A single-projector based three-dimensional display projection system and method

Abstract

The application discloses a kind of three-dimensional display projection systems and methods based on single projector, it is related to three-dimensional display projection field, system includes coding subgraph division module, and is sequentially arranged on light path projector, light beam folding device, optical modulation module and holographic functional scattering film.The application adopts single projector space-time multiplexing design on hardware structure, only with single projector is perfect equivalent replacement traditional multi-physical light machine array, completely abandon cumbersome and tedious three-axis mechanical fine-tuning fixed support, fundamentally eliminates the inherent temperature drift deformation, channel out of step, edge gap bright band and image ghosting etc. Degeneration defects of traditional multi-channel physical splicing.The application not only greatly reduces the assembly complexity, overall volume and hardware cost of light field display projection system, more with extremely simple single source single road architecture, reconstructs large viewing angle, high fusion degree, continuous blind area-free high-definition dynamic three-dimensional stereoscopic light field in free space.

Description

Technical Field

[0001] This invention relates to the field of three-dimensional display projection, and more specifically to a three-dimensional display projection system and method based on a single projector. Background Technology

[0002] 3D displays based on multi-projector arrays are an important approach to achieving stereoscopic vision. Current mainstream solutions typically employ methods such as increasing the aperture of the optical modulation system. Figure 2 As shown, the most classic architecture utilizes multiple independent high-resolution projectors arranged in a spatially segmented array. By having projectors at different physical locations project viewpoint image streams spanning specific angles, a large-angle dynamic three-dimensional light field image is ultimately reconstructed in space under the combined modulation of a microlens demodulation grating and a holographic functional scattering film. However, this multi-projector spatial splicing light field display solution suffers from the following significant technical drawbacks when advancing towards commercial deployment, desktop applications, and portable devices: First, the system's hardware architecture is redundant and bulky. Multiple independent projectors, separate control hosts, and a large three-axis mechanical fine-tuning bracket designed to eliminate splicing seams result in a significant increase in the physical size and overall weight of the entire system, making it completely impossible to achieve highly portable integrated deployment. Second, the system encoding link and hardware phase-locked loop control are extremely complex. The rendering backend needs to maintain the concurrent distribution of multiple high-bandwidth signals, and the discrete optical engines require extremely stringent hardware-level phase-locked loop frame synchronization control. Microsecond-level refresh deviations or transmission delays can cause visible screen flickering, parallax jumps, or dynamic artifacts. Third, the image optical consistency is extremely poor and correction is cumbersome. Due to the manufacturing tolerances of the core optical engines of different projectors and the uneven aging of the internal lamps, there are natural objective differences in the brightness, contrast and color saturation of the projected images from each channel. This easily leads to severe color differences and bright bands with a visually detached feel at the junction boundaries of three-dimensional voxels. Furthermore, the system is highly dependent on pixel-level homography geometric alignment correction, is sensitive to external vibrations, and has extremely high maintenance costs. Summary of the Invention

[0003] To address the aforementioned shortcomings in the existing technology, the present invention provides a three-dimensional display projection system and method based on a single projector, which solves the problems of redundant and bulky multi-projector array architectures, complex control, extremely poor image optical consistency, and cumbersome correction.

[0004] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows: A three-dimensional display projection system based on a single projector is provided, which includes an coded sub-graph partitioning module, and a projector, a beam deflection device, an optical modulation module and a holographic functional scattering film arranged sequentially in the optical path; The encoding sub-image partitioning module is used to divide the frame to be output into multiple independent encoding sub-image regions, so that each encoding sub-image region corresponds to a different spatial viewpoint range; and each encoding sub-image region is pre-embedded with the parallax texture information corresponding to the spatial viewpoint coordinates through spatial homography transformation or perspective projection matrix. A projector is used to output frame images; A beam deflector is used to construct a blue light physical channel, a green light physical channel, and a red light physical channel, thereby deflecting and expanding the corresponding beams from the projector in three dimensions, so that the outgoing beams are projected in parallel and have a preset overlapping spatial incident angle, in order to simulate or be equivalent to the outgoing light paths of multiple independent physical projection optical engines. The optical modulation module is used to perform horizontal phase smoothing, vertical gain compression, global principal ray bending, and geometric angle hard truncation on the incident beam to reconstruct the light field and thus avoid image ghosting and viewpoint crosstalk. Holographic scattering film is used to smoothly stretch and uniformly cover the input point light source or line light spot in the height dimension, thereby expanding the vertical viewing height and realizing three-dimensional display.

