WO1996040499A1 - Optical storage medium - Google Patents
Optical storage medium Download PDFInfo
- Publication number
- WO1996040499A1 WO1996040499A1 PCT/US1996/008753 US9608753W WO9640499A1 WO 1996040499 A1 WO1996040499 A1 WO 1996040499A1 US 9608753 W US9608753 W US 9608753W WO 9640499 A1 WO9640499 A1 WO 9640499A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- layer
- medium
- image
- optically readable
- metal oxide
- Prior art date
Links
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/004—Recording, reproducing or erasing methods; Read, write or erase circuits therefor
- G11B7/0055—Erasing
- G11B7/00552—Erasing involving colour change media
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/004—Recording, reproducing or erasing methods; Read, write or erase circuits therefor
- G11B7/0045—Recording
- G11B7/00455—Recording involving reflectivity, absorption or colour changes
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
- G11B7/241—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
- G11B7/242—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of recording layers
- G11B7/243—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of recording layers comprising inorganic materials only, e.g. ablative layers
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
- G11B7/241—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
- G11B7/242—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of recording layers
- G11B7/243—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of recording layers comprising inorganic materials only, e.g. ablative layers
- G11B2007/24302—Metals or metalloids
- G11B2007/24306—Metals or metalloids transition metal elements of groups 3-10
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
- G11B7/241—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
- G11B7/242—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of recording layers
- G11B7/243—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of recording layers comprising inorganic materials only, e.g. ablative layers
- G11B2007/24318—Non-metallic elements
- G11B2007/2432—Oxygen
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
- G11B7/241—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
- G11B7/252—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers
- G11B7/253—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of substrates
- G11B7/2531—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of substrates comprising glass
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
- G11B7/241—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
- G11B7/252—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers
- G11B7/253—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of substrates
- G11B7/2533—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of substrates comprising resins
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S430/00—Radiation imagery chemistry: process, composition, or product thereof
- Y10S430/146—Laser beam
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S430/00—Radiation imagery chemistry: process, composition, or product thereof
- Y10S430/163—Radiation-chromic compound
Definitions
- the present invention relates in general to a recording medium and more specifically to an erasable, high speed, high density, optical storage medium which is both erasable and writable upon demand.
- data can be stored on a wide variety of materials using various manipulable physical and/or chemical properties as state indicators.
- conventional magnetic storage media using floppy disks and hard disks utilize the sense of magnetization impressed on a selected region of a surface of a metal oxide such as Cr 2 0 3 .
- the magnetization can be changed on demand using an external field which forms the basis for both writing and erasing data.
- the data is read by simply measuring the existing sense of magnetization.
- Magnetic media are relatively slow in all functions, less dense in information storage capacity than any optically based storage medium and vulnerable to a variety of electromagnetic phenomenon.
- Currently available optical storage media typically involves the use of multiple layers of metal and plastic.
- These media are irreversibly modified when the data is written on them by irradiating a memory element with activating radiation such as laser light.
- a memory element with activating radiation such as laser light.
- These media are typically purchased with the data, such as music, being contained on the article.
- Other optical memory devices such as WORM (write once read many times) allow the user to impress the data, but again the writing process is irreversible.
- the system further provides the advantage of selectively erasing the encoded information by exposing the storage medium to a selected wavelength or heating in bulk and erasing the entire medium.
- the entire image can be erased by heating the entire medium using an oven.
- the present invention is based upon the discovery that certain solid transition metal oxides can be formed in layers on a supporting substrate and used to chemically encode information through the use of light and their intrinsic photochromic properties.
- the solid metal oxides suitable for this invention are those which undergo photoinduced and thermoenhanced loss of gas phase 0 2 to produce mixed valence oxides and include W0 3 , V 2 0 5 , Ti0 2 and Mo0 3 . Any other solid transition metal oxide which exhibits these characteristics is included within the scope of this invention.
- W0 3 is the erased state, and both oxidation states W v and W VI are present in the written state.
- the two oxidation states must have similar or identical chemical sites.
- a particular oxide can be operationally established for any possible choice of oxide by exposing a possible candidate oxide to blue-green or shorter wavelength light under vacuum and observing whether a color change occurs.
- M may be either an alkali metal ion (with nominal +1 charge) or a proton. More generally, (see P.G. Dickens and M.S. Whittingham Quart. Rev. 22, 30(1968)) it has been stated that other metal ions are also usable.
- M in some embodiments of this invention stems from three types of considerations.
- the stability and overall durability of the written and erased state depends on the nature of M.
