Aerial-floating three-dimensional volumetric display apparatus

Abstract

An aerial-floating three-dimensional volumetric display apparatus, comprising: a three-dimensional display screen (100), which is used for using light-field three-dimensional imaging technology to display three-dimensional content; and a retroreflective imaging panel (200), wherein the three-dimensional display screen (100) is obliquely arranged, reconstructed light rays pass through the retroreflective imaging panel (200) and then reconstruct a three-dimensional light field in mid-air, so as to realize the floating display of three-dimensional content, and the retroreflective imaging panel (200) comprises optical waveguides that are alternately arranged, so as to form a plurality of optical channels for the exit of the reconstructed light rays. The optical waveguides are arranged on the basis of preset dimensions, or the three-dimensional display screen (100) emits the reconstructed light rays on the basis of a preset angle, such that the reconstructed light rays are controlled to be reflected only a specified number of times in each optical waveguide. Thus, the generation of ghost images is fundamentally prevented, and after ghost images are eliminated, floating 3D display technology achieves better visual effects and enhanced clarity.

Description

A three-dimensional display device suspended in mid-air Technical Field

[0001] This invention relates to the field of three-dimensional display technology, and in particular to a three-dimensional display device that is suspended in mid-air. Background Technology

[0002] Suspended 3D (three-dimensional) display technology is a technology that integrates optics, electronics, computers, and display technologies to achieve spatial stereoscopic image display. Traditional 2D display technologies, which can only present planar image information, cannot meet the human demand for stereoscopic visual effects, especially in fields such as virtual reality, augmented reality, medical imaging, and advertising. To solve this problem, researchers have developed various 3D display technologies, among which suspended 3D display technology has gradually become a research hotspot due to its superior stereoscopic effect and the advantage of not requiring special equipment. Currently, suspended 3D displays mostly use retroreflectors to reflect 3D images into the air to achieve suspended 3D display. However, due to the structural design of traditional retroreflective imaging panels, there is a ghost image on each side of the displayed 3D image, which cannot meet the requirements of suspended 3D display. Therefore, how to eliminate ghosting in suspended 3D displays has become a key problem that urgently needs to be solved at this stage. Summary of the Invention

[0003] In view of the above-mentioned defects of the prior art, the present invention provides an aerial 3D display device to solve the technical problem of ghosting in 3D floating displays.

[0004] To achieve the above and other related objectives, the present invention provides an aerial levitation three-dimensional display device, comprising: a three-dimensional display screen for displaying three-dimensional content using light field three-dimensional imaging technology to obtain reconstructed light rays; and an anti-reflection imaging plate, wherein the three-dimensional display screen is tilted to one side of the anti-reflection imaging plate; the reconstructed light rays, after passing through the anti-reflection imaging plate, reconstruct a three-dimensional light field in the air to achieve the levitation display of the three-dimensional content; the anti-reflection imaging plate includes staggered optical waveguides to form multiple optical channels for the reconstructed light rays to be emitted; the reconstructed light rays are controlled to undergo only one reflection in each optical waveguide by setting the optical waveguides to a preset size, or the three-dimensional display screen emits reconstructed light rays at a preset angle to control the reconstructed light rays to undergo only an odd number of reflections in each optical waveguide.

[0005] In one embodiment of the present invention, the retroreflective imaging plate includes a front unit and a rear unit; the front unit is disposed on the side close to the three-dimensional display screen and is composed of a plurality of first optical waveguides arranged side by side along a first direction; the rear unit is disposed on the side away from the three-dimensional display screen and is composed of a plurality of second optical waveguides arranged side by side along a second direction; the first direction is perpendicular to the second direction and both directions are located in the horizontal plane.

[0006] In one embodiment of the present invention, the first optical waveguide is provided with a uniform width along the first direction and its height along the emission direction of the reconstructed light is set according to a first preset height; the second optical waveguide is provided with a uniform width along the second direction and its height along the emission direction of the reconstructed light is set according to a second preset height.

