KR20010015016A - Method and system for preparing holographic full-color displays - Google Patents

Abstract

PURPOSE: A method and system are provided to improve ability to display a three-dimensional holographic image in real full colors, red, green and blue, by using a non-memory PLZT ceramic display material. CONSTITUTION: By using a non-memory PLZT display medium (100), a dynamic image is reproduced on a panel (101). Next, by designing a modulation electrode or raster-writing the image on the panel, the panel is divided to pixels (102). When a user wants to realize color reproduction, three-color frames are successively written and striven in order by using an appropriate color, and then the color separation frame of the next image is started (105). In such a case, each frame is a computer generated hologram generating the image rendered by the specified color (106). By performing appropriate correction, the image is formed with the actual reproducing wavelength of the frame (108). After performing various kinds of selection in terms of design such as consecutively scanning all the depth of the respective colors or mixing every color, all the colors are displayed with the given depth (109).

Description

Holographic full color display method and system {METHOD AND SYSTEM FOR PREPARING HOLOGRAPHIC FULL-COLOR DISPLAYS}

All six pending US patent applications are assigned to the same assignee. These patents are systems and methods in which the agent management number is AT-9-99-015 and the name of the invention includes a reversible holographic recording medium, and the agent management number is RA-9-99-016 and the name of the invention. Systems and methods using a dynamic holographic display medium, agent control number RA-9-99017 and invention titled method and system for forming a holographic full color display, agent control number RA-9-99-018 And a method and system for using a virtual reality headset based on a PLZT holographic display, an agent management number of RA-9-99-019, and a method and system and agent for a back lighting and diffusion of PLZT. Control number RA-9-99-014 and entitled "System and method for controlling and monitoring an optical waveguide signal using a PLZT apparatus. All six patent applications relate to an agent control number of IBM RA-9-97-094 and US patent application Ser. No. 09 / 182,075, filed Oct. 29, 1998. This pending patent is entitled “35mm Slide Projection Panel for Use in Common Projection Apparatus” and is also incorporated by reference in the six inventions above.

The ability to display three-dimensional holographic images of true full colors red, green and blue (R, G, B) is currently limited to still images via holograms traditionally recorded using white light technology. The present invention provides a means for constructing a dynamic holographic full color display. This means is based on the progressive PLZT recording material. This PLZT holographic material is a lanthanum reinforced lead zirconate titanate composite that supports full color holographic displays. PLZT materials are used as non-memory ceramic display materials that implement the ability to display true full color red, blue, and blue (RGB) three-dimensional holographic images.

Hologram refers to a three-dimensional image record generated by holography. That is, a hologram is generated by using a method of reproducing a light interference pattern on a medium such as a photosensitive film. The hologram consists of a light interference pattern preserved in a medium such as a photosensitive film. When properly illuminated, the hologram produces an image whose appearance changes as the viewer's angle changes.

As mentioned above, the present invention is based on the progressive PLZT recording material, which serves as the basis of the present application and is a lanthanum enhanced lead zirconate titanate composite. Used as a non-memory ceramic display material, this PLZT material embodies the ability to display true full color three-dimensional holographic images of red, blue, and blue (RGB).

The ability to display three-dimensional holographic images of true full colors red, green and blue (R, G, B) is currently limited to still images via holograms traditionally recorded using white light technology. An image is recorded in triplicate using three different laser wavelengths, creating a hologram that can be recorded and reproduced using the three different wavelengths or other wavelengths. In general, recording lasers should be made with fairly strong power that is not practical for recording and reproducing devices for reasons of cost, maintenance, size, or facility. Therefore, recording and reproducing apparatuses often use lasers and wavelengths different from those for recording. Therefore, assuming an ideal recording medium in which the emulsion does not bend, even a still picture is not a perfect representation because of the aberration caused by the transition of wavelength.

In order to compensate for the shift of the wavelength, in diffraction recording, sometimes the geometry of the recording is slightly shifted so as to optimally adjust the lattice parameters to the wavelength for reproduction. As a result, some aberrations are increased so that other aberrations can be improved. Also, since local exposure to multiple wavelengths drives the material outside its linear recording regime, diffraction gratings from three colors may interfere with each other. As a result, various aberrations, scattering, color bleeding of some of the images, or major other problems may occur.

