CN218481707U

CN218481707U - Micro optical machine system and near-to-eye display equipment

Info

Publication number: CN218481707U
Application number: CN202222518481.8U
Authority: CN
Inventors: 严子深; 赵永顺; 赵鹏; 李屹
Original assignee: Appotronics Corp Ltd
Current assignee: Shenzhen Appotronics Corp Ltd
Priority date: 2022-09-22
Filing date: 2022-09-22
Publication date: 2023-02-14
Anticipated expiration: 2032-09-22

Abstract

The application discloses a micro optical-mechanical system and near-to-eye display equipment. The micro-optomechanical system includes an image source, a polarization modulator, and an optical waveguide assembly. The polarized light source comprises an image source, a polarized modulator and an optical waveguide component, wherein the image source is used for emitting polarized image light, the polarized modulator is arranged on a light path of the polarized image light emitted by the image source and comprises a plurality of polarized subareas, and the optical waveguide component is used for coupling in the polarized image light emitted by the polarized modulator and coupling out the polarized image light. The plurality of polarization subareas respectively perform polarization modulation on light entering the respective subareas, so that the light coupled into the optical waveguide component at different angles has different polarization states, and the diffraction efficiency of the polarized image light coupled into the optical waveguide component is consistent. Through the mode, the uniformity of the emergent image of the micro optical machine system is good on the view field.

Description

Micro optical machine system and near-to-eye display equipment

Technical Field

The present application relates to the field of optical imaging devices, and more particularly to a micro optical machine system and a near-to-eye display device.

Background

With the development of technology, augmented Reality (AR) display devices, such as AR glasses, need to see both the external real world and virtual images. The real scene and the virtual information are fused into a whole, and the real scene and the virtual information are mutually reinforced and mutually enhanced.

In AR devices, a micro-light engine is typically used to generate an image that is transmitted to the human eye through a display waveguide. Due to various reasons such as different transmission paths of the light rays with different angles in the display waveguide, different diffraction efficiencies of the grating for the light rays with different angles and the like, the diffraction efficiencies of the light rays with different angles are different, namely, the uniformity of an image FOV (field of view) seen by human eyes is deteriorated.

SUMMERY OF THE UTILITY MODEL

The technical problem mainly solved by the present application is to provide a micro optical-mechanical system and a near-eye display device, which can improve the uniformity of an image FOV (field angle) of the near-eye display device.

In order to solve the technical problem, the application adopts a technical scheme that: providing a micro optical-mechanical system comprising:

an image source for emitting polarized image light;

the polarization modulator is arranged on a light path of the polarized image light emitted by the image source and comprises a plurality of polarization subareas; and

the optical waveguide component is used for coupling in the polarized image light emitted by the polarization modulator and coupling out the polarized image light;

the polarization subareas respectively perform polarization modulation on the polarization image light entering the respective subareas, so that the polarization image light coupled into the optical waveguide component at different angles has different polarization states, and further the diffraction efficiency of the polarization image light in the optical waveguide component is consistent.

In order to solve the technical problem, the other technical scheme adopted by the application is as follows: the utility model provides a near-to-eye display device, including wearing the frame and the miniature ray apparatus system that this application provided, it has two window districts that the interval set up to wear the frame, the light-emitting system to at least one window district outgoing ray in two window districts.

The beneficial effect of this application is: different from the prior art, the micro optical mechanical system comprises an image source, a polarization modulator and an optical waveguide assembly, wherein the polarization modulator comprises a plurality of polarization partitions. The polarization subareas can perform polarization adjustment on the polarized image light entering the polarization subareas, so that the polarized image light which is coupled into the optical waveguide assembly at different angles has different polarization states. The light with high diffraction efficiency is adjusted to a polarization state with low diffraction efficiency; the light that originally has low diffraction efficiency is adjusted to a polarization state that has high diffraction efficiency. Further, the diffraction efficiency of the polarized image light coupled into the optical waveguide assembly is consistent, and finally the FOV of the image coupled out from the optical waveguide assembly is uniform.

