WO2022012244A1

WO2022012244A1 - Near-eye display device, optical structure suitable for near-eye display device, and assembly method for optical structure

Info

Publication number: WO2022012244A1
Application number: PCT/CN2021/100023
Authority: WO
Inventors: 赵瑜; 向恩来
Original assignee: 宁波舜宇光电信息有限公司
Priority date: 2020-07-13
Filing date: 2021-06-15
Publication date: 2022-01-20
Also published as: CN115702377A; CN113933990A

Abstract

Disclosed are an optical structure suitable for a near-eye display device and an assembly method therefor, and the near-eye display device. The optical structure suitable for the near-eye display device comprises: a first optical waveguide and a second optical waveguide, which have a preset mounting position relationship, wherein the first optical waveguide and the second optical waveguide are staggered from each other with respect to a projection direction from a projector toward the first optical waveguide, and have a preset gap therebetween; and an adhesive provided between the first optical waveguide and the second optical waveguide, wherein the gap between the first optical waveguide and the second optical waveguide ranges from 50 μm to 150 μm. The optical structure is manufactured by an active calibration process, such that the optical structure has a higher assembly precision between respective layers of the optical waveguides.

Description

Near-eye display device, optical structure suitable for near-eye display device, and assembly method thereof

technical field

The present application relates to near-eye display devices, and in particular, to near-eye display devices, optical structures suitable for near-eye display devices, and assembling methods thereof.

Background technique

In recent years, near-eye display devices (eg, virtual display devices, enhanced display devices) have received increasing attention. Compared with virtual reality, augmented display devices can build virtual scenes based on the physical environment, bringing users a new experience. Enhanced display technology includes two technical directions: the traditional Birdbath scheme, and the projector plus waveguide sheet scheme. The traditional Birdbath solution is relatively bulky and difficult to further improve the field of view, and the relatively poor experience is difficult to be favored by consumers. The solution using the waveguide sheet is relatively small and beautiful, and the user experience is better.

The waveguide sheet can diffuse light along the waveguide sheet through a diffraction grating or transflective surface, so that the viewer can observe the image over the entire visible area of the waveguide sheet. However, both the diffraction grating structure and the transflective surface have wavelength selectivity. The diffraction efficiency of light with different wavelengths is different, and the transmittance of light with different wavelengths on the transflective surface is also different, causing the viewer to The image observed at the exit pupil of the waveguide sheet will have some degree of color cast. In addition, due to the different diffraction angles of light with different wavelengths, the viewing angle of the image displayed by the waveguide sheet is limited, and at the same time, the image is prone to distortion.

In order to solve the above technical problems, a Chinese patent (patent number: CN210243962U, which is cited based on a British patent, patent number: GB2573793) proposes to use a plurality of waveguide sheets to transmit light of different wavelengths respectively. Specifically, in this patent, it includes a first waveguide sheet and a second waveguide sheet, wherein the red light and a part of the green light are transmitted in the first waveguide sheet; the other part of the green light and the blue light are transmitted in the second waveguide sheet in transmission.

However, there are some technical problems in the specific implementation of the optical structure of the multilayer waveguide sheet.

First, if the two waveguide sheets are directly attached together (ie, there is no gap between them) or there is partial contact (ie, there is no gap in some areas between the two), it will destroy the entire interior of the light in the waveguide sheet. reflection transmission.

Moreover, for the multilayer waveguide sheet to form an optical structure, if errors such as positioning error and/or assembly error occur during its installation, the final optical structure will have a matching error, resulting in ghosting of the output image. That is, the optical structure constituted by the multilayer waveguide sheet requires high matching precision, which poses a great challenge to the manufacturing and assembling process.

In addition, the waveguide sheet itself also has errors when manufacturing the grating. For example, the nano-imprinted template and the waveguide material are not completely parallel, resulting in optical deviation even if the multilayer waveguide sheet has a relatively high parallelism during installation. .

Therefore, an optimized preparation process of an optical structure suitable for a near-eye display device is required to prepare an optical structure that meets the requirements.

SUMMARY OF THE INVENTION

An advantage of the present application is to provide a near-eye display device, an optical structure suitable for a near-eye display device, and an assembling method thereof, wherein the optical structure is prepared by an active alignment process, so that each layer of optical waveguides in the optical structure is fabricated There is a high assembly accuracy between the two, so that the near-eye display device has low ghosting and/or distortion.

Another advantage of the present application is to provide a near-eye display device, an optical structure suitable for the near-eye display device, and an assembly method thereof, wherein the optical structure has high assembly strength and reliability.

Another advantage of the present application is to provide a near-eye display device, an optical structure suitable for a near-eye display device, and an assembly method thereof, wherein the optical structure has high assembly efficiency and yield.

Another advantage of the present application is to provide a near-eye display device, an optical structure suitable for the near-eye display device, and an assembling method thereof, wherein, in an embodiment of the present application, in the process of assembling the optical structure through an active calibration process , the first optical waveguide and the second optical waveguide of the optical structure have a certain gap therebetween through the adhesive disposed therebetween, so as to reduce the probability of interference, thereby improving the assembly efficiency and yield.

Another advantage of the present application is to provide a near-eye display device, an optical structure suitable for the near-eye display device, and an assembling method thereof, wherein, in an embodiment of the present application, in the process of assembling the optical structure through an active calibration process , the adhesive disposed between the first optical waveguide and the second optical waveguide of the optical structure can limit the direction of active calibration, reduce the amplitude and adjustment times of active calibration, and improve assembly efficiency and yield.

Another advantage of the present application is to provide a near-eye display device, an optical structure suitable for a near-eye display device, and an assembling method thereof, wherein, in an embodiment of the present application, the adhesive includes a plurality of particles embedded therein , so as to ensure that the gap between the first optical waveguide and the second optical waveguide of the optical structure will not be lower than the preset value during the assembly process through a plurality of the particles, resulting in light interference, so as to improve the assembly efficiency and yield. .

