CN116679476A

CN116679476A - Optical device, head-mounted display device, and adjustment method for head-mounted display device

Info

Publication number: CN116679476A
Application number: CN202310572291.0A
Authority: CN
Inventors: 杨柳; 任红恩; 丁延玉; 李晓雷
Original assignee: Weifang Goertek Electronics Co Ltd
Current assignee: Weifang Goertek Electronics Co Ltd
Priority date: 2023-05-18
Filing date: 2023-05-18
Publication date: 2023-09-01

Abstract

The embodiment of the application provides an optical device, head-mounted display equipment and an adjusting method of the head-mounted display equipment; the optical waveguide structure comprises an optical base and a first transparent substrate, and the optical base and the first transparent substrate are arranged in a stacked mode; the optical substrate is provided with a coupling-in area and a coupling-out area, and the first transparent substrate is provided with a first area and a second area; the first transparent substrate is provided with a first light modulation component in a first area, and the first light modulation component is used for converting image light projected by the display screen into circularly polarized light; the first transparent substrate is provided with a zoom group in the second area, the zoom group comprises at least one group of sub-zoom groups, the sub-zoom groups comprise a first liquid crystal layer and a first super-structure surface structure, the first liquid crystal layer is configured to switch between a first orientation and a second orientation so as to transmit circularly polarized light with different rotation directions to the first super-structure surface structure; the first super-structured surface structure forms virtual image planes of at least two focal lengths according to the received circularly polarized light of different handedness.

Description

Optical device, head-mounted display device, and adjustment method for head-mounted display device

Technical Field

The embodiment of the application relates to the technical field of augmented reality, in particular to an optical device, head-mounted display equipment and an adjusting method of the head-mounted display equipment.

Background

In AR (Augmented Reality ) products, for example, AR head-mounted display devices generally employ an optical waveguide as a core element, within which incident light can be transmitted according to the principle of total reflection. The surface of the optical waveguide is provided with a diffraction grating, and the diffraction grating is used for coupling light into the optical waveguide or coupling the light out of the optical waveguide for display imaging.

The root of the AR technology is to realize interaction between a person and the real world through fusion of the virtual world and the real world. When a human eye views an object, a stereoscopic image can be formed in the human brain by utilizing parallax of the left eye and the right eye, and when different position images are viewed, the left eye and the right eye can be automatically adjusted so that two pictures of the left eye and the right eye can be fused in the human brain.

In the related art, a single focus optical design scheme is generally adopted. Wherein the image presented by the single focus optical design is constant for the image distance of the human eye so that the human eye does not need to make refractive adjustments when viewing the image. And because the convergence rotation of human eyes and the invariable diopter adjustment generate conflict (namely convergence conflict), the human eyes are easy to generate eyestrain and dizziness when continuously watching dynamic 3D images.

Disclosure of Invention

The application aims to provide an optical device, head-mounted display equipment and a novel technical scheme of an adjusting method of the head-mounted display equipment.

In a first aspect, the present application provides an optical device as described. The optical device comprises an optical base and a first transparent substrate, wherein the optical base and the first transparent substrate are arranged in a stacked mode;

the optical substrate is provided with a coupling-in area and a coupling-out area, the first transparent substrate is provided with a first area corresponding to the coupling-in area and a second area corresponding to the coupling-out area;

the first transparent substrate is arranged on one side away from the optical base, and a first light modulation component is arranged in the first area and is configured to be capable of converting image light projected by a target display screen into circularly polarized light;

the first transparent substrate is arranged on one side away from the optical base, and a zooming group is arranged in the second area and comprises at least one group of sub-zooming groups, wherein the sub-zooming groups comprise a first liquid crystal layer and a first super-structure surface structure, and the first super-structure surface structure is arranged far away from the first transparent substrate relative to the first liquid crystal layer;

The first liquid crystal layer is configured to switch between a first orientation and a second orientation to transmit differently oriented circularly polarized light to the first super-structured surface structure; the first super-structured surface structure forms virtual image planes of at least two focal lengths according to the received differently oriented circularly polarized light.

Optionally, the first light modulating component comprises a second liquid crystal layer configured to convert the linearly polarized light into circularly polarized light.

Optionally, the first light modulating component further includes a third liquid crystal layer, the second liquid crystal layer and the third liquid crystal layer are stacked, and the third liquid crystal layer is disposed away from the first transparent substrate relative to the second liquid crystal layer;

the third liquid crystal layer is configured to convert image light projected by the target display screen into linearly polarized light.

Optionally, the first liquid crystal layer is connected to an electronic control assembly such that the first liquid crystal layer is switchable between a first orientation and the second orientation;

in the first orientation, the first liquid crystal layer is capable of reflecting first circularly polarized light while being capable of transmitting second circularly polarized light;

in the second orientation, the first liquid crystal layer is capable of reflecting the second circularly polarized light while transmitting the first circularly polarized light.

Optionally, the first liquid crystal layer is a cholesteric liquid crystal layer.

Optionally, the first super-structured surface structure is a super-structured lens.

Optionally, the first super-structure surface structure includes a plurality of structural units, and each structural unit is provided with a region for focusing the first circularly polarized light or the second circularly polarized light.

Optionally, the zoom group includes three sub-zoom groups, and the first liquid crystal layer in each sub-zoom group is separately connected with one electric control component to form a virtual image plane with six focal lengths.

Optionally, the optical device further includes a second transparent substrate, where the second transparent substrate is stacked with the optical base, and the first transparent substrate and the second transparent substrate are respectively located at two opposite sides of the optical base;

the second transparent substrate is provided with a third area corresponding to the coupling-out area;

a second light modulation component and a zooming compensation group are arranged on one side, away from the optical substrate, of the third region, and the zooming compensation group is arranged close to the second transparent substrate relative to the second light modulation component;

the second light modulation component is configured to convert ambient light into circularly polarized light;

The zoom compensation group is configured to compensate for a zoom parameter of the zoom group.

Optionally, the zoom compensation group includes at least one group of sub-zoom compensation groups, the sub-zoom compensation groups including a fourth liquid crystal layer and a second super-structured surface structure, the second super-structured surface structure being disposed close to the second transparent substrate with respect to the fourth liquid crystal layer;

the fourth liquid crystal layer is configured to switch between a first orientation and a second orientation to project circularly polarized light of different handedness to the second super-structured surface structure; the second super-structure surface structure receives the circularly polarized light and transmits the circularly polarized light to the zoom group, wherein the focal power of the second super-structure surface structure is opposite to that of the first super-structure surface structure so as to compensate the zoom parameter of the zoom group.