[0007] In one embodiment of the present invention, the first preset height is obtained by the following steps: based on the distance from the three-dimensional display screen to the retroreflective imaging plate and the serial number of the first optical waveguide, a first height of the first optical waveguide corresponding to the serial number is obtained; based on the distance from the three-dimensional display screen to the retroreflective imaging plate, the serial number of the first optical waveguide, the length of the three-dimensional display screen, and the width of the first optical waveguide, a second height of the first optical waveguide corresponding to the serial number is obtained; based on the first height and the second height, a first preset height of each first optical waveguide is obtained.

[0008] In one embodiment of the present invention, the first optical waveguide is set at the same height along the emission direction of the reconstructed light and its width along the first direction is set according to a first preset width; the second optical waveguide is set at the same height along the emission direction of the reconstructed light and its width along the second direction is set according to a second preset width.

[0009] In one embodiment of the present invention, the first preset width is obtained by the following steps: Based on the sequence number of the first optical waveguide, the cumulative width value of the first optical waveguide corresponding to that sequence number is obtained; based on the cumulative width value of the first optical waveguide, the distance from the three-dimensional display screen to the retroreflective imaging plate, the length of the three-dimensional display screen, and the height of the first optical waveguide, the first width of the first optical waveguide corresponding to that sequence number is obtained; based on the cumulative width value of the first optical waveguide, the distance from the three-dimensional display screen to the retroreflective imaging plate, and the length of the three-dimensional display screen, the second width of the first optical waveguide corresponding to that sequence number is obtained; based on the first width and the second width, the first preset width of each first optical waveguide is obtained.

[0010] In one embodiment of the present invention, the first optical waveguide is configured with an equal width along the first direction and with an equal height along the emission direction of the reconstructed light; the second optical waveguide is configured with an equal width along the second direction and with an equal height along the emission direction of the reconstructed light; the three-dimensional display screen includes a uniform backlight layer, a liquid crystal display layer, a microlens array, and a viewing angle controller. The light emitted from the uniform backlight layer is modulated by the liquid crystal display layer and then deflected by the microlens array. The viewing angle controller is used to control the light emitted from the three-dimensional display screen to be emitted at a preset angle, so as to control the reconstructed light to undergo an odd number of reflections in each optical waveguide.

[0011] In one embodiment of the present invention, the view controller is composed of multiple sub-regions, each sub-region corresponding to one optical channel, and each sub-region is used to control the light emitted by the three-dimensional display screen to be emitted at a preset angle.

[0012] In one embodiment of the present invention, the preset angle is obtained by the following steps: based on the width and height of the first optical waveguide, the distance from the three-dimensional display screen to the retroreflective imaging plate, the length of the three-dimensional display screen, and the serial number of the first optical waveguide, a first preset angle interval corresponding to the serial number is obtained; based on the width and height of the second optical waveguide, the distance from the three-dimensional display screen to the retroreflective imaging plate, the length of the three-dimensional display screen, and the serial number of the second optical waveguide, a second preset angle interval corresponding to the serial number is obtained; based on the first preset angle interval and the second preset angle interval, the preset angle is obtained.

[0013] In one embodiment of the present invention, the first optical waveguide is configured with an equal width along the first direction and with an equal height along the emission direction of the reconstructed light; the second optical waveguide is configured with an equal width along the second direction and with an equal height along the emission direction of the reconstructed light; the three-dimensional display screen includes a pointing backlight layer, a liquid crystal display layer and a microlens array, wherein the light emitted by the pointing backlight layer at a preset angle is modulated by the liquid crystal display layer and then deflected by the microlens array before being emitted.

[0014] In one embodiment of the present invention, the three-dimensional display screen corrects the parallax inversion phenomenon of the suspended three-dimensional display by using a light field reconstruction algorithm based on depth inversion.