Another advantage of the present application is to provide a near-eye display device, an optical structure suitable for a near-eye display device, and an assembling method thereof, wherein the optical structure is prepared by an active alignment process, so that the optical structure can be eliminated in terms of performance Manufacturing errors of diffraction gratings for optical waveguides described in . That is, through the active calibration process, the errors existing in the basic structural elements of the optical structure can also be effectively eliminated.

Other advantages and features of the application will become apparent from the description below and may be realized by means of the instrumentalities and combinations particularly pointed out in the claims.

In order to achieve at least one of the above objects or advantages, the present application provides a method for assembling an optical structure, which includes:

providing a first optical waveguide, a second optical waveguide, a projector and an imaging device;

Projecting a projection image with a positioning pattern onto the first diffraction grating of the first optical waveguide by the projector, wherein part of the light of the projected image enters the first diffraction grating from the coupling-in region of the first diffraction grating The first projection image is coupled out from the coupling-out region of the first diffraction grating to the imaging device in the optical waveguide after total internal reflection; the other part of the projection image is directed toward the second optical waveguide of the second optical waveguide. The direction of the diffraction grating is coupled out from the first optical waveguide and enters into the second optical waveguide from the in-coupling region of the second diffraction grating and exits the out-coupling region of the second diffraction grating after total internal reflection coupling out the second projection image to the imaging device;

Adjust the relative position between the first optical waveguide and the second optical waveguide based on the offset between the positioning pattern of the first projected image and the positioning pattern of the second projected image relationship; and

determining an installation positional relationship between the first optical waveguide and the second optical waveguide in response to the offset satisfying a preset threshold range; and

Based on the installation position relationship, the first optical waveguide and the second optical waveguide are fixed.

In the assembling method according to the present application, before projecting the projection image with the positioning pattern on the first diffraction grating of the first optical waveguide by the projector, further comprising: fixing the projector, the first light guide The waveguide and the imaging device are in preset positions.

In the assembling method according to the present application, the first optical waveguide and the The relative positional relationship between the second optical waveguides includes: moving the second optical waveguide to adjust the relative positional relationship between the first optical waveguide and the second optical waveguide.

In the assembling method according to the present application, the offset between the positioning pattern of the first projection image and the positioning pattern of the second projection image includes an offset direction and an offset distance.

In the assembling method according to the present application, fixing the first optical waveguide and the second optical waveguide together based on the installation position relationship includes: installing the first optical waveguide and the second optical waveguide together. An adhesive is arranged between the waveguides; and the adhesive is cured to fix the first optical waveguide and the second optical waveguide together.

In the assembling method according to the present application, disposing an adhesive between the first optical waveguide and the second optical waveguide includes: removing the second waveguide sheet; on the lower surface of the first waveguide sheet disposing an adhesive; and placing the second waveguide sheet back at the position determined based on the mounting position relationship.

In the assembling method according to the present application, before projecting the projection image with the positioning pattern on the first diffraction grating of the first optical waveguide by the projector, further comprising: pre-fixing the first optical waveguide with an adhesive and the second optical waveguide; wherein, based on the installation position relationship, fixing the first optical waveguide and the second optical waveguide together includes: curing the first optical waveguide and the second optical waveguide the adhesive between the second optical waveguides.

In the assembly method according to the present application, the thickness of the adhesive is in the range of 50 μm to 150 μm, and the width of the adhesive is in the range of 1 mm to 3 mm.

In the assembling method according to the present application, the adhesive is provided on the peripheral regions of the first optical waveguide and the second optical waveguide.

In the assembling method according to the present application, the adhesive has a non-closed shape.

In the assembling method according to the present application, the shape of the adhesive is a ring shape with at least one notch.

In the assembly method according to the present application, the adhesive is provided at four corner regions of the peripheral region.

In the assembling method according to the present application, the adhesive includes a plurality of particles embedded therein and uniformly distributed, and the diameter of the particles is less than or equal to the diameter range between the first optical waveguide and the second optical waveguide. gap size.

In the assembly method according to the present application, the diameter of the particles ranges from 50 μm to 150 μm.

In the assembling method according to the present application, before providing the first optical waveguide, the second optical waveguide, the projector and the imaging device, the method further includes: determining that the first optical waveguide and the second optical waveguide are the same type of light waveguide.

In the assembling method according to the present application, determining that the first optical waveguide and the second optical waveguide are the same type of optical waveguides includes: obtaining when the first optical waveguide is actively calibrated relative to a standard second optical waveguide required first offset; obtain the second offset required when the second optical waveguide is actively calibrated relative to the standard first optical waveguide; and determine the first offset and the first offset The two offsets satisfy a preset range to determine that the first optical waveguide and the second optical waveguide are optical waveguides of the same type.

In the assembling method according to the present application, the assembling method further comprises: arranging a light shielding layer on the side part of the first optical waveguide and/or the side part of the second optical waveguide.

According to another aspect of the present application, an optical structure suitable for a near-eye display device is also provided, comprising:

a first optical waveguide having a first diffraction grating;

A second optical waveguide with a second diffraction grating, the first optical waveguide and the second optical waveguide have a preset installation position relationship, the first optical waveguide and the second optical waveguide are relative to the projection by the projection The projection directions of the instrument toward the first optical waveguide are staggered from each other with a preset gap therebetween; and

The adhesive disposed between the first optical waveguide and the second optical waveguide, wherein the gap between the first optical waveguide and the second optical waveguide ranges from 50 μm to 150 μm.

In the optical structure according to the present application, the thickness dimension of the adhesive ranges from 50 μm to 150 μm, and the width dimension ranges from 1 mm to 3 mm.