[0005] Furthermore, the specific methods for dividing the frame to be output into multiple independent coded sub-map regions, so that each coded sub-map region corresponds to a different spatial viewpoint range, include: Obtain the total resolution parameters of the frames output by a single projector; The total number of viewpoints V for spatial division is set according to the number of physical channels of the beam deflection device; The frame to be output is divided into V consecutive and geometrically independent coded sub-map regions on the horizontal pixel coordinate axis according to the principle of non-overlapping; each coded sub-map region has the same width and each coded sub-map region corresponds to a physical channel.

[0006] Furthermore, specific methods for pre-embedding disparity texture information corresponding to spatial viewpoint coordinates into each coded sub-image region through spatial homography transformation or perspective projection matrix include: Based on the perspective projection relationship of the target 3D scene, the parallax image data corresponding to each viewpoint is extracted. Anisotropic geometric reconstruction and resolution scaling are performed on the images that will enter the blue light physical channel, green light physical channel and red light physical channel respectively, so that they are accurately filled into the corresponding coded sub-image regions, that is, the parallax texture information of the corresponding spatial viewpoint coordinates is embedded. All coded sub-image regions that have embedded the parallax texture information of the corresponding spatial viewpoint coordinates constitute a single frame composite image containing multi-viewpoint coding information.

[0007] Furthermore, the blue light physical channel is located to the left of the green light physical channel, and the red light physical channel is located to the right of the green light physical channel. Both the blue and red light physical channels use off-axis stereoscopic folding mirrors on the front surface, while the green light physical channel uses a coaxial splitter plane mirror on the front surface. A front-surface coaxial shunt plane mirror is used to direct the received beam into the optical modulation module at a near-zero incident angle. The front surface off-axis stereoscopic folding mirror is used to tilt the received light beam into the optical modulation module at a preset left or right off-axis angle.

[0008] Furthermore, the optical modulation module includes a horizontal quantitative diffuser, a vertical collimator, a main ray redirector, and a stray light cutoff grating sequentially arranged in the optical path; wherein: The horizontal quantitative diffuser uses a one-dimensional microlens array arranged in the horizontal direction. Through a preset arc curvature and period, it introduces fine quantitative micro-diffusion in the horizontal observation direction, smoothly fills the angle blind zone between adjacent viewing channels, eliminates the visual black slit when switching viewing angles, and thus completes horizontal phase smoothing. The vertical collimator uses an orthogonally arranged one-dimensional cylindrical microstructure to forcibly compress and press the beam of light that diverges beyond a preset angle in the vertical direction to the height plane at which the human eye is watching, preventing the light energy from being ineffectively diffused in the non-observation areas above and below, thereby improving the axial display gain and screen brightness, and completing the vertical gain compression. The master ray redirector uses asymmetric sawtooth or Fresnel phase microstructures to form a spatially gradient field lens. It dynamically assigns different deflection angles to the outgoing master rays according to the full-screen position coordinates, and precisely bends and converges the translational diverging beams emitted from the center and edge of the screen to the center of the target eyebox at a preset observation distance, thereby correcting the edge viewing area distortion under a large field angle and completing the global master ray bending. The stray light truncating grating employs a louvered three-dimensional microchannel array with a preset aspect ratio. The channel sidewalls are blackened light-absorbing sidewalls. By using the geometric angle threshold set by the channel aspect ratio, the light vector is hard-filtered, allowing the main viewing area signal light to pass through, while cutting off and absorbing stray light that exceeds the viewing angle threshold. This avoids image ghosting and viewing angle crosstalk from the physical source, thus completing the geometric angle hard truncating.

[0009] Furthermore, the period of the louvered three-dimensional microchannel array is 0.25 to 0.45 times the period of the main ray redirector display pixel, and the extension direction of the louvered three-dimensional microchannel array is tilted at an angle of 5° to 10° with the microlens direction of the horizontal quantitative diffuser, so as to eliminate the moiré interference fringes between the multilayer structure and the pixel array in the spatial frequency domain. The geometric angle threshold for the channel's aspect ratio is:

[0010] in A geometric angle threshold set for the channel's aspect ratio; The aspect ratio of the channel; It is the arctangent function.

[0011] Furthermore, the sum of the horizontal half-diffusion angle of the horizontal quantitative diffuser and the beam angle of the preceding stage is less than or equal to... This ensures that the signal light in the main viewing area passes through the stray light cutoff grating with a transmittance of more than 92%. The angle of the blackened light-absorbing sidewalls from the center of the screen towards the edge satisfies the following:

[0012] in The angle at which the light-absorbing sidewall is painted black; The angle at which the main ray redirector bends the light rays emitted from the edge of the screen; Indicates location.

