Color holographic display system based on photochromic disc

Abstract

The utility model discloses a color holographic display system based on a photochromic disc. The color holographic display system comprises a photochromic holographic storage disc, a first moving mechanism, a red light reading module, a green light reading module, a blue light storage reading module, a mounting seat of a mask plate, an image sensor and a display connected with the image sensor, the mask plate carries at least one of a mask pattern of a red channel, a mask pattern of a green channel and a mask pattern of a blue channel of a to-be-stored image; and the blue light storage reading module is used for writing image information corresponding to the mask pattern on the photochromic holographic storage disk. The photochromic holographic storage disc is relatively simple in structure, and red, green and blue three-channel information of an object can be reproduced at the same time only by irradiating the photochromic holographic storage disc by the three-color module. According to the utility model, expensive SLM equipment is eliminated, the color holographic display is realized by depending on the unique angle selection characteristic of the disc, the advantages of high-efficiency display effect and low processing cost are considered, and true three-dimensional naked eye observation can be realized.

Description

Technical Field

[0001] The utility model relates to the technical field of color holographic display, in particular to a color holographic display system based on a photochromic disc. Background Art

[0002] Since the invention of holography, especially the off-axis holography invented by Liss and Upatniks, holograms, as storage devices for three-dimensional objects, have attracted people's attention for their ability to reproduce three-dimensional scenes under appropriate lighting conditions. The optical information recorded by the hologram is the wavefront of the light wave emitted by the object. The reproduced wavefront maintains the amplitude and phase properties of the original object wave. It is a three-dimensional display that is undistorted and does not require any auxiliary visual equipment. At present, the main method for realizing color holographic display is to use the computational holography (CGH) technology that loads holograms with spatial light modulators (SLMs). However, the existing computational holographic display systems based on spatial light modulators have the following disadvantages:

[0003] The amount of holographic pixel calculation data of computational holography technology is large, and this holographic display involves filtering, spatial division, etc., which makes its system complex; it relies on SLM, which requires high-resolution and high-diffraction efficiency liquid crystal devices, which leads to a sharp increase in its cost.

[0004] In view of this, it is necessary to provide a color holographic display system that is not based on SLM to overcome the shortcomings of the prior art. Summary of the invention

[0005] The utility model aims to provide a color holographic display system based on a photochromic disc, which is not based on an SLM, and meets the requirements of a simple system and low cost.

[0006] In order to achieve the above-mentioned object, the utility model provides a color holographic display system based on a photochromic disk, comprising: a photochromic holographic storage disk, a first moving mechanism connected to the photochromic holographic storage disk, a red light reading module, a green light reading module, a blue light storage reading module, a mounting seat for mounting a mask plate, an image sensor and a display connected to the image sensor; the photochromic holographic storage disk comprises a substrate and a 200 mm thick or larger substrate disposed on the substrate. μm silver-polyvinyl alcohol photochromic film; the first moving mechanism is used to rotate the photochromic holographic storage disk, and is also used to vertically and / or horizontally move the photochromic holographic storage disk; the red light reading module, the green light reading module, the blue light storage reading module, the mounting seat and the image sensor are all set corresponding to the photochromic holographic storage disk; the mask plate carries at least one of the mask image of the red channel, the mask image of the green channel and the mask image of the blue channel of the image to be stored; the blue light storage reading module is used to write the image information corresponding to the mask image on the photochromic holographic storage disk; the red light reading module, the green light reading module and the blue light storage reading module are all used to irradiate the photochromic holographic storage disk so that the image sensor obtains the diffraction image corresponding to the image information in the photochromic holographic storage disk; the display is used to display a color reproduction image, and the color reproduction image includes the diffraction image obtained based on the red light reading module, the diffraction image obtained based on the green light reading module and the diffraction image obtained based on the blue light reading module.

[0007] In a preferred embodiment, the first moving mechanism is used to vertically move the photochromic holographic storage disk, and the first moving mechanism includes a base, a first turntable mounted on the base, a lifting rod mounted on the turntable, and a second turntable mounted on the lifting rod. The photochromic holographic storage disk is mounted on the second turntable, the first turntable can rotate around a first axis, the first axis is perpendicular to a horizontal plane, the lifting rod can drive the photochromic holographic storage disk to move vertically, and the second turntable can rotate around a second axis, and the second axis is parallel to the horizontal plane.

[0008] In a preferred embodiment, the silver-polyvinyl alcohol photochromic film is prepared from a mixed solution of silver nitrate and polyvinyl alcohol.

[0009] In a preferred embodiment, image information corresponding to a mask image of a red channel, a mask image of a green channel, and a mask image of a blue channel of the image to be stored can be written into the same point of a photochromic holographic storage disk, and the red light reading module, the green light reading module, and the blue light storage reading module are used to simultaneously illuminate the photochromic holographic storage disk so that the image sensor obtains a diffraction image corresponding to the image information in the photochromic holographic storage disk; and the display is used to display a color reproduced image in real time.

