Optical device and near-to-eye display device

Abstract

The invention provides an optical device and a near-to-eye display device. The optical device comprises a light guide part and a focusing assembly, wherein the focusing assembly comprises a partial transmission and partial reflection surface and a reflection surface which are oppositely arranged; wherein the partial transmission and partial reflection surface is arranged in the light guide part, the reflection surface is arranged on one side, deviating from the coupling-out side, of the light guide part, and the reflection surface and the light guide part are arranged at an interval; the driving mechanism drives the reflecting surface to move relative to the partial transmission and partial reflection surface; wherein the partial transmission and partial reflection surface and the reflection surface are arc-shaped surfaces; light in the light guide part is transmitted to the partial transmission and partial reflection surface, is reflected to the reflection surface through the partial transmission and partial reflection surface, then is transmitted through the partial transmission and partial reflection surface, and is emitted from the light guide part. According to the technical scheme, through cooperation of the partial transmission and partial reflection surface and the reflection surface, the depth of field presented when the light is irradiated into the pupil of the user is adjusted, the depth of field adjustment from the near to the infinity can be achieved, and the experience effect of the user is improved.

Description

Technical Field

[0001] The present application relates to the field of optical technology, and in particular to an optical device and a near-eye display device. Background Art

[0002] The existing light-guiding optical elements require collimated parallel light to be incident and propagated in the waveguide. After the parallel light is coupled out, it will form an image at infinity when it enters the human eye, that is, the image seen by the human eye is an image at infinity.

[0003] The image that the human eye sees in the real world is about 250mm at the closest and infinity at the farthest. At this stage, there is a big difference between the image displayed by the waveguide and the actual focus position of the human eye, which brings about the convergence adjustment conflict.

[0004] In natural vision, accommodation and convergence often work together, and the degree of convergence affects the accommodation of the eye lens, and vice versa, to ensure flexible and powerful vision. When we observe distant objects, the lens of the eye relaxes and the line of sight is parallel to maintain the focus state at a long distance. But when observing close objects, the eye will contract the lens to adjust the focal length so that the line of sight is focused on the object. If the brain receives mismatched cues between eye accommodation and convergence, a vergence-accommodation conflict (VAC) will occur, causing stress on the eyes. Summary of the invention

[0005] The present application provides an optical device and a near-eye display device to improve the use effect of the optical device.

[0006] The present application provides an optical device, which includes: a light guide and a focusing assembly; wherein:

[0007] The focusing assembly comprises: a partially transmissive and partially reflective surface and a reflective surface arranged opposite to each other; wherein the partially transmissive and partially reflective surface is arranged in the light guide, and the reflective surface is arranged on a side of the light guide away from the outcoupling side and is spaced apart from the light guide; and further comprises a driving mechanism for driving the reflective surface to move relative to the partially transmissive and partially reflective surface; wherein both the partially transmissive and partially reflective surface and the reflective surface are arc-shaped surfaces;

[0008] After the light in the light guide propagates to the partially transmissive and partially reflective surface, it is reflected by the partially transmissive and partially reflective surface to the reflective surface, then it is transmitted through the partially transmissive and partially reflective surface and emitted from the light guide.

[0009] In the above technical solution, by adopting the combination of a partially transmissive and partially reflective surface and a reflective surface, the depth of field presented when the light is irradiated into the user's pupil is adjusted, so that the depth of field adjustment from near to infinity can be achieved, thereby improving the user experience.

[0010] In a specific possible implementation manner, the partially transmissive and partially reflective surface is one of a spherical surface, an aspherical surface or a free-form surface;

[0011] The reflective surface is one of a spherical surface, an aspherical surface or a free-form surface corresponding to the partially transmissive and partially reflective surface.

[0012] In a specific possible implementation manner, the partially transmissive and partially reflective surface and the reflective surface satisfy the following formula:

[0013] R1 / 2+d1-R2 / 2=0;

[0014] s2'=(R1*(R1+2d1)) / (d2-d1); s2>200mm;

[0015] Among them, R1 is the curvature radius of the partially transmissive and partially reflective surface, R2 is the curvature radius of the reflective surface, d1 is the minimum distance between the partially transmissive and partially reflective surface and the reflective surface, d2 is the maximum distance between the partially transmissive and partially reflective surface and the reflective surface, and s2' is the focal length of the lens composed of the partially transmissive and partially reflective surface and the reflective surface.

