Near-eye display device
By employing a defocused lens design in the VR display device, including a combination of a central area and microlenses, the problem of axial elongation during use by nearsighted individuals is solved, achieving clear vision and slowing down the progression of myopia.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- INTERFACE ADVANCED TECH (CHENGDU) CO LTD
- Filing Date
- 2024-11-29
- Publication Date
- 2026-06-04
AI Technical Summary
When existing VR display devices are designed for nearsighted people, although adding nearsighted lenses can ensure clear vision in the center, the image light falls on the back of the peripheral retina, causing the axial length of the eye to grow and thus accelerating the development of myopia.
It adopts a defocus lens design, including a central area and microlenses surrounding the central area. The central area focuses the image light onto the retina, and the microlenses focus the image light in front of the retina. The combination of the light guiding module and the defocus lens ensures clear vision and reduces axial strain.
It effectively reduces stimulation to the axial length of the eye and lowers the probability of myopia progression, especially for people with myopia who use it to help slow down the progression of myopia.
Smart Images
Figure CN2024135767_04062026_PF_FP_ABST
Abstract
Description
Near-eye display device Technical Field
[0001] This application relates to a near-eye display device. Background Technology
[0002] With technological advancements, Virtual Reality (VR) technology is being applied to various fields, such as gaming, education, healthcare, and retail. Common optical design solutions for VR display devices currently on the market include aspherical lens designs, Fresnel lens designs, and pancake optical path designs. The surge in myopia among the population necessitates that VR display devices also meet the needs of this demographic.
[0003] Currently, most VR display devices on the market address the needs of nearsighted individuals by adding concave lenses to the optical path. However, with the addition of these lenses, the image light emitted from the VR display device is focused behind the retina of the nearsighted person due to the diverging effect of the lenses. When a nearsighted person wears such a VR display device, although the central image light falls on the center of the retina to ensure clear vision, some image light falls behind the peripheral retina. This continuously stimulates the growth of the axial length of the eye, thus accelerating the progression of myopia. Summary of the Invention
[0004] The first aspect of this application provides a near-eye display device, comprising:
[0005] Display screen, used to emit image light;
[0006] A light guiding module is used to receive and guide the image light;
[0007] A defocus lens is used to receive the image light emitted from the light guiding module and project the image light to the human eye. The defocus lens includes a first defocus surface and a second defocus surface. The first defocus surface protrudes towards the direction of the display screen. A central area located at the center of the first defocus surface and a plurality of microlenses surrounding the central area are disposed on the first defocus surface. Each microlens protrudes towards the direction of the display screen.
[0008] The central region is used to receive a portion of the image light and focus the portion of the image light onto the retina of the human eye, and the plurality of microlenses are configured to focus a portion of the image light incident outside the central region onto the front of the retina of the human eye.
[0009] The near-eye display device provided in this application embodiment, by setting a defocus lens, has a central area located at the center of the first defocus surface of the defocus lens and a plurality of microlenses surrounding the central area. Each microlens protrudes towards the display screen. The central area is used to receive a portion of the image light and focus the portion of the image light onto the retina of the human eye. The plurality of microlenses are configured to focus a portion of the image light incident outside the central area onto the retina of the human eye. This allows a portion of the image light incident from the display screen through the light guiding module onto the central area to be focused onto the retina, and a portion of the image light incident outside the central area to be focused onto the retina of the human eye. Under the premise of ensuring clear vision, this can effectively reduce the stimulation of the eye axis, thereby helping to reduce the probability of stimulating the eye axis to elongate. When myopic people use the above-mentioned near-eye display device, it helps to slow down the progression of myopia.
[0010] In one embodiment, the light guiding module includes a semi-reflective and semi-transparent film, a first lens, and a composite film layer arranged sequentially along the optical path of the image light;
[0011] The first lens includes a first surface and a second surface. The semi-reflective and semi-transparent film is attached to the first surface and is used to partially transmit and partially reflect the image light. The composite film layer is attached to the second surface and is used to receive and change the polarization state of the image light so that the image light exits to the defocus lens.
[0012] In one embodiment, the composite film layer includes a phase retardation layer and a reflective polarization layer disposed sequentially, the phase retardation layer being close to the second surface.