In the optical structure according to the present application, the installation positional relationship between the first optical waveguide and the second optical waveguide is confirmed through an active calibration process.

In the optical structure according to the present application, the adhesive includes a plurality of particles embedded therein and uniformly distributed, and the diameter range of the particles is less than or equal to the distance between the first optical waveguide and the second optical waveguide. gap.

In the optical structure according to the present application, the diameter of the particles ranges from 50 μm to 150 μm.

In the optical structure according to the present application, the optical structure further includes a light shielding layer provided on the side of the first optical waveguide and/or the side of the second optical waveguide.

In the optical structure according to the present application, the first optical waveguide and the second optical waveguide are the same type of optical waveguide, wherein the same type of optical waveguide means that the first optical waveguide is relative to the standard second optical waveguide The first offset required for active calibration and the second offset required for active calibration of the second optical waveguide relative to the standard first optical waveguide meet a preset range.

In the optical structure according to the present application, the degree of parallelism between the first optical waveguide and the second optical waveguide is less than or equal to 2'.

According to yet another aspect of the present application, a near-eye display device is also provided, comprising:

The optical structure as described above; and

A projector configured to project a projected image onto the optical structure.

Further objects and advantages of the present application will be fully realized by an understanding of the ensuing description and drawings.

These and other objects, features and advantages of the present application are fully embodied by the following detailed description, drawings and claims.

Description of drawings

The above and other objects, features and advantages of the present application will become more apparent from the detailed description of the embodiments of the present application in conjunction with the accompanying drawings. The accompanying drawings are used to provide a further understanding of the embodiments of the present application, constitute a part of the specification, and are used to explain the present application together with the embodiments of the present application, and do not constitute a limitation to the present application. In the drawings, the same reference numbers generally refer to the same components or steps.

FIG. 1 illustrates a schematic diagram of an optical structure suitable for a near-eye display device according to an embodiment of the present application.

FIG. 2 illustrates a schematic diagram of an assembly process of the optical structure according to an embodiment of the present application.

FIG. 3 illustrates another schematic diagram of an assembly process of the optical structure according to an embodiment of the present application.

FIG. 4 illustrates a schematic diagram of a positioning pattern used in the assembly process of the optical structure according to an embodiment of the present application.

FIG. 5 illustrates an imaging schematic diagram of the imaging device during the assembly process of the optical structure according to the embodiment of the present application.

FIG. 6 illustrates another schematic diagram of a positioning pattern used in the assembly process of the optical structure according to an embodiment of the present application.

FIG. 7A illustrates yet another schematic diagram of the assembly process of the optical structure according to an embodiment of the present application.

FIG. 7B illustrates yet another schematic diagram of the assembly process of the optical structure according to an embodiment of the present application.

FIG. 7C illustrates yet another schematic diagram of the assembly process of the optical structure according to an embodiment of the present application.

FIG. 8A illustrates yet another schematic diagram of the assembly process of the optical structure according to an embodiment of the present application.

FIG. 8B illustrates yet another schematic diagram of the assembly process of the optical structure according to an embodiment of the present application.

FIG. 9 illustrates a schematic diagram of an adhesive used in the assembly process of the optical structure according to an embodiment of the present application.

FIG. 10 illustrates a schematic diagram of a near-eye display device according to an embodiment of the present application.

detailed description

Hereinafter, exemplary embodiments according to the present application will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application, and it should be understood that the present application is not limited by the example embodiments described herein.

Exemplary Optical Structure

As shown in FIG. 1 , an optical structure suitable for a near-eye display device according to an embodiment of the present application is illustrated, wherein the optical structure 10 is configured to extend the projection image projected by the projector 20 to the entire optical structure 10 Visible area. In the embodiment of the present application, as shown in FIG. 1 , the optical structure 10 includes a first optical waveguide 11 and a second optical waveguide 12 , and the first optical waveguide 11 and the second optical waveguide 12 are opposite to each other by the projection The projection directions of the instrument 20 toward the first optical waveguide 11 are laterally staggered from each other with a preset gap therebetween, that is, as shown in FIG. 1 , in the embodiment of the present application, the first optical waveguide 11 and The second optical waveguides 12 are staggered from each other along the thickness direction thereof with a preset gap therebetween. The first optical waveguides 11 are used to guide a part of the light of the projected image, and the second optical waveguides 12 for deriving another portion of the light from the projected image. In particular, in the embodiment of the present application, the gap between the first optical waveguide 11 and the second optical waveguide 12 ranges from 50 μm to 150 μm, and the first optical waveguide 11 and the second optical waveguide 12 are in the range of 50 μm to 150 μm. The parallelism between them is less than or equal to 2'.

It is worth mentioning that the first optical waveguide 11 and the second optical waveguide 12 can be respectively used to transmit light of different wavelengths, or can be respectively used to transmit light of different incident angles. For example, in a specific application scenario of the present application, the light of the projected image can be configured with light with multiple wavelengths, for example, it has a first primary color, a second primary color and a third primary color (more specifically, for example, the One primary color is red, the second primary color is green, and the third primary color is blue), wherein the first optical waveguide 11 is configured to derive light of the first primary color and part of the second primary color, the second primary color The optical waveguide 12 is configured to derive portions of the second and third primary colors of light.

More specifically, as shown in FIG. 1 , in the embodiment of the present application, the first optical waveguide 11 includes a first diffraction grating 111 having an in-coupling region and an out-coupling region, wherein a part of the light of the projected image It enters the first waveguide from the coupling-in region of the first diffraction grating 111 and is coupled out from the coupling-out region of the first diffraction grating 111 after total internal reflection. The second optical waveguide 12 includes a second diffraction grating 121 having an in-coupling region and an out-coupling region, wherein another part of the projected image is light in the direction of the second diffraction grating 121 of the second optical waveguide 12 from the second diffraction grating 121. The first optical waveguide 11 is coupled out and enters the second optical waveguide 12 from the coupling-in region of the second diffraction grating 121 and is coupled from the coupling-out region of the second diffraction grating 121 after total internal reflection. out. Accordingly, the projected image coupled out from the first optical waveguide 11 and the projected image coupled out from the second optical waveguide 12 overlap each other and are seen by the viewer.

