Light field display device and light field display system

Abstract

The application relates to the technical field of 3D display, in particular to a light field display device and a light field display system. The light field display device comprises a display component, a lens array and at least one main lens which are sequentially arranged along the light-emitting direction of the display component, wherein the distance between the highest point of the lens array and the display component is equal to the focal length of the lens array; the distance between the highest point of the lens array and the main lens is less than or equal to the focal length of the main lens; during use, the light rays emitted via the display component firstly undergo once deflection and divergence angle convergence via the lens array, and then undergo twice deflection and divergence angle convergence via the main lens, and finally enter the corresponding eye point of the human eye; in summary, the divergence angle of the light rays is modulated twice by the cooperation of the lens array and the main lens, so that the resolution of the light rays entering the corresponding eye point of the human eye is improved, and the display resolution is improved.

Description

Technical Field

[0001] The present invention relates to the field of 3D display technology, and in particular to a light field display device and a light field display system. Background Art

[0002] Currently, near-eye VR / AR displays mostly use left and right eye screens to load different parallax images to provide stereoscopic vision, which will cause convergence-focus conflict and make users feel strongly dizzy. Monocular light field display can solve this problem well.

[0003] The integrated imaging display of screen + lens array is a major solution for realizing monocular light field display. The integrated imaging display is divided into real mode, virtual mode and focus mode. In the focus mode, the screen is placed on the focal plane of the lens array. The divergence angle of the light emitted by the screen is minimized after being modulated by the lens array, so a larger depth of field can be obtained, which is more suitable for the requirements of near-eye display with a large depth of field.

[0004] In the prior art, a lens array with a small single lens aperture is usually used to ensure the resolution of the light field display. However, as the aperture of a single lens decreases, the corresponding light focusing ability also decreases, resulting in a lower resolution of the above-mentioned light field display. Summary of the Invention

[0005] The purpose of this application is to provide a light field display device and a light field display system to solve the technical problem of low light field display resolution in the prior art.

[0006] (1) Technical solution

[0007] To achieve the above-mentioned objectives, the first aspect of the present invention provides a light field display device, comprising: a display component, a lens array and at least one main lens arranged in sequence along the light emitting direction of the display component, wherein the distance between the highest point of the lens array and the display component is equal to the focal length of the lens array; and the distance between the highest point of the lens array and the main lens is less than or equal to the focal length of the main lens.

[0008] As one of the optional solutions of this technical solution, the lens array is configured as a cylindrical lens array.

[0009] As one of the optional solutions of the present technical solution, the lens array is installed on the light-emitting side of the display assembly through a spacer layer.

[0010] As one of the optional solutions of the present technical solution, the refractive index of the spacer layer is equal to the refractive index of the lens array.

[0011] As one of the optional solutions of this technical solution, the main lens is spaced apart from the lens array through a mounting frame.

[0012] As one of the optional solutions of this technical solution, the main lens can at least be set as a plano-convex lens or a biconvex lens.

[0013] As one of the optional solutions of the present technical solution, when the distance between the lens array and the main lens is equal to the focal length of the main lens, the main lens has a fixed focal length.

[0014] As one of the optional solutions of the present technical solution, when the distance between the lens array and the main lens is smaller than the focal length of the main lens, the main lens has a variable focal length.

[0015] As one of the optional solutions of the present technical solution, the field of view angle β of the main lens is in the range of 90°-100°; the aperture of the main lens is less than or equal to 50 mm; and the focal length of the main lens is less than or equal to 40 mm.

[0016] As one of the optional solutions of this technical solution, the diameter size range of the light spot formed by the lens array transmitted to the main lens is as follows:

[0017]

[0018] Wherein, ε is the diameter of the light spot formed by the light transmitted to the main lens through the lens array; L' is the depth of field of the main lens; F is the focal length of the main lens; and D is the aperture of a single lens in the lens array.

[0019] As one of the optional solutions of this technical solution, the aperture size of a single lens in the lens array is as follows:

[0020]

[0021] Where D is the aperture of the lens; m is the pixel opening; e is the eye movement range; λ is the wavelength of the light emitted from the display component; L' is the depth of field of the main lens; and F is the focal length of the main lens.