[0016] In a specific possible implementation manner, the partially transmissive and partially reflective surface is a concave arc-shaped surface, and the concave direction of the concave arc-shaped surface faces away from the outcoupling side of the light guide component.

[0017] In a specific possible implementation manner, both ends of the partially transmissive and partially reflective surface extend to two opposite surfaces of the light guide; and a vertical plane of a central axis of the partially transmissive and partially reflective surface is inclined relative to the two surfaces of the light guide.

[0018] In a specific possible implementation manner, the reflective surface is a partially transmissive and partially reflective surface, and may also be a polarized reflective surface.

[0019] In a specific implementation manner, the reflectivity of the partially transmissive and partially reflective surface to light is between 2% and 10%.

[0020] In a specific possible implementation scheme, it also includes a curved mirror, which is located outside the light guide, wherein the side of the curved mirror facing away from the light guide is the reflecting surface; and the side of the curved mirror facing the light guide is a flat surface.

[0021] In a specific possible implementation manner, the driving mechanism includes a linear motor; and the curved mirror is fixedly connected to a moving end of the linear motor.

[0022] In a specific possible implementation scheme, the driving mechanism includes a lead screw and a driving motor for driving the lead screw to rotate, and the curved mirror is driven by the lead screw.

[0023] In a second aspect, a near-eye display device is provided, the near-eye display device comprising a light generator and any one of the optical devices described above; wherein:

[0024] The light emitted by the optical device propagates into the light guide member.

[0025] In the above technical solution, by adopting the combination of a partially transmissive and partially reflective surface and a reflective surface, the depth of field presented when the light is irradiated into the user's pupil is adjusted, so that the depth of field adjustment from near to infinity can be achieved, thereby improving the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a usage scenario diagram of an optical device in the prior art;

[0027] Figure 2 A schematic diagram of the structure of an optical device provided in an embodiment of the present application;

[0028] Figure 3 and Figure 4 A simulation schematic diagram of an optical device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0029] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings.

[0030] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in one or more embodiments of this specification should be understood by people with ordinary skills in the field to which this disclosure belongs. The "first", "second" and similar words used in one or more embodiments of this specification do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0031] To facilitate understanding of the optical device provided in the embodiment of the present application, its application scenario is first described. The display device provided in the embodiment of the present application is applied to different near-eye display systems such as AR (Augmented Reality, enhanced display technology) or VR (Virtual Reality, virtual display technology) to realize virtual display. However, the current near-eye display system generally has the demand that the displayed image cannot have depth of field.

[0032] like Figure 1 As shown in Figure 1 A schematic diagram of an application scenario of an optical device in the prior art is shown. The prior optical device includes a light guide 1, a light coupling device 2, a light coupling device 3 and a light generator 9. Among them, the light generator 9 is used to emit light for displaying an image. The light coupling device 2 is used to couple the light emitted by the light generator 9 into the light guide 1. The light guide 1 is used to propagate light, and it has two oppositely arranged total internal reflection surfaces. The light in the light guide 1 can propagate light through total internal reflection of the total internal reflection surfaces. The light coupling device 3 is used to couple the light in the light guide 1 into the user's eyes, so that the user can observe the image displayed by the light generator.

[0033] Depend on Figure 1 It can be seen that when it is displayed, it only relies on the light of the image in the light generator for corresponding display, and the optical device cannot adjust the depth of field, resulting in poor display effect. To this end, the embodiment of the present application provides an optical device to improve the viewing effect of the user. The following is a detailed description in conjunction with specific drawings and embodiments.

[0034] refer to Figure 2 , Figure 2 The schematic diagram of the structure of the optical device provided by the embodiment of the present application is shown. The optical device provided by the embodiment of the present application mainly includes a light guide 10 and a focusing assembly 20, wherein the light guide 10 is used to propagate light in the light guide 10 by total reflection, and the focusing assembly 20 is used to adjust the depth of field of the light when it propagates from the light guide 10 to the human eye.