It should be understood that, in order to make the projected image coupled out from the first optical waveguide 11 and the projected image coupled out from the second optical waveguide 12 be more perfectly integrated, so as to obtain a better visual experience, the A preset installation position relationship needs to be satisfied between the first optical waveguide 11 and the second optical waveguide 12 . That is, in the specific preparation process of the optical structure 10, the first optical waveguide 11 and the second optical waveguide 12 of the optical structure 10 need to have high installation and matching accuracy. If the relative positional relationship or matching accuracy cannot meet the preset requirements, undesirable visual phenomena such as color cast will occur.

In order to meet the above technical requirements, in the embodiment of the present application, the optical structure 10 is assembled by means of active alignment, so that the optical waveguides of the optical structures 10 have high assembly precision between the layers. Correspondingly, the optical structure 10 assembled and formed by active alignment has a structure as shown in FIG. 1 . Particularly,

Specifically, as shown in FIG. 1 , in the embodiment of the present application, the optical structure 10 further includes an adhesive 13 disposed between the first optical waveguide 11 and the second optical waveguide 12 . In particular, in the embodiment of the present application, the adhesive 13 has a relatively small thickness dimension (ie, a height dimension) and a relatively wide width dimension. Specifically, in the embodiment of the present application, the thickness of the adhesive 13 ranges from 50 μm to 150 μm, and the width of the adhesive 13 ranges from 1 mm to 3 mm.

In a specific example of the present application, the adhesive 13 includes a plurality of particles 131 embedded therein, so as to ensure that the first optical waveguide 11 and the second optical waveguide 11 are determined by an active calibration process through the plurality of the particles 131 . During the installation position relationship between the optical waveguides 12, there is always a certain gap between the first optical waveguide 11 and the second optical waveguide 12, so as to avoid the light interference phenomenon that the gap between the two is too small. . In the embodiment of the present application, the diameter of the particles 131 ranges from 50 μm to 150 μm and is smaller than or equal to the size of the gap between the first optical waveguide 11 and the second optical waveguide 12 .

Preferably, in the embodiment of the present application, the particles 131 are uniformly distributed in the adhesive 13 . Here, the uniform distribution of the particles 131 means that there are similar lateral gaps between the particles 131 and the particles 131 itself has approximately the same diameter.

In order to prevent external stray light from entering the inside of the optical structure 10 from the side and causing stray light to affect the visual experience, in the embodiment of the present application, the optical structure 10 further includes a side disposed on the first optical waveguide 11 . The light shielding layer 14 on the side part and/or the second optical waveguide 12, wherein the light shielding layer 14 can be generated by a blackening process, for example, an inkjet method or an ink coating method.

Schematic Assembly Process

2 to 9 illustrate schematic diagrams of an assembly process of the optical structure 10 according to an embodiment of the present application. As shown in FIG. 2 , the assembling process first includes: providing a first optical waveguide 11 , a second optical waveguide 12 , a projector 20 and an imaging device 30 . The projector 20 can project a projection image with a positioning pattern, and the imaging device 30 can capture and image the projection image.

As shown in FIG. 3 , in a specific example of the present application, the projector 20 , the first optical waveguide 11 and the imaging device 30 are fixed at preset positions, and the second optical waveguide 12 is adjustable Installed on the side of the first optical waveguide 11 to change the relative positional relationship between the second optical waveguide 12 and the first optical waveguide 11 by adjusting the posture (including position and posture) of the second optical waveguide 12 . For example, in the example shown in FIG. 3 , the second optical waveguide 12 is fixed to the adjustment platform 40 by clamping or suction, wherein the adjustment platform 40 is suitable for six degrees of freedom directions (respectively: Adjust the pose of the second optical waveguide 12 on the X, Y, Z, rotation around the X/Y/Z axis). It should be noted that in this example, the second optical waveguide 12 is adjustably mounted on the back of the first optical waveguide 11 and is in a preset position, wherein the preset position is not the second optical waveguide The final installation position of 12 is only to ensure that the light of the projected image can be coupled out to the imaging device 30 through the first optical waveguide 11 and the second optical waveguide 12 . And, in this example, when the second optical waveguide 12 is in the preset position, there is a certain gap between the second optical waveguide 12 and the first optical waveguide 11 .

It is worth mentioning that, preferably, in this example, the edge region of the second optical waveguide 12 is mounted on the adjustment platform 40 through a holding mechanism such as a suction nozzle. The optical area of the second optical waveguide 12 is not affected.

Moreover, in other examples of the present application, the relative positional relationship between the first optical waveguide 11 and the second optical waveguide 12 may be adjusted in other ways, which are not limited by the present application. For example, the second optical waveguide 12 can be fixed at a preset position to selectively adjust the pose of the first optical waveguide 11; or, the first optical waveguide 11 and the second optical waveguide 12 can be adjusted simultaneously The pose, in this regard, is not limited by this application.

Further, a projection image with a positioning pattern is projected on the first optical waveguide 11 by the projector 20 , so that it can be dilated by the imaging device after passing through the first optical waveguide 11 and the second optical waveguide 12 30 captured. In particular, in the embodiment of the present application, the projection image projected by the projector 20 includes a positioning pattern 50 that can be used to characterize the direction and position of the projection image, for example, a cross pattern (as shown in FIG. 4 ), a dot matrix Patterns, checkerboard patterns, etc.

