Near-eye display device

Abstract

The present disclosure provides a near-eye display device.The near-eye display device includes a waveguide, an out-coupling grating, a first zoom module and a control module. The waveguide includes a first surface and a second surface opposite to the first surface, wherein the waveguide is configured to transmit image light. The out-coupling grating is disposed on the first surface and configured to receive and out-couple the image light emitted from the waveguide. The first zoom module is disposed on the second surface and located in the optical paths of the image light and ambient light. The first zoom module is configured to receive the image light and the ambient light and direct them to a human eye. The control module is configured to adjust the diopter of the first zoom module to modify the focal positions of both the ambient light and the image light.

Description

[Technical Field]

[0001] This application relates to the field of near-eye display, and more particularly to a near-eye display device. [Previous Technology]

[0002] Near-eye display systems include augmented reality (AR) display systems, virtual reality (VR) display systems, mixed reality (MR) display systems, or extended reality (XR) display systems. AR display systems overlay and blend virtual scenes or information with the real environment, interactively presenting them to the user, thereby creating an environment where the virtual and real worlds share the same space.

[0003] However, users with refractive errors (such as those with myopia, hyperopia, and astigmatism) need to constantly adjust their eyes to focus on different positions in the same scene in order to see virtual objects and the real environment (such as distant objects or nearby objects), which can easily cause eye fatigue and result in a poor user experience. [Summary of the Invention]

[0004] In view of the above, this application provides a near-eye display device to improve the poor user experience of users with refractive errors. This application provides a near-eye display device, comprising: a waveguide including a first surface and a second surface opposite to the first surface, the waveguide being used to conduct image light; a coupling grating disposed on the first surface for receiving and coupling out the image light emitted from the waveguide; a first zoom module disposed on the second surface and located in the optical path of the image light and ambient light, the first zoom module being used to receive the image light and the ambient light and transmit the image light and the ambient light to the human eye; and a control module for changing the diopter of the first zoom module to adjust the focusing position of the ambient light and the image light.

[0005] The near-eye display device provided in this application embodiment includes a first zoom module and a control module. The first zoom module receives the image light and the ambient light and transmits them to the human eye. The control module changes the diopter of the first zoom module to adjust the focusing position of the ambient light and the image light. The diopter of the first zoom module can be changed according to the prescription of the user with refractive errors (e.g., myopia, hyperopia, and astigmatism). This allows the image light and ambient light to be focused on the user's retina after passing through the first zoom module and the lens of the human eye. This enables the user with refractive errors to see both the real environment and the virtual scene formed by the image light. In other words, the control module can change the diopter of the first zoom module to enable the user with refractive errors to see both the virtual scene and different external scenes. This helps reduce eye fatigue for the user with refractive errors and improves the user experience.

[0006] In some embodiments, the first zoom module includes a plurality of zoom units, the plurality of zoom units are interconnected, and the orthographic projection of the plurality of zoom units onto the waveguide covers the orthographic projection of the coupling grating onto the waveguide. Each zoom unit is used to receive the image light and the ambient light respectively. The control module is used to change the diopter of each zoom unit respectively, so that each zoom unit adjusts the focus position of the ambient light and the image light respectively.

[0007] In some embodiments, each zoom unit includes a first sub-medium, a second sub-medium, and a sub-transmitting surface between the first sub-medium and the second sub-medium, wherein the first sub-medium is disposed on the side of the second sub-medium away from the waveguide, and the sub-transmitting surface protrudes toward the direction close to the waveguide; the control module is electrically connected to each zoom unit and is used to control the curvature of the sub-transmitting surface of each zoom unit.

[0008] In some embodiments, the refractive index of the second sub-medium of each zoom unit is greater than the refractive index of the first sub-medium.

[0009] In some embodiments, the curvature of the sub-transmitting surfaces of at least two of the zoom units is different.

[0010] In some embodiments, the shape of the orthographic projection of each zoom unit onto the waveguide is the same, and the plurality of zoom units are arranged in an array.

[0011] In some embodiments, the first zoom module includes a first medium, a second medium, and a first light-transmitting surface between the first medium and the second medium, the first medium being disposed on the side away from the waveguide, and the first light-transmitting surface protruding toward the direction close to the waveguide; the control module is electrically connected to the first zoom module and is used to control the curvature of the first light-transmitting surface of the first zoom module.

[0012] In some embodiments, the refractive index of the second medium is greater than that of the first medium.