- Imaging is accomplished in combination with simultaneously exposing the oxide layer, under ambient conditions, including the presence of gas phase 0 2 , to a selected range of wavelengths of light in the blue-green or shorter (254 nm to 575 nm) spectrum, and to infrared radiation (800 nm to 10.6 ⁇ m) or heat, resulting in the formation of a chemically encoded readable image on the layer of said metal oxide.
- This image is permanent in nature and can be stored indefinitely.
- the function of the infrared radiation is to heat the medium with spatial selectivity and thereby facilitate the write process in the exposed area.
- the image can be selectively erased by simply exposing the oxide layer to infrared radiation (heat) in the presence of gaseous 0 2 which restores the exposed area to its original state prior to imaging.
- the entire image can be erased by heating the entire medium using an oven. Oxides of the metals W and Mo have been found to be particularly suitable for use in the present invention.
- a layer of W0 3 powder (particle size l-10 ⁇ m) approximately 1 mm thick is formed on a 2 cm diameter disk of fused quartz.
- an optically readable image is formed on the W0 3 layer by simultaneously exposing the layer to blue-green light and infrared light in selected regions of the layer to form a permanent optically readable image thereon.
- the image, or portions of the image may be conveniently erased by exposing the selected portions of the image to infrared radiation in the presence of gaseous 0 2 .
- the entire image can be erased by heating the entire medium using an oven.
- the medium has all of the favorable advantages, high storage density, high speed, and durability of conventional CD's.
- An example of the theory or mechanism which is involved in the imaging system of the present invention can be illustrated for the transition metal oxide W0 3 .
- the reaction which occurs during the imaging step in which the W0 3 layer is exposed to blue-green light and IR light is a change in color of the layer from bright yellow to dark blue with the reaction being described by equation 1 wp ]( perennial ___ > On + 2 A (J) (1)
- the oxide is illustrated in equation 1 as W 2 0 5(s) Because the W0 3 is the thermodynamic ground state for the tungsten-oxygen system, the reverse action is easily thermally driven and is illustrated by equation 2
- the blue color ox de state w e shown as wo u .
- the change from yellow to blue and the reverse reaction from blue to yellow constitutes the write and erase modes of the medium, respectively.
- the transition can be easily observed or read using absorption, reflectance, or Raman scattering measurements in either the UV- visible or IR spectral regions by conventional techniques available in the art.
- the Raman scattering utilized is not surface enhanced. In reading a W0 3 based medium, the Raman scattering could be resonance enhanced, but not surface enhanced.
- Fig. 1 is a side elevational sectional view of one embodiment of a device of the present invention.
- Fig. 2 depicts a schematic diagram of apparatus for use in the reading, writing, and erasing according to the present invention.
- Fig. 3 is a schematic diagram which depicts an enlarged view of the recording medium mounting area of Fig. 2.
- Fig. 1 an erasable optical storage medium of the present invention is illustrated in the form partial side sectional view of a disk 20 which comprises a supporting substrate 22 containing a thin coherent layer or film of optical memory media 24 on the substrate.
- Substrate 22 may comprise any suitable material which is capable of supporting layer or film 24, and which is substantially inert and impervious to the radiation and/or heat used in the imaging and erase process of the present invention.
- the substrate must also have appropriate thermal conductivity such that the infrared radiated spot can achieve an appropriate temperature.
- Suitable substrates include fused silica, quartz, silicon, sapphire, plastics, and the like.
- the optical storage medium 20 is normally used in the form of a circular disk. It should be understood, however, that other configurations may also be used depending on the application of the medium. For a particular embodiment which is designed to be erased in bulk, the substrate and layers must be able to withstand repeated heating and cooling cycles.
- the optical memory media 24 may comprise any compound or material which undergoes a chemical change as in equations 1 and 2 when exposed to radiation of selected wavelengths under ambient conditions which include 0 2 , and which change can be optically read or scanned. A further requirement is that the encoded change or written data may be selectively erased upon exposure to infrared radiation or to heat in the presence of 0 2 .
- Preferred materials suitable for use as the imaging medium for layer 24 comprise W0 3 and Mp0 3 .
- the thickness of layer or film 24 should be at least on the order of about 10 2 nm. A suitable range for the thickness of layer 24 would be from about 0.1-10 ⁇ m.
- the layer 24 may be in the form of a simple coherent powder layer, a powder containing a small amount of adhesive to bind the layer to substrate 22, or it may be coated in a slurry onto substrate 12 in any suitable inert binder material. In addition to the above, layer 24 can be formed on substrate 22 by other conventional techniques known to the art such as sputtering, vapor deposition or electrochemical methods.