[0015] The beneficial effects of the present invention: The present invention proposes an aerial suspended three-dimensional stereoscopic display device. The system sets up a light waveguide of a preset size or makes the three-dimensional display screen emit reconstructed light at a preset angle so that the reconstructed light can only be reflected a specified number of times in the light waveguide. This fundamentally avoids the generation of ghosting. After eliminating ghosting, the visual effect of the suspended 3D display technology is better and clearer. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 is a perspective view of a first structure provided in an embodiment of the present invention;

[0018] Figure 2 is a schematic diagram of the light rays of the first structure provided in an embodiment of the present invention;

[0019] Figure 3 is a schematic diagram of light rays in a single optical waveguide of the first structure provided in an embodiment of the present invention;

[0020] Figure 4 is a schematic diagram of the light rays of the second structure provided in an embodiment of the present invention;

[0021] Figure 5 is a schematic diagram of light rays in a single optical waveguide of the second structure provided in an embodiment of the present invention;

[0022] Figure 6 is a perspective view of the third structure provided in an embodiment of the present invention;

[0023] Figure 7 is a schematic diagram of the light rays of the third structure provided in an embodiment of the present invention;

[0024] Figure 8 is a three-dimensional schematic diagram of the fourth structure provided in an embodiment of the present invention;

[0025] Figure 9 is a flowchart of a light field reconstruction method based on depth inversion provided in an embodiment of the present invention;

[0026] Figure 10 is a schematic diagram of a light field reconstruction method based on depth inversion provided in an embodiment of the present invention;

[0027] Figure descriptions: 100, 3D display screen; 101, uniform backlight layer; 101', directional backlight layer; 102, liquid crystal display layer; 103, microlens array; 104, viewing angle controller; 200, retroreflective imaging plate; 201, first optical waveguide; 202, second optical waveguide. Detailed Implementation

[0028] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. It should be noted that, unless otherwise specified, the following embodiments and features can be combined with each other. In addition to the specific methods, equipment, and materials used in the embodiments, based on the knowledge of the prior art and the description of the present invention by those skilled in the art, any prior art methods, equipment, and materials similar to or equivalent to those described in the embodiments of the present invention can be used to implement the present invention.

[0029] It should be understood that the terminology used in the embodiments of this invention is for describing specific particular implementations and not for limiting the scope of protection of this invention. Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art.

[0030] The structures, proportions, and sizes illustrated in the accompanying drawings are solely for illustrative purposes and to aid those skilled in the art in understanding and reading the invention. They are not intended to limit the implementation of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and objectives of the invention, should still fall within the scope of the technical content disclosed herein. Furthermore, the drawings only show components relevant to the invention and are not drawn according to the actual number, shape, and size of components in practice. In actual implementation, the type, quantity, and proportion of each component can be arbitrarily changed, and the component layout may be more complex.

[0031] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the invention. However, it will be apparent to those skilled in the art that embodiments of the invention may be practiced without these specific details. In some embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the invention.

[0032] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functions, and operations that may be implemented in the methods and computer program products according to various embodiments of the present invention. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0033] Please refer to Figures 1, 4, 6, and 8. These four figures illustrate an embodiment of the present invention providing a suspended three-dimensional display device, including a three-dimensional display screen 100 and an anti-reflective imaging plate 200. The three-dimensional display screen 100 is used to display three-dimensional content using light field three-dimensional imaging technology to obtain reconstructed light rays. The three-dimensional display screen 100 (3D display screen) is the core component of the suspended 3D display system, responsible for generating three-dimensional images for suspended display. The three-dimensional display screen 100 is tilted to one side of the anti-reflective imaging plate 200. After the reconstructed light rays pass through the anti-reflective imaging plate 200, a three-dimensional light field is reconstructed in the air to achieve the suspended display of three-dimensional content. The anti-reflective imaging plate 200 includes staggered optical waveguides to form multiple optical channels for the emission of reconstructed light rays. By setting the optical waveguides to a preset size to control that the reconstructed light rays undergo only one reflection in each optical waveguide, or by emitting reconstructed light rays from the three-dimensional display screen 100 at a preset angle to control that the reconstructed light rays undergo only an odd number of reflections in each optical waveguide, the device can be configured to achieve this. Because reflections occur only a specified number of times in each optical waveguide, ghosting is fundamentally avoided. After eliminating ghosting, the visual effect of the levitating 3D display technology is better and clearer.