[0013] Furthermore, the holographic functional scattering film is attached behind the focal plane of the optical modulation module to achieve spatial energy redistribution of the off-axis reticle beam; The holographic functional scattering film has a scattering angle of 30°~80° in the vertical direction, so as to smoothly stretch and uniformly cover the input point light source or linear light spot in the height dimension, thereby expanding the vertical viewing height; the holographic functional scattering film has a diffusion angle of less than 1° in the horizontal direction.

[0014] A method for a three-dimensional display projection system based on a single projector is provided, comprising the following steps: Obtain the total resolution parameters of the frames output by a single projector; The total number of viewpoints V for spatial division is set according to the number of physical channels of the beam deflection device; The frame to be output is divided into V consecutive and geometrically independent coded sub-map regions on the horizontal pixel coordinate axis according to the principle of non-overlapping; each coded sub-map region has the same width and each coded sub-map region corresponds to a physical channel, so that each coded sub-map region corresponds to a different spatial viewpoint range. Each coded sub-image region is pre-embedded with parallax texture information corresponding to the spatial viewpoint coordinates through spatial homography transformation or perspective projection matrix, resulting in a single-frame composite image containing multi-viewpoint coding information. Within the same physical refresh cycle, a single-frame composite image containing multi-viewpoint encoding information is output through a single projector, and a three-dimensional light field image is formed outside the holographic functional scattering film.

[0015] Furthermore, when there is one blue light physical channel, one green light physical channel, and one red light physical channel, the total number of viewpoints is three. The leftmost coded sub-image area corresponds to the blue light physical channel, the middle coded sub-image area corresponds to the green light physical channel, and the rightmost coded sub-image area corresponds to the red light physical channel.

[0016] The beneficial effects of this invention are as follows: In terms of hardware structure, this invention adopts a single-projector spatiotemporal multiplexing design. Through the spatial three-dimensional folding of the off-axis stereoscopic folding mirror and the coaxial splitting plane mirror on the front surface, a single projector perfectly replaces the traditional multi-physics optical engine array, completely eliminating the bulky and cumbersome three-axis mechanical fine-tuning fixing bracket. This fundamentally eliminates the degradation defects inherent in traditional multi-channel physical splicing, such as temperature drift deformation, channel synchronization loss, bright bands at the edges, and image ghosting. With the synergistic effect of the post-stage optical modulation module and the holographic functional scattering film, this invention not only significantly reduces the assembly complexity, overall size, and hardware cost of the light field display projection system, but also, with its extremely simple single-source, single-path architecture, reconstructs a high-definition dynamic three-dimensional stereoscopic light field in free space with a wide viewing angle, high fusion, and continuous blind-spot-free operation. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the optical path of this system; Figure 2 This is a schematic diagram of the optical path of an existing multi-projector array; Figure 3 A schematic diagram illustrating the method and structure for dividing the encoded subgraph region; Figure 4 This is a schematic diagram of the optical modulation module. Figure 5 Example diagram of binocular visual field and dynamic light field panoramic visual field.

[0018] Among them: 101, physical splicing defect area; 102, multi-channel concurrent signal line; 103, physical projection optical engine; 104, three-axis mechanical fine-tuning fixing bracket; 105, traditional architecture post-stage demodulation microlens array; 106, traditional architecture holographic functional scattering film; 201, projector; 202, beam deflection device; 203, optical modulation module; 204, holographic functional scattering film. Detailed Implementation

[0019] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0020] like Figure 1As shown, the three-dimensional display projection system based on a single projector includes an coded sub-graph partitioning module, and a projector 201, a beam deflection device 202, an optical modulation module 203, and a holographic functional scattering film 204 arranged sequentially on the optical path. The encoding sub-image partitioning module is used to divide the frame to be output into multiple independent encoding sub-image regions, so that each encoding sub-image region corresponds to a different spatial viewpoint range; and each encoding sub-image region is pre-embedded with the parallax texture information corresponding to the spatial viewpoint coordinates through spatial homography transformation or perspective projection matrix. Projector 201 can be a digital projector used to output frame images; The beam deflection device 202 is used to construct a blue light physical channel, a green light physical channel and a red light physical channel, and then to deflect and expand the corresponding beams from the projector 201 in three dimensions, so that the outgoing beams are projected in parallel and have a preset overlapping spatial incident angle, in order to simulate or be equivalent to the outgoing light path of multiple independent physical projection optical engines. The optical modulation module 203 is used to perform horizontal phase smoothing, vertical gain compression, global principal ray bending, and geometric angle hard truncation on the incident beam to reconstruct the light field and thus avoid image ghosting and viewpoint crosstalk. The holographic functional scattering film 204 is used to smoothly stretch and uniformly cover the input point light source or linear light spot in the height dimension, thereby expanding the vertical viewing height and realizing three-dimensional display.