[0013] In one embodiment, the composite film layer further includes a linear polarization layer disposed between the reflective polarization layer and the defocus lens, wherein the penetration axis of the linear polarization layer is in the same direction as the penetration axis of the reflective polarization layer.
[0014] In one embodiment, the refractive index of the first lens is in the range of 1.3-2.1.
[0015] In one embodiment, the central region is circular in shape, and the diameter d1 of the central region satisfies: 0mm < d1 < 8mm.
[0016] In one embodiment, each of the microlenses is coated with an anti-reflection and anti-reflection film on the surface near the display screen. The anti-reflection and anti-reflection film is used to reduce the reflectivity of the image light on the microlens and increase the transmittance of the image light on the microlens.
[0017] In one embodiment, the projection of each microlens along the optical axis is circular, and the plurality of microlenses are randomly arranged on the first defocus surface.
[0018] In one embodiment, the density of the microlenses disposed on the first defocusing surface gradually increases in the direction away from the central region.
[0019] In one embodiment, the diameter d2 of each microlens satisfies: 0 mm < d2 < 3 mm.
[0020] In one embodiment, the projection of each microlens along the optical axis is annular, and a plurality of microlenses are concentrically nested around the central region, with the spacing between two adjacent microlenses gradually decreasing in the direction away from the central region.
[0021] In one embodiment, the defocusing amount of each microlens ranges from 2.0D to 5.0D.
[0022] In one embodiment, a first adhesive layer is provided between the light guiding module and the defocus lens. The first adhesive layer fills the space between the first defocus surface and the light guiding module to bond the light guiding module and the defocus lens.
[0023] In one embodiment, the refractive index of the defocused lens is in the range of 1.3-2.1. Attached Figure Description
[0024] [Revised according to Article 91, 22.01.2025] Figure 1 is a schematic diagram of the structure of a near-eye display device according to an embodiment of this application.
[0025] [Revised according to Article 91, 22.01.2025] Figure 2 is a schematic diagram of the optical path of a near-eye display device according to an embodiment of this application.
[0026] [Revised according to Article 91, 22.01.2025] Figure 3 is a schematic diagram of the structure of a defocus lens according to an embodiment of this application.
[0027] [Revised according to Article 91, 22.01.2025] Figure 4 is a schematic diagram of the structure of a microlens according to an embodiment of this application.
[0028] [Revised according to Article 91, 22.01.2025] Figure 5 is a schematic diagram of the structure of a defocus lens according to another embodiment of this application. [0028.1] [Correction 22.01.2025 according to Article 91] Figure 6 is a graph of the near-eye display device according to an embodiment of the present application, which simulates the change of virtual image distance of the human eye under different field of view angles.
[0029] Key component symbols: Near-eye display device 100 Display screen 1 Light guiding module 2 First lens 21 First surface 211 Second surface 213 Semi-reflective and semi-transparent film 22 Composite film layer 23 Phase retardation layer 231 Reflective polarization layer 233 Linear polarization layer 235 Defocus lens 4 First defocus surface 41 Central area 411 Microlens 413 Anti-reflection and anti-reflection film 413a Second defocus surface 43 First adhesive layer 5 Image light L1 Human eye E Retina E1
[0030] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation
[0031] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.
[0032] It should be noted that when a component is referred to as being "fixed to" or "mounted to" another component, it can be directly on the other component or there may be an intervening component. When a component is considered to be "set on" another component, it can be directly set on the other component or there may be an intervening component. The term "and / or" as used herein includes all and any combination of one or more of the associated listed items. The terminology used in this application's specification is for the purpose of describing particular embodiments only and is not intended to be limiting of this application.
[0033] To further illustrate the technical means and effects adopted by this application in achieving its intended purpose, the following detailed description of this application is provided in conjunction with the accompanying drawings and preferred embodiments.
[0034] Referring to Figures 1 and 2, the near-eye display device 100 of this embodiment includes a display screen 1, a light guiding module 2, and a defocusing lens 4. The display screen 1 emits image light L1. The light guiding module 2 is disposed between the display screen 1 and the defocusing lens 4, and is used to receive and guide the image light L1. The defocusing lens 4 receives the image light L1 emitted from the light guiding module 2 and projects the image light L1 onto the human eye E.