[0010] In a preferred embodiment, the blue-light storage reading module includes an optical path passing switch and a beam splitter for obtaining a blue double light beam, the mounting seat is arranged corresponding to the beam splitter and the photochromic holographic storage disc, the first optical path passing switch is arranged corresponding to the mounting seat, and is used to control whether the light beam corresponding to the mounting seat in the blue double light beam is irradiated onto the photochromic holographic storage disc, and the blue-light storage reading module is used to write the image information corresponding to the mask image on the photochromic holographic storage disc through the blue double light beam.

[0011] In a preferred embodiment, the Blu-ray storage reading module also includes a blue light laser, a first reflector, a second reflector, a third reflector, a collimating beam expander and a first converging lens. The blue light laser, the first reflector and the beam splitter are arranged in sequence. The transmission surface and the reflection surface of the beam splitter correspond one-to-one to the second reflector and the third reflector, or correspond one-to-one to the third reflector and the second reflector. The second reflector is arranged corresponding to the photochromic holographic storage disk, the third reflector, the collimating beam expander, the mounting seat, the first converging lens and the photochromic holographic storage disk are arranged in sequence, and the first optical path is located between the third reflector and the photochromic holographic storage disk or between the beam splitter and the third reflector through the switch.

[0012] In a preferred embodiment, the blue light storage reading module also includes a first polarizer, a first gradient attenuation filter, a second optical path through a switch and a second gradient attenuation filter, the blue light laser, the first polarizer, the first gradient attenuation filter and the first reflector are arranged in sequence, the first polarizer is used to modulate the vibration direction of the blue light into a vertically vibrating s-linear polarized light, the second optical path through the switch is located between the first reflector and the blue light laser, or between the first reflector and the beam splitter, and the second gradient attenuation filter is used to attenuate the light beam in the blue double light beam that does not pass through the corresponding mask plate.

[0013] In a preferred embodiment, the blue-ray storage reading module further comprises a reflector moving device, the second reflector is mounted on the reflector moving device, and the reflector moving device is used to horizontally move and / or rotate the second reflector to change the angle between the blue double light beams.

[0014] In a preferred embodiment, the green light reading module comprises a green light laser, a second polarizer, a third gradient attenuation filter, a fourth reflector and a fifth reflector arranged in sequence, the green light reading module further comprises a third optical path passing switch located between the green light laser and the optical path of the photochromic holographic storage disc, the second polarizer is used to modulate the vibration direction of the green light into a vertically vibrating s-linear polarized light;

[0015] The red light reading module includes a red light laser, a third polarizer, a fourth gradient attenuation filter and a sixth reflector arranged in sequence, and the red light reading module also includes a fourth light path passing switch located between the sixth reflector and the red light laser. The third polarizer is used to modulate the vibration direction of the red light into vertically vibrating s-linear polarized light.

[0016] In a preferred embodiment, the color holographic display system also includes a shell, and the photochromic holographic storage disk, the first moving mechanism, the red light reading module, the green light reading module, the blue light storage reading module, the mounting seat, and the image sensor are all located inside the shell, and the display is located outside the shell or on the shell.

[0017] Compared with the prior art, the utility model has the beneficial effect of a color holographic display system based on a photochromic disc: the utility model has a highly efficient storage color display effect based on the photochromic holographic storage disc, realizes single-wavelength storage of image information corresponding to the mask image of the three primary colors through a blue light storage reading module, realizes three-color wavelength reading through a red light reading module, a green light reading module and a blue light storage reading module, and thus can obtain a reproduced color hologram. Specifically, by utilizing the unique angle selection characteristics of the photochromic holographic storage disc, it is possible to realize single-wavelength storage of the three primary color information of the image at the same information recording point, and then select the three-color wavelengths to read simultaneously at different angles to obtain a reproduced color hologram. The color holographic display system of the utility model does not require complex calculations such as filtering and space division, nor does it require the use of a spatial light modulator, which makes the color holographic display system simple and easy to implement, and effectively reduces the system cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A structural diagram of a color holographic display system based on a photochromic disc provided by the utility model;

[0020] Figure 2 A structural diagram of the reflector moving device provided by the utility model;

[0021] Figure 3 A structural diagram of a first moving mechanism provided by the utility model;

[0022] Figure 4This is an application example diagram of a color holographic display system based on a photochromic disc provided by the utility model.

[0023] Numbers in the figure: 1, housing, 2, green laser, 3, blue laser, 4, red laser, 5, third light path through switch, 6, second polarizer, 7, third gradient attenuation filter, 8, second light path through switch, 9, first polarizer, 10, first gradient attenuation filter, 11, fourth light path through switch, 12, third polarizer, 13, fourth gradient attenuation filter, 14, fourth reflector, 15, first reflector, 16, third reflector, 17, beam splitter, 18, fifth reflector, 19, second reflector, 20, sixth reflector, 21, second gradient attenuation filter, 22, reflector moving device, 23, collimating beam expander, 24, mask plate, 25, first converging lens, 26, first moving mechanism, 27, photochromic holographic storage disk; 28, collimating lens; 29, image sensor, 30, display, 31, first light path through switch. DETAILED DESCRIPTION

[0024] The technical scheme in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is only a part of the embodiment of the utility model, rather than all the embodiments. The components of the embodiment of the utility model generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiment of the utility model provided in the drawings is not intended to limit the scope of the utility model claimed for protection, but merely represents the selected embodiment of the utility model. Based on the embodiment of the utility model, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the utility model.