[0035] The light guide 10 provided in the embodiment of the present application is a waveguide having two opposite surfaces, the two opposite surfaces being total internal reflection surfaces 11, and the light can be totally reflected and propagated through the two total internal reflection surfaces 11 in the waveguide. When the light generator couples the light into the waveguide through the coupling grating 50, the light can be propagated through the total internal reflection surface 11 and coupled out through the focusing component 20. That is, in the scheme disclosed in the present application, the focusing component 20 is used as a coupling-out component on the one hand, and is used to adjust the focal length on the other hand to change the depth of field when the human eye observes the image.

[0036] In a specific configuration, the focusing assembly 20 includes two parts that cooperate with each other, namely, a partially transmissive and partially reflective surface 21 and a reflective surface 22; wherein, the partially transmissive and partially reflective surface 21 and the reflective surface 22 are arranged opposite to each other, and the partially transmissive and partially reflective surface 21 is located inside the light guide 10, and the reflective surface 22 is located outside the light guide 10. Figure 2 As shown, when the reflective surface 22 is provided, the reflective surface 22 is located on the side of the light guide 10 away from the coupling-in grating 50. That is, the reflective surface 22 is located on the side of the light guide 10 away from the user's pupil.

[0037] When in use, after the light in the light guide 10 propagates to the partially transmissive and partially reflective surface 21, it is reflected by the partially transmissive and partially reflective surface 21 to the reflective surface 22, and then transmits through the partially transmissive and partially reflective surface 21 and is emitted from the light guide 10. Specifically, the partially transmissive and partially reflective surface 21 is used to reflect the light propagating in the light guide 10, so that the light is coupled out of the light guide 10 and propagates to the reflective surface 22. The reflective surface 22 reflects the light back to the partially transmissive and partially reflective surface 21, and transmits through the partially transmissive and partially reflective surface 21, so that the light passes through the light guide 10 and propagates to the pupil of the user. It can be seen from the above description that the partially transmissive and partially reflective surface 21 in the embodiment of the present application must meet the following requirements when transmitting and reflecting: only the light that is totally reflected from the light guide 10 to the partially transmissive and partially reflective surface 21 is reflected, and only the light that is reflected from the reflective surface 22 to the partially transmissive and partially reflective surface 21 is transmitted. Thereby, it is possible to satisfy the requirement that the light transmitted by total reflection in the light guide 10 can be reflected out of the light guide 10 through the partially transmitting and partially reflecting surface 21 (coupling out of the light guide 10), and when the light passes through the reflection surface 22 and the partially transmitting and partially reflecting surface 21, it can propagate into the user's pupil through the partially transmitting and partially reflecting surface 21 and the light guide 10, and form an image in the user's pupil.

[0038] It can be seen from the above description that the cooperation between the reflective surface 22 and the partially transmissive partially reflective surface 21 provided in the embodiment of the present application can increase the path of the light when it propagates from the optical waveguide to the human eye, thereby increasing the imaging distance. When adjusting the distance between the reflective surface 22 and the partially transmissive partially reflective surface 21, the imaging distance can be adjusted, thereby improving the effect of the user viewing the image. It should be understood that when the above-mentioned partially transmissive partially reflective surface 21 and the reflective surface 22 are set, the partially transmissive partially reflective surface 21 and the reflective surface 22 are both arc-shaped surfaces, and the concave sides of the partially transmissive partially reflective surface 21 and the reflective surface 22 are opposite, so that the light can be converged to form an image in the user's pupil.

[0039] In addition, the optical device disclosed in the present application also includes a driving mechanism, which is used to drive the reflective surface 22 to move relative to the partially transmissive and partially reflective surface 21, such as Figure 2The moving direction of the reflective surface 22 shown in the double-headed arrow example is adjusted along this direction. For example, when we observe distant objects, the lens of the eyeball will relax and the line of sight will be parallel to maintain a focused state at a long distance. But when observing nearby objects, the eye will contract the lens to adjust the focal length so that the line of sight is focused on the object. Therefore, when adjusting the reflective surface 22, it can be adjusted accordingly according to the state of the lens of the eyeball. For example, when the lens is relaxed, the control driving mechanism drives the reflective surface 22 away from the partially transmissive and partially reflective surface 21; when the lens is in a contracted state, the control driving mechanism drives the reflective surface 22 close to the partially transmissive and partially reflective surface 21. Through the above-mentioned adjustment of the reflective surface 22, the imaging position of the optical device is matched with the state of the lens of the eyeball to improve the viewing effect of the user.