In the embodiment of the present application, the first optical waveguide 11 and the second optical waveguide 12 are respectively used to transmit light of different parts of the projected image. More specifically, in the embodiment of the present application, a part of the light of the projected image enters the first waveguide from the coupling-in region of the first diffraction grating 111 and is totally internally reflected from the first diffraction grating. The out-coupling region 111 couples out the first projected image to the imaging device 30 ; the other part of the projected image is emitted from the first optical waveguide 11 along the direction toward the second diffraction grating 121 of the second optical waveguide 12 . It is coupled out and enters the second optical waveguide 12 from the coupling-in region of the second diffraction grating 121 and is coupled out from the coupling-out region of the second diffraction grating 121 to the second projection image after total internal reflection. The imaging device 30 .

For example, when the light of the projected image is light including the first primary color, the second primary color and the third primary color, the light of the first primary color and part of the second primary color of the projected image is coupled from the first diffraction grating 111 The input region enters the first waveguide and is totally internally reflected, and then couples out the first projection image from the coupling-out region of the first diffraction grating 111 to the imaging device 30; part of the second primary color of the projection image and The light of the second primary color is coupled out from the first optical waveguide 11 in the direction toward the second diffraction grating 121 of the second optical waveguide 12 and enters the second diffraction grating 121 from the coupling-in region of the second optical waveguide 12 . The second projection image is coupled out from the coupling-out region of the second diffraction grating 121 to the imaging device 30 in the second optical waveguide 12 after total internal reflection.

It should be understood that when there is an angular difference between the first optical waveguide 11 and the second optical waveguide 12 (as shown in FIG. 3 ), the light coupled from the first optical waveguide 11 and the second optical waveguide 12 The light coupled out of the optical waveguide 12 will exit at an angle, that is, there is an offset between the first projection image and the second projection image, and the effect is shown in FIG. 5 . As shown in FIG. 5 , the image generated by the imaging device 30 includes two cross patterns. Correspondingly, by measuring the offset between the two cross patterns, the required adjustment amount of the second optical waveguide 12 relative to the first optical waveguide 11 can be obtained.

Specifically, in the embodiment of the present application, the offset to be measured includes the offset distance and the offset direction between two cross patterns, so as to determine the relative relationship between the second optical waveguide 12 and the first optical waveguide 12 . The angle and direction of the optical waveguide 11 need to be adjusted. For example, in the example shown in FIG. 5 , the cross pattern of the second projection image is shifted to the right relative to the cross pattern of the first projection image, then the right side of the second optical waveguide 12 can be shifted to the right. The side area is moved upward to reduce the distance between it and the right area of the first optical waveguide 11 . Correspondingly, the relative positional relationship between the first optical waveguide 11 and the second optical waveguide 12 is continuously adjusted in real time through the cycle of measurement→calculation→adjustment→measurement→calculation→adjustment→measurement until the The offset calculated by the image collected by the imaging device 30 satisfies the preset threshold range. That is, when the offset satisfies a preset threshold range, the installation positional relationship between the first optical waveguide 11 and the second optical waveguide 12 is determined.

It is worth mentioning that when the positioning pattern 50 is implemented as the positioning pattern 50 as shown in FIG. 6 , that is, it includes a plurality of cross patterns located in different fields of view. Correspondingly, in this example, it can be calculated by calculating The offset of each cross pattern is then determined by taking the mean or median to determine the final offset, so that the image quality of each field of view can be better balanced.

It is worth mentioning that, through the above-mentioned active calibration process, the installation and positioning accuracy between the first optical waveguide 11 and the second optical waveguide 12 can be improved. In addition, the errors of the diffraction gratings of the first optical waveguide 11 and the second optical waveguide 12 can also be compensated by the above-mentioned calibration method, that is, through the active calibration process, the optical structure 10 The errors existing in the basic structural elements themselves can also be effectively eliminated

Further, it is necessary to fix the first optical waveguide 11 and the second optical waveguide 12 together based on the installation position relationship. In the embodiment of the present application, the first optical waveguide 11 and the second optical waveguide 12 are fixed together by the adhesive 13 .

Specifically, in a specific example of the present application, the process of fixing the first optical waveguide 11 and the second optical waveguide 12 together includes: first recording the second waveguide sheet and the The installation position relationship between the first optical waveguides 11 (in this example, that is, the installation position and angle of the second waveguide sheet), and the second optical waveguide 12 is removed; An adhesive 13 is provided on the lower surface of a waveguide sheet (or, the adhesive 13 is provided on the upper surface of the second optical waveguide 12; or, the upper surface of the first optical waveguide 11 and the second optical waveguide are simultaneously provided Adhesive 13 is provided on the lower surface of 12); then, the second waveguide sheet is put back to the position determined based on the installation position relationship; further, the adhesive 13 is cured to attach the first optical waveguide 11 and the The second optical waveguides 12 are fixed together.

FIG. 7A illustrates a schematic diagram of one possible deployment of adhesive 13 in the above example. As shown in FIG. 7A , the adhesive 13 is arranged on the peripheral region of the first optical waveguide 11 to avoid affecting the optical properties of the optical waveguide. In the solution shown in FIG. 7A , the adhesive 13 has a closed annular structure. Of course, the adhesive 13 can also form other shape configurations and position configurations, for example, a ring to be notched (as shown in FIG. 7B ) , or are only arranged at four corner positions of the peripheral region (as shown in FIG. 7C ), which is not limited by the present application.