[0022] As one of the optional solutions of this technical solution, the aperture of the main lens is as follows:

[0023]

[0024] Where a is the aperture of the main lens; l is the exit pupil distance; β is the field of view of the main lens.

[0025] As one of the optional solutions of the present technical solution, the size of the lens array in the Y-axis direction is equal to the size of the effective pixel area in the display component in the Y-axis direction;

[0026] And, the dimensions of the lens array in the X-axis direction are as follows:

[0027]

[0028] Where F' is the distance from the lens array to the main lens; L' is the depth of field of the main lens; θ is the divergence angle.

[0029] As one of the optional solutions of this technical solution, the size of the effective pixel area in the display component in the X-axis direction is as follows:

[0030]

[0031] Furthermore, the size of the effective pixel area in the Y-axis direction of the display component is as follows:

[0032] c y =p·M;

[0033] Where D is the aperture of the lens; b x is the size of the lens array in the X-axis direction; N is the number of pixels covered by a single lens in the X-direction; p is the pixel spacing; and M is the resolution of a single viewpoint in the Y-axis direction.

[0034] As one of the optional solutions of the present technical solution, the interval p between every two adjacent pixels in the display component is less than or equal to 10 μm.

[0035] To achieve the above-mentioned object, a second aspect of the present invention provides a light field display system, such as the light field display device described in any one of the above descriptions.

[0036] (2) Beneficial effects

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] The present invention provides a light field display device and a light field display system, which include: a display component, a lens array and at least one main lens arranged in sequence along the light output direction of the display component, wherein the distance between the highest point of the lens array and the display component is equal to the focal length of the lens array; the distance between the highest point of the lens array and the main lens is less than or equal to the focal length of the main lens; when in use, the light emitted by the display component is first deflected and the divergence angle is converged by the lens array, and then deflected and the divergence angle is converged for the second time by the main lens, and finally enters the corresponding viewpoint of the human eye; in summary, the present application performs two convergence modulations on the divergence angle of the light through the cooperation of the lens array and the main lens, so as to improve the resolution of the light entering the corresponding viewpoint of the human eye, thereby improving the display resolution. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, a person skilled in the art can derive other drawings based on these drawings without inventive work, among which:

[0041] Figure 1 is a schematic structural diagram of a light field display device according to an embodiment of the present invention;

[0042] Figure 2 is a schematic structural diagram illustrating another light field display device according to an embodiment of the present invention;

[0043] Figure 3 is a diagram showing the display principle of a light field display device according to an embodiment of the present invention;

[0044] Figure 4 is a schematic diagram illustrating imaging of a light field display device according to an embodiment of the present invention;

[0045] Figure 5 This is a schematic diagram showing the modulation and transmission of pixel light through a lens array according to an embodiment of the present invention;

[0046] Figure 6 This is a display principle diagram showing the cooperation between the main lens and the lens array in one embodiment of the present invention;

[0047] Figure 7 is a schematic structural diagram of an effective pixel area in a display component according to an embodiment of the present invention;

[0048] Figure 8 This is an embodiment of the present invention showing a display effect model of a light field display device;

[0049] Figure 9 is a schematic structural diagram showing a lens array according to another embodiment of the present invention;

[0050] Figure 10 is a schematic structural diagram of a light field display device according to another embodiment of the present invention;

[0051] Figure 11 yes Figure 10 Top view of the lens array in front of the unprinted lens.

[0052] In the figure: 1. Display component; 2. Lens array; 3. Main lens; 4. Spacer layer; 5. Mounting frame; 6. 2D viewpoint; 7. 3D viewpoint; 8. Support structure; 9. First drive electrode; 10. Second drive electrode; 11. First line electrode; 12. Second line electrode. DETAILED DESCRIPTION

[0053] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0054] The integrated imaging display of screen + lens array is a major solution for realizing monocular light field display. The integrated imaging display is divided into real mode, virtual mode and focus mode. In the focus mode, the screen is placed on the focal plane of the lens array. The divergence angle of the light emitted by the screen is minimized after being modulated by the lens array, so a larger depth of field can be obtained, which is more suitable for the requirements of near-eye display with a large depth of field.