Optionally, the second light modulating component includes a fifth liquid crystal layer and a sixth liquid crystal layer, where the fifth liquid crystal layer and the sixth liquid crystal layer are stacked, and the fifth liquid crystal layer is disposed away from the second transparent substrate relative to the sixth liquid crystal layer;

the fifth liquid crystal layer is configured to convert ambient light into linearly polarized light;

the sixth liquid crystal layer is configured to convert the linearly polarized light into circularly polarized light.

Optionally, the zoom compensation group includes three groups of sub-zoom compensation groups, the fourth liquid crystal layer in each group of sub-zoom compensation groups is separately connected with one electric control component, and the focal power of the second super-structure surface structure in each group of sub-zoom compensation groups is opposite to the focal power of the first super-structure surface structure corresponding to the second super-structure surface structure.

In a second aspect, a head mounted display device is provided. The head mounted display device comprises an optical device as described in the first aspect.

In a third aspect, a method of adjusting a head mounted display device is provided. The adjusting method comprises the following steps:

acquiring human eye information data;

determining human eye focusing position information according to the human eye information data;

and adjusting the orientation of the first liquid crystal layer according to the human eye focusing position information, wherein the first super-structure surface structure forms virtual image planes with at least two focal lengths according to the received circularly polarized light with different rotation directions, so that the optical device realizes zooming.

According to an embodiment of the present application, an optical device is provided. The optical device comprises an optical substrate and a first transparent substrate, wherein a zooming group is arranged in a second area of the first transparent substrate corresponding to the coupling-out area, a first liquid crystal layer in the zooming group can be switched between a first orientation and a second orientation, and circularly polarized lights with different rotation directions generated by the first liquid crystal layer are focused differently at human eyes through a first super-structured surface structure, so that convergence conflict is not easy to occur when a viewer views a three-dimensional image, and user experience can be improved.

Other features of the present specification and its advantages will become apparent from the following detailed description of exemplary embodiments thereof, which proceeds with reference to the accompanying drawings.

Drawings

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

Fig. 1 is a schematic structural diagram of an optical device according to an embodiment of the present application.

Fig. 2 is a view showing an optical path structure of image light projected from a target display screen through a zoom group.

Fig. 3 is a diagram showing the optical path structure of ambient light passing through the zoom compensation group and the zoom group.

Fig. 4 is a schematic diagram of the electrical principle of the zoom group.

Fig. 5 is a schematic structural diagram of a head-mounted display device according to an embodiment of the present application.

Reference numerals illustrate:

1. an optical substrate; 10. a light machine module; 100. an optical device;

2. a first transparent substrate; 21. a first light modulating component; 211. a second liquid crystal layer; 212. a third liquid crystal layer; 22. a zoom group; 221. a sub-zoom group; 222. a first liquid crystal layer; 223. a first super-structured surface structure;

3. a second transparent substrate; 31. a second light modulating component; 311. a fifth liquid crystal layer; 312. a sixth liquid crystal layer; 32. a zoom compensation group; 321. a sub-zoom compensation group; 322. a fourth liquid crystal layer; 323. a second super-structured surface structure;

4. A head-mounted display device; 41. a frame; 42. an eye tracker.

Detailed Description

Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that: the relative arrangement of the components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present application unless it is specifically stated otherwise.

The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the application, its application, or uses.

Techniques and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but should be considered part of the specification where appropriate.

In all examples shown and discussed herein, any specific values should be construed as merely illustrative, and not a limitation. Thus, other examples of exemplary embodiments may have different values.

It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further discussion thereof is necessary in subsequent figures.

The present implementation provides an optical device 100. Referring to fig. 1-4, the optical device 100 includes: an optical base 1 and a first transparent substrate 2, the optical base 1 and the first transparent substrate 2 being laminated.

The optical substrate 1 has a coupling-in region and a coupling-out region, and the first transparent substrate 2 has a first region corresponding to the coupling-in region and a second region corresponding to the coupling-out region.

On the side of the first transparent substrate 2 facing away from the optical base 1, and in the first area, a first light modulating assembly 21 is arranged, the first light modulating assembly 21 being configured to be able to convert image light projected by a target display screen into circularly polarized light.

On the side of the first transparent substrate 2 facing away from the optical base 1, and in the second area, a zoom group 22 is arranged, the zoom group 22 comprising at least one set of sub-zoom groups 221, the sub-zoom groups 221 comprising a first liquid crystal layer 222 and a first super-structured surface structure 223, the first super-structured surface structure 223 being arranged remote from the first transparent substrate 2 with respect to the first liquid crystal layer 222. The first liquid crystal layer 222 is configured to switch between a first orientation and a second orientation to transmit circularly polarized light of different handedness to the first super-structured surface structure 223; the first super-structured surface structure 223 forms virtual image planes of at least two focal lengths from the received circularly polarized light of different handedness.

In the above-described embodiment, the optical device 100 includes the optical base 1 and the first transparent substrate 2, in which the first transparent substrate 2 and the optical base 1 are stacked, and the first transparent substrate 2 plays a role of protecting the optical base 1, for example, the first transparent substrate 2 plays a role of dust-proofing and water-proofing the optical base 1. In a specific embodiment, the optical base 1 and the first transparent substrate 2 may be fixed by an adhesive, for example, may be fixed by an optical adhesive.

In the above-described embodiment, the first transparent substrate 2 is disposed near the human eye side and the light source side, which are located on the same side. For example, the optical engine module 10 is disposed at the light source side, and the image light emitted by the optical engine module 10 is coupled into the optical substrate 1 through the coupling region of the optical substrate 1 after passing through the first transparent substrate 2.

The optical substrate 1 has a coupling-in area and a coupling-out area, wherein a coupling-in grating is disposed in the coupling-in area, and a coupling-out grating is disposed in the coupling-out area, wherein the coupling-in grating couples light passing through a first area of the first transparent substrate 2 into the optical substrate 1, and the light coupled into the optical substrate 1 is totally reflected in the optical substrate 1, and finally can be coupled out from the coupling-out grating of the optical substrate 1, finally exits from a second area passing through the first transparent substrate 2, and finally enters the human eye.

In the above-described embodiment, the optical device is provided to perform zooming based on circularly polarized light, and thus it is necessary to make the light coupled into the optical substrate 1 circularly polarized. I.e. the optics modulate the circularly polarized light and not the parameters of the other light. For example, it is not the modulation of the wavelength of the light that realizes zooming (when the dispersion is easily enlarged by modulating the wavelength of the light, the imaging quality is affected, which is the case when the user does not want to see), or the modulation of the phase of the light that realizes zooming (the modulation of the phase of the light, the wavefront phase difference is easily generated).