- a disk suitable for use in the present invention was prepared as follows: W0 3 powder available from Aldrich Corporation, (purity 99.99 5%) was evenly spread and compacted into a circular recess formed in the middle of a 2 cm diameter fused quartz disk to form a coherent layer of powdered W0 3 .
- the disk has a thickness of about .3 cm.
- the recess was approximately .2 cm in diameter and .1 cm deep.
- This disk or medium is used in demonstrating the present invention and is illustrated by reference character 7 in Figs. 2 and 3 of the drawings.
- Fig. 2 depicts a schematic diagram of the Raman apparatus employed to demonstrate the write, erase and read processes of the present invention using the disk prepared above.
- CW continuous wave
- a pulse train as a continuous series of light pulses each of a given time duration.
- This pulse train enters an electro-optic pulse selector 2 and an 8 consecutive pulse section of the pulse train is selected each millisecond.
- the two pulse trains contact the medium (sample) surface after passing through a flat elliptical shaped 3 cm x 5 cm, mirror 8 with a 4 mm hole 9 in it as shown in Fig. 3.
- a Raman signal is light which has a wavelength shifted from an incident wavelength during the scattered process.
- All the light which strikes mirror 8 is collected by an uncoated aspheric lens 10.
- the spectrograph exit slit is fitted with the 1028 channel photodiode array of an EG&G OMA III system.
- the OMA III is operated in the gated mode such that it is triggered by the Q-switch synchronization pulse with a fixed 1 nsec gate width.
- the holographic edge filter is necessary to remove all the infrared and most of the incident 0.532 ⁇ m light.
- the spectrograph/OMA III system 14 allows quantification of the amount of light which is shifted in wavelength from the incident 0.532 ⁇ m light.
- this Raman signal is the read mechanism for the medium.
- the medium In order to expose the medium to light source(s), one need only block the appropriate light path(s) with an opaque object. In this way the medium can be exposed to either just 0.532 ⁇ m light for reading, both 0.532 ⁇ m and 1.064 ⁇ m for writing, or just 1.064 ⁇ m for erasing. To easily observe the reading, writing, or erasing processes, 2 minute exposures to the appropriate pulse train(s) are adequate.
- Fig. 3 depicts an enlarged view of the recording medium mounting area of Fig. 2 at a higher scale illustrating the fused silica disk 7 containing the W0 3 powder layer.
- Figure 3 depicts a schematic close-up view of the interaction zone, i.e., the region where the two light sources overlap a single bit of digital data.
- the process parameters for utilizing the recording medium of the present invention have been clearly established, the current understanding of the microscopic mechanism involved in the processes associated with the invention may be somewhat incomplete.
- the pertinent characteristics of W0 3 have been described to establish context. The interactions involving the light sources and the surface of the medium corresponding to: 1) writing; 2) erasing; and 3) reading data were then considered.
- the following theory and/or mechanisms are believed relevant to an understanding of the present invention.
- the medium is initially in the erased form, i.e., nominally W0 3 , it is yellow and possesses strong Raman features at 716 cm “1 and 805 cm “1 .
- the lattice of standard yellow W0 3 is formed from (W0 6 ) octahedral units.
- the green light has a greater effect on the medium because it is absorbed to a greater extent than the infrared.
- the green light initially excites electrons from valence bands which have at least some of their origin in wavefunctions associated with oxygen atoms. After electronic excitation, some electrons may be trapped by, or in the vicinity of, the W VI metal ions at the centers of the octahedral units thereby forming the W v metal ions responsible for the strong color change.
- each W v ion affects the bonding in the octahedral units in such a way as to weaken the bonding between the metal and at least one oxygen atom.
- An observable effect of this bonding modification is the elimination of the two largest Raman features associated with W0 3 . If an oxygen atom, whose bonding to its adjacent W V1 center is weakened, is in close enough proximity to interact with another oxygen atom, it is possible that the two oxygen atoms will bond to each other forming an 0 2 molecule.
- this 0 2 molecule may diffuse to, or on that surface and then desorb from that surface leaving behind a blue, oxygen deficient medium.
- This blue medium contains so called crystallographic shearplanes having both long and short range order.
- the yellow medium is composed of octahedra joined at the corners.
- the blue material contains octahedra joined along edges. Neither of these materials is amorphous. This is the basic mechanism of the write process, but there is another important part of the process which is essential to the present invention.
- the erase process can now be considered. This involves exposing the medium containing written data to infrared radiation alone.