[0013] In some embodiments, the near-eye display device further includes a second zoom module, which is disposed on the first surface and located in the light path of the ambient light. The second zoom module is used to receive the ambient light and transmit the ambient light to the human eye. The control module is used to change the diopter of the second zoom module to adjust the focusing position of the ambient light.

[0014] In some embodiments, the control module changes the diopter of the first zoom module and the second zoom module in any one of the following ways: spacing change, polarization switching, refractive index gradual change, pressure change, voltage change, and piezoelectric change.

[0015] In some embodiments, the second zoom module includes a third medium, a fourth medium, and a second light-transmitting surface between the third medium and the fourth medium, wherein the third medium is disposed on the side of the fourth medium near the waveguide, and the second light-transmitting surface protrudes in a direction away from the waveguide; the control module is electrically connected to the second zoom module and is used to control the curvature of the second light-transmitting surface of the second zoom module.

[0016] In some embodiments, the near-eye display device further includes a display module and a coupling grating, the display module being used to emit image light, and the coupling grating being disposed on the first surface and used to couple the image light into the waveguide.

Implementation Method

[0017] 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 of the embodiments of this application, and not all of them.

[0018] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application.

[0019] In order to further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the present application will be described in detail below with reference to the accompanying drawings and preferred embodiments.

[0020] Please refer to Figures 1 and 2. The near-eye display device 1 of this application embodiment includes a frame 10, two optical systems 11a and 11b disposed on the frame 10, and a control module 12. The two optical systems 11a and 11b have basically the same structure and function. One optical system 11a is disposed on the left side of the frame 10 and is used for imaging the user's left eye; the other optical system 11b is disposed on the right side of the frame 10 and is used for imaging the user's right eye.

[0021] The control module 12 is disposed on the frame 10 (e.g., on the temple of any side of the frame 10). The control module 12 is used to control the display content of the two optical systems 11a and 11b. The control module 12 includes a power supply (not shown) and a controller (not shown). The power supply is used to apply voltage to the two optical systems 11a and 11b and the controller. The controller is used to control the magnitude of the voltage applied to the optical systems 11a and 11b. The controller can be any of the following: a controller including an RS485 interface, a central processing unit (CPU), and a microcontroller (e.g., an STM32 microcontroller, a 51 microcontroller, a TMS microcontroller, a PIC microcontroller, or an AVR microcontroller). This application does not impose any limitation on the type of microcontroller.

[0022] The near-eye display device 1 in this embodiment is an AR display device. When a user wears the AR display device, the user's eyes can observe the projected image displayed by the two optical systems 11a and 11b. At the same time, ambient light L2 reflected by environmental objects W in the user's real environment can also enter the user's eye E through the near-eye display device 1, allowing the user's eye E to observe the image of the real world. Thus, the user's eye E can observe the projected image superimposed on the image of the real world. In other embodiments, the near-eye display device 1 can also be an MR display device or an XR display device, which is not limited in this application.

[0023] The structure and function of the optical system 11a are described below as an example.

[0024] Please refer to Figures 1, 2, and 3 together. The optical system 11a of this embodiment includes a display module 2, a waveguide 3, a coupling grating 4, a coupling grating 5, and a first zoom module 6. The display module 2 is disposed at the position where the lens is connected to the temple of the frame 10 and is used to emit image light L1. The display module 2 can be any one of a micro light-emitting diode (Micro LED) display, a mini light-emitting diode (Mimi LED) display, and an organic light-emitting diode (OLED) display. This application does not impose any limitation.

[0025] Waveguide 3 is embedded within frame 10 and is used to conduct image light L1. Waveguide 3 is generally rectangular plate-shaped and includes a first surface 31 and a second surface 32 opposite to the first surface 31. The first surface 31 and the second surface 32 have a generally rectangular outer contour. The material of waveguide 3 is any one of transparent glass and plastic, such as any one of polyethylene glycol terephthalate (PET), polycarbonate (PC), and polymethyl methacrylate (PMMA), and this application is not limited thereto.

[0026] The coupling grating 4 and the coupling grating 5 are disposed at intervals on the first surface 31. The coupling grating 4 is used to couple the image light L1 into the waveguide 3. The coupling grating 5 is used to receive and couple out the image light L1 emitted from the waveguide 3. The coupling grating 4 and the coupling grating 5 can be any one of a surface relief grating, a volume holographic grating, and a polarization volume holographic grating, and this application does not impose any limitation.

