Near-eye light field display device, VR device, and near-eye light field display method

Abstract

The application discloses a near-eye light field display device, a VR device and a near-eye light field display method. The near-eye light field display device of one embodiment comprises a display screen configured to receive and display preset display data, a spacer layer arranged on the light exit side of the display screen, and a microlens array arranged on the side of the spacer layer away from the display screen, wherein the display screen is arranged on the focal plane of each microlens. The aperture of two adjacent microlenses of the microlens array is smaller than the aperture of the pupil of the human eye, so that the images of the light emitted by each light emitting point of the display screen and entering the microlens array through the spacer layer and then entering the pupil of the human eye overlap in space, and the display data of the overlapping part is the same. The near-eye light field display device provided by the embodiment of the application has a wide application prospect, because the aperture of two adjacent microlenses of the microlens array is smaller than the aperture of the pupil of the human eye, so that the images entering the eye overlap in space and the display data of the overlapping part is the same, thereby realizing single-eye continuous depth imaging.

Description

Technical Field

[0001] This invention relates to the field of display technology, and in particular to a near-eye light field display device, a VR device, and a near-eye light field display method. Background Technology

[0002] As people's demands for display technology increase, 3D display has become an inevitable trend in future display technologies, ultimately achieving the reproduction and integration of the real world. When humans perceive the 3D world, the convergence angles of both eyes converge on the depth of the object being viewed, while the lens of each eye also focuses on the depth of the object being viewed; these two physiological mechanisms are matched. However, current 3D display technology based on binocular parallax suffers from "vergence-accommodation conflict" (VAC), which prevents continuous depth imaging by each eye. This leads to visual fatigue, dizziness, and other problems when viewing 3D images for extended periods. Summary of the Invention

[0003] To address at least one of the aforementioned problems, a first embodiment of this application provides a near-eye light field display device, comprising:

[0004] A display screen is used to receive and display preset display data;

[0005] A spacer layer disposed on the light-emitting side of the display screen; and

[0006] A microlens array is disposed on the side of the septum layer away from the display screen. The microlens array includes multiple microlenses arranged in an array. The orthographic projection of the microlens array onto the display screen covers the display screen. The display screen is disposed on the focal plane of each microlens.

[0007] The apertures of two adjacent lenses in the microlens array are smaller than the aperture of the human eye's pupil, so that the images of light emitted from each light-emitting point of the display screen that enter the microlens array through the spacer layer and are incident on the human eye's pupil overlap in space, and the display data of the overlapping part is the same.

[0008] In some alternative embodiments, the microlens array and the spacer layer satisfy the following:

[0009]

[0010]

[0011]

[0012] Where θ is the angle between the display pixel and the human eye after the image is projected onto the spatial position, and P pixel L is the pixel pitch of the display screen, and L is the distance from the image plane to the human eye. eWhere is the distance from the microlens array to the human eye, n is the refractive index of the microlens and septum, H is the placement height of the microlens array, e is the range of motion of a single eye, and P... lens L represents the aperture of each microlens in the microlens array. n Let Φ be the distance from the near-field boundary to the human eye, and Φ be the diameter of the human eye's pupil.

[0013] In some optional embodiments, the near-eye light field display device further satisfies:

[0014] L n ≤200mm,

[0015] P lens ≤1.5mm,

[0016] e≥10mm,

[0017] H≤11.2mm.

[0018] In some alternative embodiments, the focal length of each microlens in the microlens array increases sequentially outward from the center point of the microlens array.

[0019] In some alternative embodiments,

[0020] The radii of curvature of each microlens in the microlens array increase sequentially outwards from the center point of the array, as follows:

[0021]

[0022] Where R is the radius of curvature of the microlens, f is the focal length of the microlens, and n is the refractive index of the microlens;

[0023] and / or

[0024] The camber of each microlens in the microlens array decreases sequentially outward from the center point of the array, satisfying the following:

[0025] ;

[0026] Where R is the radius of curvature of the microlens, P lens denoted as the aperture of the microlens, and h as the camber.

[0027] In some alternative embodiments, the microlens array includes multiple independent annular regions, the center of each annular region being the center point of the microlens array, and the focal length of the microlenses in each annular region varies regionally from the center point of the microlens array outwards.

[0028] In some optional embodiments, the difference between the field of view of two adjacent annular regions and the human eye is a preset field of view step value.

[0029] In some alternative embodiments, the microlens array includes seven annular regions, with the difference in the field of view from two adjacent annular regions to the human eye being 5°.

[0030] In some alternative embodiments, the three adjacent annular regions in the seven annular regions, starting from the center point of the microlens array, have the same focal length, the same radius of curvature, and the same arch height.

[0031] In some alternative embodiments, the microlenses have a hexagonal structure and are closely spaced.

[0032] A second aspect of this application provides a VR device, including the near-eye light field display device as described above.

