Aerial suspension three-dimensional display device

Abstract

The invention provides an air suspension three-dimensional display device, which comprises a three-dimensional display screen used for displaying three-dimensional contents by using a light field three-dimensional imaging technology; the retro-reflection imaging plate and the three-dimensional display screen are obliquely arranged; the reconstructed light passes through the retro-reflection imaging plate and then reconstructs a three-dimensional light field in the air so as to realize suspension display of three-dimensional content; the retroreflection imaging plate comprises optical waveguides which are arranged in a staggered manner so as to form a plurality of optical channels for outgoing of reconstructed light rays; optical waveguides are arranged according to a preset size or a three-dimensional display screen emits reconstructed light rays according to a preset angle, so that the reconstructed light rays are controlled to be only reflected for a specified number of times in each optical waveguide. According to the system, the optical waveguide with the preset size is arranged or the three-dimensional display screen emits the reconstructed light according to the preset angle, so that the reconstructed light can only be reflected for specified times in the optical waveguide, the ghosting is fundamentally avoided, and after the ghosting is eliminated, the visual effect of the suspension 3D display technology is better and clearer.

Description

Technical Field

[0001] The present invention relates to the field of three-dimensional display technology, and in particular to an air-suspended three-dimensional display device. Background Art

[0002] Suspended 3D (three-dimensional) display technology is a technology that realizes spatial stereoscopic image display through the integration of optics, electronics, computers and display technology. Traditional 2D display technology can only present flat image information and cannot meet human needs for stereoscopic visual effects, especially in the fields of virtual reality, augmented reality, medical imaging, advertising display, etc. In order to solve this problem, researchers have developed a variety of 3D display technologies, among which suspended 3D display technology has gradually become a research hotspot due to its superior stereoscopic sense and the advantage of not needing to wear special equipment. At present, suspended 3D display mostly uses retroreflectors to reflect 3D images into the air to realize suspended 3D display. However, due to the structural design of traditional retroreflective imaging plates, there is a ghost image on each side of the displayed 3D image, which cannot meet the needs of suspended 3D display. Therefore, how to eliminate ghost images in suspended 3D display has become a key problem that needs to be solved for suspended 3D display at this stage. Summary of the invention

[0003] In view of the above defects of the prior art, the present invention provides an air-suspended three-dimensional display device to solve the technical problem of ghosting in suspended 3D display.

[0004] To achieve the above-mentioned purpose and other related purposes, the present invention provides a three-dimensional stereoscopic display device suspended in the air, comprising: a three-dimensional display screen, used to display three-dimensional content using light field three-dimensional imaging technology to obtain reconstructed light; and a retroreflective imaging plate, wherein the three-dimensional display screen is located at one side of the retroreflective imaging plate and is arranged obliquely; after the reconstructed light passes through the retroreflective imaging plate, a three-dimensional light field is reconstructed in the air to achieve the suspended display of the three-dimensional content; the retroreflective imaging plate includes staggered optical waveguides to form a plurality of optical channels for the reconstructed light to emit; the optical waveguides are arranged according to preset sizes to control the reconstructed light to be reflected only once in each of the optical waveguides, or the three-dimensional display screen emits the reconstructed light at a preset angle to control the reconstructed light to be reflected only an odd number of times in each of the optical waveguides.

[0005] In one embodiment of the present invention, the retroreflective imaging plate includes a front unit and a rear unit; the front unit is arranged on a 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 arranged on a 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 a horizontal plane.

[0006] In one embodiment of the present invention, the first optical waveguide is arranged with equal width along the first direction, and the height along the emission direction of the reconstructed light is set according to a first preset height; the second optical waveguide is arranged with equal width along the second direction, and the 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 according to the following steps: according to the distance from the three-dimensional display screen to the retroreflective imaging plate and the serial number of the first light waveguide, the first height of the first light waveguide corresponding to the serial number is obtained; according to the distance from the three-dimensional display screen to the retroreflective imaging plate, the serial number of the first light waveguide, the length of the three-dimensional display screen, and the width of the first light waveguide, the second height of the first light waveguide corresponding to the serial number is obtained; according to the first height and the second height, the first preset height of each of the first light waveguides is obtained.

[0008] In one embodiment of the present invention, the first optical waveguide is arranged at the same height along the emission direction of the reconstructed light, and the width along the first direction is set according to a first preset width; the second optical waveguide is arranged at the same height along the emission direction of the reconstructed light, and the 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 according to the following steps: according to the serial number of the first optical waveguide, the accumulated value of the width of the first optical waveguide corresponding to the serial number is obtained; according to the accumulated value of the width 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 the serial number is obtained; according to the accumulated value of the width 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 the serial number is obtained; according to the first width and the second width, the first preset width of each of the first optical waveguides is obtained.