Specifically, on the side of the first transparent substrate 2 facing away from the optical base 1, and in the first region, a first light modulating component 21 is provided, wherein the first light modulating component 21 is capable of converting image light projected by the display screen into circularly polarized light. Specifically, the light emitted from the display screen and the external ambient light can be converted into circularly polarized light. However, the external ambient light enters the optical substrate 1, and the transmission condition of the external ambient light does not satisfy the total reflection condition, so that the external ambient light is not transmitted in the optical substrate 1, and therefore, in this embodiment, the light transmitted from the first area of the first transparent substrate 2 into the optical substrate 1, only the image light projected by the optical engine module 10 may be finally transmitted to the coupling-out area of the optical substrate 1, and is emitted through the zoom group 22 of the first transparent substrate 2.

The circularly polarized light converted by the first light modulating component 21 is coupled into the optical substrate 1 from the coupling-in area of the optical substrate 1, and the converted circularly polarized light is totally reflected in the optical substrate 1, and then coupled out from the coupling-out area of the optical substrate 1, finally exits from the second area passing through the first transparent substrate 2, and finally enters the human eye.

In the above embodiment, the zoom group 22 is disposed on the side of the first transparent substrate 2 facing away from the optical base 1 and in the second area, and the circularly polarized light is zoomed by the zoom group 22, so that the image projected by the display screen can be displayed in the virtual image plane with multiple focal lengths, so as to avoid the convergence conflict when the human eyes watch through the optical device, and avoid the phenomena of eyestrain and dizziness when the human eyes need to readjust the focusing and adjust the convergence in the real and virtual switching process.

Specifically, on the side of the first transparent substrate 2 facing away from the optical substrate 1, and in the second area, a zoom group 22 is disposed, where the zoom group 22 includes at least one group of sub-zoom groups 221, and according to the type of circularly polarized light transmitted to the first super-structure surface structure 223, the focal length of each sub-zoom group 221 may be adjusted, so that the zoom group 22 has a different focal length, and further performs zooming processing on an image projected by the target display screen, so that the optical device may present a picture in the image in a virtual image plane corresponding to multiple focal lengths as required, that is, form multi-focal-plane display. In this embodiment, at least two focal planes may be implemented to avoid convergence conflicts when the eye views through the optics, and to avoid eye fatigue and dizziness when the eye needs to readjust focus and adjust convergence during real and virtual switching.

Specifically, the sub-zoom group 221 includes a first liquid crystal layer 222 and a first super-structured surface structure 223, wherein the first liquid crystal layer 222 is attached to the surface of the second region of the first transparent substrate 2, and the first super-structured surface structure 223 is combined with the first liquid crystal layer 222. For example, the first super-structure surface structure 223 and the first liquid crystal layer 222 are bonded together by an optical adhesive. In this embodiment, the structure of the sub-zoom group 221 is defined, and the weight of the optical device, which is applied in the head-mounted display apparatus 4, can be reduced, realizing a lightweight design of the head-mounted display apparatus 4.

The first liquid crystal layer 222 is capable of switching between a first orientation and a second orientation, the first super-structure surface structure 223 is configured to zoom based on circularly polarized light, and the first super-structure surface structure 223 generates different wave front modulation on the circularly polarized light of the first rotation direction and the circularly polarized light of the second rotation direction, and is specifically configured to have different focal lengths on the circularly polarized light of the first rotation direction and the circularly polarized light of the second rotation direction.

For example, when the first liquid crystal layer 222 allows the transmission of circularly polarized light of the second rotation direction, the first super-structured surface structure 223 receives circularly polarized light of the second rotation direction, and the circularly polarized light of the second rotation direction is focused at the first position through the first super-structured surface structure 223; when the first super-structured surface structure 223 allows the transmission of circularly polarized light of the first handedness, the first super-structured surface structure 223 receives circularly polarized light of the first handedness, which is focused at the second position by the first super-structured surface structure 223; in this embodiment, the first liquid crystal layer 222 is actively controlled such that the first liquid crystal layer 222 may selectively allow transmission of circularly polarized light of a first rotation direction or allow transmission of circularly polarized light of a second rotation direction.

That is, when the first liquid crystal layer 222 allows the circularly polarized light of the second rotation direction to be transmitted, the first super-structured surface structure 223 may focus (focus at the first position) the circularly polarized light of the second rotation direction after the circularly polarized light of the second rotation direction passes through the first super-structured surface structure 223, so as to form a first focal length;

when the first liquid crystal layer 222 allows the circularly polarized light of the first rotation direction to be transmitted, the first super-structure surface structure 223 focuses (focuses at the second position) the circularly polarized light of the first rotation direction after the circularly polarized light of the first rotation direction passes through the first super-structure surface structure 223, so as to form the second focal length.

In the process of continuously switching the state of the first liquid crystal layer 222, the first super-structured surface structure 223 receives circularly polarized light with different rotation directions, so as to focus the circularly polarized light with different rotation directions at different positions, so that the focal length of the sub-zoom group 221 is continuously changed, and a picture in the image is displayed in virtual image planes corresponding to two focal lengths (for example, the circularly polarized light with the first rotation direction corresponds to the virtual image plane of the second focal length, and the circularly polarized light with the second rotation direction corresponds to the virtual image plane of the first focal length); optionally, when the zoom group 22 includes a plurality of sub-zoom layers, the zoom group 22 is enabled to realize different zoom ranges (i.e. zooming at different focal planes), and the picture in the image is presented in a virtual image plane corresponding to a plurality of focal lengths, that is, a multi-focal-plane display is formed.

For example, it can also be understood that: the first super-structure surface structure 223 is a liquid crystal layer structure having different focusing effects on circularly polarized light of the first rotation direction and circularly polarized light of the second rotation direction, the first super-structure surface structure 223 forms virtual image planes of different focal lengths according to the received circularly polarized light of the different rotation directions, for example, the first liquid crystal layer 222 allows the circularly polarized light of the second rotation direction to transmit light, wherein the first super-structure surface structure 223 receives the circularly polarized light of the second rotation direction to focus the circularly polarized light of the second rotation direction at the first position, forming one virtual image plane. At this time, the state of the first liquid crystal layer 222 is actively switched, so that the first liquid crystal layer 222 allows the circularly polarized light with the first rotation direction to transmit, where the first super-configured surface structure 223 receives the circularly polarized light with the first rotation direction to focus the circularly polarized light with the first rotation direction at the second position, so as to form a virtual image plane, where the virtual image plane at the first position and the virtual image plane at the second position have different focal lengths, and virtual image planes with different focal lengths are formed. For example, the microstructure of the structural units in the first super-structured surface structure 223 is passively controlled, and the first super-structured surface structure 223 is prepared such that the first super-structured surface structure 223 itself has different areas, and in the first super-structured surface structure 223, the super-structured surface structures of different areas have different focusing effects on circularly polarized light of the first rotation direction and circularly polarized light of the second rotation direction.

