Novel high-fidelity light field display system

Abstract

The invention provides a novel high-fidelity light field display system which comprises a collimation light source, a chromaticity modulation film, a brightness modulation film and a bidirectional angle modulation grating, the pixel size of the chromaticity modulation film is N times of the pixel size of the brightness modulation film, N is a number larger than or equal to 3 and smaller than or equal to 30, and the brightness of the brightness modulation film is larger than or equal to 30. Wherein chromaticity information is loaded after the collimated light source passes through the chromaticity modulation film, brightness information is loaded after the collimated light source passes through the brightness modulation film, the display visual angle of the loaded chromaticity information and brightness information is adjusted through the bidirectional angle modulation grating, and the utilization rate of light information is increased by reasonably distributing the chromaticity information and the brightness information; the problem that the three-dimensional image display quality is poor is solved, high-fidelity color light field display is achieved, and the experience effect of audiences is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of light field display, and in particular to a novel high-fidelity light field display system. Background Art

[0002] Three-dimensional light field display technologies include integral imaging, holographic display, and stereoscopic display, providing various methods to achieve more realistic visual effects than traditional flat displays.

[0003] However, due to the limitations of manufacturing precision, existing light field displays find it difficult to maintain high spatial resolution and information density at a wide viewing angle, and are unable to take into account both brightness and chromaticity information at the same time, which in turn leads to insufficient display information density, reduced three-dimensional image display quality, and seriously affects the audience's experience. Summary of the invention

[0004] The present invention provides a novel high-fidelity light field display system, which is used to solve the defects of the prior art in that the display information density is insufficient and the display quality is reduced, and the problem of poor display quality of three-dimensional images is solved by reasonably allocating chromaticity and brightness information, thereby realizing high-fidelity color light field display and improving the audience's experience.

[0005] The present invention provides a novel high-fidelity light field display system, which comprises a collimated light source, a chromaticity modulation film, a brightness modulation film and a bidirectional angle modulation grating, wherein the pixel size of the chromaticity modulation film is N times the pixel size of the brightness modulation film, where N is a number greater than or equal to 3 and less than or equal to 30, wherein: The collimated light source is loaded with chromaticity information after passing through the chromaticity modulation film, and is loaded with brightness information after passing through the brightness modulation film. The loaded chromaticity information and brightness information are adjusted to display viewing angle through the bidirectional angle modulation grating.

[0006] According to a novel high-fidelity light field display system provided by the present invention, the convex surface of the cylindrical lens of the bidirectional angle modulation grating faces the collimated backlight; the bidirectional angle modulation grating selects an aspherical optical structure, and the expression of the aspherical optical structure satisfies: Where Z is the surface height, R is the radial coordinate, and k is the quadratic surface constant. is the vertex curvature, , , The aspheric parameters are aspheric parameters. The aspheric optical structure adopts an even-order aspheric microstructure array. Through ZEMAX simulation and setting of 6 preferred parameters of the light control unit in the horizontal plane and the vertical plane, the light beams incident at the same distance in the horizontal and vertical directions pass through the cylindrical lens and reach the position of the image plane at the same distance.

[0007] According to a novel high-fidelity light field display system provided by the present invention, the novel high-fidelity light field display system encodes and regulates the chromaticity information and the brightness information respectively, generates a chromaticity composite image and a grayscale brightness composite image, and loads them onto corresponding diaphragms.

[0008] According to a novel high-fidelity light field display system provided by the present invention, when preparing the chromaticity modulating film, a beam reverse tracking algorithm is used to encode the chromaticity parallax image array to generate the chromaticity composite image. The mapping relationship between the chromaticity composite image and the chromaticity parallax image is: in, Represents the chromaticity disparity image The corresponding Row, No. Column viewpoint information within the cylindrical lens; variable and represent the number of columns and rows in the chromaticity disparity image respectively; The pixel size of the reference chromaticity composite image is represented, and the chromaticity composite image is loaded onto a film sheet using multi-color inkjet printing to obtain the chromaticity modulating film.

[0009] According to a novel high-fidelity light field display system provided by the present invention, when preparing the brightness modulating film, a brightness parallax image array is used to generate the grayscale brightness synthetic image, wherein the mapping relationship between the grayscale brightness synthetic image and the brightness parallax image is: in, Representation and brightness disparity image The corresponding Row, No. Column viewpoint information within the cylindrical lens; variable and Represent the number of columns and rows in the brightness parallax image array respectively; Indicates the pixel size of the reference brightness composite image.