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

[0011] In one embodiment of the present invention, the viewing angle controller is composed of a plurality of sub-areas, each of the sub-areas corresponds to one of the light channels, and each of the sub-areas 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 according to the following steps: according to 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; according to 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; according to 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 arranged with equal width along the first direction and with equal height along the emission direction of the reconstructed light; the second optical waveguide is arranged with equal width along the second direction and with equal height along the emission direction of the reconstructed light; the three-dimensional display screen includes a directional backlight layer, a liquid crystal display layer and a microlens array, and the light emitted from 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.

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

[0015] Beneficial effects of the present invention: The present invention proposes an air-suspended three-dimensional stereoscopic display device, which sets an optical waveguide of a preset size or allows the three-dimensional display screen to emit reconstructed light at a preset angle so that the reconstructed light can only be reflected a specified number of times in the optical waveguide, thereby fundamentally avoiding the generation of ghost images. After eliminating the ghost images, the visual effect of the suspended 3D display technology is better and clearer. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 A three-dimensional schematic diagram of a first structure provided by an embodiment of the present invention;

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

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

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

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

[0022] Figure 6 A three-dimensional schematic diagram of a third structure provided by an embodiment of the present invention;

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

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

[0025] Fig. 9 A flowchart of a light field reconstruction method based on depth inversion provided by an embodiment of the present invention;

[0026] Fig.10 A schematic diagram of a light field reconstruction method based on depth inversion provided by an embodiment of the present invention;

[0027] Description of the drawings: 100, three-dimensional display screen; 101, uniform backlight layer; 101', pointing 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 DESCRIPTION

[0028] The following describes the embodiments of the present invention through specific specific embodiments, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. It should be noted that the following embodiments and the features in the embodiments can be combined with each other without conflict. In addition to the specific methods, equipment, and materials used in the embodiments, according to the technical personnel in this technical field's grasp of the prior art and the records of the present invention, any methods, equipment, and materials of the prior art that are similar or equivalent to the methods, equipment, and materials described in the embodiments of the present invention can also be used to implement the present invention.

[0029] It should be understood that the terms used in the embodiments of the present invention are for describing specific embodiments rather than for limiting the scope of protection of the present invention. Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as those generally understood by those skilled in the art.

[0030] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions under which the present invention can be implemented, so they have no substantive technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. In addition, the drawings only show the components related to the present invention rather than the number, shape, and size of the components in actual implementation. The type, quantity, and proportion of each component in actual implementation can be changed arbitrarily, and the component layout type may also be more complicated.

[0031] In the following description, numerous details are discussed to provide a more thorough explanation of the embodiments of the present invention. However, it is obvious to those skilled in the art that the embodiments of the present invention can be implemented without these specific details. In some of the embodiments, well-known structures and devices are shown in the form of block diagrams rather than in detail to avoid making the embodiments of the present invention difficult to understand.

[0032] The flowchart and block diagram in the accompanying drawings illustrate the system architecture, functions and operations that may be implemented according to the methods and computer program products of various embodiments disclosed in the present invention. In this regard, each box in the flowchart or block diagram can represent a module, a program segment, or a part of a code, and the module, the program segment, or a part of the code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or the flowchart, and the combination of the boxes in the block diagram and / or the flowchart can be implemented with a dedicated hardware-based system that performs the specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0033] See also Figure 1 , Figure 4 , Figure 6 as well as Figure 8, these four figures are a kind of suspended three-dimensional stereoscopic display device provided by an embodiment of the present invention, including a three-dimensional display screen 100 and a retroreflective imaging plate 200, wherein the three-dimensional display screen 100 is used to display three-dimensional content by using light field three-dimensional imaging technology to obtain reconstructed light; the three-dimensional display screen 100 (3D display screen) is the core part of the suspended 3D display system, responsible for generating a three-dimensional image for suspended display. The three-dimensional display screen 100 is tilted on one side of the retroreflective imaging plate 200; after the reconstructed light passes through the retroreflective imaging plate 200, a three-dimensional light field is reconstructed in the air to realize the suspended display of the three-dimensional content; the retroreflective imaging plate 200 includes staggered optical waveguides to form multiple optical channels for the reconstructed light to emit. By setting the optical waveguide according to a preset size to control the reconstructed light to be reflected only once in each optical waveguide, or the three-dimensional display screen 100 emits the reconstructed light at a preset angle to control the reconstructed light to be reflected only an odd number of times in each optical waveguide. Since only a specified number of reflections occur in each optical waveguide, this fundamentally avoids the generation of ghost images. After eliminating ghost images, the visual effect of the suspended 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 arranged on a 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 arranged on a 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 of its side surfaces (e.g. Figure 2 The right side of the structure shown in FIG. 1 is provided with a high-reflectivity coating to achieve a specified number of reflections of light inside the optical waveguide, and the other side is provided with a low-reflectivity coating (e.g. Figure 2 The second optical waveguide 202 is arranged in the same manner.