[0035] The display screen 1 is located on the side of the light guiding module 2 away from the defocusing lens 4. The display screen 1 can be any one of the following: liquid crystal display screen 1, fast response liquid crystal display screen 1, silicon-based liquid crystal display screen 1, micro light-emitting diode display screen 1, digital light processing display, laser beam scanning display, active matrix organic light-emitting diode display screen 1, and silicon-based organic light-emitting diode display screen 1. This application does not impose any restrictions.
[0036] In this embodiment, the near-eye display device 100 is a virtual reality head-mounted display device. The light guiding module 2 includes a first lens 21, a semi-reflective and semi-transparent film 22, and a composite film layer 23 arranged sequentially along the optical path of the image light L1. In other embodiments, the light guiding module 2 may also include a Fresnel lens or a freeform mirror disposed in the optical path of the image light L1, and the near-eye display device 100 may also be a mixed reality head-mounted display device; this application does not impose any limitations.
[0037] Specifically, the first lens 21 is used to receive and guide the image light L1. The refractive index of the first lens 21 is in the range of 1.3-2.1. More specifically, the refractive index of the first lens 21 can be any value in the range of 1.3-1.5, 1.5-1.7, 1.7-1.9, or 1.9-2.1, and this application does not impose any limitation. The first lens 21 includes a first surface 211 and a second surface 213. In this embodiment, both the first surface 211 and the second surface 213 are convex surfaces, and both are aspherical surfaces. That is, the first lens 21 is a biconvex aspherical mirror. The radius of curvature of the first lens 21 ranges from 20mm to 5000mm. Specifically, the radius of curvature of the first lens 21 can be any value within the ranges of 20mm-100mm, 100mm-1000mm, 1000mm-2000mm, 2000mm-3000mm, 3000mm-4000mm, or 4000mm-5000mm, and this application does not impose any limitation. The material of the first lens 21 can be either glass or plastic. For example, the material of the first lens 21 can be quartz glass, and this application does not impose any limitation. The first surface 211 or the second surface 213 of the first lens 21 may also be provided with an optical coating (not shown). The refractive index of the optical coating is between the refractive index of the first lens 21 and the refractive index of the defocus lens 4, used to achieve a transition in refractive index. The optical coating can be an anti-reflective layer, an anti-fouling layer, etc., and this application does not limit it.
[0038] A semi-reflective membrane 22 is attached to the first surface 211. The semi-reflective membrane 22 is used to partially transmit and partially reflect image light L1. Specifically, in this embodiment, the semi-reflective membrane 22 has a transmittance of 50% and a reflectance of 50% for image light L1; in other embodiments, the semi-reflective membrane 22 may have a transmittance of 60% and a reflectance of 40% for image light L1. The semi-reflective membrane 22 only needs to partially transmit and partially reflect image light L1, and this application does not impose any limitations.
[0039] The composite film layer 23 is attached to the second surface 213 and is used to receive and change the polarization state of the image light L1 so that the image light L1 exits to the defocus lens 4. Specifically, the composite film layer 23 includes a phase retardation layer 231, a reflective polarization layer 233, and a linear polarization layer 235 arranged sequentially. The phase retardation layer 231 is close to the second surface 213. The linear polarization layer 235 is disposed between the reflective polarization layer 233 and the defocus lens 4. The transmission axis of the linear polarization layer 235 is in the same direction as the transmission axis of the reflective polarization layer 233. The linear polarization layer 235 is used to allow light with a specific polarization direction to pass through. By setting the transmission axis of the linear polarization layer 235 to be in the same direction as the transmission axis of the reflective polarization layer 233, the image light L1 exiting from the reflective polarization layer 233 can pass through the linear polarization layer 235 and enter the human eye E, while filtering out other stray light.