[0021] This system primarily divides the high-resolution frame output from a single projector 201 into multiple independent coded sub-image regions by performing spatial partitioning and multiplexing in the pixel domain. Each sub-image corresponds to a different spatial viewpoint range. The total high-resolution image of a single frame output by the single projector 201 is directly recombined on the spatial pixel matrix and divided into multiple coded sub-image regions that are completely independent on geometric boundaries. Each coded sub-image region is pre-embedded with parallax texture information corresponding to a specific spatial viewpoint coordinate (e.g., several viewpoint sub-images on the left, the middle viewpoint sub-image, and several viewpoint sub-images on the right) through a specific spatial homography transformation or perspective projection matrix.

[0022] Specifically, the method for dividing the frame to be output into multiple independent coded sub-map regions, so that each coded sub-map region corresponds to a different spatial viewpoint range, includes: Obtain the total resolution parameter W of the frames output by a single projector 201. p ×H p ; The total number of viewpoints V for spatial division is set according to the number of physical channels of the beam deflection device 202; The frame to be output is divided into V consecutive and geometrically independent coded sub-map regions on the horizontal pixel coordinate axis according to the principle of non-overlapping; each coded sub-map region has the same width and each coded sub-map region corresponds to a physical channel.

[0023] Specific methods for pre-embedding disparity texture information corresponding to spatial viewpoint coordinates into each coded sub-image region through spatial homography transformation or perspective projection matrix include: Based on the perspective projection relationship of the target 3D scene, the parallax image data corresponding to each viewpoint is extracted. Anisotropic geometric reconstruction and resolution scaling are performed on the images that will enter the blue light physical channel, green light physical channel and red light physical channel respectively, so that they are accurately filled into the corresponding coded sub-image regions, that is, the parallax texture information of the corresponding spatial viewpoint coordinates is embedded. All coded sub-image regions that have embedded the parallax texture information of the corresponding spatial viewpoint coordinates constitute a single frame composite image containing multi-viewpoint coding information.

[0024] The blue light physical channel is located to the left of the green light physical channel, and the red light physical channel is located to the right of the green light physical channel. Both the blue and red light physical channels use off-axis stereoscopic folding mirrors on the front surface, while the green light physical channel uses a coaxial splitter plane mirror on the front surface. A front-surface coaxial shunt plane mirror is used to direct the received beam into the optical modulation module 203 at a near-zero incident angle. The front surface off-axis stereoscopic folding mirror is used to tilt the received light beam into the optical modulation module 203 at a preset left or right off-axis angle.

[0025] For example, such as Figure 3 As shown, when there is one blue light physical channel, one green light physical channel, and one red light physical channel, the total number of viewpoints is 3. The leftmost encoded sub-image area corresponds to the blue light physical channel and is bound to the pixel range. The middle encoded sub-image area corresponds to the green light physical channel and is bound to the pixel range. The right-hand encoded sub-image area corresponds to the red light physical channel and is bound to the pixel range. .

[0026] The composite modulated beam emitted by a single projector 201 is projected onto an off-axis asymmetric beam deflector 202. After being deflected and expanded in the spatial optical path by the front surface total reflection mirror group (including the front surface coaxial split plane mirror and the front surface off-axis stereo deflector), it evolves into multiple parallel projection beams with specific overlapping spatial incident angles and precise alignment. These beams are used to simulate or are equivalent to the output optical paths of multiple independent physical projection optical engines in a traditional architecture. The multi-parallel projection beams include multiple reticle beams corresponding to different spatial viewpoint flows. Specifically, the reticle beam corresponding to the coaxial central viewpoint flow is refracted and shaped by the coaxial split plane mirror on the front surface and then enters the optical modulation module at a nearly vertical axial angle (i.e., near zero degrees). The multiple reticle beams corresponding to each non-coaxial lateral viewpoint flow are respectively tilted into the optical modulation module at a specific left or right off-axis angle according to their corresponding lateral viewpoint flow, thereby jointly constructing a multi-view spatial light field with large-angle overlapping and convergence on the incident base surface of the optical modulation module 203.