[0033] A third aspect of this application provides a near-eye light field display method utilizing the near-eye light field display device described above. The near-eye light field display device includes a display screen and a spacer layer disposed on the light-emitting side of the display screen. A microlens array is disposed on the side of the spacer layer away from the display screen. The microlens array includes multiple microlenses arranged in an array. The orthographic projection of the microlens array onto the display screen covers the display screen. The display screen is disposed on the focal plane of each microlens. The aperture of any two adjacent lenses in the microlens array is smaller than the aperture of the human eye pupil. The method includes:

[0034] The display screen receives preset display data;

[0035] The light emitted from each light-emitting point of the display screen enters the microlens array through the septum layer and then enters the pupil of the human eye. The images formed in the pupil of the human eye overlap in space, and the display data of the overlapping parts are the same.

[0036] In some alternative embodiments,

[0037] The microlens array and septum layer satisfy the following:

[0038]

[0039]

[0040]

[0041] Where θ is the angle between the display pixel and the human eye after the image is projected onto the spatial position, and P pixel L is the pixel pitch of the display screen, and L is the distance from the image plane to the human eye. e Where is the distance from the microlens array to the human eye, n is the refractive index of the microlens and septum, H is the placement height of the microlens array, e is the range of motion of a single eye, and P... lens L represents the aperture of each microlens in the microlens array. n Let Φ be the distance from the near-field boundary to the human eye, and Φ be the diameter of the human eye's pupil.

[0042] In some alternative embodiments,

[0043] The display screen receiving preset display data further includes:

[0044] Obtain the model data of the spatial scene to be displayed. The model data includes the three-dimensional coordinate data of each point in the spatial scene to be displayed and the display data corresponding to that point.

[0045] Calculate the luminous point of each point on the display screen based on the three-dimensional coordinate data of each point;

[0046] The light-emitting point receives the display data corresponding to each point.

[0047] In some alternative embodiments,

[0048] Calculating the luminous point on the display screen based on the three-dimensional coordinate data of each point further includes:

[0049] Reconstruct the coordinates of the intersection points of the lenses through which each point must pass to connect to the boundary of the movable range of the human pupil.

[0050] The luminous point on the display screen for each point is calculated based on the intersection coordinates and the placement height of the lens array.

[0051] The beneficial effects of this invention are as follows:

[0052] This invention addresses existing problems by providing a near-eye light field display device, VR device, and near-eye light field display method. It utilizes a display screen that receives and displays pre-set display data. Through a microlens array with the apertures of two adjacent lenses and an aperture smaller than the human pupil, the images entering the eye overlap spatially, and the overlapping portion displays the same data. By focusing the lens, the user can observe the clear and blurred transitions between different imaging planes, achieving true 3D display with continuous depth imaging that can be focused by a single eye. This eliminates 3D visual fatigue, improves the user experience, and has broad application prospects. Attached Figure Description

[0053] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying 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.

[0054] Figure 1a A diagram illustrating monocular and binocular focusing when the human eye views the real world;

[0055] Figure 1bThe diagram illustrates monocular and binocular focusing in parallax 3D displays in the prior art;

[0056] Figure 2 A schematic cross-sectional view of a near-eye light field display device according to an embodiment of this application is shown;

[0057] Figure 3 A schematic diagram illustrating the imaging principle of a near-eye light field display device according to an embodiment of this application for realizing monocular continuous depth imaging;

[0058] Figure 4a A detailed imaging principle diagram is shown for a near-eye light field display device according to an embodiment of this application to achieve monocular continuous depth imaging;

[0059] Figure 4b Show Figure 4a A magnified view of the key optical path in the image;

[0060] Figure 5 A schematic cross-sectional view of a near-eye light field display device according to another embodiment of this application is shown;

[0061] Figure 6 A schematic diagram showing the geometric relationship between the arch height and radius of curvature of a microlens;

[0062] Figure 7 A schematic diagram showing the division of the microlens array region in a near-eye light field display device according to an embodiment of this application;

[0063] Figure 8 A schematic flowchart illustrating a near-eye light field display method using a near-eye light field display device according to an embodiment of this application is shown.

[0064] Figure 9 A schematic flowchart illustrating a near-eye light field display method using a near-eye light field display device according to another embodiment of this application; and

[0065] Figures 10a to 10c A schematic diagram of a rendering method according to an embodiment of the present invention is shown. Detailed Implementation

[0066] To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments and accompanying drawings, further explains the invention. Similar components in the drawings are indicated by the same reference numerals. Those skilled in the art should understand that the specific description below is illustrative rather than restrictive and should not be construed as limiting the scope of protection of the present invention.

[0067] The inventor discovered through research that, for example Figure 1aAs shown, when the human eye views a real 3D world, it primarily relies on physiological mechanisms such as binocular parallax and monocular focusing blur. This is achieved by ensuring that the monocular focusing depth and binocular focusing depth are at the same location, constantly coordinating to perceive object depth without focusing conflict. However, current 3D display technology, such as... Figure 1b As shown, depth is perceived by adjusting the convergence angle of the eyes, but the lens always focuses on the same depth and cannot adjust its focal length accordingly. This conflict between the convergence angle and monocular focusing is called "convergence-focus conflict." Therefore, although existing technologies have achieved 3D display, the "convergence-focus conflict" problem exists. During use, the existence of the "convergence-focus conflict" problem causes visual fatigue and dizziness when viewers watch 3D images for extended periods, affecting the viewing experience and preventing true 3D from being achieved.