[0040] In this embodiment, the image light L1 is circularly polarized, meaning that the polarization state of the image light L1 is circularly polarized. For example, the image light L1 can be left-handed or right-handed circularly polarized light. The image light L1 passes through the first lens 21 and is incident on the semi-reflective film 22. When incident on the semi-reflective film, half of the energy of the image light L1 passes through the semi-reflective film and is incident on the composite film layer 23. After image light L1 is incident on the composite film layer 23, the phase retardation layer 231 converts image light L1 from a circularly polarized state to a linearly polarized state. The image light L1 passing through the phase retardation layer 231 for the first time is reflected by the reflective polarization layer 233. After passing through the phase retardation layer 231 for the second time, it is again incident on the semi-transparent and semi-reflective film. A portion of the image light L1 (at this point, the energy of image light L1 is one-quarter of that before it entered the first lens 21) is reflected back to the composite film layer 23 by the semi-transparent and semi-reflective film. After passing through the phase retardation layer 231 for the third time, the linearly polarized image light L1 continues to pass through the reflective polarization layer 233 and then through the linearly polarized layer 235, which is aligned with the penetration axis of the reflective polarization layer 233, and finally enters the human eye E. In other embodiments, image light L1 can also be linearly polarized; this application does not impose any limitations.
[0041] A first adhesive layer 5 is disposed between the light guiding module 2 and the defocusing lens 4. The first adhesive layer 5 fills the space between the first defocusing surface 41 and the light guiding module 2 to bond the light guiding module 2 and the defocusing lens 4. Specifically, the first adhesive layer 5 can be any one of optically clear adhesive (OCA) or liquid optical clear adhesive (LOCA), and this application is not limited thereto. By providing the first adhesive layer 5, which fills the space between the first defocusing surface 41 and the light guiding module 2, the light guiding module 2 and the defocusing lens 4 can be bonded more firmly.
[0042] Please refer to Figures 1, 3, and 4 together. The defocus lens 4 includes a first defocus surface 41 and a second defocus surface 43. The defocus lens 4 is used to receive the image light L1 emitted from the light guiding module 2 and project the image light L1 to the human eye E. The refractive index of the defocus lens 4 is in the range of 1.3-2.1. Specifically, the refractive index of the defocus lens 4 can be any value in the range of 1.3-1.5, 1.5-1.7, 1.7-1.9, or 1.9-2.1, and this application does not impose any limitation. Both the first defocusing surface 41 and the second defocusing surface 43 protrude towards the direction close to the display screen 1, and both the first defocusing surface 41 and the second defocusing surface 43 are aspherical, that is, the defocusing lens 4 is a biconvex aspherical mirror. The radius of curvature of the defocusing lens 4 is in the range of 20mm-5000mm. Specifically, the radius of curvature of the defocusing lens 4 can be any value in the range of 20mm-100mm, 100mm-1000mm, 1000mm-2000mm, 2000mm-3000mm, 3000mm-4000mm, or 4000mm-5000mm, etc., and this application does not impose any limitation. Specifically, the material of the defocusing lens 4 can be either glass or plastic. For example, the material of the defocusing lens 4 can be quartz glass, and this application does not impose any limitation. The first defocusing surface 41 and the second defocusing surface 43 of the defocusing lens 4 may also be provided with an optical coating (not shown). The refractive index of the optical coating is between the refractive index of the first lens 21 and the refractive index of the defocusing lens 4, so as to achieve a transition of refractive index. The optical coating can be an anti-reflection layer, an anti-fouling layer, etc., and this application does not limit it.
[0043] Specifically, the first defocusing surface 41 is provided with a central region 411 located at the center of the first defocusing surface 41 and a plurality of microlenses 413 surrounding the central region 411. The central region 411 is used to receive a portion of the image light L1 and focus a portion of the image light L1 onto the retina E1 of the human eye E. The plurality of microlenses 413 are configured to focus a portion of the image light L1 incident outside the central region 411 onto the front of the retina E1 of the human eye E.
[0044] In this embodiment, the central region 411 is circular in shape; in other embodiments, the central region 411 may also be rectangular, triangular, polygonal or other irregular shapes, as long as the central region 411 can receive image light L1 and focus image light L1 onto the retina E1 of the human eye E, this application does not impose any restrictions.