Thus, in the case of moving images, there is no choice to provide a full color that can target the commercial market, i. E. The consumer market. In addition, high-speed display technology must be able to generate successive frames at as high speed as refreshing should be provided. Traditional ray tracing techniques used to generate depth due information are very advanced. Therefore, the image must be generated rapidly, but there is also a lack of excellent display technology and the ability to process the image fast enough to display the image is limited. The present invention solves these problems by the PLZT ceramic display material.

In this regard, it would be beneficial to review the related art with respect to the present invention. In the research on the technology of the present invention, the following patent documents were noted. A careful review of the following patents can readily distinguish the present invention from any of these prior art.

US Patent No. 5,198,920. This patent relates to SLM and not to holographic displays. There is nothing in this patent that can be used for full color displays (conventional or otherwise).

US Patent No. 5,457,356. This patent is a flat panel display and processing technology (two-dimensional only). This patent is not a holography technology at all. The inventors of this patent use conventional materials, but the present invention uses PLZT. In addition, the color method used is doped with phosphorous, which is completely different from the present invention.

US Patent No. 5,424,605. This patent relates to flat panel cathode ray tube (CTR) displays and is not holographic technology. There is no citation for PLZT materials. The collar is induced by phosphors that are completely different from the present invention.

US Patent No. 5,225,821. This patent relates to an active matrix flat panel display and is not a holographic technology. The method of treatment of this patent uses LCD and does not use the PLZT material as used in the present invention.

US Patent No. 4,467,325. This patent relates to flat two-dimensional displays and not to three-dimensional holographic displays. The substance does not contain PLZT. Moreover, no mention of full color is made.

US Patent No. 5,660,738. This patent is completely independent of this application. This patent does not relate to two-dimensional or three-dimensional displays. This patent relates to IC assembly and not display technology.

US Patent No. 4,720,706. This patent is related to two-dimensional plate technology and is not related to three-dimensional holography. The full color support method of this patent is very different. The inventors of this patent use optical gates to transmit and mix multiple wavelengths. The present application uses a PLZT substrate and a CGH mask to represent full colors in order.

As cited earlier and in the U.S. Patent Application, entitled 35mm Slide Projection Panel for Use in Commonly Applicable Projection Devices, the present invention serves as the basis of the present application and is a lanthanum reinforced lead zirconate tita A progressive PLZT inorganic recording material that is a composite of lanthanum enhanced lead zirconate titanate. The material is a piezo-electric / optical ceramic material. Now, a description of the compounds and properties of this PLZT ceramic material will be helpful in understanding the present invention.

PLZT can be formulated in two ways: One is mixed oxides (MO) and the other is chemical composition (CP). Applicants formulated PLZT using a mixed oxide treatment method. The mixed oxide (MO) is formed by wet mixing lead oxide (PbO). The mixture is then dried and calcined (hot solid state chemical reaction) and then milled to reduce the size of the particles to the desired level. The slug can then be cold pressed to form a slug and then warmed to form a wafer from the slug. The wafer thus produced is sliced and polished for use as a panel for liquid display. Wafers may be 15 cm in diameter and 0.5 mm to several millimeters thick after polishing. The wafer consists of a uniform microstructure with a suppressed particle size of about 2-5 um. The particle size is important because the size of the particle determines a lower limit depending on how dense the control field can be and thus limits the size of the pixel.

Although lanthanum oxide is good, it should be noted that the present invention need not be limited to lanthanum oxide. Rather, lanthanum oxide may be replaced with other oxides in the "lanthanum series" in the periodic table. This includes cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm) samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), Thulium (Tm), ytterbium (Yb) and lutetium (Lu).

The ability to display three-dimensional holographic images of true full colors red, green and blue (R, G, B) is currently limited to still images via holograms traditionally recorded using white light technology. An image is recorded in triplicate using three different laser wavelengths, creating a hologram that can be recorded and reproduced using the three different wavelengths or other wavelengths. In general, recording lasers should be made with fairly strong power that is not practical for recording and reproducing devices for reasons of cost, maintenance, size, or facility. Therefore, recording and reproducing apparatuses often use lasers and wavelengths different from those for recording. Therefore, assuming an ideal recording medium in which the emulsion does not bend, even a still picture is not a perfect representation because of the aberration caused by the transition of wavelength.