[0040] It can be seen from the above description that the optical device provided in the embodiment of the present application adjusts the depth of field presented when the light is irradiated into the user's pupil by using the cooperation of the partially transmissive and partially reflective surface 21 and the reflective surface 22, thereby realizing the depth of field adjustment from near to infinite distance, and improving the user experience. That is, the optical device disclosed in the present application can match the displayed image with the real focus position of the human eye, and improve the convergence adjustment conflict.

[0041] Continue to refer Figure 2 When the partially transmissive and partially reflective surface 21 provided in the embodiment of the present application is an arcuate surface, the partially transmissive and partially reflective surface 21 may be a spherical surface, an aspherical surface, or a free-form surface. Similarly, when the reflective surface 22 is an arcuate surface, the reflective surface 22 may also be a spherical surface, an aspherical surface, or a free-form surface corresponding to the partially transmissive and partially reflective surface 21. Thus, two components with the same surface shape may cooperate with each other to facilitate the control of the light path when the light is reflected between the two components.

[0042] When the partially transmissive and partially reflective surface 21 is specifically provided, the partially transmissive and partially reflective surface 21 is a concave arc surface, and the concave direction of the concave arc surface is away from the outcoupling side of the light guide 10. When this structure is adopted, the light is converged by the arc structure of the partially transmissive and partially reflective surface 21 and propagated to the reflective surface 22, so that the light can be imaged in the pupil of the user by cooperating with the arc structure of the reflective surface 22.

[0043] When the partially transmissive and partially reflective surface 21 and the reflective line 22 are specifically arranged, the partially transmissive and partially reflective surface 21 and the reflective surface 22 satisfy the following formula:

[0044] R1 / 2+d1-R2 / 2=0;

[0045] s2'=(R1*(R1+2d1)) / (d2-d1); s2>200mm;

[0046] Among them, R1 is the curvature radius of the partially transmissive and partially reflective surface 21, R2 is the curvature radius of the reflective surface 22, d1 is the minimum distance between the partially transmissive and partially reflective surface 21 and the reflective surface 22, d2 is the maximum distance between the partially transmissive and partially reflective surface 21 and the reflective surface 22, and s2' is the focal length of the lens composed of the partially transmissive and partially reflective surface 21 and the reflective surface 22.

[0047] Specifically, the light propagating in the waveguide is similar to parallel light, so the object distance formed is close to infinity. After entering the partially transmissive and partially reflective surface 21 in the waveguide, it will produce a convergence or divergence effect, and at this time it satisfies the Gaussian formula: f1' / s1'+f1 / s1=1, f' / f=-n' / n, f1 is the object focal length, f1' is the image focal length, n is the object refractive index, n' is the image refractive index, S1 is the object distance, and S1' is the image distance. When the system is a reflector, n'=-n, this time we can get f1 / s1'+f1 / s1=1, and when s1 is infinite, we can get s1'=f1.

[0048] After the light passes through the partially transmissive and partially reflective surface 21 for the first time, the image distance is s1'. The distance between the partially transmissive and partially reflective surface 21 and the reflective surface 22 is d. Due to the reflection, the image distance becomes the second reflection: s2 = s' + d. Continue to use the Gaussian formula: f2' / s2'+f2 / s2 = 1, f2' / f2 = -n' / n, f2 is the object focal length, f2' is the image focal length, n is the object refractive index, n' is the image refractive index, S2 is the object distance, S2' is the image distance, when the system is a reflector, n' = -n, this time we can get f2 / s2'+f2 / s2 = 1; s2' = (f2*s2) / (s2-f2) = f1*f2 / (f1+d-f2).