[0025] In an embodiment of the present invention, a color holographic display system based on a photochromic disk is provided, comprising: a photochromic holographic storage disk 27, a first moving mechanism 26 connected to the photochromic holographic storage disk 27, a red light reading module, a green light reading module, a blue light storage reading module, a mounting seat for mounting a mask plate 24, an image sensor 29, and a display 30 connected to the image sensor 29; the photochromic holographic storage disk 27 comprises a substrate and a first moving mechanism 26 connected to the photochromic holographic storage disk 27, ... μm silver-polyvinyl alcohol photochromic film; the first moving mechanism 26 is used to rotate the photochromic holographic storage disk 27, and is also used to vertically and / or horizontally move the photochromic holographic storage disk 27; the red light reading module, the green light reading module, the blue light storage reading module, the mounting seat and the image sensor 29 are all set corresponding to the photochromic holographic storage disk 27; the mask plate 24 carries at least one of the mask images of the red channel, the green channel and the blue channel, and the blue light storage reading module is used to read the photochromic holographic storage disk 27 in the blue light storage reading module. The image information corresponding to the mask image is written on the photochromic holographic storage disk 27, and the red light reading module, the green light reading module and the blue light storage reading module are all used to irradiate the photochromic holographic storage disk 27 so that the image sensor 29 obtains the diffraction image corresponding to the image information in the photochromic holographic storage disk 27; the display 30 is used to display the color reproduction image information, and the color reproduction image includes the diffraction image obtained based on the red light reading module, the diffraction image obtained based on the green light reading module and the diffraction image obtained based on the blue light reading module. The mask image of the red channel, the mask image of the green channel and the mask image of the blue channel are respectively the mask images of the red channel of the image to be stored, the mask images of the green channel of the image to be stored and the mask images of the blue channel of the image to be stored.

[0026] The principle of color holographic display in this embodiment is: decompose each color viewing angle image into three color component images of red (R), green (G), and blue (B), and use commercial mask making equipment such as laser marking machine to prepare the red, green, and blue component images into a mask plate 24 that allows light to pass through. Holographic interference is performed on the three color components at different recording angles, and recorded at the same information recording site of the photochromic holographic storage disk 27. Based on the angular selectivity of the volume holographic grating, the recorded information can only be displayed if the Bragg selectivity is met and at a specific angle. The hologram is diffracted and reproduced using the three primary color readout light (red, green, and blue), so that three monochromatic holographic reproduction images are generated in the reconstruction plane. The three monochromatic holographic reproduction images overlap to form a color hologram (R+G+B), realizing color information reproduction. It can be understood that the mask image of the red channel, the mask image of the green channel and the mask image of the blue channel can also be recorded at different points of the photochromic holographic storage disk 27. Subsequently, the diffraction images of the three colors of the same image are overlapped and combined to obtain a color reproduction image. This technology belongs to the existing technology. For example, the existing display 30 can realize the overlapping display of several received images.

[0027] See also Figure 1 The blue-light storage reading module includes an optical path through a switch and a beam splitter 17 for obtaining a blue double light beam. The mounting seat is arranged corresponding to the beam splitter 17 and the photochromic holographic storage disk 27. The first optical path through a switch 31 is arranged corresponding to the mounting seat, and is used to control whether the light beam corresponding to the mounting seat in the blue double light beam is irradiated onto the photochromic holographic storage disk 27. The blue-light storage reading module is used to write the image information corresponding to the mask image on the photochromic holographic storage disk 27 through the blue double light beam.

[0028] Specifically, in this embodiment, the blue light storage reading module includes a blue light laser 3, a first reflector 15, a second reflector 19, and a third reflector 16. The blue light laser 3 and the first reflector 15 are arranged correspondingly. The first reflector 15 is arranged corresponding to the incident surface of the beam splitter 17. The beam splitter 17 adopts a semi-reflective and semi-transparent mirror. The transmission surface of the beam splitter 17 corresponds to the second reflector 19, and the reflection surface corresponds to the third reflector 16. The second reflector 19 and the third reflector 16 are both arranged corresponding to the photochromic holographic storage disk 27. The beam splitter 17 is used to split the blue light beam emitted by the blue light laser 3 into two blue light beams, one of which is a transmission light beam and the other is a reflection light beam. It can be understood that the reflection surface of the beam splitter 17 can also correspond to the second reflector 19, and the transmission surface can correspond to the third reflector 16. The following text temporarily takes the transmission surface of the beam splitter 17 corresponding to the second reflector 19 as an example for detailed description.

[0029] The first optical path is set corresponding to the reflection surface of the beam splitter 17 through the switch 31, which is located between the reflection surface of the beam splitter 17 and the photochromic holographic storage disk 27, and is used to control whether the light beam corresponding to the mounting seat in the blue double light beam is irradiated onto the photochromic holographic storage disk 27.