[0010] According to a novel high-fidelity light field display system provided by the present invention, the grayscale brightness composite image is binarized using a novel discrete dither matrix to obtain a halftone image; wherein the novel discrete dither matrix contains 256 elements, the discrete dither matrix is ​​discretized into 16 4×4 sub-matrices, each sub-matrix contains 16 elements, the elements in the matrix are integers from 0 to 255, and the integers are used to represent the threshold used in the binarization process, The binarization process includes: Allocate the 16 sub-matrices to 16 adjacent light control units, and move each small matrix to the upper left corner of the light control unit where it is located; Comparing the grayscale threshold of each pixel in the grayscale brightness composite image covered by the submatrix of the discrete jitter matrix, if the grayscale value of the pixel exceeds the threshold, binarizing it to 1; otherwise, setting it to 0; The discrete dither matrix is ​​translated to the unbinarized area in the grayscale brightness composite image for subsequent binarization until the entire grayscale brightness composite image is completely binarized.

[0011] According to a novel high-fidelity light field display system provided by the present invention, a laser is used to expose the halftone image. Starting from laser exposure, a high-precision laser device is used to accurately expose a pre-designed image onto a photosensitive film coated with a photosensitive silver halide layer. The laser system carefully adjusts the beam intensity and positioning to project the pattern onto the photosensitive layer of the film. After exposure, the development process will display the exposed area of ​​the photosensitive layer. The film is immersed in a developer solution, and a controlled chemical reaction occurs within a specified time to form a visible pattern.

[0012] According to a novel high-fidelity light field display system provided by the present invention, a point light source and a collimating lens are placed in the high-fidelity light field display system to generate a collimated light beam, and the divergence angle of the collimated light beam is less than 1°.

[0013] The novel high-fidelity light field display system provided by the present invention loads chromaticity information through a collimated light source after passing through a chromaticity modulation film, and then loads brightness information after passing through a brightness modulation film. The two loaded information adjust the display viewing angle through a bidirectional angle modulation grating, utilizes the visual characteristics of the human eye, and reasonably distributes chromaticity and brightness information to improve the utilization rate of light information, solves the problem of poor three-dimensional image display quality, realizes high-fidelity color light field display, and improves the audience's experience effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1 It is a structural schematic diagram of a novel high-fidelity light field display system provided by the present invention.

[0016] Figure 2 It is a structural schematic diagram of the light control unit provided by the present invention.

[0017] Figure 3 It is a schematic diagram of the optical design of the vertical light control unit in the yz plane provided by the present invention.

[0018] Figure 4 It is a schematic diagram of the field of view constructed by the light control unit provided by the present invention on the positive y-axis of the yz plane.

[0019] Figure 5 It is a schematic diagram of the optical design of the horizontal light control unit in the xz plane provided by the present invention.

[0020] Figure 6 It is a schematic diagram of the field of view constructed by the light control unit provided by the present invention on the positive x-axis of the xz plane.

[0021] Figure 7 It is a schematic diagram of chromaticity synthesis image synthesis provided by the present invention.

[0022] Figure 8 It is a schematic diagram of brightness synthesis image synthesis provided by the present invention.

[0023] Fig. 9 It is a schematic diagram of a binarization process provided by the present invention.

[0024] Fig.10 It is a schematic diagram of the physical image of the chromaticity modulation film provided by the present invention.

[0025] Fig.11 It is a schematic diagram of the physical image of the brightness modulation film provided by the present invention.

[0026] Reference numerals: 100: A new type of high-fidelity light field display system; 110: A collimated light source; 120: A chromaticity modulation film; 130: A brightness modulation film; 140: A bidirectional angle modulation grating. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] Three-dimensional light field display technology not only has broad application prospects in entertainment fields such as games and movies, but also has great potential in education, medical care, industrial design and other fields. Light field display technology continues to create highly realistic experience effects, and in-depth research on key indicators such as spatial resolution and information density of the display plane. At the same time, it is necessary to ensure the market demand for large depth, high definition and wide viewing angle to meet the audience's clear true three-dimensional images at different angles.

[0029] However, due to the limitations of current manufacturing precision, existing light field displays find it difficult to maintain high spatial resolution and information density at a wide viewing angle, and are unable to take into account both brightness and chromaticity information at the same time, which in turn leads to insufficient display information density, reduced three-dimensional image display quality, and seriously affects the audience's experience.