Drawings

FIG. 1 is a schematic diagram of a near-eye display device according to an embodiment of the present application;

FIG. 2 is a schematic diagram of an embodiment of a micro optical mechanical system;

FIG. 3 is a schematic diagram of polarization partitioning for a polarization modulator in an embodiment of the present micro optical bench system;

FIG. 4 is a schematic diagram of the distribution of the front and back polarization states of polarized image light passing through the polarization modulator of FIG. 3;

FIG. 5 is a schematic diagram of the luminance distribution of the field of view of the light coupled out by the optical waveguide assembly without polarization compensation and the luminance distribution of the field of view of the light coupled out by the optical waveguide assembly with polarization compensation by the polarization modulator of FIG. 3;

FIG. 6 is a schematic diagram of polarization partitions of a polarization modulator in another embodiment of a micro-optical engine system of the present application;

FIG. 7 is a schematic diagram of polarization partitions of a polarization modulator in yet another embodiment of the micro-optical mechanical system of the present application;

FIG. 8 is a schematic structural diagram of a micro optical mechanical system according to another embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a near-eye display device according to an embodiment of the present application.

Near-eye display device 10 includes a wearing frame 11, a wearing frame 12, and a micro-opto-mechanical system 100. The wearing frame 12 is connected to the wearing frame 11.

The wearing frame 11 has two window areas 13 arranged at intervals, the micro optical mechanical system 100 is used for emitting light to the window areas 13, and human eyes can observe images through the window areas 13.

The micro optical-mechanical system 100 is a micro optical-mechanical system provided in the present application, and the micro optical-mechanical system 100 can improve the FOV uniformity of the outgoing image in the window area 13.

It should be noted that the near-eye display device in the present application may include smart glasses, virtual reality smart glasses, and the like. It should be noted that the terms "comprises" and "comprising," and any variations thereof, in the embodiments of the present application, are intended to cover non-exclusive inclusions. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those steps or elements but may alternatively include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

Referring to fig. 2, fig. 2 is a schematic structural diagram of an embodiment of a micro optical mechanical system according to the present application.

In the present embodiment, the micro-opto-mechanical system includes an image source 110, a polarization modulator 120, a lens assembly 130, and an optical waveguide assembly 140.

The image source 110 is used to generate polarized image light of a desired image. Polarized image light generated by an image source sequentially passes through the lens assembly 130 of the polarization modulator 120 and enters the optical waveguide assembly 140, the optical waveguide assembly 140 is used for coupling in the polarized image light emitted by the polarization modulator 120, and the polarized image light is coupled out after being transmitted by the optical waveguide assembly 140 and emitted to human eyes. External ambient light (e.g., outdoor sunlight, light generated by an indoor illumination lamp) can also penetrate through the optical waveguide assembly 140 and enter human eyes, so that a user can view an image in the image source 110 and an image in the external environment, thereby implementing a virtual-real combined augmented reality function.

Alternatively, the image source 110 may include a Liquid Crystal projection system such as an LCoS (Liquid Crystal On Silicon) or a 3LCD (3 Liquid Crystal Display, three-chip LCD), and may also be a DMD projection system (Digital micromirror device). Where the image source 110 comprises an LCoS projection system, the LCoS itself may emit polarized image light. In the case that the image source 110 includes a DMD projection system or the like to emit unpolarized image light, the image source 110 may further include a polarizer disposed on an optical path of the unpolarized image light for converting the unpolarized image light into emitted polarized image light.

In the embodiments of the present application, an LCoS projection system is taken as an example.

Specifically, the image source 110 includes a light source 111, a light uniformizing system 112, an LCOS113, a polarization splitting prism 114, and an analyzer 115.

The light source 111 is disposed at one side of the light uniformizing system 112, the light source 111 emits polarized light to the light uniformizing system 112, and the light uniformizing system 112 receives the polarized light emitted from the light source 111 and emits uniform polarized light after uniformizing the polarized light. The polarization splitting prism 114 is arranged at the light-emitting side of the dodging system 112. The polarization beam splitter 114 is disposed on the optical path of the polarized light, and the polarized light emitted from the light source 111 is homogenized by the light homogenizing system 112 and then uniformly enters the polarization beam splitter 114.

The polarization splitting prism 114 functions to reflect polarized light, which is perpendicular to the direction of the polarized image light, and transmit the polarized image light.

The LCOS113 is disposed on the polarized light path reflected by the polarization beam splitter 114, and after the polarized light enters the LCOS113, the polarized light is modulated by the LCOS113 and then converted into polarized image light, and the polarized image light is incident into the polarization beam splitter 114, and the polarized image light transmits through the polarization beam splitter 114.