[0034] In a specific embodiment of the present invention, the retroreflective imaging plate 200 includes a front unit and a rear unit; wherein, the front unit is disposed on the side close to the three-dimensional display screen 100 and is composed of a plurality of first optical waveguides 201 arranged side by side along a first direction; the rear unit is disposed on the side away from the three-dimensional display screen 100 and is composed of a plurality of second optical waveguides 202 arranged side by side along a second direction; the first direction is perpendicular to the second direction and both directions are located in a horizontal plane. For the first optical waveguide 201, one side (e.g., the right side of the structure shown in FIG2) is provided with a high reflectivity coating to enable light to undergo a specified number of reflections inside the optical waveguide, and the other side is provided with a low reflectivity coating (e.g., the left side of the structure shown in FIG2) to absorb stray light. The second optical waveguides 202 are arranged in the same manner.

[0035] The first and second directions mentioned here both being within the horizontal plane refer to the general configuration of the entire device as shown in Figure 1, where the retroreflective imaging plate 200 is horizontally arranged. Therefore, both the first and second directions are within the horizontal plane. It should be noted that in actual scenarios, the entire device can also be arranged at an angle. In this case, the first and second directions are not within the horizontal plane, but both directions are still within the plane of the retroreflective imaging plate 200.

[0036] To achieve a single reflection in each optical waveguide, it can be done by adjusting the size of the optical waveguide or by adjusting the emission angle of the 3D display screen 100. These two solutions are identical in concept but differ in implementation. Several embodiments are provided below for detailed explanation.

[0037] Please refer to Figures 1 and 2. In a specific embodiment of the present invention, the first optical waveguide 201 is configured with a uniform width along a first direction, and its height along the emission direction of the reconstructed light is set according to a first preset height; the second optical waveguide 202 is configured with a uniform width along a second direction, and its height along the emission direction of the reconstructed light is set according to a second preset height. In this embodiment, both the first optical waveguide 201 and the second optical waveguide 202 are configured with equal width and length, but their heights are gradually varied. By adjusting the height of the optical waveguides, it is ensured that the reconstructed light is reflected only once in each optical waveguide.

[0038] The first and second preset heights can be calculated in advance based on the dimensions of each structure, and the calculation process for the first and second preset heights is basically similar. The following explanation uses the first preset height as an example.

[0039] For ease of calculation, in the various embodiments of this invention, the 3D display screen 100 is arranged at a 45° angle, that is, one side of the 3D display screen 100 is parallel to the surface of the retroreflective imaging plate 200. In the structural diagram shown in Figure 1, the 3D display screen 100 forms a 45° angle with both the ZOY plane and the ZOX plane. The calculation steps for each preset parameter will be described in detail below through ray tracing and formula analysis.

[0040] Please refer to Figure 3. In a specific embodiment of the present invention, the first preset height is obtained as follows: based on the distance H from the 3D display screen 100 to the retroreflective imaging plate 200 and the sequence number n of the first optical waveguide 201, the first height h' of the first optical waveguide 201 corresponding to that sequence number is obtained. The first height corresponds to: the light emitted from the first voxel of the 3D display screen 100 reaches the lower right edge of the nth first optical waveguide 201 and exits from the upper left edge of that optical waveguide. For example, in the structure shown in Figure 3, the first height can be calculated by the following formula:

[0041] Based on the distance H between the 3D display screen 100 and the retroreflective imaging plate 200, the sequence number n of the first optical waveguide 201, the length L of the 3D display screen 100, and the width w of the first optical waveguide 201, the second height h of the first optical waveguide 201 corresponding to that sequence number is obtained. The second height corresponds to the light emitted by the last voxel of the 3D display screen 100 directly exiting from the upper right edge of the nth first optical waveguide 201. For example, in the structure shown in Figure 3, the second height can be calculated using the following formula:

[0042] The first preset height of each first optical waveguide 201 is obtained based on the first height h' and the second height h". The first height and the second height correspond to the range of values ​​for the first preset height. Only when the first preset height of each first optical waveguide 201 is between these two values ​​can the requirement that light undergoes only one reflection in the first optical waveguide 201 be met. The first preset height of each first optical waveguide 201 can be expressed by the formula:

[0043] Because the magnitudes of the first and second heights are uncertain during the calculation process, both scenarios can occur, making it impossible to determine which height, h' or h'", is larger. The first preset height h of the nth first optical waveguide 201... n It can be any value between the first height h' and the second height h”, so it can be easily calculated using the above formula.