The present invention is based on the advanced PLZT recording material, which serves as the basis of the present application and is a lanthanum reinforced lead zirconate titanate composite. In the present invention, this PLZT material, which is used as a non-memory ceramic display material, realizes the ability to display three-dimensional holographic images of red, blue, and blue (RGB), which are true full colors.

1 is an overview of the method used to use a PLZT recording medium as a non-memory ceramic display material that implements the ability to display true full color red, green and blue (RGB) three-dimensional holographic images. Flow chart.

2 is a front view of a slab of ceramic PLZT.

3 is a rear view of the slab of the ceramic PLZT.

4 is an enlarged view showing the alignment of the refractive index axis of each material particle in response to an applied polling electric field.

5 is a front view of a slab of ceramic PLZT depicting tricolor color reproduction using a plurality of red, green and blue (R, G, B) interference sources.

Explanation of symbols with reference to drawings

200, 300: slab

201: indium-tin-oxide

203: photoconductive layer

204, 302: electrode

301: ITO electrode

400: Slab Ceramic Material

Using non-memory PLZT ceramic display materials allows moving pictures to be reproduced on a panel. The panel may be divided into several pixels by raster writing the design or image of the modulating electrode to the panel. At any given time, a computer-generated hologram (CGH) frame or a blend of two adjacent frames is present. If subsequent frames are not very similar in terms of image reconstruction, the recording reproduction beam should be strobe in the period in which the frames are completed to avoid color mixing. Some devices may exploit the presence of similarities between frames.

In this regard, it will be beneficial to first define some terms that will be useful in describing the details of the invention.

Term Definition

PLZT is a lanthanum reinforced lead zirconate titanate material. PLZT is a piezo-electric / optical ceramic material. A description of the synthesis and properties of this PLZT ceramic material will help to understand the present invention.

Correction refers to a process of removing aberrations or flaws when projecting or constructing an optical image.

Strobes are typically timing signals that initiate and regulate the passage of data through an input / output (I / O) device interface, such as a keyboard or printer.

Partial CGH is used to mean displaying three-dimensional images by displaying successive depth layers of the three-dimensional image one at a time.

Fourier domain display refers to a display technology in which an imaging device actually includes an optical Fourier transform of a desired image field and converts it into a desired spatial image by an auxiliary optical device.

Fiber grating diffraction refers to a periodic change in the diffraction rate along the length of the fiber, caused by the illumination of ultraviolet light to the fiber.

RGB is an acronym for red, green, and blue. This is a model that describes the color generated by light emission on a video monitor rather than by absorption like ink on paper. The three cone cells in the eye respond to red light, green light and blue light, respectively. Therefore, by mixing these three primary color addition ratios, all desired colors can be obtained.

"Refreshing the display" means repeating the display and storage of the data so that the data does not slowly disappear or are lost.

Ray tracing is a conventional technique in computer graphics that renders a three-dimensional subject by inducing a deviation of color and shade caused by a particular ray corresponding to the subject. To create ray traced graphics, the designer starts by specifying the light source and its intensity.

Rendering means converting the outline into a three-dimensional image sufficiently formed in the graphic.

The process of the present invention for reproducing a color is as follows. Frames of three (or more) colors are sequentially written and strobe to the appropriate color in turn, and then the color separation frames of the next image begin. Each frame is a computer-generated hologram (CGH) for producing an image that is rendered in a particular color, and appropriate "correction" is performed to produce an image at the actual image wavelength for that frame. Depth is obtained by continuously scanning partial CGH (Computer Generated Holographic) corresponding to a predetermined depth.

Subsequently, by performing various design methods, it is possible to continuously scan all the depths for each color or to mix the colors so that all the colors can be displayed at a predetermined depth. In order to enable rapid moving picture generation, an assistive optical technique can be used to create an image from a Fourier domain display and to manipulate all the images in the Fourier space. In the case of color displays, one picture requires at least three frames, so it is crucial to be able to produce each picture quickly, and must be done within a 60+ Hz regime or higher refresh rate to avoid visual problems. do.

In order to make a three-dimensional subject into an image, a computer can manipulate the frame using a three-dimensional fast Fourier transform (FFT) that is qualified. The ability to generate depth information quickly is enhanced by this technology. This also indicates that other scanning design methods are possible that scan by spatial frequency rather than by depth.

1 is a flow diagram illustrating a general outline of a method for using a PLZT ceramic display medium for full color display.