[0027] In this embodiment, as Figure 4 As shown, the optical modulation module 203 includes a horizontal quantitative diffuser, a vertical collimator, a main ray redirector, and a stray light cutoff grating sequentially arranged in the optical path; wherein: The horizontal quantitative diffuser uses a one-dimensional microlens array arranged in the horizontal direction. Through a preset arc curvature and period, it introduces fine quantitative micro-diffusion in the horizontal observation direction, smoothly fills the angle blind zone between adjacent viewing channels, eliminates the visual black slit when switching viewing angles, and thus completes horizontal phase smoothing. The vertical collimator uses an orthogonally arranged one-dimensional cylindrical microstructure to forcibly compress and press the beam of light that diverges in the vertical direction beyond a preset angle (such as ±30°) to the height plane of human eye observation (such as within ±6°), preventing the ineffective diffusion of light energy in the upper and lower non-observation areas, thereby increasing the axial display gain and screen brightness by 2 to 3 times, and completing the vertical gain compression. The master ray redirector uses asymmetric sawtooth or Fresnel phase microstructures to form a spatially gradient field lens. It dynamically assigns different deflection angles to the outgoing master rays according to the full-screen position coordinates, and precisely bends and converges the translational diverging beams emitted from the center and edge of the screen to the center of the target eye box at a preset observation distance, thereby correcting the edge viewing distortion under a large field angle and completing the global master ray bending. The stray light truncating grating employs a louvered three-dimensional microchannel array with a preset aspect ratio. The channel sidewalls are blackened light-absorbing sidewalls. By using the geometric angle threshold set by the channel aspect ratio, the light vector is hard-filtered, allowing the main viewing area signal light (transmittance > 92%) to pass through, while simultaneously truncating and absorbing stray light exceeding the viewing angle threshold. This avoids image ghosting and viewing angle crosstalk from the physical source (crosstalk rate less than 1%), thus completing the geometric angle hard truncating.

[0028] In some feasible implementations, the period of the louvered three-dimensional microchannel array is 0.25 to 0.45 times the period of the main ray redirector display pixel, and the extension direction of the louvered three-dimensional microchannel array is tilted at an angle of 5° to 10° with the microlens direction of the horizontal quantitative diffuser, so as to eliminate moiré interference fringes between the multilayer structure and the pixel array in the spatial frequency domain. The geometric angle threshold for the channel's aspect ratio is:

[0029] This ensures that the signal light within the main viewing area passes through the stray light cutoff grating with a transmittance greater than 92%, while exceeding... Stray light, 100% of which strikes the vertical black sidewalls of the venetian blinds, is absorbed and eclipsed. The geometric angle threshold set for the channel's aspect ratio; The aspect ratio of the channel; It is the arctangent function.

[0030] The sum of the horizontal half-diffusion angle of the horizontal quantitative diffuser and the beam angle of the preceding stage is less than or equal to This ensures that the signal light in the main viewing area passes through the stray light cutoff grating with a transmittance of more than 92%. The angle of the blackened light-absorbing sidewalls from the center of the screen towards the edge satisfies the following:

[0031] To ensure that the light transmission axis of the louvers at any position on the screen is parallel to the main ray after it has been bent by the main ray redirector, the vignetting at the edges of the screen is completely eliminated; among which The angle at which the light-absorbing sidewall is painted black; The angle at which the main ray redirector bends the light rays emitted from the edge of the screen; Indicates location.

[0032] In this embodiment, to achieve efficient spatial energy redistribution of the off-axis reticle beam, a holographic functional scattering film 204 is attached behind the focal plane of the optical modulation module 203. The holographic functional scattering film 204 has a scattering angle of 30°~80° in the vertical direction, so as to smoothly stretch and uniformly cover the input point light source or linear light spot in the height dimension, thereby expanding the vertical viewing height; the holographic functional scattering film 204 has a diffusion angle of less than 1° in the horizontal direction. This polarized decoupling design ensures that the multi-view principal angle distribution determined by the beam deflector 202 in the horizontal direction is completely unconfused, and completely blocks ghosting and crosstalk between images from different viewpoints at the physical source.

[0033] It should be noted that the optical modulation module 203 is placed close to the incident side of the holographic functional scattering film 204, and is mainly used to precisely shape the angle and control the view zone boundary of the beam entering the holographic functional scattering film 204. Taking advantage of the almost non-diffusing characteristic of the holographic functional scattering film 204 in the horizontal direction, the core function of the optical modulation module 203 is to introduce quantitative and controllable fine micro-diffusivity in this non-diffusive horizontal direction (X-axis). This horizontal micro-diffusivity can precisely fill the angle blind zone and black slit generated when beams from adjacent viewing angles converge in free space, thereby controlling the continuity and viewing angle span of the horizontal view zone. Simultaneously, the optical modulation module 203, combined with its internal field mirror repositioning structure, can bend and converge the main ray of the large-angle emitted beam from the edge to the target observation eyebox area, and further cut off stray light in the vertical dimension, achieving high-gain, black-slit-free view zone reconstruction with strictly controllable crosstalk thresholds.