The first super-structure surface structure 223 is located on the light emitting side of the first liquid crystal layer 222, and the first super-structure surface structure 223 can generate different focusing effects for circularly polarized light with different rotation directions so as to perform focusing imaging at the human eyes, improve convergence conflict, and eliminate discomfort of viewers.

Thus in the above embodiments, an optical device 100 is provided. The optical device 100 comprises an optical base 1 and a first transparent substrate 2, wherein a zoom group 22 is arranged in a second area of the first transparent substrate 2 corresponding to the coupling-out area, a first liquid crystal layer 222 in the zoom group 22 can be switched between a first orientation and a second orientation, and a first super-structure surface structure 223 generates different focusing effects on circularly polarized light with different rotation directions generated by the first liquid crystal layer 222 at human eyes, so that vergence conflict is not easy to occur when a viewer views a three-dimensional image, and imaging quality is ensured. On the other hand, the zoom group 22 includes the first liquid crystal layer 222 and the first super-structured surface structure 223, reducing the weight of the optical device applied to the head-mounted display apparatus 4, realizing the lightweight head-mounted display apparatus 4.

In an alternative embodiment, the opto-mechanical module 10 includes a display screen and a collimating optical path, and can emit the light projected by the display screen into the optical device in parallel.

In one embodiment, the first light modulating assembly 21 includes a second liquid crystal layer 211, the second liquid crystal layer 211 being configured to convert the linearly polarized light into circularly polarized light.

In one embodiment, the first light modulating component further includes a third liquid crystal layer 212, the second liquid crystal layer 211 and the third liquid crystal layer 212 are stacked, and the third liquid crystal layer 212 is disposed away from the first transparent substrate 2 with respect to the second liquid crystal layer 211; the third liquid crystal layer 212 is configured to convert image light projected by the target display screen into linearly polarized light.

It should be emphasized that, when the image light emitted from the target display screen is linearly polarized, the first light modulating component 21 may include only the second liquid crystal layer 211.

In the above embodiment, the first light modulating component 21 includes the second liquid crystal layer 211 and the third liquid crystal layer 212, and the first light modulating component 21 is composed of the liquid crystal layers, and the light emitted from the display screen is modulated by the liquid crystal layers. Compared with the prior art, the present embodiment can attach a liquid crystal layer on the first transparent substrate 2 to reduce the weight of the optical device by modulating the light through the wafer.

Specifically, the second liquid crystal layer 211 and the third liquid crystal layer 212 are stacked and disposed in the first area of the first transparent substrate 2, for example, the second liquid crystal layer 211 is attached to the surface of the first area of the first transparent substrate 2 facing away from the optical substrate 1, and the third liquid crystal layer 212 is attached to the second liquid crystal layer 211, that is, the third liquid crystal layer 212 is disposed closer to the optical machine module 10 than the second liquid crystal layer 211.

Wherein the third liquid crystal layer 212 is capable of converting image light projected by the target display screen into linearly polarized light, i.e. the third liquid crystal layer 212 may achieve the effect of a polarizer. The second liquid crystal layer 211 can convert linearly polarized light into circularly polarized light, and the second liquid crystal layer 211 can achieve the effect of a 1/4 wave plate. The third liquid crystal layer 212 converts the light emitted from the display screen into linearly polarized light after passing through the third liquid crystal layer 212, then converts the linearly polarized light into circularly polarized light after passing through the second liquid crystal layer 211, and finally couples into the optical substrate 1 through the coupling region of the optical substrate 1 and transmits the circularly polarized light in the optical substrate 1.

It should be noted that, the internal structures of the second liquid crystal layer 211 and the third liquid crystal layer 212 are different, and the Pitch (Pitch) of the liquid crystal molecules in the liquid crystal layer can be adjusted, so that the liquid crystal layer has different modulation effects on light. The Pitch (Pitch) of the liquid crystal molecules in the liquid crystal layer is adjusted to make the liquid crystal layer have different modulation effects on the light (e.g. adjust the polarization state of the light), which is well known to those skilled in the art, and the internal structures of the second liquid crystal layer 211 and the third liquid crystal layer 212 are not described herein.

In this embodiment, the structure of the first light modulation element 21 is defined, the overall weight of the optical device is reduced, the optical device is applied to the head-mounted display apparatus 4, and the lightweight design of the head-mounted display apparatus 4 is realized.

In one embodiment, the first liquid crystal layer 222 is connected to an electronic control assembly such that the first liquid crystal layer 222 switches between a first orientation and the second orientation;

in the first orientation, the first liquid crystal layer 222 is capable of reflecting first circularly polarized light while transmitting second circularly polarized light;

in the second orientation, the first liquid crystal layer 222 is capable of reflecting the second circularly polarized light and transmitting the first circularly polarized light.

In the above embodiment, the first liquid crystal layer 222 is connected to the electronic control unit, for example, by controlling the voltage/electric field of the first liquid crystal layer 222, so that the first liquid crystal layer 222 can be switched between the first orientation and the second orientation, so as to realize the transmission of circularly polarized light allowing different handedness. For example, in the case where a voltage is applied to the first liquid crystal layer 222, the first liquid crystal layer 222 is in the first orientation; when no voltage is applied to the first liquid crystal layer 222, the first liquid crystal layer 222 is in the second orientation.

For example, the first liquid crystal layer 222 is in the first orientation, and the first liquid crystal layer 222 reflects circularly polarized light in the first direction and transmits circularly polarized light in the second direction. For example, the first liquid crystal layer 222 is in a right-handed state, and the first liquid crystal layer 222 may reflect right-handed circularly polarized light and transmit left-handed circularly polarized light.

The first liquid crystal layer 222 is in the second orientation, and the first liquid crystal layer 222 reflects the second circularly polarized light and transmits the first circularly polarized light. For example, the first liquid crystal layer 222 is in a left-handed state, and the first liquid crystal layer 222 may reflect left-handed circularly polarized light and transmit right-handed circularly polarized light.

In this embodiment, the zoom group 22 is disposed on the surface of the second area of the first transparent substrate 2 facing away from the optical substrate 1, the polarization state conversion of light in the zoom group 22 is implemented by the liquid crystal layer, on one hand, the zoom processing is implemented by the zoom group 22 on the image projected by the optical engine module 10, so that the picture of the image is presented in the virtual image plane with multiple focal lengths, thereby further improving the vergence conflict, eliminating the uncomfortable feeling of the viewer, on the other hand, the polarization state conversion of light in the zoom group 22 is implemented by the liquid crystal layer, the zoom group 22 can be attached on the first transparent substrate 2, the weight of the optical device is reduced, the optical device is applied to the head-mounted display device 4, and the light weight setting of the head-mounted display device 4 is implemented.