[0055] In the prior art, a lens array with a small single lens aperture is usually used to ensure the resolution of the light field display. However, as the aperture of a single lens decreases, the corresponding light focusing ability also decreases, resulting in a lower resolution of the above-mentioned light field display.

[0056] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0057] One embodiment

[0058] In order to solve the above technical problems, Figures 1-8 As shown, the present application provides a light field display system, including: a light field display device. The specific structure of the light field display device is described in detail below:

[0059] A light field display device includes a display assembly 1. In a specific embodiment, the display panel of the present invention can be configured as a Micro-LED display panel, an LCD display panel, or other OLED display panel. Preferably, the display assembly 1 is provided with an OLED display panel. Depending on its function, it can be a conventional OLED display panel, a transparent OLED display panel, etc.; depending on the light-emitting principle, it can be an RGB three-color display panel, a white light + color filter OLED display panel, a quantum dot + OLED display panel, etc. The present invention does not specifically limit the type of display panel.

[0060] A lens array 2 and at least one main lens 3 are sequentially arranged along the light-emitting direction of the display component 1. In the present embodiment, preferably, the lens array 2 is arranged as a spherical microlens array 2. Of course, the microlens array 2 is not limited to the above-mentioned example. As long as the lens array 2 can achieve light convergence, it is applicable to the present embodiment and falls within the protection scope of the present application. In a specific embodiment, the lens array 2 is installed on the light-emitting side of the display component 1 through a spacer layer 4. Each lens in the lens array 2 covers two or more pixel points on the display component 1 in the modulation direction, and the number of pixel points corresponding to each lens is equal to the number of viewpoints. The distance between the highest point of the lens array 2 and the display component 1 is equal to the focal length of the lens array 2. The distance between the highest point of the lens array 2 and the main lens 3 is equal to the focal length of the lens array 2. Less than or equal to the focal length of the main lens 3; preferably, the refractive index of the spacer layer 4 is equal to the refractive index of the lens array 2, and the size of the spacer layer 4 is equal to the size of the lens array 2, so as to ensure that the spacer layer 4 covers each lens of the lens array 2; to ensure that the light from the display component 1 can smoothly pass through the spacer layer 4 and diverge into the lens array 2, and no light loss will occur in the above process. Furthermore, in order to ensure light transmittance, the spacer layer 4 is preferably made of a transparent material. Exemplarily, the spacer layer 4 can be made of inorganic glass, organic glass or other resins, preferably, it is made of pmma resin. In summary, the spacer layer 4 in this embodiment is not limited to being made of the above materials, as long as the material has the same refractive index as the lens array 2, it is applicable to this embodiment and belongs to the protection scope of this application.

[0061] In a specific embodiment, the field of view angle β of the main lens 3 is in the range of 90°-100°; the aperture of the main lens 3 is less than or equal to 50 mm; and the focal length of the main lens 3 is less than or equal to 40 mm. The aperture of the main lens 3 can be calculated according to the following formula:

[0062]

[0063] Where a is the aperture of the main lens; l is the exit pupil distance; β is the field of view of the main lens.

[0064] For example, when the field of view angle β of the main lens is selected to be 90° and the exit pupil distance l is 20 mm, the aperture of the main lens can be determined to be 40 mm.

[0065] Specifically, the main lens 3 is spaced apart from the lens array 2 through the mounting frame 5. Specifically, both ends of the main lens 3 are fixedly connected to the mounting frame 5, or, in order to facilitate the installation and removal of the main lens 3, both ends of the main lens 3 are detachably connected to the mounting frame 5. In a preferred embodiment, the mounting frame 5 has a mounting position at one end away from the display component 1, and the shape of the mounting position is adapted to the shape of the main lens 3. In a specific embodiment, the main lens 3 and the lens array 2 can be set as spherical lenses, aspherical lenses or Fresnel lenses, and the structure can be set as follows Figure 1 The double convex lens shown and Figure 2 The plano-convex lens shown, of course, the shape and structure of the main lens 3 given in the above embodiment are only shown for the sake of ease of understanding. The shape and structure of the main lens 3 are not specifically limited in this embodiment. As long as the lens can be used to converge the light, it is applicable to this embodiment and belongs to the protection scope of this application. In addition, the number of main lenses 3 is not specifically limited in this embodiment. Exemplarily, the main lens 3 can be set as two stacked plano-convex lenses, or other matching methods, and the specific structure can be pre-set as needed; Exemplarily, when the main lens 3 is set as two stacked plano-convex lenses, preferably, the distance between the highest point of the lens array 2 and the plano-convex lens closest to the lens array 2 is equal to the focal length of the plano-convex lens.