[0049] In the above formula, d is a variable value. When the reflection surface 22 is close to the waveguide (approximately around 1mm), the system image distance needs to be infinite, so f1+d-f2=0, that is, f1=f2+d. Since the entire system needs to achieve free switching between finite image distance and infinity, under the premise of achieving f1+d1-f2=0, the finite distance must also be satisfied: s2'=f1*f2 / (f1+d2-f2), s2>200mm; at this time, the relationship between s2' and R1 and d2 is: s2'=(R1*(R1+2d1)) / (d2-d1).

[0050] It can be seen from the above description that the partially transmissive and partially reflective surface 21 and the reflection line 22 provided in the embodiment of the present application achieve switching between finite image distance and infinite image distance by matching the curvature and the distance adjustment range between the two surfaces.

[0051] In an optional solution, both ends of the partially transmissive and partially reflective surface 21 extend to two opposite surfaces of the light guide 10; and a vertical plane 30 of the central axis of the partially transmissive and partially reflective surface 21 is inclined relative to the two surfaces of the light guide 10. The vertical plane 30 of the central axis of the partially transmissive and partially reflective surface 21 is a vertical plane corresponding to a line connecting the center point of the partially transmissive and partially reflective surface 21 and its center. Figure 2 The dashed line shown in FIG. 3 indicates a vertical plane 30 of the central axis. Figure 2 It can be seen that the vertical plane 30 of the central axis is relatively inclined relative to the two surfaces of the light guide 10, such as the angle between it and one surface is α, and α satisfies: 0°<α<90°. Exemplarily, the angle α can be 30°, 50°, 70°, 80°, etc. When the above-mentioned setting mode of the partially transmissive and partially reflective surface 21 is adopted, the propagation path of the light can be changed by the partially transmissive and partially reflective surface 21, and more light can be converged on the reflective surface 22.

[0052] In an implementable solution, the reflectivity of the partially transmissive and partially reflective surface 21 provided in the embodiment of the present application to light is between 2% and 10%. That is, the transmittance of the partially transmissive and partially reflective surface 21 is between 90% and 98%, and the reflectivity is between 2% and 10%. Exemplarily, the reflectivity of the partially transmissive and partially reflective surface 21 can be 2%, 5%, 7%, 9%, and 10%, and the corresponding transmittance of the partially transmissive and partially reflective surface 21 can be 98%, 95%, 93%, 91%, and 90%. In actual use, the partially transmissive and partially reflective surface 21 with different transmittance and reflectivity can be selected according to specific needs.

[0053] In a specific possible implementation scheme, the reflective surface 22 can adopt different methods when reflecting light, such as the reflective surface 22 also adopts a partially transmissive and partially reflective surface, or the reflective surface 22 is a polarized reflective surface, which can be applied to the optical device in the embodiment of the present application and is not specifically limited in the embodiment of the present application.

[0054] Since the reflective surface 22 is located in the light guide 10 as an independent structure, when the curved mirror 40 is provided, the optical device provided in the embodiment of the present application further includes the curved mirror 40, and the curved mirror 40 is located outside the light guide 10. The side of the curved mirror 40 facing away from the light guide 10 is the reflective surface 22; the side of the curved mirror 40 facing the light guide 10 is a flat surface. Figure 2 As shown in FIG. 1 , the two opposite surfaces of the curved mirror 40 are respectively an arcuate surface and a plane, wherein the plane faces the light guide 10, and the arcuate surface faces away from the light guide 10 and serves as a reflective surface 22. When light propagates, it can directly pass through the plane and irradiate the reflective surface 22.

[0055] In an optional solution, the curved mirror 40 is made of the same material as the light guide 10 , so that the light guide 10 and the curved mirror 40 can be made of one material.

[0056] When the driving mechanism is specifically set, the driving mechanism can adopt different types of driving mechanisms, as long as it can realize linear driving of the reflection surface 22. The linear direction is the linear direction along the arrangement direction of the two total internal reflection surfaces 11 of the light guide 10.