[0068] Further research into the mechanism by which the human eye perceives the 3D world revealed that resolving the "convergence-focusing conflict" requires achieving a focusing blur function. This means the lens needs to be able to focus at any depth within the 3D scene, producing a blurring effect at non-focusing depths. If the lens can focus at any depth within the 3D scene, it can achieve continuous depth imaging. In other words, the key to solving the "convergence-focusing conflict" problem lies in how to achieve continuous depth imaging in a single eye.

[0069] To solve at least one of the above problems, such as Figure 2 As shown, an embodiment of this application provides a near-eye light field display device, comprising:

[0070] Display screen 100 is used to receive and display preset display data;

[0071] The spacer layer 200 is disposed on the light-emitting side of the display screen 100; and

[0072] A microlens array 300 is disposed on the side of the spacer layer 200 away from the display screen 100. The microlens array 300 includes multiple microlenses arranged in an array. The orthographic projection of the microlens array 300 onto the display screen 100 covers the display screen. The display screen 100 is disposed on the focal plane of each microlens.

[0073] The apertures of two adjacent lenses in the microlens array 300 are smaller than the aperture of the human eye pupil, so that the images of light emitted from each light-emitting point of the display screen 100 that enter the microlens array 300 after passing through the spacer layer and are incident on the human eye pupil overlap in space, and the display data of the overlapping part is the same.

[0074] In this embodiment, a display screen that receives and displays preset display data is used. Through a microlens array with the apertures of two adjacent lenses and an aperture smaller than that of the human eye's pupil, the images entering the eye overlap in space, and the data displayed in the overlapping part is the same. Thus, by focusing the lens, the clear and blurry changes between different imaging planes can be viewed, realizing true 3D display with continuous depth imaging that can be focused by a single eye. There is no 3D visual fatigue, thereby improving the user experience and having broad application prospects.

[0075] To facilitate understanding of the structure of the near-eye light field display device according to the embodiments of this application, the following will provide a detailed description of the near-eye light field display device and its imaging principle in conjunction with specific examples.

[0076] In a specific example, refer to Figure 2 As shown, the near-eye light field display device of this application embodiment includes a display screen 100, a septum layer 200 disposed on the light-emitting side of the display screen 100, and a microlens array 300 disposed on the side of the septum layer 200 away from the display screen 100.

[0077] The orthographic projection of the microlens array 300 onto the display screen 100 covers the display screen 100, which is positioned on the focal plane of each microlens. (Refer to...) Figure 3 As shown, this setting enables the light-emitting direction of each pixel to be aligned, obtaining a spatially known light field, thereby obtaining the light direction emitted by each pixel, forming a light field, and the single lens ensures that only one beam of light from each pixel participates in imaging.

[0078] also, Figure 3 The diagram also schematically illustrates the imaging relationship of five adjacent microlenses collimating the light emitted from the pixels in the display screen on different imaging surfaces. Figure 3 The imaging relationship diagram ① shows that images separated by one lens do not overlap spatially; the imaging relationship diagram ② shows that images separated by one lens are spatially tangent and also do not overlap. Combining the optical path diagram and the imaging relationships in the above imaging relationship diagrams ① and ②, it can be seen that images separated by one lens will overlap spatially on imaging surfaces farther from the human eye than those in imaging relationship diagram ②, and the area of ​​the overlapping portion is larger the further away the imaging surface is from the human eye. In this application, the imaging surface in imaging relationship diagram ② is referred to as the near-field boundary.

[0079] Images separated by a lens in space can form overlapping imaging surfaces. When the display data of the images formed by this overlapping portion is the same, the human eye focuses on this imaging surface. The images formed by the microlenses can completely fuse into a single, ghost-free image, resulting in a clear view. Other areas of the image are relatively blurry, giving the human eye a sense of depth. Correspondingly, it can be understood that the larger the overlapping area of ​​the images formed by images separated by a lens, the more lenses may be overlapping in that area, resulting in fewer overlapping images from the center outwards. If the display data in the overlapping portion is the same, the image clarity gradually decreases from the center outwards, creating a stronger sense of depth. Therefore, the larger the overlapping area of ​​the images formed by images separated by a lens, the greater the depth of field.

[0080] Based on the above research findings, in the embodiments of this application, the apertures of two adjacent lenses in the microlens array 300 are smaller than the aperture of the human eye's pupil. This arrangement causes the images of light emitted from each light-emitting point of the display screen, after passing through the spacer layer and entering the microlens array, to overlap spatially in the human eye's pupil. Furthermore, in the embodiments of this application, the display screen receives preset display data, ensuring that the display data for the overlapping portions is identical.

[0081] With the above settings, each imaging surface far from the near-field boundary can perceive an image with depth when focused on by a single eye, thus achieving continuous depth imaging by a single eye. This solves the problem of "convergence-focusing conflict," eliminates 3D visual fatigue, and improves the user experience.