[0035] The first direction and the second direction mentioned here are both located in the horizontal plane, which means that in general, the entire device is arranged in a horizontal plane. Figure 1 In the state shown, the retroreflective imaging plate 200 is arranged horizontally, so the first direction and the second direction are also located in the horizontal plane. It should be pointed out that in actual scenarios, the entire device can also be arranged tilted, and in this case the first direction and the second direction are not located in the horizontal plane, but both directions are located in the plane where the retroreflective imaging plate 200 is located.

[0036] If only one reflection occurs in each optical waveguide, this can be achieved by adjusting the size of the optical waveguide or by adjusting the light-emitting angle of the three-dimensional display screen 100. These two solutions are the same in technical conception, but the means of implementation are different. A variety of embodiments are provided below for detailed description.

[0037] See also Figure 1 to Figure 2 In a specific embodiment of the present invention, the first optical waveguide 201 is arranged with equal width along the first direction, and the height along the emission direction of the reconstructed light is set according to the first preset height; the second optical waveguide 202 is arranged with equal width along the second direction, and the height along the emission direction of the reconstructed light is set according to the second preset height. In this embodiment, the first optical waveguide 201 and the second optical waveguide 202 are arranged with equal width and length, but the height is gradually changed, and the height of the optical waveguide is adjusted to ensure that the reconstructed light is reflected only once in each optical waveguide.

[0038] The first preset height and the second preset height can be pre-calculated according to the size of each structure, and the calculation process of the first preset height and the second preset height is basically similar, and the first preset height is taken as an example for explanation below.

[0039] For the convenience of calculation, in each embodiment of the present invention, the three-dimensional display screen 100 is arranged at an angle of 45°, that is, one side of the three-dimensional display screen 100 is parallel to the surface of the retroreflective imaging plate 200. Figure 1 In the schematic structural diagram, the three-dimensional display screen 100 forms an angle of 45° with the ZOY plane and the ZOX plane. When describing the calculation steps of each preset parameter, a detailed introduction is given below through ray tracing and formula analysis.

[0040] See also Figure 3 In a specific embodiment of the present invention, the first preset height is obtained by the following steps: according to the distance H from the three-dimensional display screen 100 to the retroreflective imaging plate 200 and the serial number n of the first optical waveguide 201, the first height h' of the first optical waveguide 201 corresponding to the serial number is obtained. The first height corresponds to: the light emitted by the first voxel of the three-dimensional display screen 100 reaches the lower right edge of the nth first optical waveguide 201 and is emitted from the upper left edge of the optical waveguide. For example, Figure 3 In the illustrated structure, the first height can be calculated by the following formula:

[0041]

[0042] According to the distance H between the three-dimensional display screen 100 and the retroreflective imaging plate 200, the serial number n of the first light waveguide 201, the length L of the three-dimensional display screen 100, and the width w of the first light waveguide 201, the second height h" of the first light waveguide 201 corresponding to the serial number is obtained. The second height corresponds to: the light emitted by the last voxel of the three-dimensional display screen 100 is directly emitted from the upper right edge of the nth first light waveguide 201. For example, Figure 3 In the illustrated structure, the second height can be calculated by the following formula:

[0043]

[0044] The first preset height of each first optical waveguide 201 is obtained according to the first height h' and the second height h", which correspond to the value range of the first preset height. Only when the first preset height of each first optical waveguide 201 is between these two values ​​can the light be reflected only once in the first optical waveguide 201. The first preset height of each first optical waveguide 201 can be expressed by the formula:

[0045]

[0046] Since the size of the first height and the second height is not determined during the calculation process, both situations will occur, so it is impossible to determine which of the first height h' and the second height h" is greater. The first preset height h of the nth first optical waveguide 201 is n It can be any value between the first height h' and the second height h", so it can be conveniently calculated using the above formula.