[0034] For example, in the overall optical path topology and spatial three-dimensional configuration of the system, a single projector 201, serving as the initial light source, is positioned on the bottom of the system's central axis. Its exit pupil emits a spatiotemporally multiplexed beam towards the subsequent beam deflector 202. This axially centered placement of a single source ensures the consistency of brightness and color across the entire field from the source and significantly reduces the mechanical assembly complexity of the multi-optical engine architecture. The front surface total reflection mirror group is arranged laterally on the upper-stage exit optical path of the projector. It includes a horizontally centered and parallel second planar reflector (i.e., the green light physical channel), and a first deflector (i.e., the blue light physical channel) and a third deflector (i.e., the red light physical channel) positioned on the left and right sides of the second planar reflector and tilted inward at a preset acute angle.

[0035] In the optical path evolution, the coaxial beam on the central axis is directly folded vertically upward through the second plane mirror, while the large-angle edge beams on the periphery are folded three-dimensionally with long optical path and oriented off-axis inward through the first and third tilting mirrors on both sides. This forces the multiple originally separate beams to broaden laterally and overlap deeply in the spatial propagation, thereby precisely controlling and converging the off-axis edge incident angle that is finally incident on the subsequent optical modulation module 203. The composite demodulation screen, which is formed by the close bonding of the optical modulation module 203 and the holographic functional scattering film 204, is horizontally suspended at the top of the system and placed parallel to the main plane of the second plane mirror. This is to completely receive the entire composite light field after the total reflection mirror group below has folded and overlapped. In this cascaded optical path sequence, the optical modulation module 203 is placed in the front stage and the holographic functional scattering film 204 is placed in a reasonable spatial position on its rear focal plane. The core physical purpose is to allow the multi-path off-axis reticle beams to first pass through the optical module 203 for fine wavefront phase modulation and angular direction reticle division. At the moment of pixel-level high-density convergence, they are immediately injected into the holographic functional scattering film 204 attached to it to complete the directional large-angle stretching and expansion of the vertical viewing angle. This spatiotemporally ordered configuration not only effectively eliminates pixelation and moiré patterns, but also, while maintaining binocular parallax independence in horizontal space, drives multiple light beams to precisely converge in free space, reconstructing them into high-contrast, seamlessly blended spatial three-dimensional voxels. This ultimately constructs a continuous dynamic light field panoramic view, as illustrated in the following example. Figure 5 As shown.

[0036] Through cascaded optical modulation of the optical modulation module 203 and the holographic functional scattering film 204, continuously distributed three-dimensional voxels are reconstructed in space. These voxels serve as the basic radiating units for light field display, equivalent to pixels in a two-dimensional display. Each voxel radiates dense clusters of light rays with independent variable brightness and specific colors in different spatial directions from a specific three-dimensional coordinate point. The integral reconstructs a continuous and realistic wavefront of spatial objects. To maximize spatial viewpoint density and overcome spatial resolution degradation within the limited pixel bandwidth of a single projector, the optical modulation module 203 of this invention employs a four-stage cascaded microstructure consisting of a horizontal quantitative diffuser, a vertical collimator, a master ray redirector, and a stray light truncating grating. This four-stage cascaded microstructure achieves horizontal expansion and vertical collimation anisotropic light field control while precisely redirecting the master ray and physically intercepting stray light from non-target angles, thus realizing efficient light field reconstruction and resolution allocation between the horizontal and vertical dimensions.

[0037] This embodiment also provides a method for use with a three-dimensional display projection system based on a single projector, which includes the following steps: S1. Obtain the total resolution parameters of the frame images output by a single projector 201; S2. Set the total number of viewpoints V for spatial division based on the number of physical channels of the beam deflection device 202; S3. Divide the frame to be output into V consecutive and geometrically independent coded sub-image regions on the horizontal pixel coordinate axis according to the principle of non-overlapping; each coded sub-image region has the same width and each coded sub-image region corresponds to a physical channel, so that each coded sub-image region corresponds to a different spatial viewpoint range. S4. Each encoded sub-image region is pre-embedded with the parallax texture information corresponding to the spatial viewpoint coordinates through spatial homography transformation or perspective projection matrix, resulting in a single-frame composite image containing multi-viewpoint encoding information. S5. Within the same frame's physical refresh cycle, a single-frame composite image containing multi-viewpoint encoding information is output through a single projector 201, and a three-dimensional light field image is formed outside the holographic functional scattering film 204.

[0038] In contrast, such as Figure 2 As shown, the existing system that uses multiple independent high-resolution projectors to perform regional array splicing in space to achieve three-dimensional display uses a three-axis mechanical fine-tuning fixing bracket 104 to fix multiple physical projection optical engines 103. The physical projection optical engine 103 obtains the frame image to be output through multiple concurrent signal lines 102, and finally forms the corresponding image in the viewing area. However, the image has a physical splicing defect area 101. The main defects include non-uniform bright bands, optical ghosting and discontinuous viewing areas caused by physical splicing, as well as degraded ghosting voxels caused by deformation of physical projection optical engine 103 and channel out-of-synchronization.