[0044] In a specific embodiment of the present invention, it can also be directly set as follows:

[0045] h n= (h′+h″) / 2; that is, the average of the first height and the second height is used as the first preset height of the first optical waveguide 201.

[0046] Understandably, the dimensions of the second optical waveguide 202 can also be calculated in the same way, and the width of the second optical waveguide 202 can be the same as or different from the width of the first optical waveguide 201. Once the width (w) and height (h) of the first optical waveguide 201 are determined... n The structure of the retroreflective imaging plate 200 is determined by determining the width, height, and length of the second optical waveguide 202 (the length of the second optical waveguide 202 is equal to the dimension of the retroreflective imaging plate 200 along the x direction).

[0047] Please refer to Figure 4. In a specific embodiment of the present invention, the first optical waveguide 201 is set at the same height along the emission direction of the reconstructed light, and its width along the first direction is set according to a first preset width; the second optical waveguide 202 is set at the same height along the emission direction of the reconstructed light, and its width along the second direction is set according to a second preset width. In this embodiment, both the first optical waveguide 201 and the second optical waveguide 202 are set at the same height and length, but their widths are gradually varied. By adjusting the width of the optical waveguides, it is ensured that the reconstructed light is reflected only once in each optical waveguide. The following detailed explanation also uses the first optical waveguide 201 as an example.

[0048] Please refer to Figure 5. In a specific embodiment of the present invention, the first preset width is obtained according to the following steps: Based on the sequence number n of the first optical waveguide 201, the cumulative width P of the first optical waveguide 201 corresponding to that sequence number is obtained. n The formula is as follows:

[0049] P n = w1 + w2 + ... + w n ;

[0050] Based on the width accumulation value P of the first optical waveguide 201 n The distance H from the 3D display screen 100 to the retroreflective imaging plate 200, the length L of the 3D display screen 100, and the height h of the first optical waveguide 201 are used to obtain the first width of the first optical waveguide 201 corresponding to the specified number. The first width corresponds to the light emitted from the first voxel of the 3D display screen 100 reaching the lower right edge of the nth first optical waveguide 201 and exiting from the upper left edge of that waveguide. For example, in the structure shown in Figure 5, the first width can be calculated using the following formula:

[0051] Based on the accumulated width of the first optical waveguide 201, the distance from the 3D display screen 100 to the retroreflective imaging plate 200, and the length of the 3D display screen 100, the second width of the first optical waveguide 201 corresponding to this number is obtained. The second width corresponds to the light emitted by the last voxel of the 3D display screen 100 directly exiting from the upper right edge of the nth first optical waveguide 201. For example, in the structure shown in Figure 5, the second width can be calculated using the following formula:

[0052] Based on the first width w' and the second width w", the first preset width w of each first optical waveguide 201 is obtained. n The first width and the second width correspond to the range of values ​​for the first preset width. Only when the first preset width of each first optical waveguide 201 is between these two values ​​can the requirement that light undergoes only one reflection in the first optical waveguide 201 be met. The first preset width of each first optical waveguide 201 can be expressed by the formula:

[0053] Because the sizes of the first and second widths are uncertain during the calculation process, both scenarios can occur, making it impossible to determine which width, w' or w'", is larger. The first preset width w of the nth first optical waveguide 201... n It can be any value between the first width w' and the second width w”, so it can be easily calculated using the above formula.

[0054] In a specific embodiment of the present invention, it can also be directly set as follows:

[0055] w n = (w′+w″) / 2; that is, the average of the first width and the second width is used as the first preset width of the first optical waveguide 201.

[0056] In the above embodiment, after the reconstructed light emitted by the three-dimensional display screen 100 passes through the retroreflective imaging plate 200, the propagation of the light along the x and z directions (refer to the schematic diagram in Figure 1) becomes the same angle but opposite in direction, while the propagation along the y direction remains unchanged. The light then converges again in the air along the retroreflective direction to form a ghost-free three-dimensional floating display.

[0057] In addition to adjusting the size of the optical waveguide, the angle of the reconstructed light emitted by the 3D display screen 100 can also be adjusted to control the reconstructed light to undergo an odd number of reflections in each optical waveguide. The following explains the method for adjusting the angle.