[0047] In a specific embodiment of the present invention, it is also possible to directly set:

[0048] 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.

[0049] It is understandable that the size 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. n ), length (the length of the first optical waveguide 201 is equal to the dimension of the retroreflective imaging plate 200 along the z direction), and 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), the structure of the retroreflective imaging plate 200 is determined.

[0050] See also Figure 4In a specific embodiment of the present invention, the first optical waveguide 201 is arranged at the same height along the emission direction of the reconstructed light, and the width along the first direction is set according to the first preset width; the second optical waveguide 202 is arranged at the same height along the emission direction of the reconstructed light, and the width along the second direction is set according to the second preset width. In this embodiment, the first optical waveguide 201 and the second optical waveguide 202 are arranged at the same height and length, but the width is gradually changed, and the width of the optical waveguide is adjusted to ensure that the reconstructed light is reflected only once in each optical waveguide. The first optical waveguide 201 is also taken as an example for detailed description below.

[0051] See also Figure 5 In a specific embodiment of the present invention, the first preset width is obtained according to the following steps. According to the serial number n of the first optical waveguide 201, the accumulated value P of the width of the first optical waveguide 201 corresponding to the serial number is obtained. n ; The formula is as follows:

[0052] P n =w 1 +w 2 +…+w n ;

[0053] The accumulated value P is calculated based on the width of the first optical waveguide 201. n , 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 height h of the first optical waveguide 201, and the first width of the first optical waveguide 201 corresponding to the serial number is obtained. The first width corresponds to: the light emitted by the first voxel of the three-dimensional display screen 100 reaches the lower right edge of the nth first optical waveguide 201 and is emitted from the upper left edge of the optical waveguide. For example, Figure 5 In the illustrated structure, the first width can be calculated by the following formula:

[0054]

[0055] The second width of the first light waveguide 201 corresponding to the serial number is obtained according to the accumulated value of the width of the first light waveguide 201, the distance from the three-dimensional display screen 100 to the retroreflective imaging plate 200, and the length of the three-dimensional display screen 100. The second width corresponds to: the light emitted by the last voxel of the three-dimensional display screen 100 is directly emitted from the upper right edge of the nth first light waveguide 201. For example, Figure 5 In the illustrated structure, the second width can be calculated by the following formula:

[0056]

[0057] According to the first width w' and the second width w", the first preset width w of each first optical waveguide 201 is obtained. nThe first width and the second width correspond to the value range of the first preset width. Only when the first preset width of each first optical waveguide 201 is between these two values ​​can the light be reflected only once in the first optical waveguide 201. The first preset width of each first optical waveguide 201 can be expressed by the formula:

[0058]

[0059] Since the first width and the second width are not determined during the calculation process, both situations may occur, and therefore it is impossible to determine which of the first width w' and the second width w" is larger. The first preset width w of the nth first optical waveguide 201 is n It can be any value between the first width w' and the second width w", so it can be conveniently calculated using the above formula.

[0060] In a specific embodiment of the present invention, it is also possible to directly set:

[0061] 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.

[0062] In the above embodiment, after the reconstructed light emitted by the three-dimensional display screen 100 passes through the retroreflective imaging plate 200, the light is reconstructed along the x direction and the z direction (these two directions refer to Figure 1 The propagation of light along the y direction (as shown in the figure) becomes the same in angle and opposite in direction, while the propagation along the y direction does not change, and the image is re-converged in the air along the retroreflection direction, forming a ghost-free three-dimensional floating display.

[0063] In addition to adjusting the size of the optical waveguide, the angle of the reconstructed light emitted by the three-dimensional display screen 100 can also be adjusted to control the reconstructed light to have only an odd number of reflections in each optical waveguide. The following describes the angle adjustment scheme.

[0064] See also Figure 6 and Figure 8 In a specific embodiment of the present invention, the first optical waveguide 201 is arranged with equal width along the first direction and with equal height along the emission direction of the reconstructed light; the second optical waveguide 202 is arranged with equal width along the second direction and with equal height along the emission direction of the reconstructed light; the lengths of the first optical waveguide 201 and the second optical waveguide 202 are also fixed, corresponding to the size of the retroreflective imaging plate 200 along the z direction and the size 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 arranged with equal height and width as an example, and the height is unified as h and the width is unified as w.