In one embodiment, the first liquid crystal layer 222 is a cholesteric liquid crystal layer.

In the above specific embodiment, the first liquid crystal layer 222 is a cholesteric liquid crystal layer, that is, cholesteric liquid crystal molecules having a helical structure in the first liquid crystal layer 222 perform voltage/electric field control on the cholesteric liquid crystal molecules having a helical structure, so as to allow circularly polarized light having different directions of rotation to pass through.

In one embodiment, the first super-structured surface structure 223 is a super-structured lens.

Specifically, the wave front modulation generated by the structures of different areas of the same structural unit in the super-structure lens on the left-handed circularly polarized light and the right-handed circularly polarized light is different, specifically, the focal lengths of the left-handed circularly polarized light and the right-handed circularly polarized light are different, namely, the super-structure lens generates different focusing effects on the circularly polarized light with different directions of rotation.

In one embodiment, the first super-structure surface structure 223 includes a plurality of structural units, and each structural unit has a region for focusing the first circularly polarized light or the second circularly polarized light disposed therein.

Specifically, modulation of circularly polarized light is achieved by providing structural units (microstructures) inside the first super-structured surface structure 223. For example, the control of the structural units in the super-structured lens is that each structural unit is about 100 nanometers, and each structural unit is about 100 nanometers and the inside of each structural unit is divided into a region which is specially focused for left-handed circularly polarized light or right-handed circularly polarized light. In a specific embodiment, the structural unit comprises two regions, the two regions being structurally different, wherein one region is focused exclusively on right-handed circularly polarized light and the other region is focused exclusively on left-handed circularly polarized light.

It should be noted that, modulating imaging performance such as chromatic aberration, polarization regulation, wavelength adjustment, etc. of the super-configured lens is a means known to those skilled in the art, but the embodiment of the present application prepares a structure unit structure inside the super-configured lens to implement modulation specifically for polarization. Compared with the modulation of the wavelength of the light (the easy occurrence of the expanding dispersion effect) or the modulation of the phase of the light (the easy occurrence of the wave front phase difference), the embodiment of the application realizes better multi-focal-plane imaging effect through the polarization modulation.

In one embodiment, referring to fig. 2 and 3, the zoom group 22 includes three sub-zoom groups 221, and the first liquid crystal layer 222 in each sub-zoom group 221 is individually connected to one electronic control unit to form a virtual image plane with six focal lengths.

In the above embodiment, the zoom group 22 includes three sub-zoom groups 221. Wherein the three sub-zoom groups 221 include a first sub-zoom group, a second sub-zoom group, and a third sub-zoom group. The first sub-zoom group, the second sub-zoom group, and the third sub-zoom group are stacked in the second region of the first transparent substrate 2. Thus in this embodiment, 6 focal planes are realized by the three sub-zoom groups 221, so that the zoom group 22 can be switched over 6 different focal length ranges, achieving near-eye to infinity.

For example, the first sub-zoom group comprises a first liquid crystal layer 222 and a first super-structure surface structure 223. The second sub-zoom group comprises a first liquid crystal layer 222 and a first super-structure surface structure 223. The third sub-zoom group comprises a first liquid crystal layer 222 and a first super-structure surface structure 223.

Wherein the first super-structured surface structure 223 in the first sub-zoom group, the first super-structured surface structure 223 in the second sub-zoom group 221 and the first super-structured surface structure 223 in the third sub-zoom group 221 must not be of identical design to focus at the same focal length position; nor must it be possible to focus at the same focus position after zooming is completed during zooming.

For example, for a first sub-zoom group, wherein the circularly polarized light transmitted within the optical substrate 1 first passes through the first liquid crystal layer 222 of the first sub-zoom group 221, e.g. when the first liquid crystal layer 222 is in a first orientation, the first liquid crystal layer 222 allows transmission of circularly polarized light opposite to its rotation, after which the first super-structured surface structure 223 focuses the circularly polarized light to a first focal plane depending on the type of circularly polarized light it receives; if the first liquid crystal layer 222 is in the second orientation at this time, the first liquid crystal layer 222 allows the circularly polarized light having the opposite rotation direction to be transmitted, and after the circularly polarized light is transmitted, the first super-structure surface structure 223 focuses the circularly polarized light to the second focal plane according to the type of the circularly polarized light it receives. In this embodiment, therefore, the first sub-zoom group 221 has two different focal lengths for circularly polarized light of different handedness, forming two focal planes. Wherein the focal lengths of the two focal planes are substantially different.

Likewise, for the second sub-zoom group, the circularly polarized light transmitted from the first sub-zoom group passes through the first liquid crystal layer 222 of the second sub-zoom group, controls the orientation of the first liquid crystal layer 222 in the second sub-zoom group 221, selectively allows one of the circularly polarized light of one rotation direction to pass through, and after the circularly polarized light passes through, the first super-structured surface structure 223 in the second sub-zoom group 221 focuses the circularly polarized light to the third focal plane according to the type of circularly polarized light it receives; if the orientation of the first liquid crystal layer 222 in the second sub-zoom group 221 is changed at this time, the first super-structured surface structure 223 in the second sub-zoom group focuses the circularly polarized light to the fourth focal plane according to the type of circularly polarized light it receives.

Likewise, for the third sub-zoom group, the circularly polarized light transmitted from the second sub-zoom group passes through the first liquid crystal layer 222 of the third sub-zoom group, controls the orientation of the first liquid crystal layer 222 in the third sub-zoom group, selectively allows one of the circularly polarized light to pass through, and after the circularly polarized light passes through, the first super-structured surface structure 223 in the third sub-zoom group focuses the circularly polarized light to the fifth focal plane according to the type of circularly polarized light it receives; if the orientation of the first liquid crystal layer 222 in the third sub-zoom group is changed at this time, the first super-structured surface structure 223 in the third sub-zoom group 221 focuses the circularly polarized light to the sixth focal plane according to the type of circularly polarized light it receives.

For example, the first super-structure surface structure 223 in the first sub-zoom group, the first super-structure surface structure 223 in the second sub-zoom group 221, and the structure within the structural unit in the first super-structure surface structure 223 in the third sub-zoom group 221 may be changed, the first super-structure surface structure 223 being passively controlled. For example, the first super-structured surface structure 223 in the three sub-zoom group 221 is differently prepared such that the first super-structured surface structure 223 in the three sub-zoom group 221 has different focal lengths for circularly polarized light of different handedness.

In this embodiment, the zoom group 22 includes three sub-zoom groups 221, each sub-zoom group 221 includes a first liquid crystal layer 222 and a first super-structure surface structure 223, and voltages are applied to the three first liquid crystal layers 222, respectively, so that the zoom group 22 can realize zooming of six focal planes (for example, can realize a zoom range of 0-2.5D), and the zoom range is enlarged.