[0058] Please refer to Figures 6 and 8. In a specific embodiment of the present invention, the first optical waveguide 201 is set with a uniform width along a first direction and a uniform height along the emission direction of the reconstructed light rays; the second optical waveguide 202 is set with a uniform width along a second direction and a uniform height along the emission direction of the reconstructed light rays; the lengths of the first optical waveguide 201 and the second optical waveguide 202 are also fixed, corresponding to the dimensions of the retroreflective imaging plate 200 along the z-direction and along the x-direction, respectively. The width and height of the first optical waveguide 201 and the second optical waveguide 202 can be different or the same. In the following embodiments, the two are set with equal width and height as an example, with the height uniformly denoted as h and the width uniformly denoted as w.

[0059] Referring to Figure 6, in a specific embodiment of the present invention, the three-dimensional display screen 100 includes a uniform backlight layer 101, a liquid crystal display layer 102, a microlens array 103, and a viewing angle controller 104. Light emitted from the uniform backlight layer 101 is modulated by the liquid crystal display layer 102 and then deflected by the microlens array 103. The viewing angle controller 104 controls the light emitted from the three-dimensional display screen 100 to exit at a preset angle, ensuring that the reconstructed light undergoes only an odd number of reflections in each optical waveguide. The viewing angle controller is a composite Bragg grating structure, exhibiting angle selectivity. Each Bragg grating corresponds to one optical channel, and each Bragg grating is used to filter light at a preset angle.

[0060] Please refer to Figure 8. In a specific embodiment of the present invention, the three-dimensional display screen 100 includes a backlight layer 101', a liquid crystal display layer 102, and a microlens array 103. The light emitted by the backlight layer 101' at a preset angle is modulated by the liquid crystal display layer 102 and then deflected by the microlens array 103 before being emitted.

[0061] In both embodiments described above, the angle of the emitted light from the 3D display screen 100 is controlled by either setting a viewing angle controller 104 in front of the microlens array 103 or by setting a direction pointing to the backlight layer 101'. The principle behind these two embodiments is the same; only the implementation methods differ.

[0062] In a specific embodiment of the present invention, the viewing angle controller 104 (or pointing to the backlight layer 101') is composed of multiple sub-regions, each sub-region corresponding to an optical channel. Each sub-region is used to control the light emitted by the three-dimensional display screen 100 at a preset angle. Taking N first optical waveguides 201 and M second optical waveguides 202 as an example, they together divide the retroreflective imaging plate 200 into N×M optical channels. When controlling the emitted light angle of the three-dimensional display screen 100, it is also divided into corresponding regions for control, that is, the three-dimensional display screen 100 is divided into N×M sub-regions, and then the light emission angle of each sub-region is controlled respectively.

[0063] Meanwhile, when performing preset angle calculations, each sub-region needs to calculate an angle range in one direction (i.e., the angle range in the XOY plane) based on the first optical waveguide 201, and also needs to calculate an angle range in another direction (i.e., the angle range in the YOZ plane) based on the second optical waveguide 202. Finally, the angle of each sub-region is controlled by combining these two angle ranges.

[0064] Please refer to Figure 7. In a specific embodiment of the present invention, the preset angle is obtained according to the following steps: based on the width w and height h of the first optical waveguide 201, the distance H from the three-dimensional display screen 100 to the retroreflective imaging plate 200, the length L of the three-dimensional display screen 100, and the sequence number n of the first optical waveguide 201, the first preset angle interval (θ) corresponding to the sequence number is obtained. 2n-1 ,θ 2n ), where n∈(1,2,…,N), θ 2n-1 The corresponding light emitted from the intermediate voxel of the 3D display screen 100 exits directly from the upper right edge of the nth first optical waveguide 201, θ 2n This corresponds to the light emitted from the intermediate voxel of the 3D display screen 100 reaching the lower right edge of the nth first optical waveguide 201 and exiting from the upper left edge of that waveguide. For example, in the structure shown in Figure 7, the first preset angle interval (θ) 2n-1 ,θ 2n The two angles in the equation can be calculated using the following formula:

[0065] In the above formula, l' is the distance from the middle voxel of the 3D display screen 100 to the upper right edge of the nth first optical waveguide 201, and l” is the distance from the middle voxel of the 3D display screen 100 to the lower right edge of the nth first optical waveguide 201. Based on these two distances, the first preset angle interval can be calculated.