[0082] Those skilled in the art will understand that this invention is not intended to specifically limit the near-field boundary position, that is, it is not intended to limit the imaging depth that enables continuous depth imaging. Monocular continuous depth imaging can be achieved as long as the apertures of two adjacent lenses in the microlens array are smaller than the aperture of the human eye pupil, and the display data of the overlapping portion is the same.

[0083] However, the smaller the size of the microlens, the larger the overlapping area of ​​images formed by two lenses at the same distance from the human eye. This results in a greater maximum overlap from multiple microlenses and a wider depth of field. Those skilled in the art can rationally set the size of the microlenses to determine the size of the overlapping area and thus the depth of field. However, the size of the microlenses will affect the light field resolution. For near-eye light field display devices, a higher light field resolution is desirable under the same conditions.

[0084] Specifically, in the embodiments of this application, based on the geometric relationship of the imaging principle diagram of the light field, the specific physical parameters of the near-eye light field display device that satisfies monocular continuous imaging are designed. (Refer to...) Figure 4aAs shown in the figure, the light field imaging resolution is represented by angular resolution, which is the angle θ between the pixel and the human eye after the pixel is imaged to its spatial position. (Refer to...) Figure 4b As shown in the magnified view of the key ray, incident rays from pixels B and C on the display screen are directed to point A of the same microlens. These microlenses then form two image points, B′ and C′, on the imaging plane at a distance L from the human eye. Therefore... ABC and AB'C' satisfies the geometric relationship of similar triangles. Since the angular resolution θ is typically only a few minutes, the angle is extremely small, and quantitatively, θ can be taken as tanθ, which can be expressed as sinθ. Therefore, according to... Figure 4b The assemblage relationship shown satisfies the following angular resolution:

[0085] (1)

[0086] Among them, P pixel L is the pixel pitch of the display screen, and L is the distance from the image plane to the human eye. e Where n is the distance from the microlens array to the human eye, n is the refractive index of the microlens and the septum layer, and H is the placement height of the microlens array.

[0087] Furthermore, it should be noted that in expression (1), in order to accurately represent the geometric positional relationship of the pixels and thus precisely represent the angular resolution relationship, the total thickness of the spacer layer and the microlens (i.e., the placement height H of the microlens array) and the influence of the refractive indices of the microlens array and the spacer layer on the light are taken into account. In this example, the refractive indices of the spacer layer and the microlens are set to be equal, both being n.

[0088] Furthermore, in the embodiments of this application, the number of viewpoints entering a single eye after imaging via the same microlens array is greater than or equal to 2. Therefore, continuing to refer to... Figure 4a As shown in the imaging principle diagram, when two pixels separated by one microlens aperture are imaged by the same microlens, the image point of the incoming light rays should fall within the boundary of the range that the human eye can move. Therefore, according to the principle of similar triangles, we can obtain:

[0089] (2)

[0090] Where e is the range of motion of a single eye, P lens Let H be the aperture of each microlens in the microlens array. Similarly, in order to accurately represent the geometric positional relationship of the pixels and thus precisely represent the angular resolution, the total thickness of the spacer layer and microlenses (i.e., the placement height H of the microlens array) and the influence of the refractive index of the microlens array and spacer layer on light are considered.

[0091] Furthermore, the embodiments of this application need to satisfy monocular continuous imaging, and the near-field boundary is the boundary condition for achieving clear imaging with a sense of depth. Therefore, in the embodiments of the application, it is desirable to express the critical geometric relationship of monocular continuous depth imaging by using the optical path relationship of the image point N where the images formed by two microlenses separated by one lens are tangent in the imaging plane where the near-field boundary is located. That is, referring to Figure 4a As shown, based on the geometric relationship of the triangle formed by the line connecting the tangent image points of the images formed by two microlenses separated by one lens and the boundary of the human eye's pupil, we can obtain:

[0092] (3)

[0093] Where Φ is the diameter of the human pupil.

[0094] Those skilled in the art will understand that it is desirable to use expressions (1), (2) and (3) to obtain the maximum light field resolution design that satisfies the 3D imaging conditions of monocular continuous depth imaging.

[0095] The inventors derived the following conclusions by analyzing expressions (1), (2), and (3). First, the larger the light field resolution, the smaller the required angular resolution θ. According to expression (1), the angular resolution θ is inversely proportional to the placement height H; to achieve a larger resolution (smaller angular resolution θ), a larger placement height H is required. According to expression (2), the placement height H is inversely proportional to the monocular range of motion e; the larger the placement height H, the smaller the monocular range of motion, but this will result in a smaller field of view. According to expression (2), the placement height H is inversely proportional to the aperture P of the microlens. lens Inversely proportional, when the monocular range of motion e remains constant, increasing the placement height H will increase the aperture P of the microlens. lens Increase accordingly, according to expression (3), the distance L from the near-field boundary to the human eye. n As the depth of field increases, the range from the near edge to infinity decreases.