[0027] The first zoom module 6 is disposed on the second surface 32 and located on the optical path of the image light L1 and the ambient light L2. The orthographic projection of the first zoom module 6 on the waveguide 3 has a generally rectangular outer contour and covers the orthographic projection of the coupling grating 5 on the waveguide 3. The first zoom module 6 is used to receive the image light L1 and the ambient light L2 and transmit the image light L1 and the ambient light L2 to the human eye E. When the user wears the near-eye display device 1, part of the ambient light L2 reflected by the environmental object W passes through the waveguide 3 and the first zoom module 6 in sequence and enters the eye box range. Part of the ambient light L2 reflected by the environmental object W passes through the coupling grating 5, the waveguide 3 and the first zoom module 6 in sequence and enters the eye box range. The image light L1 emitted from the display module passes through the coupling grating 4, the waveguide 3, the coupling grating 5 and the first zoom module 6 in sequence and enters the eye box range. The image light L1 and the ambient light L2 are received by the human eye E together, so that the human eye E can observe the AR image.

[0028] Please refer to Figures 2 and 4 together. For users with refractive errors, light cannot be focused precisely on the retina E3 after passing through their cornea E1 and lens E2. For example, for farsighted users, light is focused behind the retina E3 after passing through their cornea E1 and lens E2, and cannot be focused precisely on the retina E3, causing the human eye E to only be able to see distant objects and not nearby objects.

[0029] The control module 12 is also used to change the diopter of the first zoom module 6 to adjust the focusing position of the ambient light L2 and the image light L1. For example, the control module 12 can adjust the diopter of the first zoom module 6 according to the user's farsightedness (or nearsightedness), that is, adjust the focal length of the first zoom module 6, so that the image light L1 coupled from the coupling grating 5 passes through the first zoom module 6 and then passes through the user's cornea E1 and lens E2 in sequence before being focused on the focal point Q2 of the retina E3. The part of the ambient light L2 reflected from the environmental object W passes through the waveguide 3 and the first zoom module 6 and then passes through the user's cornea E1 and lens E2 in sequence before being focused on the focal point Q1 of the retina E3, so that the user with refractive error can see the virtual scene and different external scenes clearly.

[0030] By setting a first zoom module 6 and a control module 12, the control module 12 is used to change the diopter of the first zoom module 6 to adjust the focusing position of the ambient light L2 and the image light L1. The diopter of the first zoom module 6 can be changed according to the glasses prescription of the user with refractive error (such as myopia, hyperopia and astigmatism). After the image light L1 and the ambient light L2 pass through the first zoom module 6 and the human eye's lens E2, they can both be focused on the user's retina E3. This allows the user with refractive error to see the real environment and the virtual scene formed by the image light L1 at the same time. That is, the control module 12 can change the diopter of the first zoom module 6 to enable the user with refractive error to see the virtual scene and different external scenes. This helps to reduce the eye fatigue of the user with refractive error and thus improve the user's user experience.

[0031] In some embodiments, the control module 12 changes the diopter of the first zoom module 6 in any one of the following ways: spacing change, polarization switching, refractive index gradual change, pressure change, voltage change, and piezoelectric change.

[0032] For example, when the control module 12 changes the diopter of the first zoom module 6 by a spacing change, the first zoom module 6 includes multiple lenses (not shown) stacked on the second surface 32, each with refractive power. The control module 12 changes the relative positions of the multiple lenses, thereby changing the overall effective focal length of the first zoom module 6, i.e., changing the diopter of the first zoom module 6, thus adjusting the focusing positions of the ambient light L2 and the image light L1. When the control module 12 changes the diopter of the first zoom module 6 by a polarization switching method, the first zoom module 6 includes a liquid crystal lens (not shown) disposed on the second surface 32. The control module 12 can change the diopter of the first zoom module 6 by changing the polarization direction of the image light L1 and the ambient light L2. When the control module 12 changes the diopter of the first zoom module 6 to a refractive index gradient type, the first zoom module 6 includes a transparent liquid crystal cell (not shown) disposed on the second surface 32. The control module 12 is electrically connected to the first zoom module 6 and is used to apply different voltages to the first zoom module 6 to control the arrangement of liquid crystal molecules in the first zoom module 6, thereby changing the refractive index of the first zoom module 6 and thus changing the diopter of the first zoom module 6. When the control module 12 changes the diopter of the first zoom module 6 to a pressure-changing type, the first zoom module 6 includes a liquid lens (not shown) disposed on the second surface 32. The liquid lens includes a shell containing liquid material. The control module 12 is used to control the volume of liquid material in the shell, thereby controlling the overall radius of curvature of the liquid lens and thus controlling the diopter of the first zoom module 6. When the control module 12 changes the diopter of the first zoom module 6 to a piezoelectric change method, the first zoom module 6 includes a piezoelectric lens (not shown) disposed on the second surface 32. The piezoelectric lens includes a piezoelectric material layer (not shown). The control module 12 is electrically connected to the first zoom module 6 and is used to apply different voltages to the first zoom module 6 to control the volume of the piezoelectric material layer in the first zoom module 6, thereby changing the overall curvature of the piezoelectric lens and thus changing the diopter of the first zoom module 6.