For example, in the present embodiment, the polarized light enters the polarization beam splitter prism 114 and is split into two vertically linearly polarized light-P polarized light and S polarized light. The P polarized light passes through completely, the S polarized light is reflected at an angle of 45 degrees, and the exit direction forms an angle of 90 degrees with the P polarized light.

The LCOS113 is disposed at the exit of the S-polarized light in the polarization splitting prism 114, and receives the S-polarized light exiting from the polarization splitting prism 114. When the pixel point of the LCOS113 is in a bright state, the S-polarized light is modulated and reflected by the LCOS113 to become P-polarized image light, and enters the polarization beam splitter 114 according to the original path, and the polarized image light passes through the polarization beam splitter 114 and exits from the other side of the polarization beam splitter 114. When the pixel point of the LCOS113 is in a dark state, the S-polarized light is not converted into a polarized image light, and cannot be reflected by the polarization splitting prism 114 after being reflected by the LCOS 113.

The analyzer 115 is disposed on the side of the polarization beam splitter 114 that emits the P-polarized light from the LCOS113, and is configured to analyze the light, and the polarized image light transmitted by the polarization beam splitter 114 is emitted after passing through the analyzer 115.

In this embodiment, the optical waveguide assembly 140 may specifically include an incoupling grating 141 and a waveguide substrate 142, wherein the incoupling grating 141 is carried on the waveguide substrate 142 and is used for coupling light into the waveguide substrate 142. The waveguide substrate 142 is a medium for guiding light to propagate therein, the light emits total reflection inside the waveguide substrate 142 for propagating light of the light source to human eyes, and the waveguide substrate 142 may be a planar optical waveguide. Optionally, the waveguide substrate 142 is made of high-refractive-index glass, and the refractive index of the waveguide substrate 142 is greater than or equal to 1.7 and less than or equal to 2.3, which is beneficial to ensuring the high-refractive-index characteristic of the waveguide substrate 142, and the high refractive index can increase the size of the field angle, so as to implement the optical waveguide sheet with an ultra-large field angle. Of course, different materials can be selected according to actual requirements.

Further, the optical waveguide assembly 140 may further include a turning grating (not shown) for expanding the pupil and a coupling-out grating (not shown) for coupling light out of the waveguide substrate 142, which are within the understanding of those skilled in the art and will not be described herein.

The polarization modulator 120 is disposed on an optical path of light emitted from the image source 110, and is configured to receive the light emitted from the image source 110 and perform polarization modulation on the light.

Specifically, the polarization modulator 120 is disposed on one side of the analyzer 115, and the light emitted from the polarization splitting prism 114 passes through the analyzer 115 and enters the polarization modulator 120, wherein the incident light enters the polarization modulator 120 in a uniform polarization state.

Lens assembly 130 may include a plurality of lens groups for imaging. The lens assembly 130 converts the areal distribution of the picture into an angular distribution and then directs the light rays from different locations on the resulting image out of the lens assembly 130 at different angles.

In the present embodiment, lens assembly 130 is disposed between polarization modulator 120 and optical waveguide assembly 140. The polarized image light after polarization modulation by the polarization modulator 120 enters the lens assembly 130, the polarized image light is imaged inside the lens assembly 130, and the polarized image light imaged by the lens assembly 130 enters the incoupling grating 141 of the optical waveguide assembly 140 at different angles.

As can be seen from the above description, the polarized image lights coupled into the coupling-in grating 141 of the optical waveguide assembly 140 have different incident angles, and the transmission paths of the polarized image lights with different angles in the waveguide substrate 142 are different, which results in different diffraction efficiencies of the polarized image lights in the optical waveguide assembly 140, and finally, the brightness of the image observed by human eyes is not uniform. In the present application, the diffraction efficiency of the polarized image light refers to a ratio of energy of the polarized image light coupled into the optical waveguide member 140 to energy of the polarized image light coupled out from the optical waveguide member 140.

In order to solve the above problem, the micro optical mechanical system in this embodiment is provided with the polarization modulator 120, and the polarization modulator 120 is disposed on the light path of the polarized image light emitted from the image source 110.