[0096] Based on the above principles, we can select a monocular range of motion *e* and a near-field boundary that are suitable for the human eye. For example, we can design a monocular range of motion *e* that covers the pupil and ensures a certain range of movement within that range; therefore, we can choose *e* = 10mm. Furthermore, because it is smaller than the near-field boundary *L*... n The image cannot be clearly focused on the retina; the distance L from the edge of the near scene to the human eye... n Generally greater than 125mm. Therefore, the near-field boundary L can be taken. n The distance to the human eye is L n =125mm. Additionally, the distance L from the microlens array to the human eye can be adjusted according to the specific application scenario of the near-eye light field display device. eFor example, a common viewing distance of 50mm can be set. Furthermore, by substituting the known pupil diameter Φ, the refractive index of the microlens array and the septum material, and the pixel size into expressions (1), (2), and (3), the aperture of the microlens can be designed. The embodiments of this application provide microlens apertures and placement height H that maximize light field resolution.

[0097] For example, if we take L n =125mm, e=10mm, L e =50mm, Φ=4mm, n=1.45, P pixel =8.5μm, then substituting into expressions (1), (2) and (3), we can obtain the values ​​of each microlens P. lens The diameter is 1.2mm and the placement height H is 8.94mm.

[0098] In an optional embodiment, a depth of field range of 200mm to infinity is acceptable. That is, more preferably, it can be:

[0099] L n ≤200mm,

[0100] P lens ≤1.5mm,

[0101] e≥10mm,

[0102] H≤11.2mm.

[0103] Based on the above settings, the key design parameters for a near-eye light field display device that enables continuous depth imaging in a single eye—the microlens aperture and placement height H—can be obtained. It should be noted that the above values ​​are not limiting; those skilled in the art can rationally select parameters based on actual needs and the development level of manufacturing processes and equipment to maximize light field resolution. For example, currently used displays can achieve a pixel density of 3000 PPI, with angular resolutions of 2.9′ at a 200mm image distance, 3.2′ at a 300mm image distance, and 3.9′ at infinity. To achieve an angular resolution of 2′ across the entire imaging depth range, a display with 5800 PPI is required. With future advancements in display technology and improved manufacturing processes, high-PPI displays will gradually emerge, and the light field resolution will be correspondingly improved across the entire imaging depth range. Consequently, the optimal value ranges for each parameter will also change, which will not be elaborated upon here.

[0104] While microlens arrays can converge light emitted from sub-pixels, they are still subject to aberrations due to their single-lens nature. When all microlenses in the array have the same focal length, and the microlenses are bonded to the display screen, light emitted from pixels near the center of the screen is collimated with a small beam width, while light rays diverging towards the edges have a wider beam width. This results in a rapid decrease in image quality at the edge field of view, reducing pixel utilization for 3D display and narrowing the viewing angle.

[0105] To further increase the field of view, in some alternative embodiments, such as Figure 5 As shown, the focal length of each microlens in the microlens array 300′ increases sequentially from the center point of the microlens array outwards.

[0106] This setting enables both center and edge pixels to achieve light collimation, mitigating the image quality degradation at the edge field of view, increasing the viewing angle, and effectively improving screen utilization.

[0107] It is important to note that although the focal length *f* of the microlens is used as a limiting condition here, those skilled in the art should understand that for a microlens, its focal length, camber, and radius of curvature have a clear mathematical correlation. When describing the variation of the focal length, the camber and radius of curvature also have clear variation patterns. Therefore, the limiting condition for the focal length is also a limiting condition for the camber and radius of curvature. That is, the radius of curvature *R* and the camber *h* characterize the focal length *f*.

[0108] Specifically, the focal length f of each microlens is defined to increase sequentially outward from the center point of the microlens array, which also means that the radius of curvature R of each microlens is defined to increase sequentially outward from the center point of the microlens array.

[0109] (4)

[0110] Where R is the radius of curvature of the microlens, f is the focal length of the microlens, and n is the refractive index of the microlens.

[0111] At the same time, refer to Figure 6 As shown, EO = FO = radius of curvature R, and ED is the microlens aperture P. lens FG represents the arch height h. EOG forms a right triangle because EO 2 =EG 2 +GO 2 Therefore, the arch height satisfies:

[0112] (5)

[0113] Where R is the radius of curvature of the microlens, P lensLet f be the aperture of the microlens and h be the camber. Therefore, according to the relationship in expression (5), when the focal length f of each microlens is increased sequentially from the center point of the microlens array 300′ outwards, the camber h of each microlens is also decreased sequentially from the center point of the microlens array outwards, i.e. Figure 2 As shown, the arch heights h1, h2...h6 decrease sequentially.

[0114] In some optional embodiments, the microlens array 300' includes multiple independent annular regions, the center of each annular region being the center point of the microlens array 300', and the focal length of the microlenses in each annular region varies regionally from the center point of the microlens array outwards.

[0115] In this embodiment, considering the technological limitations in practical applications, the multiple microlenses in each annular region have the same focal length, that is, the same radius of curvature and camber. In other words, the parameters of each microlens located in one annular region are the same first parameter, and the parameters of each microlens located in another annular region are the same second parameter. Specifically, the focal length of the microlenses in each annular region exhibits regional variation while satisfying a sequential change from the center point of the microlens array outwards. This achieves a good 3D display effect while meeting the limitations of the technological limitations.

