US 3717945 A
Arrays of laterally spaced orifices, all communicating with a liquid pressure supply, all subjected to vibration at the same frequency to separate the liquid jets into streams of individual drops, provide a system for locating all of the drops with a predetermined space-time correlation by irradiating the drops in space at a predetermined time to make them visible, thus creating variable three dimensional visible shapes for study.
Description (OCR text may contain errors)
United States Patent 1191 Taylor et al.
1 51 Feb. 27, 1973 IMAGE CONSTRUCTION SYSTEM USING MULTIPLE ARRAYS OF DROP GENERATORS  Inventors: Richard P. Taylor; Russell H. Van Brlmer; Fred E. Culp, Dayton, all of Ohio 45402  Assignee: The Mead Corporation, Dayton,
 Filed: Sept. 8, 1970 21 Appl. N0; 70,337
Related 11s. Application Data  Division of Ser. No. 768,790, Oct. 18, 1968, Pat. No.
52 US. 01. ..40/106.25 1 51 1m. 01. ..o091 19/02  Field 61 Search ..40/13o A, 106.25, 106.54; 346/75; 178/66  ReferencesCited UNITED STATES PATENTS 3,416,153 12/1968 l-lertzetal ..346/75 TIMING CONTROL 3,373,437 3/1968 Sweet et al. ..346/75 3,334,816 8/1967 Shuzo Mizuno ..40/13O A X OTHER PUBLICATIONS I High-Frequency 'Oscillography with Electrostatically Deflected lnk Jets by Richard G. Sweet AD 437951 March 1964 Stanford University, Stanford California.
Primary Examiner-Robert W. Michell Assistant Examiner-J. H. Wolff Attorney-Marechal, Biebel, French and Bugg [5 7] ABSTRACT Arrays of laterally spaced orifices, all communicating with a liquid pressure supply, all subjected to vibration at the same frequency to separate the liquid jets into streams of individual drops, provide a system for locating all of the drops with a predetermined spacetime correlation by irradiating the drops in space at a predetermined time to make them visible, thus creating variable three dimensional visible shapes for study.
2 Claims, 2 Drawing Figures PATENTEDFEBZYIBTS T v T. 5 w T 4 I,
FIG-1 TIMING CONTROL IMAGE CONSTRUCTION SYSTEM USING MULTIPLE ARRAYS OF DROP GENERATORS CROSS REFERENCE TO RELATED APPLICATION This application is a division of 768,790 filed Oct. 5
BACKGROUND OF THE INVENTION to achieve a predetermined space-time correlation. his
proposed that a drop generating device include a plurality of arrays of orifices from which common size drops are projected at a common frequency. Selected drops are switched or deflected into catchers,- while the remainder follow their trajectory to create a pattern in space and time.
The prior art has suggested various ways of producing the uniformly sized and synchronously generated drops, a typical example being a system such as disclosed in the U. S. Pat. to Sweet etal., No. 3,373,437. Little attention has been given, however, to drop spacetime correlation or to packing a large number of orifices in near enough proximity to permit solid area coverage by parallel digital switching.
SUMMARY OF THE INVENTION The present invention relates to a method and apparatus by means of which a plurality of drops of fluid, such as a marking substance, can be selectively 'projected and closely spaced in timed spatial relation. By applying intelligencesignals to the control electrodes of the individual drop generating units in each of the arrays, it is possible to control the spatial position of any given drop. Considering an image area or pattern to be produced, each drop generated by each array is destined for a particular cell or coordinate position, in an X-Y matrix of the image or pattern, and whether or not that particular drop reaches its cell depends on the intelligence imposed on the corresponding controlled electrodes. In other words, the intelligence signal determines whether or not a drop is desired at each particular X- Y coordinate, and determines whether or not the drop is deflected or permitted to proceed as the portion of the image or pattern being generated. Thus, it is possible to produce variable thtee-dimensional displays, using a plurality of arrays, in-line or staggered, and using control over the individual drops to locate them in a pattern, then irradiating the drops at a predetermined time, as by high speed flashes of light which are timed with reference to some beginning of drop generation. The control drop generation enables the resulting three-dimensional display to be changed in shape-or size within limits of the system.
BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic electrical diagram illustrating the manner in which a single drop generating and controlling device functions; and
FIG. 2 shows the variable three-dimensional display system.
DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, which illustrate a preferred embodiment of the invention, a pressurized liquid substance is supplied to a plurality of closely arranged arrays, indicated by the general reference number 85 (FIG. 2). The liquid may be supplied by a system such as disclosed in our U.S. Pat. No. 3,560,641, and, as described therein, the liquid has high frequency vibration imposed thereon.
The liquid is directed to a cross manifold in each of the arrays, and these manifolds in turn have a large number of small orifices 40 (FIG. 1) from which a fine I5 liquid stream isexpelled. As a result of the high frequency vibration, the stream rapidly breaks into individual drops which are accordingly spaced. In a typical embodiment the orifices 40 are each of a size in the order of 1.5 mils, and the resultant drops are of a size in the order of 3 mils diameter.
control structure immediately below the orifice40.