In the present embodiment, the polarization modulator 120 includes several polarization sections. Wherein the polarization sections polarization-modulate the polarized light passing therethrough, changing their polarization state. After the polarized image light of the image formed by the lens assembly 130 enters the polarization modulator 120, the polarization partitions respectively perform polarization modulation on the polarized image light entering the respective partitions, and the polarized image light passing through the polarization modulator 120 is coupled into the optical waveguide assembly 140 at different angles.

The diffraction efficiency of polarized image light at optical waveguide assembly 140 is affected by its polarization state in addition to the angle of incidence. For the light ray with low diffraction efficiency influenced by the incident angle, the polarization state of the light ray can be changed into the polarization state with higher diffraction efficiency. For the light ray with high diffraction efficiency influenced by the incident angle, the polarization state of the light ray can be changed into the polarization state with lower diffraction efficiency. Through polarization modulation, the diffraction efficiency of the light with low original diffraction efficiency is high, and the diffraction efficiency of the light with high original diffraction efficiency is low, so that the diffraction efficiency of polarization images incident at different angles tends to be consistent.

Therefore, in this embodiment, the polarization image light entering the polarization partition of the polarization modulator 120 is polarization-modulated by the polarization partitions, so that the polarization image light is polarization-compensated, the polarization image light with low diffraction efficiency is improved, and the polarization image light with high diffraction efficiency is reduced, so that the diffraction efficiency is consistent when the polarization image light coupled into the optical waveguide assembly 140 at different angles is optically coupled out, and the luminance of the coupled light out of the optical waveguide assembly 140 is uniform.

Alternatively, the polarization modulator 120 may be a birefringent crystal optical element capable of polarization modulating light. For polarization sections that serve different polarization modulation effects, it is possible to vary the optical axis direction and/or thickness of the birefringent crystal optical element so that different polarization sections can have different modulation effects.

Referring specifically to fig. 3, fig. 3 is a schematic diagram of polarization partitions of a polarization modulator in an embodiment of a micro-optics system of the present application.

In this embodiment, the polarization modulator 120 is a wave plate having the plurality of polarization sections, and the crystal optic axis directions and/or thicknesses of the plurality of polarization sections are different, so that different polarization sections can have different modulation effects.

Specifically, in the light incident side plane of the polarization modulator 120, the polarization modulator 120 is divided into m rows × n columns of quadrants, where each quadrant is a polarization partition. Each polarization partition may be a closed two-dimensional shape, e.g., a rectangle, polygon, or free-form area.

In this embodiment, the polarization modulator 120 is divided into 2 rows by 3 columns of polarization partitions. In other embodiments, the polarization modulator 120 may be divided into polarization partitions of 3 rows × 2 columns, 4 rows × 4 columns, 4 rows × 5 columns, and 5 rows × 4 columns.

Optionally, when the polarization partitions of the polarization modulator 120 are rectangular partitions, the length and width of the rectangular partitions are 10um to 10mm, and the larger the size of each polarization partition, the lower the processing difficulty, and the fewer the controllable polarization partitions. The person skilled in the art can adapt this to the actual situation.

In this embodiment, there are 4 sections that act as a polarization modulation effect of the 1/2 wave plate, and the polarized image light passing through the polarization sections changes the polarization direction of the original polarized light. While the other 2 sections do not have the effect of polarization modulation on the polarized image light passing through them.

Referring to fig. 4, fig. 4 is a schematic diagram illustrating the distribution of the front and rear polarization states of the polarized image light passing through the polarization modulator of fig. 3.

As can be seen from fig. 3, the polarization modulator 120 is divided into 2 rows × 3 columns of polarization partitions, 4 of which have the polarization modulation effect of a 1/2 wave plate, and the polarization state passing through the partition is changed. The other 2 subareas do not have polarization modulation effect on the light passing through the subareas, and the polarization state of the light passing through the subareas is not changed.

Fig. 3 shows only one embodiment, and those skilled in the art can also change the position and number of the polarization partitions based on the embodiment.

Referring to fig. 5, fig. 5 is a schematic diagram of luminance distribution of the light-coupled out field of view of the optical waveguide device without polarization compensation and luminance distribution of the light-coupled out field of view of the optical waveguide device with polarization compensation by the polarization modulator of fig. 3.

When the light is not subjected to polarization compensation, the brightness distribution of the field of view of the light coupled out from the optical waveguide component 140 is not uniform, and the brightness of a partial area is larger because the diffraction efficiency of the light with different incident angles is different. After the polarization compensation of the polarization modulator 120, the diffraction efficiency of the light with larger brightness in the original region is reduced, and the brightness of the light field coupled out by the optical waveguide component 140 in the region is reduced, so that the brightness distribution of the light field coupled out by the optical waveguide component 140 is uniform.