[0033] In this embodiment, the control module 12 changes the diopter of the first zoom module 6 by voltage change. The first zoom module 6 includes a first housing 6a and a first medium 61, a second medium 62, and a first light-transmitting surface 63 disposed within the first housing 6a; both image light L1 and ambient light L2 can pass through the first medium 61, the second medium 62, and the first light-transmitting surface 63.

[0034] The first dielectric 61 is disposed on the side of the second dielectric 62 away from the waveguide 3, and the second dielectric 62 is disposed between the waveguide 3 and the first dielectric 61. Both the first dielectric 61 and the second dielectric 62 are liquids and immiscible with each other, thereby forming a first light-transmitting surface 63 between the first dielectric 61 and the second dielectric 62. The first light-transmitting surface 63 protrudes towards the direction close to the waveguide 3.

[0035] The refractive indices of the first medium 61 and the second medium 62 are different. Specifically, the refractive index of the second medium 62 is greater than that of the first medium 61. For example, the second medium 62 is a conductive liquid (e.g., an organic salt solution), and the first medium 61 is a non-conductive solution (e.g., an organic polymer solution such as silicone oil); or the second medium 62 is a non-conductive liquid, and the first medium 61 is a conductive solution. This application does not impose any limitations. The refractive index of the second medium 62 is set to be greater than that of the first medium 61, and the first light-transmitting surface 63 bulges towards the direction close to the waveguide 3, so that the shape of the second medium 62 with the larger refractive index is approximately concave lens-shaped, which can diverge light.

[0036] The control module 12 is electrically connected to the first zoom module 6 and utilizes the principle of electrowetting effect to control the curvature of the first light-transmitting surface 63 of the first zoom module 6 by applying an external voltage, thereby changing the refractive power of the first zoom module 6 and adjusting the focusing position of the ambient light L2 and the image light L1. For farsighted users, the light passes through their cornea E1 and lens E2 and focuses behind the retina E3, failing to focus precisely on the retina E3. The control module 12 controls the curvature of the first light-transmitting surface 63 of the first zoom module 6 by applying an external voltage, thereby changing the refractive power of the first zoom module 6 to adapt to the farsighted user's glasses prescription. This causes the virtual image point formed by the image light L1 to move from infinity toward the direction closer to the human eye E, allowing the image light L1 to focus on the focal point Q2 on the retina E3 after passing through the first zoom module 6, cornea E1, and lens E2, thus enabling the human eye E to clearly see the virtual image formed by the image light L1.

[0037] Referring to Figures 4 and 5 together, in some embodiments, the optical system 11a further includes a second zoom module 7. The second zoom module 7 is disposed on the first surface 31 and located in the optical path of the ambient light L2. The second zoom module 7 is used to receive the ambient light L2 and transmit the ambient light L2 to the human eye E. The orthographic projection of the second zoom module 7 on the waveguide 3 covers the orthographic projection of the coupling grating 5 on the waveguide 3, and the size of the orthographic projection of the second zoom module 7 on the waveguide 3 is approximately equal to the size of the orthographic projection of the first zoom module 6 on the waveguide 3. The control module 12 is also used to change the diopter of the second zoom module 7 to adjust the focusing position of the ambient light L2. That is, the control module 12 can change the diopter of the first zoom module 6 and the second zoom module 7 respectively to adjust the focusing positions of the ambient light L2 and the image light L1 respectively.