Downstream of the charging electrode is a set of deflecting electrodes 44 which, provides a continuous deflecting field operating to deflect charged drops from the stream into a catcher unit 45. The drops that are deflected into the catcher accumulate and may be recirculated to the reservoir.
. The charge applying electrode 42 thus functions as a means for selectively charging drops which are not to continue their flight, and together with the deflecting 45 displays, at the top of the figure there are a plurality of closely arranged arrays, indicated by the general reference numeral 85. It will be understood that each array consistsof a large number of individual drop generating units such as shown in. FIG. 1. These arrays are closely stacked and regularly spaced, such that drops from each generating unit will fall along a predetermined path, precisely spacedwith respect to each other, as indicated by the vertical lines in FIG. 2. Since the individual drop generating units can be controlled to project drops at a regular and high frequency,
if cross-currents of air or the like are eliminated, as by operating in a vacuum or under reduced pressure and controlled conditions, then the drops will project in the same regularly spaced positions toward the catching basin 87 shown at the bottom of FIG. 2. If a single drop generating unit is switched to the on condition, and continues to generate drops at regularly spaced intervals for predetermined time, these drops will proceed in a train-like rnanner toward the lower catch basin 87.
At any given time, these drops will be located in space with respect to theirpoint of origin in the drop generating unit and with respect to each other. It is possible therefore to time the switching of the individual unit such that the drops will be in the form of a patterned line or sequence proceeding vertically downward from the origin at the drop generating unit. Multiplying this arrangement many times, it is thus possible to have a plurality of such vertical drop patterns all precisely related to each other, since the generating unit can be excited at the same high frequency. Therefore, if such an arrangement be producedunder controlled light conditions, for example, it is possible to irradiate the drops at a predetermined time, for example by using high speed flashes of light, to make a three-dimensional pattern visible to an observer.
For example, the plurality ofarrays shown in FIG. 2 is surrounded by the number of high speed flash lamp units 90. These can be of conventional design, sometimes referred to as stroboscopic flash lamps, and preferably are arranged to fire simultaneously, thereby projecting light from a number of different directions toward the falling drops from the arrays. The speed of light flash is in the order of a microsecond, thus it is possible to stop the flight of the drops insofar as the observer is concerned. A suitable timing control, shown schematically at 95, programs the unit such that initiation of a plurality of drop patterns from the various drop generating units starts a time sequence, and when a desired number of drops have fallen in a predetermined pattern, to a predetermined point, the flash lamps are triggered to illuminate the resultant pattern and essentially fix it in space, so far as the observer is concerned, due to persistence of vision. The operation can be repeated at high speeds a number of times.
For example, one can compare the operation to a moving picture display where repetition in theorder of 16 frames per second, coupled with the visual persistence of the viewer, produces an image which appears to be either stationary, or to move in a regular manner. By controlling the operation of the individual drop generating units it is thus possible to produce a three-dimensional display which can be essentially static, and viewed from many different angles, and which can be varied by changing the programming of the drop generating unit. This enables an observer to change the shape of the three-dimensional display as he may desire. Such a device is usable in studying various shapes for purposes of mechanical design, artistic design, in the study of mathematical problems dealing with complex three-dimensional objects, or topographical problems, to name just a few uses.
From the foregoing, it will be apparent that the embodiment described includes a plurality of arrays of drop generators, all stimulated from a common vibration source. Each generator has a switching means to permit deflecting of selected individual drops from their normal trajectory, thus providing the capability to generate a pattern by locating the remaining drops in predetermined space-time correlation, under the control of a data matrix which responds to some master intelligence such as a memory and buffer input to the system.
While the method herein described, and the forms of apparatus for carrying this method into effect, constitute preferred embodiments of the invention, it is to be understood that the invention is not limited to this precise method and forms of apparatus, and that changes may be made in either without departing from the scope of the invention.
What is claimed is:
1. Display apparatus for controlled placement in space and time of repetitiously generated liquid drops comprising:
a plurality of arrays of orifices for generation of a plurality of rows of liquid jets each directed along specific parallel trajectories related to the other jets,
liquid supply means providing liquid under pressure to all of said orifices,
means for stimulating all of said jets at a common frequency to separate each jet into individual drops,
switching means for selective removal of drops from the respective trajectories of said jets,
data transfer means for continuous generation of a data matrix in response to a master intelligence input and operative to produce a three-dimensional visible display of said matrix by communication with and control of said switching means, stroboscopic illumination source arranged to irradiate the liquid jets for direct three-dimensional observation in space of said matrix formed by said unremoved drops in said jets, and control incorporated in said data transfer means connected to actuate said illumination source in synchronized relation with said switching means.
2. The method of creating a three-dimensional display pattern in space by selective spatial and positional control over a large number of small liquid drops, comprising the steps of a. generating a plurality of rows of liquid jets all directed along parallel trajectories in space,
b. stimulating each of such jets at a common frequency to cause each jet to break into individual drops having related positions in space,
c. switching selected ones of said drops from their respective trajectories and removing such drops from the system and thus causing the remaining drops periodically to from a pattern of predetermined three-dimensional configuration, an
d. irradiating the remaining drops at predetermined time intervals coordinated with the stimulating frequency and the switching to make a plurality of the drops simultaneously visible at the instant when such drops form a three-dimensional pattern in a selected region-in space.