In another embodiment, referring to FIG. 6, FIG. 6 is a polarization division diagram of a polarization modulator in another embodiment of a micro-optical bench system of the present application.

In this embodiment, the polarization modulator 120 is an electrically controlled liquid crystal sheet. The electrically controlled liquid crystal panel includes a plurality of liquid crystal pixels 121. Therein, the polarization state of the polarized image light passing through the pixel 121 can be changed so that the diffraction efficiency of the polarized image light is changed. Thus, each pixel acts as a separate polarization partition at the polarization modulator 120.

The pixels 121 are configured to control the polarization angle of the liquid crystal after the voltage is applied, so that the polarization modulation effect of the pixels 121 can be dynamically adjusted under the action of the voltage to ensure uniform brightness of the light field emitted from the final waveguide assembly 140.

Alternatively, the pixels 121 may be closed two-dimensional shapes, for example, rectangles, circles, or polygons, each having a size of 0.5um to 1mm.

Compared with the previous embodiment, the polarization modulator 120 in this embodiment improves the fineness of polarization modulation, can more accurately perform polarization modulation on light, can dynamically modulate the modulation effect of each polarization partition, and improves the uniformity of the FOV of the image coupled out by the optical waveguide component 140.

In addition to the birefringent crystal described above, the polarization modulator 120 may also be a microstructured device having the number of polarization zones.

Referring to fig. 7, fig. 7 is a schematic diagram of polarization partitions of a polarization modulator in another embodiment of a micro optical mechanical system according to the present application.

The polarization modulator 120 includes a plurality of microstructure partitions therein, each of which is a separate polarization partition.

According to the diffraction formula:

d(sinα+sinβ)＝mλ

where d is the polarization partition period, α is the angle of incidence, β is the angle of diffraction, m is the diffraction order, and λ is the wavelength in the medium. Then when d < lambda/2,

|mλ|＝d|(sinα+sinβ)|＜2×A/2＝λ

when the period d of the polarization subareas is less than one half wavelength, only zero-order light exists in emergent light of the polarization subareas, and diffracted light of other orders does not exist. Therefore, the polarization partition period of the microstructure device in this embodiment should be less than one-half of the wavelength of the polarized image light, which is the polarized image light incident into the polarization modulator 120.

Alternatively, the microstructure device may be one or more of a grating, a super-surface, or a diffractive optical element, i.e., the polarization modulator 120 may be a grating, a super-surface, or a diffractive optical element.

Optionally, the size of the micro-structure partition is 0.1um to 10mm.

Different microstructure partitions have different polarization modulation effects on the polarized image light incident into the partition. The microstructure partitions the polarized image light with low diffraction efficiency under the influence of an incident angle, so that the polarization state of the polarized image light is changed into a polarization state with higher diffraction efficiency; the microstructure partitions the polarized image light with high diffraction efficiency under the influence of the incident angle, so that the polarization state of the polarized image light is changed into the polarization state with lower diffraction efficiency, the diffraction efficiency of the polarized image light incident at different angles tends to be consistent, and the uniformity of the FOV (field of view) of the coupled image of the waveguide component 140 is improved.

Alternatively, the polarization modulation effect of the microstructure partitions can be achieved by changing one or more of the shape, the refractive index, the arrangement direction, the depth and the duty ratio of each microstructure partition, and the polarization modulation effect can be set by a person skilled in the art according to actual situations.

Therefore, in this embodiment, the polarization modulator employs a microstructure device, which can also achieve the effect of compensating for the polarization of light, and improve the uniformity of the FOV of the image finally observed by human eyes.

Referring to fig. 8, fig. 8 is a schematic structural diagram of a micro optical mechanical system according to another embodiment of the present application.

The image source 110 is configured to generate polarized image light of a desired image, the polarized image light generated by the image source sequentially passes through the lens assembly 130 of the polarization modulator 120 and enters the optical waveguide assembly 140, and the optical waveguide assembly 140 optically couples out the polarized image and emits the polarized image to human eyes. External ambient light (e.g., outdoor sunlight, light generated by an indoor illumination lamp) can also penetrate through the optical waveguide assembly 140 and enter human eyes, so that a user can view an image in the image source 110 and an image in the external environment, thereby implementing a virtual-real combined augmented reality function. The image source 110 may be a liquid crystal projection system such as LCoS, or a DMD projection system. In the present embodiment, the image source 110 emits polarized light.

