for interferometric modulators|
|US20060066871 *||Nov 17, 2005||Mar 30, 2006||William Cummings||Process control monitors for interferometric modulators|
|US20060066872 *||Nov 17, 2005||Mar 30, 2006||William Cummings||Process control monitors for interferometric modulators|
|US20060066876 *||Feb 24, 2005||Mar 30, 2006||Manish Kothari||Method and system for sensing light using interferometric elements|
|US20060066936 *||Aug 22, 2005||Mar 30, 2006||Clarence Chui||Interferometric optical modulator using filler material and method|
|US20060067633 *||Aug 26, 2005||Mar 30, 2006||Gally Brian J||Device and method for wavelength filtering|
|US20060067641 *||Jan 28, 2005||Mar 30, 2006||Lauren Palmateer||Method and device for packaging a substrate|
|US20060067642 *||Mar 25, 2005||Mar 30, 2006||Karen Tyger||Method and device for providing electronic circuitry on a backplate|
|US20060067652 *||Sep 1, 2005||Mar 30, 2006||Cummings William J||Methods for visually inspecting interferometric modulators for defects|
|US20060076634 *||Apr 8, 2005||Apr 13, 2006||Lauren Palmateer||Method and system for packaging MEMS devices with incorporated getter|
|US20060076637 *||Jun 10, 2005||Apr 13, 2006||Gally Brian J||Method and system for packaging a display|
|US20060077122 *||Mar 11, 2005||Apr 13, 2006||Gally Brian J||Apparatus and method for reducing perceived color shift|
|US20060077126 *||Mar 11, 2005||Apr 13, 2006||Manish Kothari||Apparatus and method for arranging devices into an interconnected array|
|US20060077145 *||Mar 7, 2005||Apr 13, 2006||Floyd Philip D||Device having patterned spacers for backplates and method of making the same|
|US20060077149 *||Apr 29, 2005||Apr 13, 2006||Gally Brian J||Method and device for manipulating color in a display|
|US20060077381 *||Nov 17, 2005||Apr 13, 2006||William Cummings||Process control monitors for interferometric modulators|
|US20060077393 *||May 27, 2005||Apr 13, 2006||Gally Brian J||System and method for implementation of interferometric modulator displays|
|US20060077503 *||Apr 29, 2005||Apr 13, 2006||Lauren Palmateer||System and method of providing MEMS device with anti-stiction coating|
|US20060077512 *||Feb 4, 2005||Apr 13, 2006||Cummings William J||Display device having an array of spatial light modulators with integrated color filters|
|US20060077514 *||Jan 21, 2005||Apr 13, 2006||Sampsell Jeffrey B||System and method of reducing color shift in a display|
|US20060077521 *||Jul 29, 2005||Apr 13, 2006||Gally Brian J||System and method of implementation of interferometric modulators for display mirrors|
|US20060077523 *||Apr 1, 2005||Apr 13, 2006||Cummings William J||Electrical characterization of interferometric modulators|
|US20060077524 *||Apr 8, 2005||Apr 13, 2006||Lauren Palmateer||System and method for display device with end-of-life phenomena|
|US20060077527 *||Jun 16, 2005||Apr 13, 2006||Cummings William J||Methods and devices for inhibiting tilting of a mirror in an interferometric modulator|
|US20060077617 *||Aug 30, 2005||Apr 13, 2006||Floyd Philip D||Selectable capacitance circuit|
|US20060079098 *||Mar 16, 2005||Apr 13, 2006||Floyd Philip D||Method and system for sealing a substrate|
|US20060103643 *||Jul 15, 2005||May 18, 2006||Mithran Mathew||Measuring and modeling power consumption in displays|
|US20060154041 *||Dec 9, 2003||Jul 13, 2006||Yoshito Hashimoto||Plastic substrate and liquid crystal display having same|
|US20060219435 *||May 18, 2006||Oct 5, 2006||Manish Kothari||Modifying the electro-mechanical behavior of devices|