[0045] The diameter d1 of the central region 411 satisfies the condition: 0mm < d1 < 8mm, meaning the diameter d1 of the central region 411 is greater than 0mm and less than 8mm. Specifically, the diameter d1 of the central region 411 can be any value within the range of 0.1mm-1mm, 1mm-3mm, 3mm-5mm, 5mm-7mm, or 7mm-8mm, and this application does not impose any restrictions on this. By setting a central region 411 of a suitable size, it is beneficial to focus the image light L1 of appropriate intensity onto the retina E1 of the human eye E. To improve the light transmittance of the central region 411, the central region 411 can also be coated with an antireflection film to further improve the transmittance of the image light L1 (not shown in the figure), and this application does not impose any restrictions on this.
[0046] Each microlens 413 protrudes towards the display screen 1. Each microlens 413 has an anti-reflection coating 413a deposited on its surface near the first lens 21. The anti-reflection coating 413a reduces the reflectivity of image light L1 on the microlens 413 and increases the transmittance of image light L1 on the microlens 413. The defocusing amount of each microlens 413 ranges from 2.0D to 5.0D. Specifically, the defocusing amount of each microlens 413 can be any value within the range of 2.0D-3.0D, 3.0D-4.0D, or 4.0D-5.0D; this application does not impose any limitation on this.
[0047] In this embodiment, the projection of each microlens 413 along the optical axis is circular, and multiple microlenses 413 are randomly arranged on the first defocus surface 41. The density of the microlenses 413 disposed on the first defocus surface 41 gradually increases in the direction away from the central region 411. By setting the density of the microlenses 413 on the first defocus surface 41 to gradually increase in the direction away from the central region 411, the overall defocus amount of the defocus lens 4 gradually increases with the density of the microlenses 413 in the direction away from the central region 411. That is, the defocus amount of the outer periphery of the defocus lens 4 is greater than the defocus amount of the inner periphery of the defocus lens 4. This allows the focusing position of the image light L1 incident from the defocus lens 4 to the human eye E to adapt to the shape of the human eye E, thereby further reducing the probability of stimulating axial elongation and helping to slow down the progression of myopia in the human eye E.
[0048] The diameter d2 of each microlens 413 satisfies the following condition: 0 mm < d2 < 3 mm. Specifically, the diameter d2 of each microlens 413 can be any value within the range of 0.1 mm - 1 mm, 1 mm - 2 mm, or 2 mm - 3 mm, and this application does not impose any restrictions on this.
[0049] Please refer to Figures 1, 4, and 5 together. In another embodiment, the projection of each microlens 413 along the optical axis can also be annular. Multiple microlenses 413 are concentrically nested around the central region 411, and the spacing between two adjacent microlenses 413 gradually decreases in the direction away from the central region 411. By providing a central region 411 and multiple microlenses 413 on the first defocusing surface 41 of the defocusing lens 4, the central region 411 is used to receive image light L1 and focus the image light L1 onto the retina E1 of the human eye E. The multiple microlenses 413 are configured to simultaneously focus the incident image light L1 onto the front of the retina E1 of the human eye E. Please refer to Figure 6. Figure 6 shows the curve of the near-eye display device 100 in this embodiment simulating the change of the virtual image distance of the human eye E under different field of view angles. The virtual image distance under different field of view angles decreases as the absolute value of the field of view angle increases. That is, the distance between the projected virtual image and the pupil of the human eye first increases and then decreases. Thus, it can be seen that part of the image light L1 emitted from the near-eye display device 100 can be focused onto the retina E1, and part of the image light L1 is focused onto the front of the retina E1 of the human eye E. Under the premise that the human eye E can see clearly, the stimulation of the human eye E's axial length can be reduced more effectively, which is conducive to reducing the probability of stimulating the axial length to lengthen, and thus helps to slow down the progression of myopia in the human eye E.
[0050] Please refer to Figures 1 and 2 again. The near-eye display device 100 provided in this embodiment of the application includes a defocus lens 4. The first defocus surface 41 of the defocus lens 4 has a central region 411 located at the center of the first defocus surface 41 and a plurality of microlenses 413 surrounding the central region 411. Each microlens 413 protrudes towards the display screen 1. The central region 411 is used to receive a portion of the image light L1 and focus a portion of the image light L1 onto the retina E1 of the human eye E. The plurality of microlenses 413 are configured to focus the image light L1 outside the central region 411 onto the retina E1 of the human eye E. Image light L1 is focused in front of the retina E1 of the human eye E, so that part of the image light L1 incident from the display screen 1 through the light guiding module 2 to the central area 411 can be focused onto the retina E1, and part of the image light L1 incident outside the central area 411 is focused in front of the retina E1 of the human eye E. Under the premise of ensuring clear vision of the human eye E, the stimulation of the human eye E axis can be reduced more effectively, thereby helping to reduce the probability of stimulating the elongation of the eye axis. When myopic people use the above-mentioned near-eye display device 100, it helps to slow down the progression of myopia in the human eye E.