[0030] Based on the above problems, the present invention provides a high-fidelity light field display system, which loads chromaticity information through a collimated light source passing through a chromaticity modulation film, and then loads brightness information through a brightness modulation film. The two loaded information are used to adjust the display viewing angle through a bidirectional angle modulation grating, thereby achieving full parallax high-fidelity color display, and utilizing the visual characteristics of the human eye to improve the utilization efficiency of light information.

[0031] Combine the following Figure 1-Figure 11 The highly realistic light field display system of the present invention is described, and the system can be applied to three-dimensional image display in any field.

[0032] Figure 1 is a schematic diagram of the structure of a novel high-fidelity light field display system provided by the present invention. Figure 1 As shown, the light field display system 100 includes: a collimated light source 110, a chromaticity modulation film 120, a brightness modulation film 130 and a bidirectional angle modulation grating 140, wherein the pixel size of the chromaticity modulation film is N times the pixel size of the brightness modulation film, and N is a number greater than or equal to 3 and less than or equal to 30, wherein the collimated light source is loaded with chromaticity information after passing through the chromaticity modulation film, and then loaded with brightness information after passing through the brightness modulation film, and the loaded chromaticity information and the brightness information are adjusted through the bidirectional angle modulation grating to adjust the display viewing angle.

[0033] It should be noted that the rod cells in the retina of the eye are mainly responsible for combining light of different wavelengths to perceive brightness, and have poor color discrimination ability. In contrast, color perception is achieved by activating three types of cone cells, each of which responds to different wavelength components. Cone cells are densely concentrated in the macula, especially in the "fovea" area of ​​the retina, while rod cells are more widely distributed in the peripheral retina and are more numerous. Therefore, the human eye perceives chromaticity and brightness information independently, and the resolution of brightness information is higher than that of chromaticity information. In order to improve the utilization of information, the system encodes and regulates chromaticity information and brightness information separately, generates chromaticity composite images and grayscale brightness composite images, and loads them onto the corresponding membrane.

[0034] In the embodiment of the present invention, chromaticity information is loaded after a collimated light source passes through a chromaticity modulation film, and brightness information is loaded after passing through a brightness modulation film. The two types of loaded information are used to adjust the display viewing angle through a bidirectional angle modulation grating, thereby utilizing the visual characteristics of the human eye and reasonably allocating chromaticity and brightness information to improve the utilization rate of light information, thereby solving the problem of poor display quality of three-dimensional images, achieving highly realistic color light field display, and improving the audience's experience.

[0035] The convex surface of the cylindrical lens of the bidirectional angle modulation grating faces the collimated backlight; The bidirectional angle modulation grating selects an aspherical optical structure, and the expression of the aspherical optical structure satisfies: Where Z is the surface height, R is the radial coordinate, and k is the quadratic surface constant. is the vertex curvature, , , The aspheric parameters are aspheric parameters. The aspheric optical structure adopts an even-order aspheric microstructure array. Through ZEMAX simulation and setting of 6 preferred parameters of the light control unit in the horizontal plane and the vertical plane, the light beams incident at the same distance in the horizontal and vertical directions pass through the cylindrical lens and reach the position of the image plane at the same distance, and the field of view distribution diagrams of different planes are constructed.

[0036] For example, in order to achieve a high-definition display effect, when the viewing distance of the display system is 1.1 meters, considering the human visual acuity (about 1 arc minute), the spacing between the xz (horizontal) and yz (vertical) cylindrical lenses of the bidirectional angle modulation grating is preferably designed to be 0.3175 mm; in order to achieve a wide-viewing angle display effect, the convex surface of the cylindrical lens of the grating needs to face the collimated backlight, so as to achieve a large-angle light beam refraction and form a larger viewing angle; in order to ensure a large-depth display effect, it is necessary to construct a uniformly distributed viewpoint, preferably an aspherical optical structure, and the radial coordinate of the vertical light control unit is 0. 087, the vertex curvature is 0.3175, the quadratic surface constant is -0.909, and the aspheric surface parameters are -0.147, -18.531, and -256.045 respectively; the radial coordinate of the horizontal light control unit is 0.086, the vertex curvature is 0.3175, the quadratic surface constant is -0.909, and the aspheric surface parameters are -0.147, -18.546, and -256.051 respectively. The above parameter experiments show that the best optical display effect is presented when the light beams incident at the same distance in the horizontal and vertical directions pass through the cylindrical lens and reach the position of the image plane at the same distance.