[0066] During use, the light emitted by the display component 1 is first deflected once and the divergence angle is converged by the lens array 2, and then deflected twice and the divergence angle is converged by the main lens 3, and finally enters the corresponding viewpoint of the human eye; in summary, the present application adopts a lens array 2 with a small single lens aperture to cooperate with the main lens 3 to achieve two convergence modulations of the divergence angle of the light, thereby improving the resolution of the corresponding viewpoint entering the human eye, and then improving the display resolution.

[0067] In the above embodiment, since the distance between the highest point of the lens array 2 and the display component 1 is equal to the focal length of the lens array 2, the divergence angle of the light emitted by the display component 1 is adjusted once, and the above-mentioned divergence angle is adjusted to the minimum. In order to further modulate the divergence angle, the present application is provided with a main lens 3 on the side of the lens array 2 away from the display component 1, wherein, preferably, the main lens 3 has a fixed focal length, and the distance between the highest point of the lens array 2 and the main lens 3 is less than the focal length of the main lens 3, so as to achieve secondary focusing of the light emitted by the lens array 2, wherein a single lens in the lens array 2 uses a smaller aperture to further reduce the spot diameter of the light generated by the lens array 2 on the main lens 3, thereby improving the light field display resolution; further, in order to modulate the divergence angle of the light emitted by the lens array 2 to the minimum, preferably, the distance between the highest point of the lens array 2 and the main lens 3 is equal to the focal length of the main lens 3.

[0068] According to one embodiment of the present invention, the dimensions of the lens array 2 are as follows:

[0069]

[0070] Where F' is the distance from the lens array to the main lens; L' is the depth of field of the main lens; θ is the divergence angle.

[0071] Furthermore, the size of the effective pixel area in the display component is as follows:

[0072]

[0073] Where D is the aperture of the lens; b x is the size of the lens array; N is the number of pixels covered by a single lens; p is the pixel spacing; and M is the resolution of a single viewpoint in the Y-axis direction.

[0074] In the aforementioned embodiment, preferably, the interval p between every two adjacent pixels in the display component 1 is less than or equal to 10 μm.

[0075] The following embodiment uses the example where the lens array 2 is a microlens array 2, and the distance between the highest point of the lens array 2 and the display assembly 1 is set to be equal to the focal length of the lens array 2; and the distance between the highest point of the lens array 2 and the main lens 3 is set to be equal to the focal length of the main lens 3 to explain the display principle.

[0076] In the aforementioned embodiment, the light field display angular resolution α can be described by the divergence angle θ of the light spot presented on the main lens 3 relative to the human eye, and the corresponding relationship is as follows:

[0077]

[0078] Wherein, D is the aperture of a single lens in the lens array 2; F is the focal length of the main lens 3.

[0079] According to the above formula, it can be seen that the ratio between the aperture of a single lens in the lens array 2 and the focal length of the main lens 3 determines the size of the divergence angle θ after modulation by the main lens 3. Since the light field display angular resolution α is equal to the divergence angle θ after modulation by the main lens 3, the above ratio will determine the size of the light field display angular resolution α. ​​In theory, the smaller the divergence angle θ after modulation, the higher the corresponding light field display angular resolution α. ​​However, when the light field display angular resolution α is 1 arc minute, it has reached the resolution limit of the human eye's retina. Therefore, in order to ensure the highest light field display resolution within the visible range of the human eye, the corresponding light field display angular resolution α has a value range of greater than or equal to 1 arc minute.