[0065] See also Figure 6In 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. The light emitted by 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 is used to control the light emitted by the three-dimensional display screen 100 to be emitted at a preset angle, so as to control the reconstructed light to only reflect an odd number of times in each optical waveguide. The viewing angle controller is a composite Bragg grating structure with angle selectivity. Each Bragg grating corresponds to an optical channel, and each Bragg grating is used to filter the light of a preset angle to pass through.

[0066] See also Figure 8 In a specific embodiment of the present invention, the three-dimensional display screen 100 includes a directional backlight layer 101', a liquid crystal display layer 102 and a microlens array 103. The light emitted from the directional 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.

[0067] In the above two embodiments, the angle of the outgoing light of the three-dimensional display screen 100 is controlled by arranging the viewing angle controller 104 in front of the micro lens array 103 or arranging the viewing angle controller 104 to point to the backlight layer 101'. The principles of the two embodiments are the same, but the implementation methods are different.

[0068] In a specific embodiment of the present invention, the viewing angle controller 104 (or the backlight layer 101') is composed of a plurality of sub-areas, each of which corresponds to an optical channel, and each sub-area is used to control the light emitted by the three-dimensional display screen 100 to be emitted at a preset angle. Taking N first optical waveguides 201 and M second optical waveguides 202 as an example, they jointly divide the retroreflective imaging plate 200 into N×M optical channels. When the angle of the emitted light of the three-dimensional display screen 100 is controlled, it is also divided into corresponding areas for control, that is, the three-dimensional display screen 100 is divided into N×M sub-areas, and then the light emission angle of each sub-area is controlled separately.

[0069] At the same time, when performing preset angle calculation, each sub-region needs to calculate the angle interval in one direction (i.e., the angle interval in the XOY plane) according to the first optical waveguide 201, and also needs to calculate the angle interval in another direction (i.e., the angle interval in the YOZ plane) according to the second optical waveguide 202. Finally, these two angle intervals are combined to control the angle of each sub-region.

[0070] See also Figure 7In a specific embodiment of the present invention, the preset angle is obtained according to the following steps: according to the width w and height h of the first light 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 serial number n of the first light waveguide 201, the first preset angle interval (θ ) corresponding to the serial number is obtained. 2n-1 ,θ 2n ), where n∈(1,2,…,N), θ 2n-1 The corresponding light emitted by the middle voxel of the three-dimensional display screen 100 is directly emitted from the upper right edge of the nth first optical waveguide 201, θ 2n Correspondingly, the light emitted by the middle voxel of the three-dimensional display screen 100 reaches the lower right edge of the nth first optical waveguide 201 and is emitted from the upper left edge of the optical waveguide. For example, Figure 7 In the illustrated structure, the first preset angle interval (θ 2n-1 ,θ 2n The two angles in ) can be calculated by the following formula:

[0071]

[0072] In the above formula, l' is the distance from the middle voxel of the three-dimensional 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 three-dimensional 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.

[0073] Similarly, the second preset angle interval (θ ) corresponding to the serial number can be obtained according to the width and height of the second light waveguide 202, the distance from the three-dimensional display screen 100 to the retroreflective imaging plate 200, the length of the three-dimensional display screen 100, and the serial number of the second light waveguide 202. 2m-1 ,θ 2m ), where m∈(1,2,…,M).

[0074] Finally, the preset angle is obtained according to the first preset angle interval and the second preset angle interval, that is, for the n×mth sub-area, it is only necessary to control the light emission angle to meet the first preset angle interval in the XOY plane and the second preset angle interval in the YOZ plane. This preset angle is applicable to the viewing angle controller 104 and also to the backlight layer 101'.

[0075] Through the above embodiments, it is clear how to set the optical waveguide to a preset size or the three-dimensional display screen 100 to emit reconstruction light at a preset angle, so as to control the reconstruction light to be reflected only a specified number of times in each optical waveguide.