Note that, in the present embodiment, the number of sub-zoom groups 221 included in the zoom group 22 is not limited, as long as real-time zooming of the zoom group 22 can be achieved by processing the sub-zoom groups 221.

In one embodiment, referring to fig. 1, the optical device further includes a second transparent substrate 3, where the second transparent substrate 3 is stacked with the optical base 1, and the first transparent substrate 2 and the second transparent substrate 3 are respectively located on two opposite sides of the optical base 1;

The second transparent substrate 3 has a third region corresponding to the coupling-out region;

a second light modulating component 31 and a zoom compensation group 32 are arranged on one side, away from the optical substrate 1, of the third region, and the zoom compensation group 32 is arranged close to the second transparent substrate 3 relative to the second light modulating component 31;

the second light modulating assembly 31 is configured to convert ambient light into circularly polarized light;

the zoom compensation group 32 is configured to compensate for zoom parameters of the zoom group 22.

In this embodiment, the optical device further comprises a second transparent substrate 3, wherein the second transparent substrate 3 and the first transparent substrate 2 are arranged on opposite sides of the optical base 1. For example, the second transparent substrate 3 is disposed on a side facing away from the human eye, and the second transparent substrate 3 and the optical base 1 may be fixed by using an adhesive, for example, may be fixed by using an optical adhesive.

In general, ambient light on the side of the optical substrate 1 facing away from the human eye will enter the human eye through the second transparent substrate 3, the optical substrate 1 and the zoom group 22, that is, the zoom group 22 zooms circularly polarized light transmitted by the optical substrate 1, and the ambient light on the side facing away from the human eye is correspondingly zoomed, so that light transmitted in the optical substrate 1 cannot be clearly displayed in the human eye. For example, the composition of the ambient light is complex, most of the ambient light is circularly polarized light, and after the circularly polarized light in the ambient light passes through the optical substrate 1 and the zoom group 22, the circularly polarized light in the ambient light has focal length compensation, which is undesirable and may cause unclear condition of viewing the picture by human eyes. That is, in the present embodiment, only the zooming process is desired for the projected image light in the opto-mechanical module 10, and the zooming process is not desired for the ambient light.

Therefore, in the above-described embodiment, the second transparent substrate 3 has the third region corresponding to the coupling-out region, and the second light modulation element 31 and the zoom compensation group 32 are provided on the side of the third region facing away from the optical base 1.

Specifically, the ambient light is converted into circularly polarized light by the second light modulation assembly 31. The zoom parameters of the zoom group 22 are compensated by the zoom compensation group 32, for example, if the zoom group 22 achieves a diopter adjustment of 1D, it is desirable that the zoom compensation group 32 can achieve a diopter adjustment of-D to counteract the effect of the zoom group 22 on ambient light.

For example, the ambient light is modulated by the second light modulating component 31 to be circularly polarized light, and the circularly polarized light is subjected to the zoom compensation group 32, the optical substrate 1 and the zoom group 22 to offset the influence of the optical device on the ambient light, so that the definition of the image watched by human eyes is improved.

In one embodiment, referring to fig. 1 and 3, the zoom compensation group 32 includes at least one sub-zoom compensation group 321, the sub-zoom compensation group 321 including a fourth liquid crystal layer 322 and a second super-structure surface structure 323, the second super-structure surface structure 323 being disposed close to the second transparent substrate 3 with respect to the fourth liquid crystal layer 322;

The fourth liquid crystal layer 322 is configured to switch between a first orientation and a second orientation to project circularly polarized light of different handedness to the second super-structured surface structure 323; the second super-structure 323 receives the circularly polarized light and transmits the circularly polarized light to the zoom group 22, wherein the optical power of the second super-structure 323 is opposite to the optical power of the first super-structure 223 to compensate for the zoom parameters of the zoom group 22.

In the above embodiment, the zoom compensation group 32 includes the fourth liquid crystal layer 322 and the second super-structured surface structure 323, wherein the second super-structured surface structure 323 may be adhered to the surface of the second transparent substrate 3, and the fourth liquid crystal layer 322 may be adhered to the second super-structured surface structure 323.

In the above-described embodiment, the fourth liquid crystal layer 322 is capable of switching between the first orientation and the second orientation. The fourth liquid crystal layer 322 functions as the first liquid crystal layer 222 discussed above, and selectively allows one of the circularly polarized light to pass therethrough. Therefore, in this embodiment, the fourth liquid crystal layer 322 will not be described in detail.

In the above embodiment, after the second super-structure surface structure 323 receives the circularly polarized light with different rotation directions, and transmits the corresponding circularly polarized light through the optical substrate 1, the first liquid crystal layer 222 and the first super-structure surface structure 223, since the optical powers of the second super-structure surface structure 323 and the first super-structure surface structure 223 are opposite, after the circularly polarized light with different rotation directions sequentially passes through the second super-structure surface structure 323 and the first super-structure surface structure 223, the circularly polarized light with different rotation directions is equivalent to passing through a flat glass, and the human eye can observe the virtual image and the scene in the environment which are amplified and projected by the zoom group 22 in the focusing position thereof, so as to realize AR display.

Referring to fig. 3, the zoom compensation group 32 includes three sub-zoom compensation groups 321, specifically, a left-side zoom compensation group (including a fourth liquid crystal layer 322 and a second super-structure surface structure 323), a middle-side zoom compensation group (including a fourth liquid crystal layer 322 and a second super-structure surface structure 323), and a right-side zoom compensation group (including a fourth liquid crystal layer 322 and a second super-structure surface structure 323).

The zoom group 22 includes three sub-zoom groups 221, specifically, a left-side zoom group (including the first liquid crystal layer 222 and the first super-structure surface structure 223), a middle-side zoom group (including the first liquid crystal layer 222 and the first super-structure surface structure 223), and a right-side zoom group (including the first liquid crystal layer 222 and the first super-structure surface structure 223).

Wherein the optical power of the second super-structured surface structure 323 in the left-hand zoom compensation group is opposite to the optical power of the first super-structured surface structure 223 in the left-hand zoom group; the optical power of the second super-structured surface structure 323 in the middle of the zoom compensation group is opposite to the optical power of the first super-structured surface structure 223 in the middle of the zoom group; the optical power of the second super-structured surface structure 323 in the zoom compensation group on the right is opposite to the optical power of the first super-structured surface structure 223 in the zoom group on the right.

Thus, in the above embodiment, in a specific embodiment, the zoom group on the side of the optical substrate 1 close to the human eye may implement 5D diopter adjustment, and the zoom compensation group on the outer side of the optical substrate may implement-5D diopter adjustment to offset the effect of the zoom system on ambient light.