|US20060250337 *||Mar 28, 2006||Nov 9, 2006||Miles Mark W||Photonic MEMS and structures|
|US20060274400 *||May 12, 2006||Dec 7, 2006||Miles Mark W||Method and device for modulating light with optical compensation|
|US20060277486 *||Jun 2, 2005||Dec 7, 2006||Skinner David N||File or user interface element marking system|
|US20060284877 *||Jun 1, 2006||Dec 21, 2006||Miles Mark W||Photonic mems and structures|
|US20070052921 *||Oct 31, 2006||Mar 8, 2007||Richard Muisener||Methods for Coating Lenses|
|US20070058095 *||Nov 4, 2005||Mar 15, 2007||Miles Mark W||System and method for charge control in a MEMS device|
|US20070132843 *||Jan 24, 2007||Jun 14, 2007||Idc, Llc||Method and system for interferometric modulation in projection or peripheral devices|
|US20070177129 *||Jun 15, 2006||Aug 2, 2007||Manish Kothari||System and method for providing residual stress test structures|
|US20070242008 *||Apr 17, 2006||Oct 18, 2007||William Cummings||Mode indicator for interferometric modulator displays|
|US20070247704 *||Apr 21, 2006||Oct 25, 2007||Marc Mignard||Method and apparatus for providing brightness control in an interferometric modulator (IMOD) display|
|US20070253054 *||Apr 30, 2007||Nov 1, 2007||Miles Mark W||Display devices comprising of interferometric modulator and sensor|
|US20070290961 *||Jun 15, 2006||Dec 20, 2007||Sampsell Jeffrey B||Method and apparatus for low range bit depth enhancement for MEMS display architectures|
|US20080002210 *||Jun 30, 2006||Jan 3, 2008||Kostadin Djordjev||Determination of interferometric modulator mirror curvature and airgap variation using digital photographs|
|US20080115569 *||Jan 28, 2008||May 22, 2008||Idc, Llc||System and method of testing humidity in a sealed mems device|
|US20080115596 *||Jan 28, 2008||May 22, 2008||Idc, Llc||System and method of testing humidity in a sealed mems device|
|US20090052029 *||Oct 12, 2007||Feb 26, 2009||Cambrios Technologies Corporation||Functional films formed by highly oriented deposition of nanowires|
|US20090201583 *||Apr 19, 2007||Aug 13, 2009||Fujifilm Corporation||Polarizing film for window and front window for means of traveling|
|US20090219604 *||Jan 26, 2009||Sep 3, 2009||Qualcomm Mems Technologies, Inc.||Photonic mems and structures|
|US20090225394 *||Feb 25, 2008||Sep 10, 2009||Idc, Llc||System and method of illuminating interferometric modulators using backlighting|
|US20100245370 *||Mar 23, 2010||Sep 30, 2010||Qualcomm Mems Technologies, Inc.||Em shielding for display devices|
|US20100328770 *||Sep 10, 2010||Dec 30, 2010||Perkins Raymond T||Multilayer wire-grid polarizer with off-set wire-grid and dielectric grid|
|US20110053304 *||Oct 14, 2010||Mar 3, 2011||Qualcomm Mems Technologies, Inc.||Method of making an electronic device with a curved backplate|
|US20110177745 *||Mar 28, 2011||Jul 21, 2011||Qualcomm Mems Technologies, Inc.||Interconnect structure for mems device|
|USRE40436||Jul 7, 2005||Jul 15, 2008||Idc, Llc||Hermetic seal and method to create the same|
|USRE42119||Jun 2, 2005||Feb 8, 2011||Qualcomm Mems Technologies, Inc.||Microelectrochemical systems device and method for fabricating same|
|WO2015006011A1||Jun 12, 2014||Jan 15, 2015||Carestream Health, Inc.||Liquid crystalline assembly of metal nanowires on films|
|WO2015112270A1||Dec 9, 2014||Jul 30, 2015||Carestream Health, Inc.||Patterning of silver nanowire transparent conductive films using polarized laser|
|U.S. Classification||359/487.3, 359/487.2|
|Cooperative Classification||G02B5/3058, G02B5/3033|
|European Classification||G02B5/30P1, G02B5/30P2|