[0037] For example, Figure 2 is a schematic diagram of the structure of the light control unit provided by the present invention, such as Figure 2 As shown, the small frame area on the left represents the object plane, and its small dots represent equidistant object points on the plane. The large frame area on the right represents the image plane, where the object points from the object plane are mapped into uniformly equidistant image points through optical structure mapping, and the dark large dots represent these image points on the image plane. The cylindrical lens can adjust the uniformity of the viewpoint.

[0038] the following Figure 3-Figure 6 This is the simulation result of the light control unit using simulation software.

[0039] Figure 3 is a schematic diagram of the optical design of the vertical light control unit in the yz plane provided by the present invention, such as Figure 3 As shown, the light lines represent collimated incident beams entering the object plane at equal intervals.

[0040] Figure 4 is a schematic diagram of the field of view constructed by the light control unit provided by the present invention on the positive y-axis of the yz plane, such as Figure 4 As shown, the rays represent the outgoing light paths corresponding to the equidistant incident light beams.

[0041] Figure 5 is a schematic diagram of the optical design of the horizontal light control unit in the xz plane provided by the present invention, such as Figure 5 As shown, the light lines represent collimated incident beams entering the object plane at equal intervals.

[0042] Figure 6 Schematic diagram of the field of view constructed by the light control unit provided by the present invention on the positive x-axis of the xz plane, such as Figure 6 As shown, the rays represent the outgoing light paths corresponding to the equally spaced incident light beams. Combination Figure 3-Figure 6 It can be seen that only by passing the light beams incident at the same distance in the horizontal and vertical directions through the cylindrical lens and reaching the position of the image plane at the same distance can a uniformly distributed viewpoint be constructed to present the best optical display effect, laying a good foundation for subsequent pixel encoding.

[0043] In one embodiment, the novel high-fidelity light field display system encodes and regulates the chromaticity information and the brightness information separately, generates a chromaticity composite image and a grayscale brightness composite image, and loads them onto corresponding diaphragms.

[0044] In one embodiment, when preparing the chromaticity modulating film, the chromaticity parallax image array is encoded using a beam reverse tracking algorithm to generate the chromaticity composite image. The mapping relationship between the chromaticity composite image and the chromaticity parallax image is: in, Represents the chromaticity disparity image The corresponding Row, No. Column viewpoint information within the cylindrical lens; variable and represent the number of columns and rows in the chromaticity disparity image respectively; The pixel size of the reference chromaticity composite image is represented, and the chromaticity composite image is loaded onto a film sheet using multi-color inkjet printing to obtain the chromaticity modulating film.

[0045] It should be noted that since the human eye is not very sensitive to chromatic information, low-pixel-density multi-color inkjet printing is used to produce chromaticity composite images. The chromaticity parallax image array can be encoded into a low-pixel-density chromaticity composite image using a beam backtracking algorithm, which can then be produced using multi-color inkjet printing technology.

[0046] For example, Figure 7 Schematic diagram of chromaticity synthesis image synthesis provided by the present invention, such as Figure 7As shown, the large color image with an xy coordinate system on the left represents a low-pixel chromaticity composite image, the grid image in the center shows an enlarged portion of the chromaticity composite image, the image array on the right represents a chromaticity parallax image array, and the arrows near the lens represent the pixel mapping relationship between the chromaticity parallax image array and the chromaticity composite image. After the chromaticity composite image is obtained, it is preferred to load the chromaticity composite image onto a diaphragm by multi-color inkjet printing with a low pixel density, and the diaphragm loaded with the chromaticity composite image is a chromaticity modulation diaphragm.

[0047] In an embodiment of the present invention, the chromaticity modulating film is assigned a lower pixel density to optimize information utilization efficiency.

[0048] In one embodiment, when preparing the brightness modulating film, a brightness parallax image array is used to generate the grayscale brightness composite image, wherein the mapping relationship between the grayscale brightness composite image and the brightness parallax image is: in, Representation and brightness disparity image The corresponding Row, No. Column viewpoint information within the cylindrical lens; variable and Represent the number of columns and rows in the brightness parallax image array respectively; Indicates the pixel size of the reference brightness composite image.