[0038] The control module 12 changes the diopter of the second zoom module 7 in any one of the following ways: spacing change, polarization switching, refractive index gradual change, pressure change, voltage change, and piezoelectric change. The control module 12 can change the diopter of the second zoom module 7 in the same way as it changes the diopter of the first zoom module 6, or the method can be different; this application does not impose any restrictions.

[0039] In this embodiment, the control module 12 changes the diopter of the second zoom module 7 by voltage change. The second zoom module 7 includes a second housing 7a and a third medium 71, a fourth medium 72, and a second light-transmitting surface 73 disposed within the second housing 7a; ambient light L2 can pass through the third medium 71, the fourth medium 72, and the second light-transmitting surface 73.

[0040] A third medium 71 is disposed on the side of the fourth medium 72 near the waveguide 3, and is located between the waveguide 3 and the fourth medium 72. Both the third medium 71 and the fourth medium 72 are liquids and immiscible, thereby forming a second light-transmitting surface 73 between them. The second light-transmitting surface 73 bulges away from the waveguide 3. The refractive indices of the third medium 71 and the fourth medium 72 are different. Specifically, the refractive index of the third medium 71 is greater than that of the fourth medium 72. For example, the third medium 71 is a conductive liquid and the fourth medium 72 is a non-conductive solution; or the third medium 71 is a non-conductive liquid and the fourth medium 72 is a conductive solution. This application does not impose any limitations. The refractive index of the third medium 71 is set to be greater than that of the fourth medium 72, and the second light-transmitting surface 73 bulges away from the waveguide 3, so that the shape of the third medium 71 with the larger refractive index is approximately convex lens-shaped, which can converge the ambient light L2.

[0041] The control module 12 is electrically connected to the second zoom module 7 and uses the principle of electrowetting effect to control the curvature of the second light-transmitting surface 73 of the second zoom module 7 by means of an external voltage, thereby changing the diopter of the second zoom module 7, and thus adjusting the focus position of the ambient light L2 and the image light L1.

[0042] For example, the control module 12 can adjust the diopter of the first zoom module 6 according to the user's farsightedness (or nearsightedness), that is, adjust the focal length of the first zoom module 6 so that the virtual image point formed by the image light L1 moves from infinity toward the direction closer to the human eye E, so that the image light L1 can be focused on the focal point Q2 on the retina E3 after passing through the first zoom module 6, the cornea E1 and the lens E2, so that the human eye E can see the virtual image formed by the image light L1 clearly. Once the human eye E can clearly see the virtual image formed by the image light L1, the control module 12 adjusts the diopter of the second zoom module 7 according to the user's farsightedness (or nearsightedness), that is, adjusts the focal length of the second zoom module 7, so that part of the ambient light L2 reflected from the environmental object W passes through the second zoom module 7, waveguide 3 and the first zoom module 6 and enters the human eye E, and then passes through the user's cornea E1 and lens E2 in sequence and is focused on the focal point Q1 of the retina E3, so that the user with refractive error can see different external scenes clearly, and thus the user can see virtual objects and different external scenes at the same time. Furthermore, when a user wants to see distant (or nearby) objects clearly, the control module 12 can further adjust the diopter of the second zoom module 7 so that the ambient light L2 is focused onto the focal point Q3 of the retina E3 after passing through the user's cornea E1 and lens E2. This allows users with refractive errors to see external environmental objects W in different positions, which helps reduce eye strain and improves the user's experience.

[0043] Please refer to Figures 4, 6, and 7 together. In some embodiments, the optical system 11a includes a display module 2, a waveguide 3, a coupling grating 4, a coupling grating 5, and a first zoom module 6. The first zoom module 6 includes multiple zoom units 60, which are interconnected and arranged in an array. The orthographic projection of each zoom unit 60 onto the waveguide 3 has the same shape and is hexagonal. In other embodiments, the orthographic projection of the zoom unit 60 onto the waveguide 3 can also be any one of a circle, a triangle, or a quadrilateral.

[0044] The orthographic projection of the first zoom module 6 onto the waveguide 3 covers the orthographic projection of the coupling grating 5 onto the waveguide 3. The orthographic projections of the plurality of zoom units 60 onto the waveguide 3 are located within the orthographic projection of the coupling grating 5 onto the waveguide 3, and the orthographic projections of the plurality of zoom units 60 onto the waveguide 3 are located outside the orthographic projection of the coupling grating 5 onto the waveguide 3. The plurality of zoom units 60 are used to receive image light L1 and ambient light L2, and the plurality of zoom units 60 are only used to receive ambient light L2. The control module 12 is used to change the diopter of each zoom unit 60 respectively, so that each zoom unit 60 adjusts the focus position of ambient light L2 and image light L1 respectively.