[0080] Under the above conditions, the conditions for clear imaging of the aforementioned light field display device are determined, and the specific process is as follows:

[0081] According to the Rayleigh criterion, the condition for adjacent light spots to be clearly distinguished is: the radius of the light spot r < the distance between adjacent light spots d, such as Figure 4 As shown, the microlens array emits light with a certain divergence angle, which is transmitted to the main lens surface to form a light spot with a diameter of ε. The main lens modulates the divergence angle of the received light, and the modulated divergence angle is θ = D / F. After transmitting a certain distance L', the resulting light spot diameter is 2r = ε + L'·D / F. Based on the object-image relationship, the spacing between adjacent light spots after modulation by the main lens can be obtained as d = L'·D / F.

[0082] At this time, according to r <d,可以确定经由所述透镜阵列传输至所述主透镜形成的光斑直径尺寸在如下范围内,从而使得前述光场显示器件清晰成像:

[0083]

[0084] Wherein, ε is the diameter of the light spot formed by the light transmitted to the main lens through the lens array; L' is the depth of field of the main lens; F is the focal length of the main lens; and D is the aperture of the lens.

[0085] When the main ray is used to represent the light, it can be expressed according to Figure 1 The relationship between the device parameters is derived as follows:

[0086]

[0087]

[0088] Among them, F is the focal length of the main lens; f is the focal length of the microlens; D is the aperture of a single lens in the microlens array; p is the pixel spacing; e is the size of the eye movement range; N is the number of viewpoints in the eye movement range; l is the exit pupil distance.

[0089] In summary, the aperture of a single lens in the microlens array can be determined according to formula (2), and the depth of field L' of the main lens can be calculated according to L'=F*l / (FI). Substituting the calculated value into the above formula, the clear imaging condition of the light field display device can be determined.

[0090] More specifically, Figure 5 As shown, the spot diameter ε formed by the light transmitted to the main lens through the lens array is as follows:

[0091]

[0092] Where m is the pixel opening and λ is the wavelength of light.

[0093] According to the above formula, the size of the spot diameter ε formed by the current light transmitted through the lens array to the main lens can be calculated, and it can be determined whether the current spot diameter ε is smaller than the condition for clear imaging of the light field display device. If it is larger, the parameters between the relevant devices need to be adjusted until they are adjusted to meet the conditions for clear imaging of the aforementioned light field display device.

[0094] At the same time, according to the above correspondence, the aperture size of a single lens in the lens array can be determined as follows:

[0095]

[0096] Where D is the aperture of the lens; m is the pixel opening; e is the eye movement range; λ is the wavelength; L' is the depth of field of the main lens; and F is the focal length of the main lens.

[0097] For ease of understanding, the following description will be given in the form of specific embodiments. Figure 8 As shown, two or more viewpoints in the pupil can render a light field image. The size of the human pupil is generally about 4 mm. The viewpoint interval is 2 mm to ensure that there are two 2D viewpoints 6 in the pupil. The eye movement range e is designed to be 8 mm, that is, it is determined that 5*5 2D viewpoints 6 are included in the eye movement range; using a pixel interval p of 8.5 μm, it can be determined by substituting it into the above formula that the size of the effective pixel area in the display component 1 is 80*80 mm, and a near-eye light field display model is designed based on this LCD black and white screen, so that the 5*5 2D viewpoints 6 are evenly arranged in the eye movement range; wherein, the main lens 3 uses a VR lens, the focal length F is 40 mm, the aperture of the main lens 3 is 40 mm, the field of view angle β of the main lens 3 is 90°*90°, the exit pupil distance l is 20 mm, and the pixel opening m is 3 μm*3 μm.

[0098] According to formula (1) and formula (2), the focal length f of a single lens in lens array 2 can be calculated to be 212.5 μm; the size D is 42.39 μm; according to the above formula, the lateral angular resolution α of the light field display can be calculated to be approximately 3.6 arc minutes; and the depth of field range for clear imaging of 3.6 arc minutes can be calculated to be 0.8 m to infinity;

[0099] The following table shows the detailed device parameters:

[0100] Screen size c Pixel spacing p Pixel opening m Lens array focal length f Main lens aperture a Main lens focal length F 80*80mm 8.5um 3um*3um f=212.5um 40mm 40mm

[0101] The following is the light field effect obtained:

[0102] Eye movement range Number of viewpoints N Angular resolution α Field of view β 8*8mm 5*5 3.6 arc minutes 90°*90°