[0030] Furthermore, the Blu-ray storage reading module also includes a collimating beam expander 23 and a first converging lens 25 . The collimating beam expander 23 , a mounting seat, a first converging lens 25 and a photochromic holographic storage disk 27 are arranged in sequence, and the collimating beam expander 23 is arranged corresponding to the third reflector 16 .

[0031] Specifically, the first optical path passes through the switch 31 in the optical path of the beam splitter 17, the third reflector 16, the collimating beam expander 23, the mounting seat, the first converging lens 25 and the photochromic holographic storage disk 27, and is used to control whether the light beam corresponding to the mounting seat in the blue double light beam (the reflected light beam in the blue double light beam) is irradiated onto the photochromic holographic storage disk 27. The switch 31 is specifically located between the third reflector 16, the collimating beam expander 23 and the photochromic holographic storage disk 27.

[0032] Preferably, the blue light storage reading module further comprises a first polarizer 9 and a first gradient attenuation filter 10. The gradient attenuation filter described herein may be a circular gradient attenuation filter. The polarizer described herein is used to modulate the laser vibration direction into a vertically vibrating s-linear polarized light. The gradient attenuation filter is used to adjust the power of the laser beam. The blue light laser 3, the first polarizer 9, the first gradient attenuation filter 10, and the first reflector 15 are arranged in sequence. Further, the blue light storage reading module further comprises a second optical path through a switch 8. The second optical path through the switch 8 may be located between the first reflector 15 and the blue light laser 3, or between the first reflector 15 and the beam splitter 17. The second optical path through the switch 8 is used to control whether a blue light beam reaches the photochromic holographic storage disk 27.

[0033] The above-mentioned blue-ray storage reading module also includes a second gradient attenuation filter 21, which is used to attenuate the light beam in the blue double light beam that does not pass through the corresponding mask plate 24. Here, it is located between the transmission surface of the beam splitter 17 and the holographic storage module, specifically between the transmission surface of the beam splitter 17 and the second reflector 19.

[0034] See also Figure 2The blue-ray storage reading module further includes a reflector moving device 22, on which the second reflector 19 is mounted, and is used to horizontally move and / or rotate the second reflector 19 to change the angle between the blue double light beams (transmitted light beam and reflected light beam). By adjusting the reflector moving device 22, the coherent superposition of the transmitted light beam and the reflected light beam on the photochromic holographic storage disk 27 is conveniently achieved. Specifically, the reflector moving device 22 can horizontally move and rotate the second reflector 19, and the reflector moving device 22 includes a horizontally rotating electric rotating stage (rotating the second reflector 19 along a vertical axis) and a horizontal electric displacement stage (moving in the horizontal direction, for example, only capable of moving forward and backward), the horizontally rotating electric rotating stage is located on the horizontal electric displacement stage, and the second reflector 19 is mounted on the horizontally rotating electric rotating stage, which is used to control the recording angle of the reference light (blue light that does not pass through the mask plate 24).

[0035] In this embodiment, the mask plate 24 and the mounting seat are detachably connected, and the mounting seat is used to mount any one of the first mask plate, the second mask plate and the third mask plate. The first mask plate carries the mask image of the blue channel of the image to be stored, the second mask plate carries the mask image of the red channel of the image to be stored, and the third mask plate carries the mask image of the green channel of the image to be stored; the first mask plate, the second mask plate and the third mask plate are collectively referred to as the mask plate 24, and the mask plate 24 can be located in the optical path of the color holographic display system. It can be understood that for ease of use, the mask images of the three color channels can be set on one mask plate 24. Furthermore, the mounting seat can move the mask plate 24. When the image is stored and displayed again, there is no need to disassemble and replace the mask plate 24. The mask images of different primary color channels can be located in the corresponding optical paths by moving the mask plate 24 through the mounting seat.

[0036] In this embodiment, the blue double light beams (the transmitted light beam and the reflected light beam) of the blue light storage reading module can be coherently superimposed on the photochromic holographic storage disk 27, and the mask image corresponding to any primary color of the three primary colors of color light on the mask plate 24 is recorded on the photochromic holographic storage disk 27, that is, the image information corresponding to the mask image is written on the photochromic holographic storage disk 27 through the blue double light beams. The blue light storage reading module is also used to illuminate the writing position of the mask image of the blue channel in the photochromic holographic storage disk 27 to obtain a blue diffraction image, and then the image sensor 29 obtains the blue diffraction image.

[0037] In this embodiment, the green light reading module is used to illuminate the writing position of the mask pattern of the green channel in the photochromic holographic storage disk 27 to obtain a green diffraction image, and then the image sensor 29 acquires the green diffraction image.

[0038] The green light reading module includes a green light laser 2, a fourth reflector 14 and a fifth reflector 18 arranged in sequence, wherein the fourth reflector 14 is arranged corresponding to the green light laser 2, and the fifth reflector 18 is arranged corresponding to the fourth reflector 14 and the photochromic holographic storage disk 27. The fourth reflector 14 and the fifth reflector 18 are used to reflect the green light emitted by the green light laser 2 onto the photochromic holographic storage disk 27.