[0057] In an optional solution, the driving mechanism may include a linear motor, and the curved mirror 40 is fixedly connected to the moving end of the linear motor, so that the curved mirror 40 is directly driven to move by the linear motor. The moving distance of the curved mirror 40 can be achieved by controlling the moving distance of the linear motor. Of course, when the driving mechanism is connected to the curved mirror 40, the curved mirror 40 can be fixed to a support seat, and the moving end of the linear motor is fixedly connected to the support seat.

[0058] In an optional solution, the driving mechanism includes a lead screw and a driving motor for driving the lead screw to rotate, and the curved mirror 40 is driven by the lead screw. Specifically, when this structure is adopted, the curved mirror 40 can be assembled to a supporting structure supporting the light guide 10, and slidably connected to the supporting structure, and the sliding direction is along the arrangement direction of the two total internal reflection surfaces 11 of the light guide 10. The nut in the lead screw of the driving mechanism is fixedly connected to the curved mirror 40, and the lead screw lever is connected to the output shaft of the driving motor. When the output shaft of the driving motor rotates, the nut can be driven to move by the lead screw lever, thereby adjusting the distance between the curved mirror 40 and the partially transmitting and partially reflecting surface 21.

[0059] It should be understood that the driving mechanism in the above example is a common linear driving mechanism, and therefore, a schematic diagram of a specific driving mechanism is not illustrated in the embodiments of the present application.

[0060] To facilitate understanding of the optical device provided in the embodiment of the present application, the imaging effect thereof is described below with reference to a simulation result of a specific example.

[0061] Exemplarily, the thickness of the light guide 10 is 1.5 mm, the inclination angle between the vertical plane of the central axis of the partially transmissive and partially reflective surface 21 in the light guide 10 and the surface of the light guide 10 is 27°, the radius of curvature of the partially transmissive and partially reflective surface 21 is 150 mm, and it plays a divergent reflection role for parallel light. The reflectivity of the partially transmissive and partially reflective surface 21 is 5%, and the light is reflected after saving 5% of the energy and emitted from the light guide 10.

[0062] After leaving the light guide 10, the light passes through an optical material with a thickness of 1 mm and reaches the surface of the external reflective surface 22. The curvature radius of the reflective surface 22 is 125 mm. At this time, the surface of the external reflective surface 22 is coated with a reflective film that reflects in a specific polarization direction. After the S-direction light is reflected by the reflective film, since the curved reflective surface 22 has a converging and reflecting effect on optics, the light continues to propagate in the direction of the light guide 10 after convergence, and passes through the light guide 10 to reach the human eye.

[0063] like Figure 3 As shown, when the outer reflective surface 22 of the light guide 10 is 10 mm away from the surface of the light guide 10, the light enters the human eye and forms an image close to infinity, and its spot is shown in the figure, and the RMS (Root Mean Square) radius is 22 um, and the convergence effect is good;

[0064] like Figure 4 As shown, when the distance between the outer reflective surface 22 of the light guide 10 and the surface of the light guide 10 is adjusted to 0.6 mm, the light enters the human eye and forms an image of about 250 mm, which is close to the closest clear vision distance of the human eye. The spot is shown in the figure, and the RMS radius is 25 μm. The convergence effect is acceptable.

[0065] It can be seen from the simulation example that when the reflective surface 22 moves a distance of 9.4 mm, the image distance of the optical system changes from infinity to 250 mm. By changing the spacing between the two components (partially transmitting and partially reflecting surface 21 and reflective surface 22), the virtual image distance is adjusted to achieve the effect of focal plane transformation in the current system.

[0066] An embodiment of the present application also provides a near-eye display device, which includes a light generator and any one of the above-mentioned optical devices; wherein the light emitted by the optical device propagates into a light guide.

[0067] It can be seen from the above description that the optical device provided in the embodiment of the present application adjusts the depth of field presented when the light is irradiated into the user's pupil by using the cooperation of the partially transmissive and partially reflective surface 21 and the reflective surface 22, thereby realizing the depth of field adjustment from near to infinite distance, and improving the user experience. That is, the optical device disclosed in the present application can match the displayed image with the real focus position of the human eye, and improve the convergence adjustment conflict.