[0103] Yet another embodiment

[0104] Compared with the light field display device provided in one embodiment, the light field display device provided in this embodiment has the following differences: Figure 9 As shown, the lens array 2 is set to a cylindrical lens array 2. In the aforementioned embodiment, due to the use of the microlens array 2 design, it can be modulated in both the X-axis direction and the Y-axis direction, but the modulation direction that can be observed by the human eye is only the X-axis direction, which causes the resolution of the display component 1 in the Y-axis direction to be sacrificed, resulting in the light field display resolution in this application not being significantly improved; in order to solve the above technical problems, in this embodiment, the lens array 2 is set to a cylindrical lens array 2, so that it is modulated only in the X-axis direction that can be observed by the human eye, thereby achieving the goal of providing horizontal parallax images only in the direction of the human eye, and not providing horizontal parallax images in the Y-axis direction which is not a modulated direction, that is, without sacrificing the resolution of the display component 1 in the Y-axis direction, thereby further improving the light field display resolution.

[0105] According to one embodiment of the present invention, the size of the lens array 2 in the Y-axis direction is equal to the size of the effective pixel area in the display component 1 in the Y-axis direction;

[0106] And, the dimensions of the lens array 2 in the X-axis direction are as follows:

[0107]

[0108] Where F' is the distance from the lens array to the main lens; L' is the depth of field of the main lens; θ is the divergence angle.

[0109] According to one embodiment of the present invention, Figure 7 As shown, the size of the effective pixel area in the display component in the X-axis direction is as follows:

[0110]

[0111] Furthermore, the size of the effective pixel area in the Y-axis direction of the display component is as follows:

[0112] c y =p·M;

[0113] Where D is the aperture of the lens; b x is the size of the lens array in the X-axis direction; N is the number of pixels covered by a single lens; p is the pixel spacing; and M is the resolution of a single viewpoint in the Y-axis direction.

[0114] For example, the color pixel arrangement of the display component is as follows Figure 7 As shown, when the 2D viewpoints are distributed in the x direction, the pixel spacing p=N*px=3*py, where px and py are the sizes of a single sub-pixel in the x and y directions respectively, and N is the number of 2D viewpoints in the x direction.

[0115] Yet another embodiment

[0116] Compared with the light field display device provided in yet another embodiment, the light field display device provided in this embodiment has the following differences:

[0117] When the distance between the lens array and the main lens is smaller than the focal length of the main lens, the divergence angle θ1 after secondary modulation by the main lens is greater than the divergence angle θ2 after secondary modulation by the main lens when the distance between the lens array and the main lens is set to be equal to the focal length of the main lens. This will result in the corresponding optical display resolution α1 when the distance between the lens array and the main lens is smaller than the focal length of the main lens being smaller than the corresponding optical display resolution α2 when the distance between the lens array and the main lens is smaller than the focal length of the main lens, resulting in the optical display resolution being lower in this embodiment and failing to achieve the optimal effect.

[0118] Therefore, in order to solve the above technical problems, in this embodiment, Figure 10-11 As shown, when the distance between the lens array 2 and the main lens 3 is smaller than the focal length of the main lens 3, the main lens 3 is designed to have a variable focal length; specifically, during the adjustment process, it is only necessary to reduce the focal length of the main lens 3 accordingly until the distance between the lens array 2 and the main lens 3 is adjusted to a position equal to the focal length of the main lens 3, so as to adjust the optical display resolution to the optimal value.

[0119] For ease of understanding, the following specific embodiments are described by exemplifying the main lens 3 as a plano-convex lens. Specifically, the side close to the lens array 2 is set to a planar structure, and the side away from the lens array 2 is set to a curved structure.

[0120] In a specific embodiment, the light field display device further comprises an adjusting structure, the main lens 3 is installed in the adjusting structure, and the main lens 3 is made of an electrostrictive material, and the adjusting structure deforms the main lens 3 in a direction of reducing the arch height of the main lens 3 under the control of the field.

[0121] For example, the electrostrictive material can be polyurethane, polyvinylidene fluoride or the like, which can be deformed under the control of the field; and the main lens 3 is correspondingly installed on the adjusting structure; wherein the adjusting structure deforms the main lens 3 in a direction of reducing the arch height of the main lens 3 under the control of the field, preferably, the field is set as an electric field, and of course, it can also be set as a magnetic field, as long as the field can realize the deformation of the main lens 3. In order to facilitate understanding, the field is set as an electric field and is described in detail below.