[0066] Similarly, based on the width and height of the second optical waveguide 202, the distance from the 3D display screen 100 to the retroreflective imaging plate 200, the length of the 3D display screen 100, and the serial number of the second optical waveguide 202, the second preset angle interval (θ) corresponding to that serial number can be obtained. 2m-1 ,θ 2m ), where m∈(1,2,…,M).

[0067] Finally, based on the first and second preset angle intervals, a preset angle is obtained. That is, for the n×m sub-region, it is only necessary to control the emission angle of its light rays to satisfy the first preset angle interval in the XOY plane and the second preset angle interval in the YOZ plane. This preset angle applies to both the viewing angle controller 104 and the backlight layer 101'.

[0068] Through the above embodiments, it is clear how to set the optical waveguide to a preset size or how to emit reconstructed light from the 3D display screen 100 at a preset angle, so as to control the reconstructed light to undergo only a specified number of reflections in each optical waveguide.

[0069] Besides the ghosting problem mentioned above, parallax inversion also exists in 3D floating display technology. Referring to Figures 9 and 10, in a specific embodiment of this invention, the 3D display screen 100 corrects the parallax inversion phenomenon in 3D floating displays using a light field reconstruction algorithm based on depth inversion. For any 2D image, firstly, its depth map is extracted to obtain the depth information of each object in the scene. A coordinate system for the scene is established using the depth map. Based on the parameters of the 3D display screen 100, the size and depth range of the image that the 3D display screen 100 can reproduce are determined, and the coordinate scene is scaled to fit the 3D display screen 100. Then, based on the depth map from near to far, the scene in the 2D image is sliced ​​at equal depth intervals to obtain N depth slice images, where 1 represents the closest to the viewer and N represents the farthest from the viewer, as shown in the left-hand diagram of Figure 10. Then, all depth slice images are set with depth inversion, where 1 represents the farthest from the viewer and N represents the closest to the viewer, as shown in the right-hand diagram of Figure 10. A viewing plane composed of numerous viewpoints is set at a certain distance from the slice image N. Inverse ray tracing is performed on the depth slice images according to viewpoint order. First, it is determined whether the last depth slice image contains content. If content exists, the determination stops, and the content traced by the rays is retained. If no content exists in the last layer, the second-to-last depth slice image is checked, and so on, traversing all depth slice images. Inverse ray tracing is performed on all set viewpoints to obtain a multi-viewpoint image. Based on the encoding rules of the element images for integrated imaging 3D display, the multi-viewpoint image is loaded onto the liquid crystal display layer 102 to form a reconstructed light field. This embodiment effectively solves the problem of parallax inversion in 3D images.

[0070] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A three-dimensional display device suspended in mid-air, characterized in that, include: A 3D display screen is used to display 3D content using light field 3D imaging technology to obtain reconstructed light rays; as well as An antireflective imaging plate is provided, with the three-dimensional display screen tilted to one side of the antireflective imaging plate. The reconstructed light rays pass through the antireflective imaging plate and reconstruct a three-dimensional light field in the air to achieve the floating display of the three-dimensional content. The antireflective imaging plate includes staggered optical waveguides to form multiple optical channels for the reconstructed light rays to exit. By setting the optical waveguides to a preset size to control the reconstructed light to be reflected only once in each optical waveguide, or by emitting reconstructed light from the three-dimensional display screen at a preset angle to control the reconstructed light to be reflected only an odd number of times in each optical waveguide.

2. The aerial levitation three-dimensional display device according to claim 1, characterized in that, The retroreflective imaging plate includes a front unit and a rear unit; The front unit is located on one side close to the three-dimensional display screen and is composed of multiple first optical waveguides arranged side by side along the first direction; The rear structure is located on the side away from the three-dimensional display screen and is composed of multiple second optical waveguides arranged side by side along the second direction; The first direction is perpendicular to the second direction, and both directions are located in the horizontal plane.