[0068] In an optional solution, the near-eye display device provided in the embodiment of the present application also includes a camera for collecting the state of the lens of the user's eyes and a data processing chip. The data processing chip can learn the user's viewing state through the state of the lens captured by the camera, and adjust the distance from the reflective surface to the light guide according to the state of the lens, so that the position where the user's eyes are focused matches the position where the optical device is imaged. It should be understood that the correspondence between the above-mentioned lens state and the distance from the reflective surface to the light guide can be constructed through multiple information collections before using the near-eye display device. For example, when the lens is contracted, the distance from the reflective surface to the light guide is adjusted until the human eye can observe a clear image. According to the different degrees of contraction or expansion of the lens, the corresponding reflective surface adjustment is performed for each state of the lens to construct the corresponding relationship between the distance from the reflective surface to the light guide corresponding to different states of the lens.

[0069] One or more embodiments of this specification are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of one or more embodiments of this specification should be included in the scope of protection of this disclosure.

[0070] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. An optical device, characterized in that: include: Light guide and focusing assembly; wherein, The focusing assembly comprises: a partially transmissive and partially reflective surface and a reflective surface arranged opposite to each other; wherein the partially transmissive and partially reflective surface is arranged in the light guide, and the reflective surface is arranged on a side of the light guide away from the outcoupling side and is spaced apart from the light guide; and further comprises a driving mechanism for driving the reflective surface to move relative to the partially transmissive and partially reflective surface; wherein both the partially transmissive and partially reflective surface and the reflective surface are arc-shaped surfaces; After the light in the light guide propagates to the partially transmissive and partially reflective surface, it is reflected by the partially transmissive and partially reflective surface to the reflective surface, then it is transmitted through the partially transmissive and partially reflective surface and emitted from the light guide.

2. The optical device according to claim 1, characterized in that The partially transmissive and partially reflective surface is one of a spherical surface, an aspherical surface or a free-form surface; The reflective surface is one of a spherical surface, an aspherical surface or a free-form surface corresponding to the partially transmissive and partially reflective surface.

3. The optical device according to claim 2, characterized in that: The partially transmissive and partially reflective surface and the reflective surface satisfy the following formula: R1 / 2+d1-R2 / 2=0; s2'=(R1*(R1+2d1)) / (d2-d1); s2>200mm; Among them, R1 is the curvature radius of the partially transmissive and partially reflective surface, R2 is the curvature radius of the reflective surface, d1 is the minimum distance between the partially transmissive and partially reflective surface and the reflective surface, d2 is the maximum distance between the partially transmissive and partially reflective surface and the reflective surface, and s2' is the focal length of the lens composed of the partially transmissive and partially reflective surface and the reflective surface.

4. The optical device according to claim 2, characterized in that: The partially transmissive and partially reflective surface is a concave arc surface, and the concave direction of the concave arc surface is away from the outcoupling side of the light guide component.

5. The optical device according to claim 4, characterized in that: Both ends of the partially transmissive and partially reflective surface extend to two opposite surfaces of the light guide; and a vertical plane of a central axis of the partially transmissive and partially reflective surface is inclined relative to the two surfaces of the light guide.

6. The optical device according to claim 2, characterized in that: The reflecting surface is a partially transmissive and partially reflective surface, and may also be a polarized reflective surface.

7. The optical device according to claim 6, characterized in that: The reflectivity of the partially transmissive and partially reflective surface to light is between 2% and 10%.

8. The optical device according to any one of claims 1 to 7, characterized in that: It also includes a curved mirror, which is located outside the light guide, wherein the side of the curved mirror facing away from the light guide is the reflecting surface; and the side of the curved mirror facing the light guide is a flat surface.

9. The optical device according to claim 8, characterized in that: The driving mechanism includes a linear motor; the curved mirror is fixedly connected to the moving end of the linear motor; or, The driving mechanism includes a lead screw and a driving motor for driving the lead screw to rotate, and the curved mirror is driven by the lead screw.

10. A near-eye display device, characterized in that: It comprises a light generator and an optical device as claimed in any one of claims 1 to 9; wherein: The light emitted by the optical device propagates into the light guide member.

Images