[0122] Further, in order to ensure accurate control of the main lens 3, the shape of the adjusting structure is matched with the shape of the main lens 3, preferably, as shown in Figure 11 the embodiment, the main lens 3 is set as a cylindrical convex lens structure, therefore, correspondingly, the adjusting structure is set as a cylinder, of course, the shape of the main lens 3 and the corresponding shape of the adjusting structure are not limited to the above cylindrical structure, and other structures such as square, hexagonal structure can also be used, and the shape is not limited in the embodiment.

[0123] In order to adjust the distance between the highest point of the cylindrical lens array 2 and the main lens to the focal length position of the main lens, so as to further reduce the divergence angle of the light emitted by the cylindrical lens array 2, the embodiment proposes that the main lens 3 is made of an electrostrictive material, and correspondingly, an adjusting structure is arranged on the main lens 3, and the field generated by the adjusting structure reduces the arch height of the main lens 3 in the vertical direction, so as to reduce the focal length of the main lens 3 to a position equal to the distance between the highest point of the cylindrical lens array 2 and the main lens; specifically, when the field is negative, the main lens 3 will deform along the vertical direction to reduce the arch height in the vertical direction, and then reduce the focal length of the main lens 3; with the change of the field intensity, the deformation degree of the main lens 3, that is, the arch height, also changes correspondingly; specifically, with the increase of the field intensity, the deformation degree of the main lens 3 is larger, the arch height is reduced more, and the focal length of the main lens 3 is reduced smaller.

[0124] In a preferred embodiment, as shown in the figure, the adjusting structure comprises: a first driving electrode 9 and a second driving electrode 10 which are spaced apart by a support structure 8, and the main lens 3 is installed in the space formed between the first driving electrode 9 and the second driving electrode 10.

[0125] During operation, an electric field with adjustable strength is generated between the first drive electrode 9 and the second drive electrode 10. This electric field penetrates the main lens 3 made of a high-transmittance electrostrictive material, causing the main lens 3 to deform along the direction of the electric field. In this embodiment, in order to change the vertical arch height of the main lens 3, the first drive electrode 9 and the second drive electrode 10 are spaced apart along the vertical direction by the support structure 8. For ease of understanding, the direction in which the second drive electrode 10 diverges the electric field toward the first drive electrode 9 is set to be opposite. When the focal length of the main lens 3 needs to be reduced, it is only necessary to reduce the arch height of the main lens 3. In this case, it is sufficient to ensure that the second drive electrode 10 diverges a negative electric field toward the first drive electrode 9. In this case, under the action of the negative electric field, the main lens 3 will deform in the vertical direction in the direction of decreasing the arch height, thereby reducing the focal length of the main lens 3.

[0126] According to one embodiment of the present invention, as shown in the figures and the figures, a focusing structure is further provided on the outer side of the main lens 3, and the focusing structure corresponds to the adjustment structure and is used to prevent the main lens 3 from diffusing. Specifically, in this solution, the initial state of the main lens 3 is a droplet, and it is printed onto the corresponding first driving electrode 9 through printing technology, and finally the main lens 3 is formed by solidification. In order to avoid the main lens 3 from diffusing during the printing process and affecting the molding of the main lens 3, this solution adds a focusing structure to circumvent the above technical problem.

[0127] In one embodiment, the aggregate structure comprises:

[0128] The focusing structure includes a first wire electrode 11 and a second wire electrode 12 that match each other. The second wire electrode 12 is staggered above the first wire electrode 11 . The main lens 3 is installed in the area formed by the staggered first and second wire electrodes 11 and 12 .

[0129] In another embodiment, the aggregation structure is configured as a hydrophobic layer, and the hydrophobic layer is disposed on the side wall surface of the support structure 8 close to the primary lens 3; so that the surface tension of the side wall surface and the lower wall surface of the support structure 8 close to the primary lens 3 are different, thereby ensuring that the droplets of the primary lens 3 are aggregated between two adjacent support columns and will not remain on the side wall surface of the support structure 8, thereby ensuring the molding effect of the primary lens 3.