The polarization splitting prism 114 functions to reflect polarized light perpendicular to the direction of the polarized image light and transmit the polarized image light.

For example, in the present embodiment, the polarized light enters the polarization beam splitter prism 114 and is split into two vertically linearly polarized light, P-polarized light and S-polarized light. Wherein the P polarized light passes completely, and the S polarized light is reflected at a 45 degree angle, the exit direction making a 90 degree angle with the P polarized light.

The LCOS113 is disposed at the exit of the S-polarized light in the polarization splitting prism 114, and receives the S-polarized light exiting from the polarization splitting prism 114. When the pixel point of the LCOS113 is in a bright state, the S-polarized light is modulated and reflected by the LCOS113 to become P-polarized image light, and enters the polarization beam splitter 114 according to the original path, and the polarized image light passes through the polarization beam splitter 114 and exits from the other side of the polarization beam splitter 114. When the pixel point of the LCOS113 is in a dark state, the S-polarized light is not converted into a polarized image light, and cannot be reflected by the polarization beam splitter prism 114 after being reflected by the LCOS 113.

The analyzer 115 is disposed on a side of the polarization beam splitter 114 from which the polarized image light from the LCOS113 exits, and is configured to analyze the polarized image light, and the polarized image light transmitted by the polarization beam splitter 114 is transmitted through the analyzer 115 and then exits.

The lens assembly 130 is disposed at the light-emitting end of the analyzer 115 and is configured to receive the polarized image light analyzed by the analyzer 115.

Lens assembly 130 may include a plurality of lens groups for imaging, and polarized image light emitted from an image source enters lens assembly 130 and is imaged by lens assembly 130. The lens assembly 130 receives the polarized image light emitted through the analyzer 115, converts the plane distribution of the picture of the polarized image light into an angular distribution, and then emits the polarized image light from the lens assembly 130 at different angles.

At the light exit end of the lens assembly 130 disposed on the polarization modulator 120, the polarized image light incident into the lens assembly 130 exits at different angles and then enters the polarization modulator 120.

Lens assembly 130 is disposed between polarization modulator 120 and optical waveguide assembly 140. The polarization modulator 120 performs polarization modulation on the polarized image light with different incident angles, so that the polarized image light with different incident angles has different polarization states, and then the polarized image light with different incident angles transmits through the polarization modulator 120 and enters the optical waveguide assembly 140 again at different incident angles.

The optical waveguide assembly 140 may specifically include a coupling-in grating 141 and a waveguide substrate 142, the coupling-in grating 141 being carried on the waveguide substrate 142 for coupling the polarized image light into the waveguide substrate 142. The waveguide substrate 142 is a medium in which guided light propagates.

In the present embodiment, the polarization modulator 120 includes several polarization sections. The polarization sections polarization-modulate the polarized image light passing therethrough, changing their polarization state. Wherein the effect of the polarization partitions to polarization modulate the polarized image light passing through them is determined based on the incident angle of the light entering the polarization modulator 120.

The polarization image light incident at different angles into the polarization modulator 120 is subjected to different polarization modulations, so that the polarization image light incident at different angles into the incoupling grating 141 has different polarization states. For polarized image light that is affected by the angle of incidence and has a low diffraction efficiency, the polarization modulator 120 may change its polarization state to a polarization state with a higher diffraction efficiency. For the polarized image light with high diffraction efficiency influenced by the incident angle, the polarization modulator 120 may change the polarization state to a polarization state with lower diffraction efficiency. As a result of the polarization modulation, the diffraction efficiency of the polarized image light having low diffraction efficiency originally becomes high, the diffraction efficiency of the polarized image light having high diffraction efficiency originally becomes low, and finally the diffraction efficiencies of all the polarized image lights become uniform.

Alternatively, the polarization modulator 120 may be a birefringent crystal, such as a waveplate, an electrically controlled liquid crystal, or a microstructure device, such as a grating, a super-surface, or a diffractive optical element.