[0049] For example, Figure 8 Schematic diagram of brightness synthesis image synthesis provided by the present invention, such as Figure 8 As shown, the large image on the left, using an xy coordinate system, represents a high-pixel-density brightness synthesis image, the grid image in the center shows an enlarged portion of the brightness synthesis image, the image array on the right represents a brightness parallax image array, and the arrows near the lens show the pixel mapping relationship between the brightness parallax image array and the brightness synthesis grayscale image. After obtaining the brightness synthesis image, the brightness synthesis image is binarized to obtain a brightness modulation membrane.

[0050] In the embodiment of the present invention, the brightness modulation film is assigned a higher pixel density to ensure excellent high-fidelity display performance.

[0051] Furthermore, the grayscale brightness composite image is binarized using a new discrete dithering matrix to obtain a halftone image; wherein the new discrete dithering matrix contains 256 elements, the discrete dithering matrix is ​​discretized into 16 4×4 sub-matrices, each sub-matrix contains 16 elements, the elements in the matrix are integers from 0 to 255, and the integers are used to represent the thresholds used in the binarization process. The binarization process includes: Allocate the 16 sub-matrices to 16 adjacent light control units, and move each small matrix to the upper left corner of the light control unit where it is located; Comparing the grayscale threshold of each pixel in the grayscale brightness composite image covered by the submatrix of the discrete jitter matrix, if the grayscale value of the pixel exceeds the threshold, binarizing it to 1; otherwise, setting it to 0; The discrete dither matrix is ​​translated to the unbinarized area in the grayscale brightness composite image for subsequent binarization until the entire grayscale brightness composite image is completely binarized.

[0052] Here, the discrete jitter matrix is ​​a 4×4 large sub-matrix containing 256 elements. The area outlined by the thick line represents a 4×4 sub-matrix, each of which contains 16 elements. The elements in the matrix are integers from 0 to 255, representing the threshold used in the binarization process, corresponding to the color gradient from dark colors to light colors, with dark color pixels having smaller values ​​and light color pixels having larger values.

[0053] It should be noted that if a dithering matrix with a smaller number of pixels is selected, the difference between the grayscale pixels of the sub-matrix will be relatively close and the pixel elements will be limited, which cannot fully match the threshold with the grayscale image. Large areas of 0 or 1 may appear, resulting in large errors in the synthesized halftone image. If a dithering matrix with a larger pixel element range is selected, high-frequency information will be crosstalked, resulting in a blurred image quality.

[0054] Here, the method of determining the target element value in the brightness synthesis image may be to set the target pixel value to 1 if the element value in the submatrix is ​​less than the pixel value in the brightness synthesis image, and to set the target pixel value to 0 otherwise.

[0055] For example, Fig. 9 It is a schematic diagram of a binarization process provided by the present invention, such as Fig. 9 As shown in the figure, c is a new discrete dither matrix of the 4×4 large sub-matrix; d is an enlarged view of the brightness synthesis image in the 4×4 light control unit. The large area outlined by the dark line represents the synthetic coded image in a single light control unit, and the smaller area outlined by the thick line contains 4×4 pixels, corresponding to c Figure 4 ×4 is the sub-matrix of the thick line area; e is the halftone image obtained by binarizing the brightness composite image using a discrete dither matrix.

[0056] For example, Fig. 9The binarization is explained by taking the new discrete dither matrix and brightness synthesis image in as an example. First, the 16 sub-matrices of the separation dither matrix are distributed to 16 neighboring light control units, and each small matrix is ​​moved to the upper left corner of the light control unit where it is located; then, the grayscale threshold is compared with the pixels in each brightness information synthesis grayscale image covered by the sub-matrices of the dither matrix. If the grayscale value of the pixel exceeds the threshold, it is binarized to 1; otherwise, it is set to 0; then, the separation dither matrix is ​​translated as a whole to the unbinarized area in the brightness synthesis grayscale image for subsequent binarization, until the entire image is completely binarized to obtain a halftone image.

[0057] It should be noted that if a dither matrix with a small number of pixels is selected, the difference of the grayscale pixels of the submatrix is ​​relatively close and the pixel elements are limited, which cannot be fully matched with the grayscale image. Large areas of 0 or 1 may appear, resulting in large errors in the synthesized halftone image; if a dither matrix with a larger pixel element range is selected, high-frequency information will be crosstalked, resulting in a fuzzy image. Figure e shows the halftone image obtained by binarizing the brightness synthesized grayscale image using a discrete dither matrix, which can be used to manufacture brightness modulation films.