3. The aerial levitation three-dimensional display device according to claim 2, characterized in that, The first optical waveguide is set with a uniform width along the first direction, and its height along the emission direction of the reconstructed light is set according to a first preset height; the second optical waveguide is set with a uniform width along the second direction, and its height along the emission direction of the reconstructed light is set according to a second preset height.

4. The aerial levitation three-dimensional display device according to claim 3, characterized in that, The first preset height is obtained by the following steps: Based on the distance from the three-dimensional display screen to the retroreflective imaging plate and the serial number of the first optical waveguide, the first height of the first optical waveguide corresponding to the serial number is obtained; The second height of the first optical waveguide corresponding to the specified number is obtained based on the distance from the three-dimensional display screen to the retroreflective imaging plate, the serial number of the first optical waveguide, the length of the three-dimensional display screen, and the width of the first optical waveguide. Based on the first height and the second height, a first preset height is obtained for each of the first optical waveguides.

5. The aerial levitation three-dimensional display device according to claim 2, characterized in that, The first optical waveguide is set at the same height along the emission direction of the reconstructed light and its width along the first direction is set according to a first preset width; the second optical waveguide is set at the same height along the emission direction of the reconstructed light and its width along the second direction is set according to a second preset width.

6. The aerial levitation three-dimensional display device according to claim 5, characterized in that, The first preset width is obtained by the following steps: Based on the sequence number of the first optical waveguide, the cumulative width value of the first optical waveguide corresponding to that sequence number is obtained; The first width of the first optical waveguide corresponding to the given number is obtained based on the cumulative width value of the first optical waveguide, the distance from the three-dimensional display screen to the retroreflective imaging plate, the length of the three-dimensional display screen, and the height of the first optical waveguide. The second width of the first optical waveguide corresponding to the specified number is obtained based on the cumulative width value of the first optical waveguide, the distance from the three-dimensional display screen to the retroreflective imaging plate, and the length of the three-dimensional display screen. Based on the first width and the second width, a first preset width is obtained for each of the first optical waveguides.

7. The aerial levitation three-dimensional display device according to claim 2, characterized in that, The first optical waveguide is configured with a uniform width along the first direction and a uniform height along the emission direction of the reconstructed light ray; the second optical waveguide is configured with a uniform width along the second direction and a uniform height along the emission direction of the reconstructed light ray. The three-dimensional display screen includes a uniform backlight layer, a liquid crystal display layer, a microlens array, and a viewing angle controller. The light emitted from the uniform backlight layer is modulated by the liquid crystal display layer and then deflected by the microlens array. The viewing angle controller is used to control the light emitted from the three-dimensional display screen to be emitted at a preset angle, so as to control the reconstructed light to undergo an odd number of reflections in each optical waveguide.

8. The aerial levitation three-dimensional display device according to claim 7, characterized in that, The preset angle is obtained through the following steps: Based on the width and height of the first optical waveguide, the distance from the three-dimensional display screen to the retroreflective imaging plate, the length of the three-dimensional display screen, and the serial number of the first optical waveguide, the first preset angle range corresponding to the serial number is obtained; Based on the width and height of the second optical waveguide, the distance from the three-dimensional display screen to the retroreflective imaging plate, the length of the three-dimensional display screen, and the serial number of the second optical waveguide, the second preset angle range corresponding to the serial number is obtained; The preset angle is obtained based on the first preset angle range and the second preset angle range.

9. The aerial levitation three-dimensional display device according to claim 2, characterized in that, The first optical waveguide is configured with a uniform width along the first direction and a uniform height along the emission direction of the reconstructed light ray; the second optical waveguide is configured with a uniform width along the second direction and a uniform height along the emission direction of the reconstructed light ray. The three-dimensional display screen includes a directional backlight layer, a liquid crystal display layer, and a microlens array. The light emitted by the directional backlight layer at a preset angle is modulated by the liquid crystal display layer and then deflected by the microlens array before being emitted.

10. The aerial levitation three-dimensional display device according to claim 1, characterized in that, The 3D display screen corrects the parallax inversion phenomenon of the floating 3D display by using a light field reconstruction algorithm based on depth inversion.

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