[0039] The green light reading module further comprises a second polarizer 6 and a third gradient attenuation filter 7. The green light laser 2, the second polarizer 6, the third gradient attenuation filter 7 and the fourth reflector 14 are arranged in sequence.

[0040] The green light reading module further comprises a third optical path switch 5 , which is located between the green light laser 2 and the photochromic holographic storage disk 27 . The third optical path switch 5 is used to control whether a green light beam reaches the photochromic holographic storage disk 27 .

[0041] In this embodiment, the red light reading module is used to illuminate the writing position of the mask image of the red channel in the photochromic holographic storage disk 27 to obtain a red diffraction image, and then the image sensor 29 acquires the red diffraction image.

[0042] The red light reading module includes a red light laser 4 and a sixth reflector 20, which is arranged corresponding to the red light laser 4 and the photochromic holographic storage disk 27. The sixth reflector 20 is used to reflect the red light emitted by the red light laser 4 onto the photochromic holographic storage disk 27.

[0043] The red light reading module further includes a third polarizer 12 and a fourth gradient attenuation filter 13. The red light laser 4, the third polarizer 12, the fourth gradient attenuation filter 13, and the sixth reflector 20 are sequentially arranged. Further, the red light reading module further includes a fourth light path through switch 11, the fourth light path through switch 11 is located between the sixth reflector 20 and the red light laser 4, and the fourth light path through switch 11 is used to control whether a red light beam reaches the photochromic holographic storage disk 27.

[0044] Here, the red laser 4 uses a 671 nm laser, the green laser 2 uses a 532 nm laser, and the blue laser uses a 473 nm laser. The 473 nm laser will be used as the information recording light for the double-beam holographic interference process, and the color information reading process uses 671 nm laser, 532 nm laser, and 473 nm laser as the reading light respectively.

[0045] In this embodiment, the image sensor 29 is used to obtain diffraction images (red light diffraction images, blue light diffraction images, and green light diffraction images) corresponding to the image information in the photochromic holographic storage disk 27. Specifically, a color CMOS image sensor is used to capture the color information reproduced by diffraction and transmit it to the display 30.

[0046] Furthermore, the color holographic display system further includes a collimating lens 28 , which is located between the photochromic holographic storage disk 27 and the image sensor 29 and is used to converge the diffraction image onto the detection surface of the image sensor 29 .

[0047] It can be understood that the display 30 as an image receiving end displays the color reproduced image information in real time, and can also display the diffraction image of red light, the diffraction image of blue light and the diffraction image of green light simultaneously or separately under the red, green and blue laser reading modules.

[0048] Preferably, the image information corresponding to the mask image of the red channel, the mask image of the green channel and the mask image of the blue channel of the image to be stored can be written into the same point of the photochromic holographic storage disk, i.e., multi-angle storage. The red light reading module, the green light reading module and the blue light storage reading module are used to simultaneously illuminate the photochromic holographic storage disk so that the image sensor obtains the diffraction image corresponding to the image information in the photochromic holographic storage disk 27. At this time, the color reproduction image is directly obtained on the detection surface of the image sensor 29, and the display is used to display the color reproduction image in real time.

[0049] Please see again Figure 1 , is an implementation diagram of the positional relationship of various parts in a color holographic display system, wherein the color holographic display system also includes a shell 1, which is made of metal. A blue laser 3, a red laser 4, a green laser 2 and an image sensor 29 are located on the right side of the shell 1, a first reflector 15, a second reflector 19, a third reflector 16, a beam splitter 17, a reflector moving device 22, and a second gradient attenuation filter 21 are located on the left side of the shell 1, and other structures are located in the middle of the shell 1.

[0050] In this embodiment, all light paths through switches can be electrically controlled or manually controlled. Here, as an example, the electrical control buttons of all light paths through switches and the switches of the lasers are located on the housing 1;

[0051] In this embodiment, all reflectors are made of all-aluminum reflectors.

[0052] In this embodiment, the color holographic display system includes a first moving mechanism 26, which is used to move the photochromic holographic storage disk 27, and can realize rotation, and can also realize at least one of two moving modes of vertical movement and horizontal movement. The rotation can be rotation along a horizontal axis and rotation along a vertical axis, preferably rotation along a horizontal axis and rotation along a vertical axis. The horizontal movement can be movement in the front-back direction.

[0053] Here, the first moving mechanism 26 is used to rotate and vertically move the photochromic holographic storage disk 27. Figure 3 As shown in the example, the first moving mechanism 26 includes: a base mounted on the housing 1, a first turntable mounted on the base, a lifting rod mounted on the turntable, and a second turntable mounted on the lifting rod. The photochromic holographic storage disk 27 is mounted on the second turntable. Here, the photochromic holographic storage disk 27 is parallel to the second turntable. The first turntable can rotate around a first axis, which is perpendicular to the horizontal plane. The lifting rod can drive the photochromic holographic storage disk 27 to move vertically. The second turntable can rotate around a second axis, which is parallel to the horizontal plane.