It can be seen that the process is initiated in step 100 by using a non-memory PLZT display medium, and then in step 101 a moving picture is displayed on the panel. The process continues at step 102 where the panel is divided into a plurality of pixels by the design of the modulation electrodes or by raster writing an image into the panel. The process then requires the creation of a computer generated holographic frame or a mixture of two adjacent frames. In step 103 a question is raised as to whether the user wishes to generate color reproduction. If the answer is no, then the process is completed at step 110 of FIG.

If the answer to step 104 is "yes", the process moves to step 105 of FIG. Frames relating to the three colors are recorded in sequence, and strobe to the appropriate color one after another, and color separation frames for the next image are started. Each image is then a hologram made using a computer for producing an image rendered in a particular color in step 107. After proper correction is made, an image is created at step 108 with the actual reproduction wavelength for that frame. By performing various design methods, for example, if all the depths for each color are continuously scanned or the colors are mixed, then in step 109 all colors can be displayed at a predetermined depth. The process then ends at 110.

As noted above, FIG. 1 shows a flow diagram and general outline of a method for using a PLZT ceramic display medium for holographic full color display.

FIG. 2 shows a “front view” of slab 200 of ceramic PLZT with transparent indium-tin-oxide (ITO) electrode 201 on photoconductive layer 203. Another electrode 204 is also shown. 3 shows a "back view" of a slab 303 having a transparent ITO electrode 301 and another electrode 302.

4 illustrates slab ceramic material 400, depicting 401 as an enlarged view 402, and depicts an alignment 403 of the index of refraction axis within each material particle in response to an applied polling field.

5 shows a front view of a ceramic PLZT display depicting the reproduction of three colors using coherent light sources of R, G, B of a plurality of red 505, green 506, blue 507. FIG. 5 shows a “front view” of a slab 500 of ceramic PLZT with a transparent indium-tin-oxide (ITO) electrode 501 on the photoconductive layer 503. Another electrode 504 is also shown.

The present invention is based on the advanced PLZT recording material, a lanthanum-enhanced lead zirconate titanate composite, and by this PLZT material used as a non-memory ceramic display material, the present invention is a true full color red, blue, blue An effect that can display a three-dimensional holographic image of (RGB) is realized.

Claims (12)

A computer based holographic full color image display system, Permanent holographic recording medium means used as a non-memory ceramic display; Means for performing the image dynamically; Means for providing a red, green, blue (RGB) representation display in which the holographic recording medium is full color Computer-based display system comprising a. The system of claim 1, wherein the holographic recording medium is based on PLZT. 3. The system of claim 2, wherein the PLZT holographic recording medium provides the full color (RGB) representation display dynamically, quickly, and refreshed. 3. The system of claim 2, wherein the use of the PLZT display medium facilitates displaying a moving picture on the medium. 4. The apparatus according to claim 3, wherein frames relating to three or more colors are sequentially recorded and strobe in an appropriate color order, followed by color separation frames for the next frame, each frame producing an image that is rendered in a particular color and the A computer-generated hologram that produces an image at an actual reproduction wavelength for a frame. 6. The system of claim 5, wherein the depth is obtained by successive scanning of computer-generated holography that corresponds to a predetermined depth. 7. The system of claim 6, wherein the method of design can be done by continuously scanning all the depths for each color to display the colors and displaying all the colors to a predetermined depth. 7. The system of claim 6, wherein the rapid generation of moving images is achieved using assistive optical techniques used to make an image from a Fourier domain display, and all image manipulations are performed in Fourier space. 3. The system of claim 2, wherein the PLZT holographic medium is derived from a mixture of metal oxides consisting of lead, lanthanum, zirconium and titanium. 10. The system of claim 9, wherein the metal oxides are lead oxide (PbO), lanthanum oxide (La ₂ O ₃ ), titanium oxide (TiO ₂ ) and zirconium oxide (ZrO ₂ ). The method of claim 10, wherein the lanthanum oxide is cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm) samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), thulium (Tm), ytterbium (Yb), ruthetium (Lu) of the elements of the "lanthanum" element, characterized in that it can be replaced with other oxides in the periodic table. As a method of using a dynamic holographic full color image display, Providing a permanent holographic recording medium means used as a non-memory ceramic display; Providing means for performing the image dynamically; Using the holographic recording medium to produce a display in full color red, green, blue (RGB) representation Method comprising a.