[0058] Fig.10 is a schematic diagram of the physical image of the chromaticity modulation film provided by the present invention, such as Fig.10 As shown, the left image shows a macroscopic view of the color modulation film, and the right image provides a close-up of its microscopic details.

[0059] Fig.11 is a schematic diagram of a physical image of a brightness modulation film provided by the present invention, such as Fig.11 As shown, the left image shows a macroscopic view of the brightness modulating film, and the right image provides a close-up of its microstructure.

[0060] from Fig.10 and Fig.11 It can be seen that when only the brightness modulation film is retained, the brightness details of the 3D image are clearly visible, but the color is only black and white, and the chromaticity information cannot be highlighted; when only the color modulation film is retained, the color outline of the 3D image is effectively displayed, but the brightness detail information cannot be highlighted, and the viewing needs of the audience cannot be fully met; when both brightness and chromaticity modulation films are used, the brightness information and color information of the 3D image can be well restored.

[0061] Further, the halftone image is exposed using a laser. Starting with laser exposure, a high-precision laser device is used to accurately expose a pre-designed image onto a photosensitive film coated with a photosensitive silver halide layer. The laser system carefully adjusts the beam intensity and positioning to project the pattern onto the photosensitive layer of the film. After exposure, the development process displays the exposed area of ​​the photosensitive layer. The film is immersed in a developer solution, and a controlled chemical reaction occurs within a specified time to form a visible pattern.

[0062] Exemplarily, the spot diameter is preferably less than 6.25 micrometers (µm), the pixel density of the halftone image is preferably greater than 4000 dots per inch (DPI), and the thickness of the photosensitive film is preferably 0.188 mm.

[0063] Furthermore, a point light source and a collimating lens are placed in the high-fidelity light field display system to generate a collimated light beam, and the divergence angle of the collimated light beam is less than 1°.

[0064] Exemplarily, it is preferred to place a point light source and a collimating lens at the bottom of the high-fidelity light field display system to generate a collimated light beam.

[0065] In the implementation of the present invention, a nearly collimated light beam is obtained by using a point light source and a collimating lens. Compared with a traditional divergent light source, the collimated light beam can better place the defocus, ensuring that the light source completely covers the chromaticity modulation film and the brightness modulation film, thereby improving the display effect of the three-dimensional image.

[0066] The following is a new type of high-fidelity light field display system provided by the present invention, which relates to the field of light field display, improves information utilization efficiency by independently modulating chromaticity information and brightness information, and uses a bidirectional angle modulation grating and a collimated light source to establish uniformly distributed viewpoints, brightness modulation films, and chromaticity modulation films to modulate light field information. The innovative light field display system provides a full parallax high-fidelity color display with a 98.2° horizontal and 97.7° vertical field of view. Without changing the resolution of the light field display, a display effect with a large depth, high definition, and a wide viewing angle is achieved, the utilization efficiency of light information is enhanced, and the problem of dimensionality fitting is effectively solved. The system includes: a collimated light source, a brightness modulation film, a chromaticity modulation film, and a bidirectional angle modulation grating.

[0067] When preparing the bidirectional angle modulated grating, the roller is precisely machined with a diamond tip tool designed to achieve nanometer-level precision. The diamond tool runs on a high-precision lathe to engrave cylindrical lens array microstructures with a period of 317.5µm on the roller surface. The surface roughness of the roller is maintained at less than 10 nanometers (nm) to ensure the best optical performance of the resulting grating. After engraving, the roller is ultrasonically cleaned to remove any residual material and ensure the quality of subsequent imprinting. Next, a 200µm layer of cured resin is coated on a 188µm thick polyethylene terephthalate (PET) substrate film. The now clean roller is contacted with the coated PET film in a precision imprinting device. By carefully controlling the imprinting pressure and rolling speed, the microstructure on the roller is accurately transferred to the film resin layer. This imprinting process must be carried out in a cleanroom environment to prevent particle contamination, which may compromise the integrity of the microstructure. Finally, the UV resin was cured using a light source with a wavelength of 365nm, an irradiation intensity of 120 mW / cm², and a curing time of 45 seconds. This step ensures that the cylindrical lens structure within the resin is stable and permanently fixed to the PET film.