[0054] In this embodiment, the color holographic display system may further include a second moving mechanism, which is used to move the image sensor 29, and can realize rotation, and can also realize at least one of the two moving modes of vertical movement and horizontal movement. The structure may be the same as the first moving mechanism 26, and will not be described in detail here.

[0055] It can be understood that the movement of the photochromic holographic storage disk 27 by the first moving mechanism 26 and the movement of the reflector moving device 22 and the second reflector 19 can be realized electrically or manually.

[0056] In this embodiment, the photochromic holographic storage disk 27 also includes a protective layer. The substrate, the silver-polyvinyl alcohol photochromic film and the protective layer are arranged in sequence. The silver-polyvinyl alcohol photochromic film serves as an information recording layer. The information recording layer on the photochromic holographic storage disk 27 is a silver-polyvinyl alcohol composite film. Silver and polyvinyl alcohol are a mixture and are located in the same layer. The silver-polyvinyl alcohol photochromic film has a high diffraction efficiency and light response speed, and has a low preparation cost and can be stored for a long time. It can be understood that the substrate is a transparent substrate, and the silver-polyvinyl alcohol photochromic film is a transparent light yellow film. The protective layer can be a layer of light or heat curing waterproof material coated on the silver-polyvinyl alcohol photochromic film.

[0057] The following is an example of an existing preparation method of an existing silver and polyvinyl alcohol photochromic film, which is only an example and not a limitation. Preferably, the silver-polyvinyl alcohol photochromic film is a transparent light yellow film prepared from a silver nitrate-polyvinyl alcohol mixed solution, and the preparation method comprises:

[0058] S1. Prepare a silver nitrate-polyvinyl alcohol mixed solution.

[0059] S2, coating a layer of silver-polyvinyl alcohol mixed solution on the circular glass substrate by drop coating in front of the doctor blade pouring the silver nitrate-polyvinyl alcohol mixed solution;

[0060] S3, heating the coating layer by a hot plate, drying it to form a film, and obtaining a silver-polyvinyl alcohol photochromic film.

[0061] The specific process of S1 is as follows: weigh 5 g of polyvinyl alcohol solid powder and dissolve it in 45 mL of ultrapure water, heat it in a water bath at 80 °C and stir it magnetically for 2 h, turn off the heating and continue stirring until the solution cools to room temperature. Add 1.7 g of silver nitrate powder to the polyvinyl alcohol aqueous solution and stir it magnetically for 30 min to mix it evenly. After stirring, the mixed solution needs to be placed in a vacuum drying oven for room temperature vacuum for 1 h, and the cycle is repeated twice.

[0062] The specific process of S2 above is: first, wipe the coater clean with a dust-free cloth moistened with alcohol, place the cleaned circular optical disc glass sheet on the scraper coater, then evenly pour an appropriate amount of mixed solution in front of the scraper, set the coating speed and scraper height of the coater, and form a layer of silver nitrate-polyvinyl alcohol photochromic recording layer on the surface of the glass optical disc through the automatic scraper coater.

[0063] The specific process of S3 is as follows: placing the photochromic disc on a hot plate and heating it to dry it into a film, and keeping it at 80°C for 50 minutes until the information recording layer is completely solidified. The thickness of the silver-polyvinyl alcohol photochromic film is greater than or equal to 200 μm, which ensures that a volume grating can be formed therein, and multiple angles of the same point can be multiplexed for storage.

[0064] The specific steps of the color holographic display described in this embodiment are:

[0065] Holographic recording: Install the first mask plate on the mounting seat, turn on the blue light storage reading module, the second light path through the switch 8 and the first light path through the switch 31, the blue light beam emitted by the blue laser 3 sequentially passes through the first polarizer 9 to adjust the polarization state, the first gradient attenuation filter 10 to attenuate, the first reflector 15 to reflect, and the beam splitter 17 to semi-reflect and semi-transmit to obtain a blue double beam, one beam sequentially passes through the second gradient attenuation filter 21 to attenuate, and the second reflector 19 to reflect and directly irradiate the photochromic hologram The other beam is reflected by the third reflector 16, collimated and expanded by the collimating beam expander 23, passes through the mask pattern on the mask plate 24, and converged by the first converging lens 25 before being incident on the same point on the photochromic holographic storage disk 27. At this point, the two blue light beams are coherently superimposed on the photochromic holographic storage disk 27, and the image information corresponding to the mask pattern of the blue channel is written on the first position (an information recording point) of the photochromic holographic storage disk 27, and the first optical path is closed through the switch 3. 1; replace the first mask plate with the second mask plate, adjust the angle of the photochromic holographic storage disk 27, adjust the position and angle of the second reflector 19, move horizontally away from the beam splitter 17, open the first light path through the switch 31, the two blue light beams are coherently superimposed on the photochromic holographic storage disk 27 to achieve writing the image information corresponding to the mask of the red channel at the first position of the photochromic holographic storage disk 27, and close the first light path through the switch 31; replace the second mask plate with the third mask plate, adjust the angle of the photochromic holographic storage disk 27, adjust the position and angle of the second reflector 19, move horizontally close to the beam splitter 17, open the first light path through the switch 31, the two blue light beams are coherently superimposed on the photochromic holographic storage disk 27 to achieve writing the image information corresponding to the mask of the green channel at the first position of the photochromic holographic storage disk 27, close the first light path through the switch 31 and the second light path through the switch 8, so far, the storage of the three primary colors and three channels of the color light of an image is completed. Adjust the position and / or angle of the photochromic holographic disk and repeat the above operation to store the three primary colors and three channels of the second image at the second position (information recording point). Repeat the above operation to realize the recording of multiple color images and obtain n information recording sites.