[0130] In one embodiment, the focusing structure includes: a micro-nano structure composed of two spaced-apart protrusion structures. Under the focusing effect of the micro-nano structure, the droplets of the main lens 3 will be gathered on the micro-nano structure without diffusion, thereby ensuring the forming effect of the droplets. Among them, the specific micro-nano structure can be selected from micro-nano gratings, pits, protrusions and other structures. In this embodiment, micro-nano gratings are preferably selected.

[0131] Each embodiment in this specification is described in a progressive manner. Some embodiments focus on the differences from other embodiments, and the same or similar parts between the embodiments can be referenced to each other.

[0132] It should be noted that, in the specification and claims of this application and the above-mentioned drawings, relational terms such as "first" and "second" are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or specific order or precedence between these entities or operations. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of the present application described herein can, for example, be implemented in an order other than those illustrated or described herein.

[0133] Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, or any other variants thereof, are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also includes other elements not expressly listed or that are inherent to such process, method, article, or apparatus. For example, a process, method, system, product, or apparatus that includes a list of steps or units is not necessarily limited to those steps or units expressly listed but may include other steps or units not expressly listed or that are inherent to such process, method, product, or apparatus. In the absence of further limitations, an element limited by the phrase "comprising a . . . ." does not preclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0134] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figures. For example, if the device in the drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0135] The above is only a specific embodiment of the present application, so that those skilled in the art can understand or implement the present application. Various modifications and variations to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features applied for herein.

Claims

1. A light field display device, characterized in that: include: A display assembly, wherein a lens array and at least one main lens are sequentially arranged along a light emitting direction of the display assembly, wherein the distance between the highest point of the lens array and the display assembly is equal to the focal length of the lens array; and the distance between the highest point of the lens array and the main lens is less than the focal length of the main lens; The lens array is configured as a cylindrical lens array; The light field display device further includes an adjustment structure, in which the main lens is mounted. The main lens is made of an electrostrictive material. Under the action of the adjustment structure, the field controls the main lens to deform in a direction of reducing its arch height.

2. The light field display device according to claim 1, characterized in that The lens array is mounted on the light-emitting side of the display assembly through a spacer layer.

3. The light field display device according to claim 2, characterized in that The refractive index of the spacer layer is equal to the refractive index of the lens array.

4. The light field display device according to claim 2, characterized in that The main lens is spaced apart from the lens array via a mounting frame.

5. The light field display device according to claim 1, characterized in that The main lens can at least be configured as a plano-convex lens or a biconvex lens.

6. The light field display device according to claim 1, characterized in that The field angle β of the main lens ranges from 90° to 100°; the aperture of the main lens is less than or equal to 50 mm; and the focal length of the main lens is less than or equal to 40 mm.

7. The light field display device according to claim 6, characterized in that: The diameter range of the light spot formed by the lens array and transmitted to the main lens is as follows: Wherein, ε is the diameter of the light spot formed by the light transmitted to the main lens through the lens array; L' is the depth of field of the main lens; F is the focal length of the main lens; and D is the aperture of a single lens in the lens array.

8. The light field display device according to claim 7, characterized in that: The aperture size of a single lens in the lens array is as follows: Where D is the aperture of the lens; m is the pixel opening; e is the eye movement range; λ is the wavelength of light emitted from the display component; L' is the depth of field of the main lens; and F is the focal length of the main lens.

9. The light field display device according to claim 8, characterized in that: The aperture of the main lens is as follows: Where a is the aperture of the main lens; l is the exit pupil distance; β is the field of view of the main lens.

10. The light field display device according to claim 9, characterized in that: The size of the lens array in the Y-axis direction is equal to the size of the effective pixel area in the display component in the Y-axis direction; And, the dimensions of the lens array in the X-axis direction are as follows: Wherein, F' is the distance from the lens array to the main lens; L' is the depth of field of the main lens; θ is the divergence angle of the light spot on the main lens relative to the human eye.

11. The light field display device according to claim 10, characterized in that: The interval p between two adjacent pixels in the display component is less than or equal to 10 μm.

12. A light field display system, characterized in that: The light field display device according to any one of claims 1 to 11.

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