- the medium absorbs the infrared strongly which again results in heating and softening of the lattice. Collisions between the gas phase 0 2 and the various surface species are constantly occurring during the infrared exposure.
- the lattice heating facilitates the chemical reaction in which 0 2 from the ambient air reacts with the surface W0 25 to reform yellow W0 3 .
- the blue-green light is not present so the reaction in which the W V1 is converted to W v does not occur appreciably.
- the read process can be accomplished using conventional reflectance, absorption or Raman scattering. It should be understood that any process which is selectively sensitive to the presence of W0 2 , and W0 3 is a potential read mechanism. In the case of films this also includes electrical properties. In each case only a small amount of one color light is incident on the medium surface which is not sufficient to either heat the medium or, by electronic excitation, weaken many metal to oxygen bonds so no detectable chemical reactions occur. The data is read by detecting the amount of reflected or scattered light from the medium surface or by the amount of light which passes through a layer. These are standard conventional measurements known to anyone familiar with modern spectroscopic techniques. The spectroscopic properties of the parent oxides and their derived mixed valence oxides are so different that virtually any detection
- At least two colors, i.e. wavelengths, of light are needed.
- One light source heats the medium.
- the other light source provides electronic excitation to the medium.
- the "read” process may involve the electronic excitation light source.
- the “write” process involves the simultaneous use of both sources.
- the “erase” process involves only the heating source. In a further embodiment, it is also possible to utilize three sources.
- the lasers used in the present invention may be either pulsed or continuous wave (CW). Either CW GaAs lasers, operated at less than 100% duty cycle, or YAG based devices would be suitable.
- a single YAG laser as the source of all the wavelengths even in the three color schemes. It may also be possible to use an optical parametric oscillator.
- a single GaAs based laser source can also be used to supply all the colors. For either a single YAG or a GaAs device to provide all the colors, harmonic generation would be used. This option has been commercially available in the field for some time. If operated CW, any of the laser sources for heating would be adequate provided at least lO'-lO 2 mW average power were available.
- the medium of the present invention has two states corresponding to the written and erased states, respectively.
- the erased state corresponds to a fully oxygenated metal oxide as exemplified by yellow W0 3 .
- CW continuous wave
- the erased state can be reached from the written state by exposing the medium to a sufficiently intense IR radiation at atmospheric oxygen pressure or by simply heating it in ambient air in a furnace and allowing the medium to equilibrate.
- W0 3 as an example, the transition in the furnace requires about 10' - 10 2 seconds in a tube furnace at about 400°C.
Abstract
Description
Claims
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP9501250A JPH11510635A (en) | 1995-06-07 | 1996-06-05 | Optical storage media |
EP96917134A EP0846055A4 (en) | 1995-06-07 | 1996-06-05 | Optical storage medium |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US08/481,818 | 1995-06-07 | ||
US08/481,818 US5691091A (en) | 1995-06-07 | 1995-06-07 | Optical storage process |
Publications (2)
Publication Number | Publication Date |
---|---|
WO1996040499A1 true WO1996040499A1 (en) | 1996-12-19 |
WO1996040499B1 WO1996040499B1 (en) | 1997-01-16 |
Family
ID=23913510
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US1996/008753 WO1996040499A1 (en) | 1995-06-07 | 1996-06-05 | Optical storage medium |
Country Status (5)
Country | Link |
---|---|
US (2) | US5691091A (en) |
EP (1) | EP0846055A4 (en) |
JP (1) | JPH11510635A (en) |
CA (1) | CA2224072A1 (en) |
WO (1) | WO1996040499A1 (en) |
Families Citing this family (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH10214424A (en) * | 1997-01-29 | 1998-08-11 | Ekisupaato Magnetics Kk | Method and device for erasing cd-r |
US6461594B1 (en) * | 1999-01-28 | 2002-10-08 | Syracuse University | Photochromic materials suitable for cosmetic and sunblocking effects |