In one embodiment, the second optical adjustment component includes a fifth liquid crystal layer 311 and a sixth liquid crystal layer 312, the fifth liquid crystal layer 311 and the sixth liquid crystal layer 312 being stacked, the fifth liquid crystal layer 311 being disposed away from the second transparent substrate 3 with respect to the sixth liquid crystal layer 312;

the fifth liquid crystal layer 311 is configured to convert ambient light into linearly polarized light;

the sixth liquid crystal layer 312 is configured to convert the linearly polarized light into circularly polarized light.

In the above embodiment, the second light modulating component 31 is composed of a liquid crystal layer, through which the modulation of the ambient light is achieved. Compared with the prior art, the present embodiment can attach a liquid crystal layer on the second transparent substrate 3 to reduce the weight of the optical device by modulating the light through the wafer.

Specifically, the fifth liquid crystal layer 311 and the sixth liquid crystal layer 312 are stacked and disposed in the third region of the second transparent substrate 3.

The fifth liquid crystal layer 311 can convert the ambient light into the linearly polarized light, that is, the fifth liquid crystal layer 311 can realize the effect of the polarizer, the sixth liquid crystal layer 312 can convert the linearly polarized light into the circularly polarized light, and the sixth liquid crystal layer 312 can realize the effect of the 1/4 wave plate.

It should be noted that, the internal structures of the fifth liquid crystal layer 311 and the sixth liquid crystal layer 312 are different, and the Pitch (Pitch) of the liquid crystal molecules in the liquid crystal layers can be adjusted to make the liquid crystal layers have different modulation effects on light. The adjustment of the Pitch (Pitch) of the liquid crystal molecules in the liquid crystal layer to make the liquid crystal layer have different modulation effects on the light (e.g. adjusting the polarization state of the light), which are well known to those skilled in the art, will not be described herein.

In this embodiment, the structure of the second light modulation member 31 is defined, the overall weight of the optical device is reduced, the optical device is applied to the head-mounted display apparatus 4, and the lightweight design of the head-mounted display apparatus 4 is realized.

In one embodiment, the zoom compensation group 32 includes three groups of sub-zoom compensation groups 321, wherein the fourth liquid crystal layer 322 in each group of sub-zoom compensation groups 321 is individually connected to one electronic control component, and the optical power of the second super-structure surface structure 323 in each group of sub-zoom compensation groups 321 is opposite to the optical power of the first super-structure surface structure 223 corresponding to the second super-structure surface structure.

In the above-described embodiment, the zoom compensation group 32 and the zoom group 22 are structurally mirror symmetrical with respect to the optical substrate 1.

In this embodiment, the zoom compensation group 32 includes three sub-zoom compensation groups 321. Wherein the three sub-zoom-compensation-groups 321 include a first sub-zoom-compensation-group, a second sub-zoom-compensation-group, and a third sub-zoom-compensation-group. The first, second, and third sub-zoom compensation groups are stacked in a third region of the second transparent substrate 3. The first sub-zoom compensation group and the first sub-zoom group correspond in position, the second sub-zoom compensation group and the second sub-zoom group correspond in position, and the third sub-zoom compensation group and the third sub-zoom group correspond in position. The zoom compensation group 32 and the zoom group 22 have opposite optical powers.

For example, the first sub-zoom compensation group comprises a fourth liquid crystal layer 322 and a second super-structured surface structure 323, wherein the second super-structured surface structure 323 corresponds to the first super-structured surface structure 223 in the first sub-zoom group and has opposite optical powers, e.g. the first super-structured surface structure 223 corresponds to two focal lengths and the second super-structured surface structure 323 corresponds to two focal lengths, the focal lengths of the two super-structured surface structures being opposite such that the first super-structured surface structure 223 and the second super-structured surface structure 323 have opposite optical powers;

The second sub-zoom compensation group comprises a fourth liquid crystal layer 322 and a second super-structured surface structure 323, wherein the second super-structured surface structure 323 corresponds to the first super-structured surface structure 223 in the second sub-zoom group, and the optical power of the second super-structured surface structure are opposite.

The third sub-zoom compensation group comprises a fourth liquid crystal layer 322 and a second super-structured surface structure 323, wherein the second super-structured surface structure 323 corresponds to the first super-structured surface structure 223 in the third sub-zoom group, and the optical power of the second super-structured surface structure are opposite.

In this embodiment, the structures of the zoom compensation group 32 and the zoom group 22 are defined such that the zoom group 22 on the side of the optical substrate 1 close to the human eye achieves positive diopter (e.g., 5D power) adjustment, and the zoom compensation group 32 on the outside of the optical substrate 1 achieves-5D diopter adjustment to offset the effect of the optics on ambient light.

The optical substrate 1 may be a waveguide substrate, or may be another substrate or an optical device according to the embodiment of the present application, which is not limited in this disclosure.

In a second aspect, a head mounted display device 4 is provided. The head-mounted display device 4 includes:

a housing; and

the optical device of the first aspect, the optical device disposed on the housing.

In some examples of the application, the headset may be augmented reality smart glasses or the like. The specific implementation manner of the headset according to the embodiment of the present application may refer to each embodiment of the optical device, and will not be described herein.

In a third aspect, a method of adjusting a head mounted display device 4 is provided. The adjusting method comprises the following steps:

s01: acquiring human eye information data;

s02: determining human eye focusing position information according to the human eye information data;

s03: the orientation of the first liquid crystal layer 222 is adjusted according to the human eye focus position information so that the optical device realizes zooming.

In the above-described embodiments, the head-mounted display device 4 may be, for example, augmented reality smart glasses.

The smart glasses comprise two frames 41, one of the above-described optical devices being provided on each frame 41.

In the above-described step S01, the manner of acquiring the human eye information data includes, for example, providing two eye trackers 42 on the smart glasses. When the eyes watch different objects, the distance between the pupils of the two eyes is changed, the pupil size can be changed, and the distance between the two pupils, the size of the pupil and the direction in which the eyes look can be identified through the two eye tracker 42 (the eye tracker 42 is arranged beside the nose pad) arranged on the intelligent glasses. I.e. the eye information data comprises the distance between the two pupils, the size of the pupil and the direction in which the eye looks.

Of course, there are many ways to obtain human eye information data, including but not limited to the above description.

In the above step S02, the information data of the human eye obtained by the eye tracker 42 is sent to the built-in processing unit for calculation, so as to obtain the current focusing position of the eye, and the position information is converted into a control signal, so that the focusing position information of the human eye is determined.