So, polarization modulation is carried out to the polarization image light that incides into respective subregion respectively to a plurality of polarization subregion of polarization modulator 120 in this embodiment, polarization image light has obtained polarization compensation, the polarization image light that incides into incoupling grating 141 with different angles has different polarization states, polarization image light that diffraction efficiency is low originally has obtained the promotion, polarization image light that diffraction efficiency is high originally has reduced diffraction efficiency, diffraction efficiency when making the optical coupling-out of incoupling light waveguide component 140 unanimously, the image FOV of outcoupling light waveguide component 140 is even. The comfort level of human eyes is improved.

In the description of the present application, reference to the description of the terms "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., means that a particular feature, mechanism, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, mechanisms, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Moreover, various embodiments or examples and features of various embodiments or examples described in this specification can be combined and combined by one skilled in the art without being mutually inconsistent.

The above description is only an example of the present application and is not intended to limit the scope of the present application, and all modifications of equivalent structures and equivalent processes, which are made by the contents of the specification and the drawings, or which are directly or indirectly applied to other related technical fields, are intended to be included within the scope of the present application.

Claims

1. A micro optical-mechanical system, comprising:

an image source for emitting polarized image light;

the polarization subareas respectively perform polarization modulation on the polarization image light entering the respective subareas, so that the polarization image light which is coupled into the optical waveguide component at different angles has different polarization states, and the diffraction efficiency of the polarization image light in the optical waveguide component is consistent.

2. The micro-opto-mechanical system of claim 1,

the micro optical-mechanical system further comprises a lens assembly, the lens assembly is arranged between the polarization modulator and the optical waveguide assembly, polarized image light polarized and modulated by the polarization modulator enters the lens assembly, the lens assembly images in the lens assembly, and the polarized image light imaged by the lens assembly is coupled into the optical waveguide assembly at different angles.

3. The micro optical bench system of claim 1 wherein,

the micro optical-mechanical system further comprises a lens assembly, the lens assembly is arranged between the image source and the polarization modulator, polarized image light emitted by the image source enters the lens assembly and is imaged by the lens assembly, the imaged polarized image light formed by the lens assembly enters the polarization modulator, the polarized image light entering each partition is subjected to polarization modulation by the plurality of polarization partitions, and the polarized image light passing through the polarization modulator is coupled into the optical waveguide assembly at different angles.

4. The microanahment system of any one of claims 1 to 3,

the polarization modulator is a birefringent crystal optical element, and the directions and/or thicknesses of the crystal optical axes of a plurality of polarization subareas are different.

5. The micro optical bench system of claim 4 wherein,

the polarization modulator is a wave plate with the plurality of polarization partitions, each partition of the wave plate is a rectangular partition, and the length and width of the rectangular partition are 10 um-10 mm.

6. The micro optical bench system of claim 4 wherein,

the polarization modulator is an electrically controlled liquid crystal sheet, each pixel of the electrically controlled liquid crystal sheet is an independent one of the polarization partitions, the liquid crystal of each pixel is configured to be capable of controlling a polarization angle so as to dynamically change a polarization modulation effect of each of the polarization partitions, and the size of each pixel is 0.5 um-1 mm.

7. The micro optical mechanical system according to any one of claims 1 to 3,

the polarization modulator is a microstructure device with the plurality of polarization partitions, the period of the plurality of polarization partitions is less than one half wavelength of polarized image light, and one or more of the shape, the refractive index, the arrangement direction, the depth and the duty ratio of the plurality of polarization partitions are different.

8. The micro optical mechanical system of claim 7,

the microstructure device is one or more of a grating, a super surface or a diffraction optical element, and the size of each polarization partition is 0.1 um-10 mm.

9. The micro-opto-mechanical system of claim 1 wherein the image source comprises:

a light source emitting polarized light;

the polarization beam splitter prism is arranged on a light emitting path of the light source and used for reflecting the polarized light and transmitting the polarized image light, and the polarization direction of the polarized light is vertical to that of the polarized image light;

the polarized light emitted by the light source enters a polarization beam splitter prism, is reflected to the LCOS, is modulated by the LCOS, is converted into the polarized image light and is emitted to the polarization beam splitter prism, and the polarized image light transmits the polarization beam splitter prism;

and the polarization analyzer is used for emitting the polarized image light transmitted by the polarization beam splitter prism after transmitting the polarization analyzer.

10. A near-eye display device comprising the micro-opto-mechanical system of any of claims 1-9.