[0116] Specifically, according to the light field display device of this application embodiment, the annular region is divided according to the difference between the field of view angles of two adjacent annular regions to the human eye satisfying a preset field of view angle step value. For example, the annular region of the microlens array 300′ is set with a field of view angle step value of 5°.

[0117] Specifically, refer to Figure 7 As shown, taking a 4.2-inch monochrome display screen as an example, the aperture P of the microlens has been obtained according to expressions (1), (2), and (3). lens With a thickness of 1.2mm and a placement height H of 8.94mm, the microlens can be divided into 7 regions, each with a 5° field of view step. The figure shows the size division of the display screen, indicating the size of each region. Specifically, 8.80 indicates that the diameter of the circle in region 1 is 8.80mm, 17.60 indicates that the diameter of the circle in region 2 is 17.60mm, 26.80 indicates that the diameter of the circle in region 3 is 26.80mm, 36.40 indicates that the diameter of the circle in region 4 is 36.40mm, 46.60 indicates that the diameter of the circle in region 5 is 46.60mm, and 57.8 indicates that the diameter of the circle in region 4 is 57.80mm.

[0118] Those skilled in the art should understand that the near-field viewing distance of the near-eye light field display device in this application embodiment is a 70° field of view, that is, the overall range of the annular area is set with a 35° half-field of view. However, those skilled in the art should understand that this is not limiting. When the near-eye light field display device of this application is applied to other viewing scenarios, or when it is necessary to change the distance between the display screen of the near-eye light field display device and the human eye in other application situations, the overall field of view range of the divided area can also be changed. For example, when the display screen is far away from the human eye, the field of view can be less than 70°.

[0119] Furthermore, optical software can be used to model and simulate based on the central field of view of each region, thereby further optimizing the radius of curvature. For example, based on... Figure 7 After dividing the microlens array into regions as shown, the center field of view of each region is input, and optical simulation software is used to model and simulate the process. For example, according to the principle that the focal length of the microlens in each region increases sequentially from the center point of the microlens array, the simulation aims to ensure that the beam width of the light emitted from each light-emitting point of the display screen is less than a preset width threshold when it enters the pupil of the human eye. The focal length f, radius of curvature, and camber of the microlens in other regions are obtained, so that the center viewing angle of each region is collimated, thereby ensuring a smooth transition of image quality between regions without abrupt changes.

[0120] Table 1 provides the corresponding values ​​for the radius of curvature of each region in an example microlens array, illustrated using the design principles described above and a 4.2-inch display screen as an example. However, those skilled in the art should understand that the specific values ​​in this table are not intended to limit this application. They can reasonably determine the specific values ​​for each region based on actual examples and the device structure designed in this application, following conventional simulation testing methods in the prior art.

[0121] Table 1

[0122]

[0123] It is worth noting that, considering process limitations, the difference in the radius of curvature between different regions should be greater than the process deviation. In the example shown in Table 1, the radius of curvature parameters of the microlenses in regions 1 and 2 are very close. If we take a process deviation of ±35μm as an example, the parameters of the two regions can be adjusted to be the same, for example, the parameters of the two regions can be combined to 2.99mm. In other regions, the focal length of the microlenses in each region increases sequentially from the center point of the microlens array outward.

[0124] In some alternative embodiments, the microlenses are hexagonal in structure to improve space utilization efficiency. A regular hexagonal structure is preferred, with the microlenses closely spaced and their edges in close contact.

[0125] Based on the same inventive concept, and corresponding to the light field display device of this application, embodiments of this application also provide a VR device, including the near-eye light field display device as described in the above embodiments. The principle by which this VR device solves the problem is similar to that of the aforementioned near-eye light field display device; therefore, the specific implementation of this VR device can be found in the implementation of the aforementioned light field display device, and the repeated parts will not be described again here.

[0126] In practical implementation, the display device can be any VR product or component with 3D display capabilities. Other essential components of this device are understood by those skilled in the art and will not be described further here, nor should they be construed as limiting this application.

[0127] Based on the same inventive concept, such as Figure 8 As shown, embodiments of this application also provide a light field display method for the light field display device of the above embodiments. The near-eye light field display device includes a display screen and a spacer layer disposed on the light-emitting side of the display screen. A microlens array is disposed on the side of the spacer layer away from the display screen. The microlens array includes a plurality of microlenses arranged in an array. The orthographic projection of the microlens array onto the display screen covers the display screen. The display screen is disposed on the focal plane of each microlens. The aperture of two adjacent lenses in the microlens array is smaller than the aperture of the human eye pupil, including:

[0128] S1. The display screen receives preset display data;

[0129] S2. The light emitted from each light-emitting point of the display screen enters the microlens array through the septum layer and then enters the pupil of the human eye. The images formed in the pupil of the human eye overlap in space, and the display data of the overlapping parts are the same.