[0068] In order to achieve a high-definition display effect, when the viewing distance of the display system is 1.1 meters, taking into account the human visual acuity (about 1 arc minute), the spacing between the xz (horizontal) and yz (vertical) cylindrical lenses of the bidirectional angle modulation grating is designed to be 0.3175 mm; in order to achieve a wide-viewing angle display effect, the convex surface of the cylindrical lens of the grating needs to face the collimated backlight, so as to achieve a large-angle light beam refraction and form a larger viewing angle; in order to ensure a large-depth display effect, it is necessary to construct a uniformly distributed viewpoint, preferably an aspherical optical structure, and the radial coordinate of the vertical light control unit is 0.087 , the vertex curvature is 0.3175, the quadratic surface constant is -0.909, and the aspheric surface parameters are -0.147, -18.531, and -256.045 respectively; the radial coordinate of the horizontal light control unit is 0.086, the vertex curvature is 0.3175, the quadratic surface constant is -0.909, and the aspheric surface parameters are -0.147, -18.546, and -256.051 respectively. The above parameter experiments show that: when the light beams incident at the same distance in the horizontal and vertical directions pass through the cylindrical lens and reach the position of the image plane at the same distance, the best optical display effect is presented.

[0069] When preparing the chromaticity modulating film, it is necessary to first encode the chromaticity parallax map on the bidirectional angle modulated grating plane. According to the reverse tracking algorithm, and considering the different sensitivities of the human eye to chromaticity and brightness information, a 9×9 chromaticity parallax image array is preferably used to prepare the chromaticity film, and an inkjet printer with a resolution of 2880×1440 DPI is configured. The system default black ink is removed and the printer is preheated for 30 minutes. Seven high adhesion inks are preferred-cyan, bright magenta, yellow, light cyan, light bright magenta black, light black and very light black. Next, a PET film with a refractive index of 1.58 and a thickness of 0.2 mm is selected as the printing substrate. Then the prepared chromaticity composite image is imported into the printer with a specification of 720PPI (information entropy reaches 12.44Mbit per square inch), and the light field chromaticity composite image is printed. The ink is dried to complete the manufacture of the chromaticity modulating film.

[0070] When preparing the brightness modulated film, the brightness parallax map is encoded in the bidirectional angle modulated grating plane. According to the reverse tracking algorithm and considering the high sensitivity of the human eye to brightness information, a 100×100 brightness parallax image array is preferably used to generate a brightness composite image of 8000 PPI. Due to the correlation between adjacent brightness parallax images and adjacent pixels, a discrete dither matrix is ​​proposed to convert the 8000 PPI grayscale image into an 8000 DPI halftone image. The brightness composite image is then printed using an 8000 DPI laser typesetting machine to produce a brightness film. Starting with laser exposure, a high-precision laser device is used to accurately expose the pre-designed image to a 0.188 mm thick photosensitive film coated with a 3 micron thick photosensitive silver halide layer. The laser system carefully adjusts the beam intensity and positioning to project a pattern of 8000 DPI (information entropy reaches 64Mbit per square inch) onto the photosensitive layer of the film. After exposure, the development process will display the exposed area of ​​the photosensitive layer. The film is immersed in a developer solution where a controlled chemical reaction occurs over a specified time, causing the exposed portions of the photosensitive layer to dissolve or harden, creating a visible pattern. This developing step requires precise control of time and temperature to ensure the clarity and accuracy of the pattern. Finally, the fixing process removes the unexposed photosensitive material, making the image permanently visible on the film. After treatment with the fixing solution, the film's image becomes stable and able to resist further exposure, ensuring long-term preservation.

[0071] A collimating light guide plate is placed at the bottom of the system, and the light source is directly injected into the light guide plate. In order to ensure that the outgoing light is completely collimated, a large collimating lens needs to be added to the plate. The preferred diameter of the lens is greater than 25cm, and the error angle of the collimated light is within 1°. A chromaticity modulation film and a brightness modulation film are placed above the collimating light guide plate, respectively. It is necessary to ensure that the light source completely covers these two modulation films. The audience can watch the three-dimensional display effect at the bidirectional angle modulation grating. The system can achieve a full parallax high-fidelity color display with a horizontal field of view of 98.2° and a vertical field of view of 97.7°.

[0072] The system embodiment described above is merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art may understand and implement it without creative work.