[0045] In this embodiment, the control module 12 changes the diopter of each zoom unit 60 by voltage change. Each zoom unit 60 includes a first sub-house 60a and a first sub-medium 601, a second sub-medium 602, and a sub-transmitting surface 603 between the first sub-medium 601 and the second sub-medium 602, all housed within the first sub-house 60a. The first sub-medium 601 is disposed on the side away from the waveguide 3. Both the first sub-medium 601 and the second sub-medium 602 are liquid and immiscible, thereby forming a sub-transmitting surface 603 between the first sub-medium 601 and the second sub-medium 602. The refractive index of the second sub-medium 602 of each zoom unit 60 is greater than the refractive index of the first sub-medium 601. The sub-transmitting surface 603 bulges towards the direction closer to the waveguide 3, so that the shape of the second sub-medium 602 with the larger refractive index is approximately concave lens-shaped, which can diverge light.

[0046] Please refer to Figures 4, 6, and 8 together. The control module 12 is electrically connected to each zoom unit 60 and uses the principle of electrowetting effect to control the curvature of the sub-transmitting surface 603 of each zoom unit 60 by applying an external voltage, thereby changing the diopter of the first zoom module 6 and thus adjusting the focusing position of the ambient light L2 and the image light L1. The control module 12 controls the curvature of the sub-transmitting surface 603 of each zoom unit 60 by applying an external voltage, so that the curvature of the sub-transmitting surface 603 of at least two zoom units 60 is different, thereby changing the diopter of each zoom unit 60 to meet the needs of users with different refractive errors.

[0047] For example, if a user has astigmatism in the left eye and myopia in the right eye, the control module 12 can apply different voltages to the two optical systems 11a and 11b to individually control the diopter of each zoom unit 60, so that the image light L1 and ambient light L2 received by the user's eyes can be focused onto the retina E3 after passing through the first zoom module 6, the cornea E1 and the lens E2, thereby enabling the user with refractive error to see virtual objects and external scenes clearly. Or, when a user is farsighted but wants to see both a virtual scene and an external scene in different locations, the control module 12 controls the curvature of the sub-transmitting surfaces 603 of multiple zoom units 60 located within the range of the orthographic projection of the coupling grating 5 onto the waveguide 3 by an external voltage. This controls the focusing position of the image light L1 emitted from the coupling grating 5, causing the virtual image point formed by the image light L1 to move from infinity toward the direction closer to the human eye E. This allows the image light L1 to be focused on the focal point Q2 on the retina E3 after passing through the first zoom module 6, the cornea E1, and the lens E2, so that the human eye E can clearly see the virtual image formed by the image light L1. Once the human eye E can clearly see the virtual image formed by the image light L1, the control module 12 controls the curvature of the sub-transmitting surfaces 603 of multiple zoom units 60 located outside the range of the orthogonal projection of the coupled grating 5 onto the waveguide 3 by using an external voltage. This controls the focusing position of the ambient light L2 incident on the first zoom module 6 through the waveguide 3, so that the ambient light L2 passes through the user's cornea E1 and lens E2 in sequence and is focused onto the focal point Q1 of the retina E3. This allows the user with refractive errors to see different external scenes clearly, and thus allows the user to see virtual objects and different external scenes simultaneously.

[0048] Furthermore, when a user wants to see distant (or near) objects clearly, the control module 12 can further adjust the diopter of the zoom unit 60 located at different positions, so that the user with refractive error can see the external environmental objects W at different positions, which helps reduce the eye fatigue of the user with refractive error. By controlling the diopter of the zoom unit 60 located at different positions, the curvature of the light-transmitting surface 603 of the zoom unit 60 located at different positions is different, so that the ambient light L2 passes through the user's cornea E1 and lens E2 in sequence and focuses on the focal point Q3 of the retina E3. The diopter of each zoom unit 60 can be changed to adapt to the glasses prescription of the farsighted user, so that the user with refractive error can see the real environment and the virtual scene formed by the image light L1 at the same time, which helps reduce the eye fatigue of the user with refractive error and thus improves the user's user experience.