[0130] In this embodiment, the display screen receives preset display data, and the light emitted by each light-emitting point of the display screen enters the microlens array through the septum layer and then enters the pupil of the human eye. The images formed in the pupil of the human eye overlap in space, and the display data of the overlapping parts are the same. Thus, by focusing the lens, the clear and blurry changes between different imaging planes can be viewed, realizing true 3D display with continuous depth imaging that can be focused by a single eye. There is no 3D visual fatigue, thereby improving the user experience and having broad application prospects.

[0131] In some alternative embodiments, specifically, the microlens array and the spacer layer satisfy the following:

[0132]

[0133]

[0134]

[0135] Where θ is the angle between the display pixel and the human eye after the image is projected onto the spatial position, and P pixel L is the pixel pitch of the display screen, and L is the distance from the image plane to the human eye. e Where n is the distance from the microlens array to the human eye, n is the refractive index of the microlens and the septum layer, H is the placement height of the microlens array, e is the range of motion of a single eye, and P is the distance from the microlens array to the human eye. lens L represents the aperture of each microlens in the microlens array. n Let Φ be the distance from the near-field boundary to the human eye, and Φ be the diameter of the human eye's pupil.

[0136] With the above settings, continuous depth imaging can be achieved in a single eye, balancing clear display and pixel resolution within the limited size of the screen.

[0137] Preferably, the display data for each pixel can be obtained through a light field image rendering method. Specifically, refer to... Figure 9 and 10a As shown in -10c, step S1 further includes:

[0138] Step S11: Obtain the model data of the spatial scene to be displayed. The model data includes the three-dimensional coordinate data of each point in the spatial scene to be displayed and the display data corresponding to that point.

[0139] Specifically, the spatial scene can be a 3D continuous depth scene to be displayed in each frame, and its model data, as the source, can be 3D model data in .ply format. The 3D coordinate data of each point is, for example... Figure 10a P shown i (x, y, z). Point P i The corresponding display data can be color information, such as the specific color and grayscale.

[0140] In step S12, the luminous point of each point on the display screen is calculated based on the three-dimensional coordinate data of each point.

[0141] like Figure 10b As shown, specifically, reconstructing each point P i (x, y, z) are the coordinates of the intersection points of the lenses that must be traversed to connect the boundary of the movable range of the human eye pupil.

[0142] Those skilled in the art will understand that restoring each point P i The calculation of the lens intersection points (x, y, z) required to connect the boundary of the movable range of the human eye pupil is based on the known boundary coordinates of the movable range of the human eye pupil. That is, a Cartesian coordinate system is pre-established to determine the boundary coordinate values ​​of the movable range of the human eye pupil. Simultaneously, the intersection coordinates of these lens intersection points are also pre-stored. In other words, the coordinates of each point on each microlens are calculated after establishing a Cartesian coordinate system with the surface of the microlens array as a reference.

[0143] After restoring the intersection coordinates, the luminous point on the display screen for each point is calculated based on the intersection coordinates and the placement height H of the lens array.

[0144] Specifically, P is determined based on the law of reflection. i (x, y, z) represents the path (x, y, z) into the human eye's pupil. Preferably, to more accurately locate the light source, the refraction angle after the light enters the microlens and passes through the septum is taken into account. Based on the refractive indices of the microlens and septum, the coordinates of the pixel point to which the light rays will return after entering the microlens and septum from the intersection point are calculated. This pixel point is the image P formed in space after the pixel emits light, passes through the septum and microlens, and enters the human eye. i The initial emitting point (x, y, z). It can be understood that the coordinates of this pixel can also be the coordinates of each sub-pixel calculated in advance based on a Cartesian coordinate system established with the surface of the display screen as the reference.

[0145] Step S13: The light-emitting point receives the display data corresponding to each point. Specifically, P... i The display data amplitude corresponding to (x, y, z) is assigned to the sub-pixel that serves as the light source.

[0146] Next, by traversing all the points in the source material and assigning display data such as grayscale to the sub-pixels of each luminous point, display data for display on the screen can be obtained. When viewing spatial scenes using this near-eye light field display device, continuous depth imaging of a single eye can be achieved. Even if the 3D scene on the screen is focused on for a long time, visual fatigue will not occur, greatly improving the viewer's sensory experience.

[0147] This invention addresses existing problems by providing a near-eye light field display device, VR device, and near-eye light field display method. It utilizes a display screen that receives and displays pre-set display data. Through a microlens array with the apertures of two adjacent lenses and an aperture smaller than the human pupil, the images entering the eye overlap spatially, and the overlapping portion displays the same data. By focusing the lens, the user can observe the clear and blurred transitions between different imaging planes, achieving true 3D display with continuous depth imaging that can be focused by a single eye. This eliminates 3D visual fatigue, improves the user experience, and has broad application prospects.