[0066] Color holographic display: the first optical path is kept closed by the switch 31, while the second optical path is turned on by the switch 8, the blue light storage reading module, the third optical path is turned on by the switch 5, the green light reading module, the fourth optical path is turned on by the switch 11, the red light reading module and the image sensor 29, so that the blue light beam emitted by the blue laser 3 sequentially passes through the first polarizer 9 to obtain an s-polarized light beam, is attenuated by the first gradient attenuation filter 10, is reflected by the first reflector 15, is transmitted by the beam splitter 17, is reflected by the second reflector 19, and then is incident on the first position of the photochromic holographic storage disk 27. At the same time, the green light beam emitted by the green laser 2 sequentially passes through the second polarizer 6 to obtain an s-polarized light beam, is attenuated by the third gradient attenuation filter 7, is reflected by the fourth reflector 14 and the fifth reflector 18, and then is incident on The red light reading module is placed at the first position of the photochromic holographic storage disk 27. At the same time, the red light beam emitted by the red laser 4 passes through the third polarizer 12 to obtain an s-polarized light beam, is attenuated by the fourth gradient attenuation filter 13, and is reflected by the sixth reflector 20 before being incident on the first position of the photochromic holographic storage disk 27. The image sensor 29 receives the reproduced image of the three-channel simultaneous diffraction. The image is a color reproduced image, which is composed of the diffraction image obtained based on the red light reading module, the diffraction image obtained based on the green light reading module, and the diffraction image obtained based on the blue light reading module. The color reproduced image is transmitted to the display 30, and the display 30 can display the color reproduced image. Thus, a color holographic display of the color image stored in the holographic storage is obtained. Figure 4 , Figure 4 This is an example diagram of a color holographic display in a practical application of the utility model (the diagram is a black and white schematic diagram of a color diagram).

[0067] In this preferred embodiment, the three-color writing of a pattern is completed at the same position point and different angles. A single recording wavelength is used, and angle multiplexing technology is adopted. Three pairs of independent light beams at different angles are used to record the holograms of red, green and blue components. The reference light angles of the holograms corresponding to different colors differ by more than 5° to avoid color crosstalk during reading. The volume holographic interference pattern recorded on the photochromic holographic storage disk 27 can only be diffracted at a specific angle when the Bragg condition is met. Therefore, it is necessary to use lasers of different wavelengths as read-out light at the corresponding writing angles to diffract the corresponding holograms at the corresponding angles.

[0068] In summary, a color holographic display system based on a photochromic disc of the utility model can record and display color information according to user needs, and has the characteristics of small size, low cost, high mobility, etc. The color holographic display realized by using a photochromic holographic storage disc 27 (i.e., a photochromic disc) instead of a spatial light modulator avoids the dependence on a high refresh rate spatial light modulator, effectively reduces the system cost, reduces the system complexity, and easily realizes color holographic display. Since a spatial light modulator is not used, it belongs to the computational holographic technology, and there is no problem of large amount of calculation. A color holographic display system based on a photochromic disc of the utility model is a color holographic display system that takes into account efficient display effects, simple system implementation and low processing cost. Specifically, by utilizing the unique angle selection characteristics of the photochromic holographic storage disc 27, it can form a volume grating, which can realize the single-wavelength storage of the three primary colors of the image at the same information recording point, and then select the three-color wavelengths at different angles to read simultaneously, so that the color reproduction image can be read in real time when the laser is turned on.

[0069] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back...) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0070] In addition, in the present utility model, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present utility model.

[0071] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A color holographic display system based on a photochromic disc, characterized in that: include: A photochromic holographic storage disk, a first moving mechanism connected to the photochromic holographic storage disk, a red light reading module, a green light reading module, a blue light storage reading module, a mounting seat for mounting a mask plate, an image sensor, and a display connected to the image sensor; the photochromic holographic storage disk comprises a substrate and a silver-polyvinyl alcohol photochromic film with a thickness greater than or equal to 200 μm arranged on the substrate; the first moving mechanism is used to rotate the photochromic holographic storage disk, and is also used to vertically move and / or horizontally move the photochromic holographic storage disk; the red light reading module, the green light reading module, the blue light storage reading module, the mounting seat, and the image sensor are all arranged corresponding to the photochromic holographic storage disk; the mask plate carries at least one of a mask image of a red channel, a mask image of a green channel, and a mask image of a blue channel of an image to be stored; the blue light storage reading module is used to write image information corresponding to the mask image on the photochromic holographic storage disk; The red light reading module, the green light reading module and the blue light storage reading module are all used to irradiate the photochromic holographic storage disk so that the image sensor obtains the diffraction image corresponding to the image information in the photochromic holographic storage disk; the display is used to display a color reproduction image, and the color reproduction image includes the diffraction image obtained based on the red light reading module, the diffraction image obtained based on the green light reading module, and the diffraction image obtained based on the blue light reading module.