In the step S03, after the position information of the focusing of the human eye is obtained, the focal length of the zoom group 22 may be adjusted according to the virtual image plane corresponding to the position information of the focusing of the human eye, so as to bring more realistic immersive visual experience to the viewer.

Specifically, the information of the focusing position of the human eye is transmitted to the electronic control component, the electronic control component applies a voltage to the first liquid crystal layer 222, so that one of the circularly polarized light with a rotation direction can be selectively allowed to pass through, and the first super-structure surface structure 223 projects the circularly polarized light to a virtual image plane according to the type of the circularly polarized light, so as to realize the zooming of the optical device.

The foregoing embodiments mainly describe differences between the embodiments, and as long as there is no contradiction between different optimization features of the embodiments, the embodiments may be combined to form a better embodiment, and in consideration of brevity of line text, no further description is given here.

While certain specific embodiments of the invention have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the invention. It will be appreciated by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims

1. An optical device, characterized by comprising an optical base (1) and a first transparent substrate (2), the optical base (1) and the first transparent substrate (2) being arranged in a stack;

the optical substrate (1) has a coupling-in region and a coupling-out region, the first transparent substrate (2) having a first region corresponding to the coupling-in region and a second region corresponding to the coupling-out region;

a side of the first transparent substrate (2) facing away from the optical base (1), and a first light modulating component (21) is arranged in the first area, wherein the first light modulating component (21) is configured to convert image light projected by a target display screen into circularly polarized light;

a side of the first transparent substrate (2) facing away from the optical base (1), and a zoom group (22) is arranged in the second region, the zoom group (22) comprising at least one group of sub-zoom groups (221), the sub-zoom groups (221) comprising a first liquid crystal layer (222) and a first super-structured surface structure (223), the first super-structured surface structure (223) being arranged away from the first transparent substrate (2) with respect to the first liquid crystal layer (222);

The first liquid crystal layer (222) is configured to switch between a first orientation and a second orientation to transmit differently oriented circularly polarized light to the first super-structured surface structure (223); the first super-structured surface structure (223) forms virtual image planes of at least two focal lengths from the received differently oriented circularly polarized light.

2. An optical device according to claim 1, characterized in that the first light modulating assembly (21) comprises a second liquid crystal layer (211), the second liquid crystal layer (211) being configured to convert linearly polarized light into circularly polarized light.

3. The optical device according to claim 2, wherein the first light modulating assembly further comprises a third liquid crystal layer (212), the second liquid crystal layer (211) and the third liquid crystal layer (212) being arranged in a stack, and the third liquid crystal layer (212) being arranged away from the first transparent substrate (2) with respect to the second liquid crystal layer (211);

the third liquid crystal layer (212) is configured to convert image light projected by the target display screen into linearly polarized light.

4. The optical device according to claim 1, wherein the first liquid crystal layer (222) is connected to an electronic control assembly such that the first liquid crystal layer (222) is switchable between a first orientation and the second orientation;

In the first orientation, the first liquid crystal layer (222) is capable of reflecting first circularly polarized light while being capable of transmitting second circularly polarized light;

in the second orientation, the first liquid crystal layer (222) is capable of reflecting second circularly polarized light while transmitting first circularly polarized light.

5. An optical device according to claim 1, characterized in that the first liquid crystal layer (222) is a cholesteric liquid crystal layer.

6. The optical device according to claim 1, wherein the first super-structured surface structure (223) is a super-structured lens.

7. The optical device of claim 1 or 6, wherein the first super-structure surface structure comprises a plurality of structural units, each structural unit having disposed therein a region that distinguishes between focusing of either the first circularly polarized light or the second circularly polarized light.

8. An optical device according to claim 1, characterized in that the zoom group (22) comprises three sets of said sub-zoom groups (221), the first liquid crystal layer (222) in each set of said sub-zoom groups (221) being individually connected to one electronic control assembly to form a virtual image plane of six focal lengths.

9. The optical device according to claim 1, further comprising a second transparent substrate (3), the second transparent substrate (3) being arranged in a stack with the optical base (1), and the first transparent substrate (2) and the second transparent substrate (3) being located on opposite sides of the optical base (1), respectively;

The second transparent substrate (3) has a third region corresponding to the out-coupling region;

a second light modulation component (31) and a zooming compensation group (32) are arranged on one side, away from the optical substrate (1), of the third region, and the zooming compensation group (32) is arranged close to the second transparent substrate (3) relative to the second light modulation component (31);

-the second light modulating assembly (31) is configured to convert ambient light into circularly polarized light;

the zoom compensation group (32) is configured to compensate for a zoom parameter of the zoom group (22).

10. The optical device according to claim 9, characterized in that the zoom compensation group (32) comprises at least one set of sub-zoom compensation groups (321), the sub-zoom compensation groups (321) comprising a fourth liquid crystal layer (322) and a second super-structured surface structure (323), the second super-structured surface structure (323) being arranged close to the second transparent substrate (3) with respect to the fourth liquid crystal layer (322);

the fourth liquid crystal layer (322) is configured to switch between a first orientation and a second orientation to project circularly polarized light of different handedness to a second super-structured surface structure (323); the second super-structured surface structure (323) receives circularly polarized light and transmits the circularly polarized light to the zoom group (22), wherein the optical power of the second super-structured surface structure (323) is opposite to the optical power of the first super-structured surface structure (223) to compensate the zoom parameter of the zoom group (22).

11. The optical device according to claim 10, wherein the second light modulating assembly (31) comprises a fifth liquid crystal layer (311) and a sixth liquid crystal layer (312), the fifth liquid crystal layer (311) and the sixth liquid crystal layer (312) being arranged in a stack, the fifth liquid crystal layer (311) being arranged away from the second transparent substrate (3) with respect to the sixth liquid crystal layer (312);

the fifth liquid crystal layer (311) is configured to convert ambient light into linearly polarized light;

the sixth liquid crystal layer (312) is configured to convert the linearly polarized light into circularly polarized light.

12. The optical device according to claim 10, wherein the zoom compensation group (32) comprises three sub-zoom compensation groups (321), the fourth liquid crystal layer (322) in each sub-zoom compensation group (321) being individually connected to one electronic control assembly, the optical power of the second super-structured surface structure (323) in each sub-zoom compensation group (321) being opposite to the optical power of its corresponding first super-structured surface structure (223).

13. A head-mounted display device, comprising: the optical device of any one of claims 1-12.

14. A method of adjusting a head mounted display device as recited in claim 13, wherein the method of adjusting comprises:

Acquiring human eye information data;

the orientation of the first liquid crystal layer (222) is adjusted according to the human eye focusing position information, and the first super-structure surface structure (223) forms virtual image planes with at least two focal lengths according to the received circularly polarized light with different rotation directions, so that the optical device realizes zooming.