It is worth mentioning that, when the adhesive 13 is implemented as a closed annular structure, preferably, the adhesive 13 is a non-thermally cured adhesive 13, such as UV glue cured by ultraviolet rays, ultraviolet rays and natural light UV glue that can be cured, moisture-curable glue, or hot melt glue, etc. When the configuration shown in FIG. 7C and FIG. 7B is set, an adhesive 13 having a relatively large adhesive strength such as thermosetting adhesive or UV thermosetting adhesive may be preferably used. In addition, by adopting the non-closed layout as shown in FIG. 7B and FIG. 7C , the air in the closed space between the first optical waveguide 11 and the second optical waveguide 12 can be prevented from being thermally expanded during heating and curing. The first optical waveguide 11 and/or the second optical waveguide 12 are deformed or even broken. In addition, non-closed layout can also use non-heat-cured glue to improve production efficiency. Also, when the configuration shown in FIG. 7B is implemented, the gap can be re-sealed after the adhesive 13 is cured to prevent dust, moisture and other contaminants from entering the first optical waveguide 11 and the second optical waveguide 11 . The inner space set by the optical waveguide 12 .

It should be understood that in this example, the first optical waveguide 11 and the second optical waveguide 12 are adhesively fixed by the adhesive 13, and the adhesive 13 must have sufficient adhesive strength In order to ensure a certain air gap between the first optical waveguide 11 and the second optical waveguide 12 . Generally, the method of increasing the bonding strength is to increase the width dimension of the adhesive 13 , however, the increase in the width dimension is often accompanied by an increase in the thickness dimension. It should be noted that, in the embodiment of the present application, the increase of the thickness dimension of the adhesive 13 means that the possibility and degree of deformation are greater, so as to cause the gap between the first optical waveguide 11 and the second optical waveguide 12 The installation accuracy is affected. Therefore, in this example, preferably, the adhesive 13 has a relatively large width dimension and a relatively small thickness dimension. More specifically, in this example, the thickness dimension of the adhesive 13 ranges from 50μm-150μm, its width size range is 1mm-3mm. Such size configuration can be achieved by applying the adhesive 13 multiple times.

It is worth mentioning that, in the assembly process of this example, a rotating device can also be provided for rotating the first optical waveguide 11 and the second optical waveguide 12 and the adjustment platform 40 in the horizontal and vertical directions rotate. For example, during the process of determining the installation positional relationship between the first optical waveguide 11 and the second optical waveguide 12 through an active calibration process, the first waveguide sheet and the second waveguide sheet may be placed vertically to The pose of the optical structure 10 during use is simulated, the consistency between the production scene and the use scene is improved, and unforeseen problems in actual use are avoided. For another example, when the adhesive 13 is arranged and cured on the first optical waveguide 11 , preferably, the first optical waveguide 11 is placed horizontally to prevent the glue from flowing.

In other examples of the present application, the adhesive 13 may be pre-arranged between the first optical waveguide 11 and the second optical waveguide 12 in the process of active calibration. Correspondingly, in this example, after the installation positional relationship between the first optical waveguide 11 and the second optical waveguide 12 is determined through an active calibration process, the first optical waveguide 11 is further directly cured and disposed on the first optical waveguide 11 . and the adhesive 13 between the second optical waveguide 12 and the first optical waveguide 11 to bond the first optical waveguide 11 and the second optical waveguide 12 together.

It is worth mentioning that, in this example, preferably, as shown in FIG. 9 , the adhesive 13 is implemented as an adhesive 13 including a plurality of particles 131 embedded therein. Correspondingly, a plurality of the particles 131 can effectively limit the distance between the first optical waveguide 11 and the second optical waveguide 12 from being too small, so as to ensure that the interference phenomenon of the waveguide sheet does not occur during the active calibration process. occur. When a plurality of the particles 131 are implemented as spherical particles 131, and the plurality of spherical particles 131 are uniformly arranged in the adhesive 13, the adhesive 13 can also make the first optical waveguide 11 and the The second optical waveguide 12 has a relatively high parallelism before the active calibration, so as to reduce the adjustment range and the adjustment times of the subsequent active calibration.

It can be understood that, when the above-mentioned solution of performing active calibration first and then curing and bonding by the adhesive 13 is adopted, the adhesive 13 used can also be configured as an adhesive including a plurality of particles 131 embedded therein. 13. Correspondingly, the plurality of particles 131 in the adhesive 13 can limit the distance between the first optical waveguide 11 and the second optical waveguide 12 (especially the distance in the vertical direction), and can also The phenomenon that the gap between the first optical waveguide 11 and the second optical waveguide 12 is too small or inclined due to the shrinkage of the adhesive 13 is effectively avoided.

Further, the assembling process of the optical structure 10 further includes arranging a light shielding layer 14 on the side of the first optical waveguide 11 and/or the side of the second optical waveguide 12 . In a specific example of the present application, black coating may be performed on the sides of the first optical waveguide 11 and the second optical waveguide 12 to form the light shielding layer 14 to prevent external light from entering the first optical waveguide from the side. The formation of stray light inside the optical waveguide 11 and the second optical waveguide 12 affects the visual experience, and the blackening process may adopt an inkjet method or an ink application method.

Optionally, the first optical waveguide 11 and the second optical waveguide 12 may be painted black respectively, and then the first optical waveguide 11 and the second optical waveguide 12 are fixed together, As shown in Figure 8B. Preferably, the first optical waveguide 11 and the second optical waveguide 12 can be actively aligned and fixed together, and then blackened, as shown in FIG. 8A , which can reduce the process of blackening. , improve production efficiency. The light shielding layer 14 including the adhesive 13 can be provided on the entire side of the optical structure 10 by assembling the first optical waveguide 11 and the second optical waveguide 12 together and then performing black coating. It is also covered by the light-shielding layer 14 to prevent external light from entering the interior of the optical structure 10 through the adhesive 13 to form stray light and affect the user experience. In addition, the light shielding layer 14 also protects the adhesive 13 to a certain extent, so as to avoid failure of the adhesive interface of the optical structure 10 due to being exposed to the outside world.