[0073] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A new type of high-fidelity light field display system, characterized in that: The high-fidelity light field display system comprises a collimated light source, a chromaticity modulation film, a brightness modulation film and a bidirectional angle modulation grating, wherein the pixel size of the chromaticity modulation film is N times the pixel size of the brightness modulation film, where N is a number greater than or equal to 3 and less than or equal to 30, wherein: The collimated light source is loaded with chromaticity information after passing through the chromaticity modulation film, and is loaded with brightness information after passing through the brightness modulation film. The loaded chromaticity information and brightness information are adjusted to display viewing angle through the bidirectional angle modulation grating.

2. The novel high-fidelity light field display system according to claim 1, characterized in that: The convex surface of the cylindrical lens of the bidirectional angle modulation grating faces the collimated backlight; The bidirectional angle modulation grating selects an aspherical optical structure, and the expression of the aspherical optical structure satisfies: Where Z is the surface height, R is the radial coordinate, and k is the quadratic surface constant. is the vertex curvature, , , The aspheric parameters are aspheric surface parameters. The aspheric optical structure adopts an even-order aspheric surface microstructure array. Through Zemax simulation and setting of 6 parameters of the light control unit in the horizontal plane and the vertical plane, the light beams incident at the same distance in the horizontal and vertical directions pass through the cylindrical lens and reach the position of the image plane at the same distance.

3. The novel high-fidelity light field display system according to claim 1, characterized in that: The novel high-fidelity light field display system encodes and regulates the chromaticity information and the brightness information respectively, generates a chromaticity composite image and a grayscale brightness composite image, and loads them onto corresponding diaphragms.

4. The novel high-fidelity light field display system according to claim 3 is characterized in that: When preparing the chromaticity modulating film, the chromaticity parallax image array is encoded by using a beam reverse tracking algorithm to generate the chromaticity composite image. The mapping relationship between the chromaticity composite image and the chromaticity parallax image is: in, Represents the chromaticity disparity image The corresponding Row, No. Column viewpoint information within the cylindrical lens; variable and represent the number of columns and rows in the chromaticity disparity image respectively; The pixel size of the reference chromaticity composite image is represented, and the chromaticity composite image is loaded onto a film sheet using multi-color inkjet printing to obtain the chromaticity modulating film.

5. The novel high-fidelity light field display system according to claim 3 is characterized in that: When preparing the brightness modulating film, a brightness parallax image array is used to generate the grayscale brightness composite image, wherein the mapping relationship between the grayscale brightness composite image and the brightness parallax image is: in, Representation and brightness disparity image The corresponding Row, No. Column viewpoint information within the cylindrical lens; variable and Represent the number of columns and rows in the brightness parallax image array respectively; Indicates the pixel size of the reference brightness composite image.

6. The novel high-fidelity light field display system according to claim 5, characterized in that: The grayscale brightness composite image is binarized using a new discrete dithering matrix to obtain a halftone image; wherein the new discrete dithering matrix contains 256 elements, the discrete dithering matrix is ​​discretized into 16 4×4 sub-matrices, each sub-matrix contains 16 elements, the elements in the matrix are integers from 0 to 255, and the integers are used to represent the threshold used in the binarization process, The binarization process includes: Allocate the 16 sub-matrices to 16 adjacent light control units, and move each small matrix to the upper left corner of the light control unit where it is located; Comparing the grayscale threshold of each pixel in the grayscale brightness composite image covered by the submatrix of the discrete jitter matrix, if the grayscale value of the pixel exceeds the threshold, binarizing it to 1; otherwise, setting it to 0; The discrete dither matrix is ​​translated to the unbinarized area in the grayscale brightness composite image for subsequent binarization until the entire grayscale brightness composite image is completely binarized.

7. The novel high-fidelity light field display system according to claim 6, characterized in that: The halftone image is exposed using a laser. Starting with laser exposure, a high-precision laser device is used to accurately expose a pre-designed image onto a photosensitive film coated with a photosensitive silver halide layer. The laser system carefully adjusts the beam intensity and positioning to project the pattern onto the photosensitive layer of the film. After exposure, the development process displays the exposed area of ​​the photosensitive layer. The film is immersed in a developer solution, and a controlled chemical reaction occurs within a specified time to form a visible pattern.

8. The novel high-fidelity light field display system according to claim 1, characterized in that: A point light source and a collimating lens are placed in the high-fidelity light field display system to generate a collimated light beam, and the divergence angle of the collimated light beam is less than 1°.

Images