2. A color holographic display system based on a photochromic disc as claimed in claim 1, characterized in that: The first moving mechanism is used to vertically move the photochromic holographic storage disk. The first moving mechanism includes a base, a first turntable installed on the base, a lifting rod installed on the turntable, and a second turntable installed on the lifting rod. The photochromic holographic storage disk is installed on the second turntable. The first turntable can rotate around a first axis, and the first axis is perpendicular to a horizontal plane. The lifting rod can drive the photochromic holographic storage disk to move vertically. The second turntable can rotate around a second axis, and the second axis is parallel to the horizontal plane.

3. A color holographic display system based on a photochromic disc as claimed in claim 1, characterized in that: Image information corresponding to a mask image of a red channel, a mask image of a green channel, and a mask image of a blue channel of the image to be stored can be written into the same point of the photochromic holographic storage disk. The red light reading module, the green light reading module, and the blue light storage reading module are used to simultaneously illuminate the photochromic holographic storage disk so that the image sensor obtains a diffraction image corresponding to the image information in the photochromic holographic storage disk; and the display is used to display a color reproduced image in real time.

4. A color holographic display system based on a photochromic disc as claimed in claim 1, characterized in that: The blue-light storage reading module includes an optical path passing switch and a beam splitter for obtaining a blue double light beam, the mounting seat is arranged corresponding to the beam splitter and the photochromic holographic storage disc, the first optical path passing switch is arranged corresponding to the mounting seat, and is used to control whether the light beam corresponding to the mounting seat in the blue double light beam is irradiated onto the photochromic holographic storage disc, and the blue-light storage reading module is used to write the image information corresponding to the mask image on the photochromic holographic storage disc through the blue double light beam.

5. A color holographic display system based on a photochromic disc as claimed in claim 4, characterized in that: The blue-ray storage reading module also includes a blue-ray laser, a first reflector, a second reflector, a third reflector, a collimating beam expander and a first converging lens. The blue-ray laser, the first reflector and the beam splitter are arranged in sequence. The transmission surface and the reflection surface of the beam splitter correspond to the second reflector and the third reflector one by one, or correspond to the third reflector and the second reflector one by one. The second reflector is arranged corresponding to the photochromic holographic storage disk, the third reflector, the collimating beam expander, the mounting seat, the first converging lens and the photochromic holographic storage disk are arranged in sequence, and the first optical path is located between the third reflector and the photochromic holographic storage disk or between the beam splitter and the third reflector through a switch.

6. A color holographic display system based on a photochromic disc as claimed in claim 5, characterized in that: The blue light storage reading module also includes a first polarizer, a first gradient attenuation filter, a second optical path through a switch and a second gradient attenuation filter. The blue light laser, the first polarizer, the first gradient attenuation filter and the first reflector are arranged in sequence. The first polarizer is used to modulate the vibration direction of the blue light into s-linear polarized light with vertical vibration. The second optical path through the switch is located between the first reflector and the blue light laser, or between the first reflector and the beam splitter. The second gradient attenuation filter is used to attenuate the light beam in the blue double light beam that does not pass through the corresponding mask plate.

7. A color holographic display system based on a photochromic disc as claimed in claim 5, characterized in that: The blue-ray storage reading module further comprises a reflector moving device, on which the second reflector is mounted, and the reflector moving device is used for horizontally moving and / or rotating the second reflector to change the angle between the blue double light beams.

8. A color holographic display system based on a photochromic disc as claimed in claim 1, characterized in that: The green light reading module comprises a green light laser, a second polarizer, a third gradient attenuation filter, a fourth reflector and a fifth reflector arranged in sequence, the green light reading module further comprises a third optical path passing switch located between the green light laser and the optical path of the photochromic holographic storage disk, the second polarizer is used to modulate the vibration direction of the green light into a vertically vibrating s-linear polarized light; The red light reading module includes a red light laser, a third polarizer, a fourth gradient attenuation filter and a sixth reflector arranged in sequence, and the red light reading module also includes a fourth light path passing switch located between the sixth reflector and the red light laser. The third polarizer is used to modulate the vibration direction of the red light into vertically vibrating s-linear polarized light.

9. A color holographic display system based on a photochromic disc as claimed in claim 1, characterized in that: The color holographic display system also includes a shell, the photochromic holographic storage disk, the first moving mechanism, the red light reading module, the green light reading module, the blue light storage reading module, the mounting seat, and the image sensor are all located inside the shell, and the display is located outside the shell or on the shell.

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