It is worth mentioning that generally, the wider the ink is sprayed, the higher the thickness, and the higher thickness is likely to cause unevenness of the ink-jet surface, and the higher thickness of the ink layer is also unfavorable for the assembly of the optical structure 10 . Preferably, in the embodiment of the present application, the light shielding layer 14 may be formed by spraying multiple times, so that the light shielding layer 14 has a larger width and a smaller thickness.

Further, the assembling process of the optical structure 10 may further include setting a frame on the side of the optical structure 10 to protect the optical structure 10 from being bumped or scratched when it is installed in a module or a wearable device .

It is worth mentioning that, in order to improve the assembly yield and efficiency, preferably, the first optical waveguide 11 and the second optical waveguide 12 to be assembled are implemented as optical waveguides of the same type, wherein the The offset of the optical waveguide satisfies a preset range.

Accordingly, whether the first optical waveguide 11 and the second optical waveguide 12 to be assembled belong to the same category of optical waveguides can be determined in the following manner.

First, a standard first waveguide sheet and a standard second waveguide sheet are provided, wherein the standard first waveguide sheet and the standard second waveguide sheet represent the first waveguide sheet and the second waveguide sheet with very high machining accuracy;

Next, the first offset required by the first optical waveguide 11 relative to the standard second optical waveguide 12 is determined through the active calibration process as described above, and the first offset required by the active calibration process as described above is determined. the second offset required by the second optical waveguide 12 relative to the standard first optical waveguide 11;

Then, it is determined whether the first offset and the second offset belong to a preset range, and when the first offset and the second offset belong to a preset range, the first offset The optical waveguide 11 and the second optical waveguide 12 are the same type of optical waveguide. In the embodiment of the present application, the preset range is that the difference in the offset distance between the first offset and the second offset is ±10um, and the difference in the offset angle is ±1 °. For example, the first offset is an offset distance of 100um and an offset angle of 5°, and the second offset is an offset distance of 99um and an offset angle of 4.9°. It is determined that the first optical waveguide 11 and the The second optical waveguide 12 is an optical waveguide of the same type.

It should be understood that when the first optical waveguide 11 and the second optical waveguide 12 are the same type of optical waveguide, the process of active calibration can be greatly shortened and the assembly efficiency can be improved.

To sum up, the assembling process of the optical structure 10 based on the embodiment of the present application has been clarified, which enables the optical waveguides of the optical structure 10 to have high assembling precision between the layers through the active calibration process.

Correspondingly, the present application also provides an assembly method of the optical structure 10, which includes:

S110, providing the first optical waveguide 11, the second optical waveguide 12, the projector 20 and the imaging device 30;

S120 , project a projection image having the positioning pattern 50 on the first diffraction grating 111 of the first optical waveguide 11 by the projector 20 , where the light of the projection image has a first primary color, a second primary color and a third primary color, wherein , the light with the first primary color wavelength and the second primary color wavelength in the light of the projected image enters the first waveguide from the coupling region of the first diffraction grating 111 and is totally internally reflected from the first The outcoupling region of the diffraction grating 111 couples out the first projected image to the imaging device 30 ; the light with the second primary color wavelength and the third primary color wavelength in the light of the projected image is along the second direction toward the second optical waveguide 12 . The direction of the diffraction grating 121 is coupled out from the first optical waveguide 11 and enters the second optical waveguide 12 from the coupling-in region of the second diffraction grating 121 , and then exits the second diffraction grating after total internal reflection. The coupling-out area of 121 couples out the second projection image to the imaging device 30;

S130: Adjust the first optical waveguide 11 and the second optical waveguide based on the offset between the positioning pattern 50 of the first projection image and the positioning pattern 50 of the second projection image the relative positional relationship between 12; and

S140, in response to the offset satisfying a preset threshold range, determine the installation position relationship between the first optical waveguide 11 and the second optical waveguide 12; and

S150, based on the installation position relationship, fix the first optical waveguide 11 and the second optical waveguide 12.

In one example, in the assembling method according to the present application, before projecting the projection image with the positioning pattern 50 on the first diffraction grating 111 of the first optical waveguide 11 by the projector 20 , the method further includes: fixing the The projector 20, the first optical waveguide 11 and the imaging device 30 are in preset positions; wherein, the positioning pattern 50 based on the first projected image and the positioning pattern of the second projected image Adjusting the relative positional relationship between the first optical waveguide 11 and the second optical waveguide 12 includes: moving the second optical waveguide 12 to adjust the first optical waveguide 11 and the relative positional relationship between the second optical waveguide 12 .

In one example, in the assembling method according to the present application, the offset between the positioning pattern 50 of the first projected image and the positioning pattern 50 of the second projected image, including the offset direction and offset distance.

In one example, in the assembly method according to the present application, the positioning pattern 50 is a cross pattern.

In one example, in the assembling method according to the present application, fixing the first optical waveguide 11 and the second optical waveguide 12 together based on the installation position relationship includes: An adhesive 13 is disposed between the waveguide 11 and the second optical waveguide 12 ; and the adhesive 13 is cured to fix the first optical waveguide 11 and the second optical waveguide 12 together.

In one example, in the assembling method according to the present application, disposing the adhesive 13 between the first optical waveguide 11 and the second optical waveguide 12 includes: removing the second waveguide sheet; The adhesive 13 is provided on the lower surface of the first waveguide sheet; and the second waveguide sheet is placed back to the position determined based on the installation position relationship.

In an example, in the assembling method according to the present application, before projecting the projection image with the positioning pattern 50 on the first diffraction grating 111 of the first optical waveguide 11 by the projector 20 , the method further includes: by adhering The agent 13 pre-fixes the first optical waveguide 11 and the second optical waveguide 12; wherein, based on the installation position relationship, the first optical waveguide 11 and the second optical waveguide 12 are fixed together, Including: curing the adhesive 13 disposed between the first optical waveguide 11 and the second optical waveguide 12 .