[0148] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A near-eye light field display device, characterized in that, include: A display screen is used to receive and display preset display data; A spacer layer disposed on the light-emitting side of the display screen; as well as A microlens array is disposed on the side of the spacer layer away from the display screen. The microlens array includes multiple microlenses arranged in an array. The orthographic projection of the microlens array onto the display screen covers the display screen. The display screen is disposed on the focal plane of each microlens. The apertures of two adjacent lenses in the microlens array are smaller than the aperture of the human eye's pupil, so that the images of light emitted from each light-emitting point of the display screen that enter the microlens array through the spacer layer and are incident on the human eye's pupil overlap in space, and the display data of the overlapping portion are the same.

2. The near-eye light field display device according to claim 1, characterized in that, The microlens array and the spacer layer satisfy the following: Where θ is the angle between the display pixel and the human eye after the image is projected onto the spatial position, and P pixel L is the pixel pitch of the display screen, and L is the distance from the image plane to the human eye. e Where n is the distance from the microlens array to the human eye, n is the refractive index of the microlens and the septum layer, H is the placement height of the microlens array, e is the range of motion of a single eye, and P is the distance from the microlens array to the human eye. lens L represents the aperture of each microlens in the microlens array. n Let Φ be the distance from the near-field boundary to the human eye, and Φ be the diameter of the human eye's pupil.

3. The near-eye light field display device according to claim 2, characterized in that, The near-eye light field display device further satisfies: L n ≤200mm, P lens ≤1.5mm, e≥10mm, H≤11.2mm.

4. The near-eye light field display device according to claim 1, characterized in that, The focal length of each microlens in the microlens array increases sequentially outward from the center point of the microlens array.

5. The near-eye light field display device according to claim 4, characterized in that, The radius of curvature of each microlens in the microlens array increases sequentially outward from the center point of the microlens array, as follows: Where R is the radius of curvature of the microlens, f is the focal length of the microlens, and n is the refractive index of the microlens; and / or The camber of each microlens in the microlens array decreases sequentially outward from the center point of the microlens array, satisfying the following: ； Where R is the radius of curvature of the microlens, and P lens denoted as the aperture of the microlens, and h as the camber.

6. The near-eye light field display device according to claim 5, characterized in that, The microlens array comprises multiple independent annular regions, with the center of each annular region being the center point of the microlens array. The focal length of the microlenses in each annular region varies regionally from the center point of the microlens array outwards.

7. The near-eye light field display device according to claim 6, characterized in that, The difference between the field of view angles of two adjacent annular regions and the human eye is the preset field of view angle step value.

8. The near-eye light field display device according to claim 7, characterized in that, The microlens array comprises seven annular regions, with the difference in the field of view from two adjacent annular regions to the human eye being 5°.

9. The near-eye light field display device according to claim 8, characterized in that, The seven annular regions have the same focal length, radius of curvature, and arch height when starting from the center point of the microlens array and moving outwards from each of the three adjacent annular regions.

10. The near-eye light field display device according to claim 1, characterized in that, The microlenses have a hexagonal structure and are closely spaced together.

11. A VR device, characterized in that, Including the near-eye light field display device as described in any one of claims 1-10.

12. A method for displaying the near-eye light field using the near-eye light field display device according to any one of claims 1-10, characterized in that, The near-eye light field display device includes a display screen and a spacer layer disposed on the light-emitting side of the display screen. A microlens array is disposed on the side of the spacer layer away from the display screen. The microlens array includes multiple microlenses arranged in an array. The orthographic projection of the microlens array onto the display screen covers the display screen. The display screen is disposed on the focal plane of each microlens. The aperture of any two adjacent lenses in the microlens array is smaller than the aperture of the human eye pupil. The method includes: The display screen receives preset display data; The light emitted from each light-emitting point of the display screen enters the microlens array through the septum layer and then enters the pupil of the human eye. The images formed in the pupil of the human eye overlap in space, and the display data of the overlapping parts are the same.

13. The near-eye light field display method according to claim 12, characterized in that, The microlens array and the spacer layer satisfy the following: Where θ is the angle between the display pixel and the human eye after the image is projected onto the spatial position, and P pixel L is the pixel pitch of the display screen, and L is the distance from the image plane to the human eye. e Where n is the distance from the microlens array to the human eye, n is the refractive index of the microlens and the septum layer, H is the placement height of the microlens array, e is the range of motion of a single eye, and P is the distance from the microlens array to the human eye. lens L represents the aperture of each microlens in the microlens array. n Let Φ be the distance from the near-field boundary to the human eye, and Φ be the diameter of the human eye's pupil.

14. The near-eye light field display method according to claim 12, characterized in that, The display screen receiving preset display data further includes: Obtain model data of the spatial scene to be displayed, wherein the model data includes the three-dimensional coordinate data of each point in the spatial scene to be displayed and the display data corresponding to that point; Calculate the luminous point of each point on the display screen based on the three-dimensional coordinate data of each point; The light-emitting point receives the display data corresponding to each point.

15. The light field display method according to claim 14, characterized in that, The step of calculating the luminous point of each point on the display screen based on the three-dimensional coordinate data of each point further includes: Reconstruct the coordinates of the intersection points of the lenses through which each point must pass to connect to the boundary of the movable range of the human pupil. The luminous point of each point on the display screen is calculated based on the coordinates of the intersection point and the placement height of the lens array.

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