[0051] Those skilled in the art should recognize that the above embodiments are only used to illustrate this application and are not intended to limit this application. Any appropriate changes and variations made to the above embodiments within the essential spirit and scope of this application fall within the scope of protection claimed in this application.
Claims
1. A near-eye display device, characterized in that, include: Display screen, used to emit image light; A light guiding module is used to receive and guide the image light; A defocus lens is used to receive the image light emitted from the light guiding module and project the image light to the human eye. The defocus lens includes a first defocus surface and a second defocus surface. The first defocus surface protrudes towards the direction of the display screen. A central area located at the center of the first defocus surface and a plurality of microlenses surrounding the central area are disposed on the first defocus surface. Each microlens protrudes towards the direction of the display screen. The central region is used to receive a portion of the image light and focus the portion of the image light onto the retina of the human eye, and the plurality of microlenses are configured to focus a portion of the image light incident outside the central region onto the front of the retina of the human eye.
2. The near-eye display device as described in claim 1, characterized in that, The light guiding module includes a semi-reflective and semi-transparent film, a first lens, and a composite film layer arranged sequentially along the optical path of the image light. The first lens includes a first surface and a second surface. The semi-reflective and semi-transparent film is attached to the first surface and is used to partially transmit and partially reflect the image light. The composite film layer is attached to the second surface and is used to receive and change the polarization state of the image light so that the image light exits to the defocus lens.
3. The near-eye display device as described in claim 2, characterized in that, The composite film layer includes a phase retardation layer and a reflective polarization layer arranged sequentially, with the phase retardation layer close to the second surface.
4. The near-eye display device as described in claim 3, characterized in that, The composite film layer further includes a linear polarization layer, which is disposed between the reflective polarization layer and the defocus lens, and the transmission axis of the linear polarization layer is in the same direction as the transmission axis of the reflective polarization layer.
5. The near-eye display device as described in claim 2, characterized in that, The refractive index of the first lens is in the range of 1.3-2.
1.
6. The near-eye display device as claimed in claim 1, characterized in that, The central region is circular in shape, and the diameter d1 of the central region satisfies: 0mm < d1 < 8mm.
7. The near-eye display device as claimed in claim 1, characterized in that, Each of the microlenses has an anti-reflection coating deposited on the surface near the display screen. The anti-reflection coating is used to reduce the reflectivity of the image light on the microlens and increase the transmittance of the image light on the microlens.
8. The near-eye display device as claimed in claim 1, characterized in that, Each of the microlenses projects a circle along the optical axis, and the plurality of microlenses are randomly arranged on the first defocus surface.
9. The near-eye display device as claimed in claim 8, characterized in that, The density of the microlenses disposed on the first defocusing surface gradually increases in the direction away from the central region.
10. The near-eye display device as claimed in claim 8, characterized in that, The diameter d2 of each microlens satisfies: 0mm < d2 < 3mm.
11. The near-eye display device as claimed in claim 1, characterized in that, Each microlens projects into a ring shape along the optical axis, and multiple microlenses are concentrically nested around the central region, with the spacing between two adjacent microlenses gradually decreasing in the direction away from the central region.
12. The near-eye display device as claimed in claim 1, characterized in that, The defocusing range of each microlens is 2.0D-5.0D.
13. The near-eye display device as claimed in claim 1, characterized in that, A first adhesive layer is provided between the light guiding module and the defocus lens. The first adhesive layer fills the space between the first defocus surface and the light guiding module to bond the light guiding module and the defocus lens.
14. The near-eye display device as claimed in claim 1, characterized in that, The refractive index of the defocused lens is in the range of 1.3-2.1.