[0049] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present invention and are not intended to limit the present invention. Any appropriate changes and variations made to the above embodiments within the essential spirit and scope of the present invention shall fall within the scope of protection claimed by the present invention. [Simplified Explanation of the Diagram]

[0050] Figure 1 is a schematic diagram of the structure of a near-eye display device according to an embodiment of this application.

[0051] Figure 2 is a schematic diagram of an optical system and control module according to an embodiment of this application.

[0052] Figure 3 is a schematic diagram of the planar structure of the optical system in Figure 2.

[0053] Figure 4 is a schematic diagram of the human eye focusing situation after correction by the near-eye display device according to the embodiment of this application.

[0054] Figure 5 is a schematic diagram of an optical system and control module according to another embodiment of this application.

[0055] Figure 6 is a schematic diagram of an optical system and control module according to another embodiment of this application.

[0056] Figure 7 is a top view of the first zoom module in Figure 6.

[0057] Figure 8 is a schematic diagram of the control module in Figure 6 changing the curvature of the sub-transmitting surfaces of multiple zoom units.

Claims

1. A near-eye display device, the improvement of which includes: A waveguide, including a first surface and a second surface opposite to the first surface, is used to conduct image light; A coupling grating is disposed on the first surface for receiving and coupling out the image light emitted from the waveguide; A first zoom module is disposed on the second surface and located on the light path between the image light and the ambient light. The first zoom module is used to receive the image light and the ambient light and transmit the image light and the ambient light to the human eye. The system also includes a control module for changing the diopter of the first zoom module to adjust the focus position of the ambient light and the image light. The first zoom module comprises multiple zoom units interconnected, and the orthographic projections of the multiple zoom units onto the waveguide cover the orthographic projection of the coupling grating onto the waveguide. Each zoom unit receives the image light and the ambient light respectively. The control module changes the diopter of each zoom unit to adjust the focus position of the ambient light and the image light respectively.

2. The near-eye display device as described in claim 1, wherein, Each zoom unit includes a first sub-medium, a second sub-medium, and a sub-transmitting surface between the first sub-medium and the second sub-medium. The first sub-medium is disposed on the side of the second sub-medium away from the waveguide, and the sub-transmitting surface protrudes toward the direction close to the waveguide. The control module is electrically connected to each zoom unit and is used to control the curvature of the sub-transmitting surface of each zoom unit.

3. The near-eye display device as described in claim 2, wherein, In each of the zoom units, the refractive index of the second sub-medium is greater than the refractive index of the first sub-medium.

4. The near-eye display device as described in claim 2, wherein, The curvature of the sub-transmitting surfaces of at least two of the zoom units is different.

5. The near-eye display device as described in claim 1, wherein, Each zoom unit has the same shape when projected onto the waveguide, and the plurality of zoom units are arranged in an array.

6. The near-eye display device as described in claim 1, wherein, The first zoom module includes a first medium, a second medium, and a first light-transmitting surface between the first medium and the second medium. The first medium is disposed on the side of the second medium away from the waveguide, and the first light-transmitting surface protrudes toward the direction close to the waveguide. The control module is electrically connected to the first zoom module and is used to control the curvature of the first light-transmitting surface of the first zoom module.

7. The near-eye display device as described in claim 6, wherein, The refractive index of the second medium is greater than that of the first medium.

8. The near-eye display device as described in claim 1, wherein, The near-eye display device further includes a second zoom module, which is disposed on the first surface and located in the light path of the ambient light. The second zoom module is used to receive the ambient light and transmit the ambient light to the human eye. The control module is used to change the diopter of the second zoom module to adjust the focusing position of the ambient light.

9. The near-eye display device as described in claim 8, wherein, The control module changes the diopter of the first zoom module and the second zoom module in any one of the following ways: spacing change, polarization switching, refractive index gradual change, pressure change, voltage change, and piezoelectric change.

10. The near-eye display device as described in claim 8, wherein, The second zoom module includes a third medium, a fourth medium, and a second light-transmitting surface between the third medium and the fourth medium. The third medium is disposed on the side of the fourth medium near the waveguide, and the second light-transmitting surface protrudes in a direction away from the waveguide. The control module is electrically connected to the second zoom module and is used to control the curvature of the second light-transmitting surface of the second zoom module.

11. A near-eye display device as described in any one of claims 1-10, wherein, The near-eye display device further includes a display module and a coupling grating. The display module is used to emit image light, and the coupling grating is disposed on the first surface and used to couple the image light into the waveguide.

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