[0039] In summary, this invention employs a single-projector spatiotemporal multiplexing design in its hardware structure. Through the spatial three-dimensional folding of the off-axis stereoscopic folding mirror and the coaxial splitting plane mirror on the front surface, a single projector perfectly replaces the traditional multi-physics optical engine array, completely eliminating the bulky and cumbersome three-axis mechanical fine-tuning fixing bracket 104. This fundamentally eliminates the degradation defects inherent in traditional multi-channel physical splicing, such as temperature drift deformation, channel synchronization loss, bright bands at the edges, and image ghosting. With the synergistic effect of the post-stage optical modulation module 203 and the holographic functional scattering film 204, this invention not only significantly reduces the assembly complexity, overall size, and hardware cost of the light field display projection system, but also reconstructs a high-definition dynamic three-dimensional stereoscopic light field with a wide viewing angle, high fusion, and continuous blind-spot-free characteristics in free space using a minimalist single-source, single-path architecture.

Claims

1. A three-dimensional display projection system based on a single projector, characterized in that, It includes an coded subgraph partitioning module, and a projector, a beam deflector, an optical modulation module, and a holographic functional scattering film arranged sequentially on the optical path; The encoding sub-image partitioning module is used to divide the frame to be output into multiple independent encoding sub-image regions, so that each encoding sub-image region corresponds to a different spatial viewpoint range; and each encoding sub-image region is pre-embedded with the parallax texture information corresponding to the spatial viewpoint coordinates through spatial homography transformation or perspective projection matrix. A projector is used to output frame images; A beam deflector is used to construct a blue light physical channel, a green light physical channel, and a red light physical channel, thereby deflecting and expanding the corresponding beams from the projector in three dimensions, so that the outgoing beams are projected in parallel and have a preset overlapping spatial incident angle, in order to simulate or be equivalent to the outgoing light paths of multiple independent physical projection optical engines. The optical modulation module is used to perform horizontal phase smoothing, vertical gain compression, global principal ray bending, and geometric angle hard truncation on the incident beam to reconstruct the light field and thus avoid image ghosting and viewpoint crosstalk. Holographic scattering film is used to smoothly stretch and uniformly cover the input point light source or line light spot in the height dimension, thereby expanding the vertical viewing height and realizing three-dimensional display.

2. The three-dimensional display projection system based on a single projector according to claim 1, characterized in that, The specific methods for dividing the frame to be output into multiple independent coded sub-map regions, so that each coded sub-map region corresponds to a different spatial viewpoint range, include: Obtain the total resolution parameters of the frames output by a single projector; The total number of viewpoints V for spatial division is set according to the number of physical channels of the beam deflection device; The frame to be output is divided into V consecutive and geometrically independent coded sub-map regions on the horizontal pixel coordinate axis according to the principle of non-overlapping; each coded sub-map region has the same width and each coded sub-map region corresponds to a physical channel.

3. The three-dimensional display projection system based on a single projector according to claim 1, characterized in that, Specific methods for pre-embedding disparity texture information corresponding to spatial viewpoint coordinates into each coded sub-image region through spatial homography transformation or perspective projection matrix include: Based on the perspective projection relationship of the target 3D scene, the parallax image data corresponding to each viewpoint is extracted. Anisotropic geometric reconstruction and resolution scaling are performed on the images that will enter the blue light physical channel, green light physical channel and red light physical channel respectively, so that they are accurately filled into the corresponding coded sub-image regions, that is, the parallax texture information of the corresponding spatial viewpoint coordinates is embedded. All coded sub-image regions that have embedded the parallax texture information of the corresponding spatial viewpoint coordinates constitute a single frame composite image containing multi-viewpoint coding information.

4. The three-dimensional display projection system based on a single projector according to claim 1, characterized in that, The blue light physical channel is located to the left of the green light physical channel, and the red light physical channel is located to the right of the green light physical channel. Both the blue and red light physical channels use off-axis stereoscopic folding mirrors on the front surface, while the green light physical channel uses a coaxial splitter plane mirror on the front surface. A front-surface coaxial shunt plane mirror is used to direct the received beam into the optical modulation module at a near-zero incident angle. The front surface off-axis stereoscopic folding mirror is used to tilt the received light beam into the optical modulation module at a preset left or right off-axis angle.