[0076] In addition to the ghosting problem mentioned above, there is also parallax inversion in the floating 3D display technology. Fig. 9 and Fig.10 In a specific embodiment of the present invention, the three-dimensional display screen 100 corrects the parallax inversion phenomenon of the suspended three-dimensional display through a light field reconstruction algorithm based on depth inversion. For any two-dimensional image, first, extract its depth map to obtain the depth information of each object in the scene. Use the depth map to establish the coordinate system of the scene, and determine the picture size and depth range that the three-dimensional display screen 100 can reproduce based on the parameters of the three-dimensional display screen 100, and scale the coordinate scene to adapt to the three-dimensional display screen 100. Then, according to the depth map, from near to far, the scene in the two-dimensional image is sliced ​​at the same depth interval to obtain N depth slice images, 1 represents the closest to the viewer, and N represents the farthest from the viewer, such as Fig.10 The left diagram in the figure. Then all the depth slice images are set to invert according to the depth, 1 represents the farthest from the viewer, and N represents the closest to the viewer. The inverted diagram is as follows Fig.10 As shown on the right side of . A viewing plane consisting of a plurality of viewpoints is set at a certain distance from the slice image N. The depth slice images are reversely traced ray by ray in the order of viewpoints. First, determine whether there is content in the depth slice image of the last layer. If there is content, stop determining and retain the content traced by the ray. If there is no content in the last layer, determine the second-to-last layer of depth slice image, and traverse all depth slice images in sequence. Reverse ray tracing is performed on all set viewpoints to obtain multi-viewpoint images. According to the encoding rules of the element images of the integrated imaging three-dimensional display, the multi-viewpoint images are loaded onto the liquid crystal display layer 102 to form a reconstructed light field. Through this embodiment, the problem of parallax inversion of three-dimensional images can be well solved.

[0077] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may 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 a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A three-dimensional display device suspended in the air, characterized in that: include: A three-dimensional display screen for displaying three-dimensional content using light field three-dimensional imaging technology to obtain reconstructed light; as well as A retroreflective imaging plate, wherein the three-dimensional display screen is arranged obliquely on one side of the retroreflective imaging plate; after the reconstructed light passes through the retroreflective imaging plate, a three-dimensional light field is reconstructed in the air to realize the suspended display of the three-dimensional content; the retroreflective imaging plate includes staggered optical waveguides to form a plurality of optical channels for the reconstructed light to emit; The optical waveguide is set to a preset size to control the reconstruction light to be reflected only once in each optical waveguide, or the three-dimensional display screen emits the reconstruction light at a preset angle to control the reconstruction light to be reflected only an odd number of times in each optical waveguide.

2. The air-suspended 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 arranged at a 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 structure is arranged at a 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 a horizontal plane.

3. The air-suspended three-dimensional display device according to claim 2, characterized in that: The first optical waveguide is arranged with equal 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 arranged with equal 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 air-suspended three-dimensional display device according to claim 3, characterized in that: The first preset height is obtained by the following steps: According to 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; According to 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; A first preset height of each of the first optical waveguides is obtained according to the first height and the second height.

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

6. The air-suspended three-dimensional display device according to claim 5, characterized in that: The first preset width is obtained by the following steps: According to the serial number of the first optical waveguide, obtaining the accumulated value of the width of the first optical waveguide corresponding to the serial number; Obtaining a first width of the first optical waveguide corresponding to the sequence number according to the accumulated value of the width 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; Obtaining a second width of the first optical waveguide corresponding to the sequence number according to the accumulated value of the width 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; A first preset width of each of the first optical waveguides is obtained according to the first width and the second width.

7. The air-suspended three-dimensional display device according to claim 2, characterized in that: The first optical waveguides are arranged with equal widths along the first direction and with equal heights along the emission direction of the reconstructed light; the second optical waveguides are arranged with equal widths along the second direction and with equal heights 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 by 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 by the three-dimensional display screen to be emitted at a preset angle, so as to control the reconstructed light to be reflected only an odd number of times in each of the optical waveguides.

8. The air-suspended three-dimensional display device according to claim 7, characterized in that: The preset angle is obtained by the following steps: According to the width and height of the first light 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 light waveguide, a first preset angle interval corresponding to the serial number is obtained; According to the width and height of the second light 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 light waveguide, a second preset angle interval corresponding to the serial number is obtained; The preset angle is obtained according to the first preset angle interval and the second preset angle interval.

9. The air-suspended three-dimensional display device according to claim 2, characterized in that: The first optical waveguides are arranged with equal widths along the first direction and with equal heights along the emission direction of the reconstructed light; the second optical waveguides are arranged with equal widths along the second direction and with equal heights along the emission direction of the reconstructed light; The three-dimensional display screen includes a directional backlight layer, a liquid crystal display layer and a micro lens array. The light emitted from the directional backlight layer at a preset angle is modulated by the liquid crystal display layer and then deflected by the micro lens array before being emitted.

10. The air-suspended three-dimensional display device according to claim 1, characterized in that: The three-dimensional display screen corrects the parallax inversion phenomenon of the suspended three-dimensional display by a light field reconstruction algorithm based on depth inversion.

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