US6180318B1 (en) * | 1999-05-19 | 2001-01-30 | 3M Innovative Properties Company | Method of imaging an article |
FR2832251B1 (en) * | 2001-11-12 | 2006-08-25 | Univ Toulouse | USES OF OXIDABLE SPINAL OXIDES AS SENSITIVE LAYER MATERIALS OF AN OPTICAL SUPPORT RECORDABLE ONLY ONCE |
JP2003237242A (en) * | 2002-02-22 | 2003-08-27 | Sony Corp | Optical recording medium and method |
CN100380485C (en) * | 2002-10-10 | 2008-04-09 | 索尼株式会社 | Method of manufacturing original disk for optical disks, and method of manufacturing optical disk |
US8119043B2 (en) * | 2003-01-09 | 2012-02-21 | Sony Corporation | Method of making master for manufacturing optical disc and method of manufacturing optical disc |
EP1475793B1 (en) * | 2003-04-15 | 2007-12-05 | Ricoh Company, Ltd. | Write-once-read-many optical recording medium and process for recording and reproducing of the optical medium |
JP4626284B2 (en) * | 2003-12-05 | 2011-02-02 | 住友金属鉱山株式会社 | Method for producing tungsten oxide fine particles for forming solar shield, and tungsten oxide fine particles for forming solar shield |
US7911673B1 (en) | 2006-11-27 | 2011-03-22 | Hrl Laboratories, Llc | Display screen with optical memory |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5279932A (en) * | 1989-09-13 | 1994-01-18 | Fuji Photo Film Co., Ltd. | Optical response element |
Family Cites Families (16)
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US3971874A (en) * | 1973-08-29 | 1976-07-27 | Matsushita Electric Industrial Co., Ltd. | Optical information storage material and method of making it |
JPS5528530A (en) * | 1978-08-17 | 1980-02-29 | Matsushita Electric Ind Co Ltd | Optical information recording method |
JPH0697513B2 (en) * | 1982-01-12 | 1994-11-30 | 大日本インキ化学工業株式会社 | Optical recording medium |
JPS59185048A (en) * | 1983-04-01 | 1984-10-20 | Matsushita Electric Ind Co Ltd | Member for recording optical information and its recording method |
JPS605436A (en) * | 1983-06-21 | 1985-01-12 | Ricoh Co Ltd | Optical recording medium |
JPS61133065A (en) * | 1984-12-03 | 1986-06-20 | Hitachi Ltd | Optical information recording device |
US4960679A (en) * | 1985-01-31 | 1990-10-02 | Canon Kabushiki Kaisha | Image forming device |
JPS61211850A (en) * | 1985-03-15 | 1986-09-19 | Matsushita Electric Ind Co Ltd | Production of recording material |
US4711815A (en) * | 1985-03-07 | 1987-12-08 | Matsushita Electric Industrial Co., Ltd. | Recording medium |
GB8606651D0 (en) * | 1986-03-18 | 1986-04-23 | Green M | Electrochromic data recording systems |
US4774702A (en) * | 1986-04-03 | 1988-09-27 | Ltv Aerospace And Defense Company | Erasable optical memory employing a marmen alloy to effect phase-change erasing in a chalcogenide film |
EP0337553B1 (en) * | 1988-04-13 | 1993-12-01 | Koninklijke Philips Electronics N.V. | Laminated product, compound used in the laminated product and optical information carrier provided with the laminated product |
CA2000597C (en) * | 1988-10-21 | 1995-07-11 | Toshio Ishikawa | Optical recording element |
DE68921325T2 (en) * | 1988-12-28 | 1995-09-21 | Matsushita Electric Ind Co Ltd | Medium for data storage. |
US5272667A (en) * | 1989-12-29 | 1993-12-21 | Matsushita Electric Industrial Co., Ltd. | Optical information recording apparatus for recording optical information in a phase change type optical recording medium and method therefor |
DE69127926T2 (en) * | 1990-03-16 | 1998-03-12 | Canon Kk | Electro-coated part, process for its production and composition for electro-coating |
-
1995
- 1995-06-07 US US08/481,818 patent/US5691091A/en not_active Expired - Fee Related
-
1996
- 1996-06-05 EP EP96917134A patent/EP0846055A4/en not_active Withdrawn
- 1996-06-05 CA CA002224072A patent/CA2224072A1/en not_active Abandoned
- 1996-06-05 JP JP9501250A patent/JPH11510635A/en active Pending
- 1996-06-05 WO PCT/US1996/008753 patent/WO1996040499A1/en not_active Application Discontinuation
-
1997
- 1997-05-01 US US08/846,848 patent/US5837424A/en not_active Expired - Lifetime
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5279932A (en) * | 1989-09-13 | 1994-01-18 | Fuji Photo Film Co., Ltd. | Optical response element |
Also Published As
Publication number | Publication date |
---|---|
CA2224072A1 (en) | 1996-12-19 |
EP0846055A4 (en) | 1998-10-28 |
US5837424A (en) | 1998-11-17 |
EP0846055A1 (en) | 1998-06-10 |
JPH11510635A (en) | 1999-09-14 |
US5691091A (en) | 1997-11-25 |
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