5. The three-dimensional display projection system based on a single projector according to claim 1, characterized in that, The optical modulation module includes a horizontal quantitative diffuser, a vertical collimator, a main ray redirector, and a stray light cutoff grating, which are sequentially arranged on the optical path; wherein: The horizontal quantitative diffuser uses a one-dimensional microlens array arranged in the horizontal direction. Through a preset arc curvature and period, it introduces fine quantitative micro-diffusion in the horizontal observation direction, smoothly fills the angle blind zone between adjacent viewing channels, eliminates the visual black slit when switching viewing angles, and thus completes horizontal phase smoothing. The vertical collimator uses an orthogonally arranged one-dimensional cylindrical microstructure to forcibly compress and press the beam of light that diverges beyond a preset angle in the vertical direction to the height plane at which the human eye is watching, preventing the light energy from being ineffectively diffused in the non-observation areas above and below, thereby improving the axial display gain and screen brightness, and completing the vertical gain compression. The master ray redirector uses asymmetric sawtooth or Fresnel phase microstructures to form a spatially gradient field lens. It dynamically assigns different deflection angles to the outgoing master rays according to the full-screen position coordinates, and precisely bends and converges the translational diverging beams emitted from the center and edge of the screen to the center of the target eyebox at a preset observation distance, thereby correcting the edge viewing area distortion under a large field angle and completing the global master ray bending. The stray light truncating grating employs a louvered three-dimensional microchannel array with a preset aspect ratio. The channel sidewalls are blackened light-absorbing sidewalls. By using the geometric angle threshold set by the channel aspect ratio, the light vector is hard-filtered, allowing the main viewing area signal light to pass through, while cutting off and absorbing stray light that exceeds the viewing angle threshold. This avoids image ghosting and viewing angle crosstalk from the physical source, thus completing the geometric angle hard truncating.

6. The three-dimensional display projection system based on a single projector according to claim 5, characterized in that, The period of the louvered three-dimensional microchannel array is 0.25 to 0.45 times the period of the pixel displayed by the main ray redirector. The extension direction of the louvered three-dimensional microchannel array is tilted at an angle of 5° to 10° with the microlens direction of the horizontal quantitative diffuser, so as to eliminate the moiré interference fringes between the multilayer structure and the pixel array in the spatial frequency domain. The geometric angle threshold for the channel aspect ratio setting is: in A geometric angle threshold set for the channel's aspect ratio; The aspect ratio of the channel; It is the arctangent function.

7. The three-dimensional display projection system based on a single projector according to claim 6, characterized in that, The sum of the horizontal half-diffusion angle of the horizontal quantitative diffuser and the beam angle of the preceding stage is less than or equal to This ensures that the signal light in the main viewing area passes through the stray light cutoff grating with a transmittance of more than 92%. The angle of the blackened light-absorbing sidewalls from the center of the screen towards the edge satisfies the following: in The angle at which the light-absorbing sidewall is painted black; The angle at which the main ray redirector bends the light rays emitted from the edge of the screen; Indicates location.

8. The three-dimensional display projection system based on a single projector according to claim 1, characterized in that, A holographic functional scattering film is attached behind the focal plane of the optical modulation module to achieve spatial energy redistribution of the off-axis reticle beam; The holographic functional scattering film has a scattering angle of 30°~80° in the vertical direction, so as to smoothly stretch and uniformly cover the input point light source or linear light spot in the height dimension, thereby expanding the vertical viewing height; the holographic functional scattering film has a diffusion angle of less than 1° in the horizontal direction.

9. A method for a three-dimensional display projection system based on a single projector as described in any one of claims 1 to 8, characterized in that, Includes the following steps: Obtain the total resolution parameters of the frames output by a single projector; The total number of viewpoints V for spatial division is set according to the number of physical channels of the beam deflection device; The frame to be output is divided into V consecutive and geometrically independent coded sub-map regions on the horizontal pixel coordinate axis according to the principle of non-overlapping; each coded sub-map region has the same width and each coded sub-map region corresponds to a physical channel, so that each coded sub-map region corresponds to a different spatial viewpoint range. Each coded sub-image region is pre-embedded with parallax texture information corresponding to the spatial viewpoint coordinates through spatial homography transformation or perspective projection matrix, resulting in a single-frame composite image containing multi-viewpoint coding information. Within the same physical refresh cycle, a single-frame composite image containing multi-viewpoint encoded information is output through a single projector, and a three-dimensional light field image is formed outside the holographic functional scattering film.

10. The method according to claim 9, characterized in that, When there is one blue light physical channel, one green light physical channel, and one red light physical channel, the total number of viewpoints is 3. The leftmost coded sub-image area corresponds to the blue light physical channel, the middle coded sub-image area corresponds to the green light physical channel, and the rightmost coded sub-image area corresponds to the red light physical channel.

Images