In an example, in the assembling method according to the present application, in a specific example, the thickness of the adhesive 13 ranges from 50 μm to 150 μm, and the width of the adhesive 13 ranges from 1 mm to 3 mm.

In an example, in the assembling method according to the present application, in a specific example, the adhesive 13 is disposed on the peripheral regions of the first optical waveguide 11 and the second optical waveguide 12 .

In one example, in the assembly method according to the present application, the adhesive 13 has a non-closed shape.

In one example, in the assembling method according to the present application, the shape of the adhesive 13 is a ring shape with at least one notch.

In one example, in the assembly method according to the present application, the adhesive 13 is provided at four corner regions of the peripheral region.

In one example, in the assembling method according to the present application, the adhesive 13 includes a plurality of particles 131 embedded therein and uniformly distributed, and the diameter of the particles 131 is smaller than or equal to the first optical waveguide 11 and the The gap between the second optical waveguides 12 is sized so as to be ensured by a plurality of the particles 131 between the positioning pattern 50 based on the first projected image and the positioning pattern 50 based on the second projected image In the step of adjusting the relative positional relationship between the first optical waveguide 11 and the second optical waveguide 12, the distance between the first optical waveguide 11 and the second optical waveguide 12 is always with a certain gap.

In one example, in the assembly method according to the present application, the diameter of the particles 131 ranges from 50 μm to 150 μm.

In one example, in the assembling method according to the present application, before providing the first optical waveguide 11 , the second optical waveguide 12 , the projector 20 and the imaging device 30 , the method further includes: determining the first optical waveguide 11 and the imaging device 30 . The second optical waveguide 12 is an optical waveguide of the same type.

In one example, in the assembling method according to the present application, determining that the first optical waveguide 11 and the second optical waveguide 12 are the same type of optical waveguides includes: obtaining the relative relationship between the first optical waveguide 11 and the standard The first offset required when the second optical waveguide 12 is actively calibrated; the second offset required when the second optical waveguide 12 is actively calibrated relative to the standard first optical waveguide 11 is obtained; and, determining The first offset amount and the second offset amount satisfy a preset range to determine that the first optical waveguide 11 and the second optical waveguide 12 are the same type of optical waveguide.

In one example, in the assembling method according to the present application, the assembling method further includes: arranging a light shielding layer 14 on the side of the first optical waveguide 11 and/or the side of the second optical waveguide 12 .

It should be understood that although in the embodiments of the present application, the assembling method is used for the optical structure 10 including two optical waveguides as an example, it should be understood that the assembling method can also be applied to a larger number of optical waveguides In the optical structure 10 described above, this is not limited by the present application.

Schematic near-eye display device

According to yet another aspect of the present application, a near-eye display device is also provided. FIG. 9 illustrates a schematic diagram of a near-eye display device according to an embodiment of the present application. As shown in FIG. 9 , the near-eye display device 100 includes a projector 20 and the optical structure 10 as described above, wherein the projector 20 The projected image is projected on the optical structure 10, and the optical structure 10 dilates the projected image for viewing by the viewer to obtain an enhanced display visual experience.

It should be understood by those skilled in the art that the embodiments of the present invention shown in the above description and the accompanying drawings are only examples and do not limit the present invention. The objects of the present invention have been fully and effectively achieved. The functional and structural principles of the present invention have been shown and described in the embodiments, and the embodiments of the present invention may be modified or modified in any way without departing from the principles.

Claims

A method for assembling an optical structure, comprising:

providing a first optical waveguide, a second optical waveguide, a projector and an imaging device;

A projection image with a positioning pattern is projected onto the first diffraction grating of the first optical waveguide by the projector, wherein part of the light of the projected image enters the first diffraction grating from the coupling-in region of the first diffraction grating The first projection image is coupled out from the coupling-out region of the first diffraction grating to the imaging device in the optical waveguide after total internal reflection; the other part of the projection image is directed toward the second optical waveguide of the second optical waveguide. The direction of the diffraction grating is coupled out from the first optical waveguide and enters into the second optical waveguide from the in-coupling region of the second diffraction grating and exits the out-coupling region of the second diffraction grating after total internal reflection coupling out the second projection image to the imaging device;

Adjust the relative position between the first optical waveguide and the second optical waveguide based on the offset between the positioning pattern of the first projected image and the positioning pattern of the second projected image relationship; and

determining an installation positional relationship between the first optical waveguide and the second optical waveguide in response to the offset satisfying a preset threshold range; and

Based on the installation position relationship, the first optical waveguide and the second optical waveguide are fixed.
The assembling method according to claim 1, wherein before projecting the projection image with the positioning pattern on the first diffraction grating of the first optical waveguide by the projector, further comprising: fixing the projector, the The first optical waveguide and the imaging device are in preset positions.
The assembling method of claim 2, wherein the first optical waveguide is adjusted based on an offset between the positioning pattern of the first projected image and the positioning pattern of the second projected image The relative positional relationship with the second optical waveguide includes: moving the second optical waveguide to adjust the relative positional relationship between the first optical waveguide and the second optical waveguide.
The assembling method according to claim 1 or 3, wherein the offset between the positioning pattern of the first projected image and the positioning pattern of the second projected image includes offset direction and offset move distance.
The assembling method according to claim 1, wherein, based on the installation position relationship, fixing the first optical waveguide and the second optical waveguide together comprises:

disposing an adhesive between the first optical waveguide and the second optical waveguide; and

The adhesive is cured to secure the first optical waveguide and the second optical waveguide together.
The assembling method of claim 5, wherein disposing an adhesive between the first optical waveguide and the second optical waveguide comprises:

removing the second waveguide sheet;

disposing an adhesive on the lower surface of the first waveguide sheet; and

The second waveguide sheet is placed back to the position determined based on the mounting position relationship.
The assembling method according to claim 5, wherein before projecting the projection image with the positioning pattern on the first diffraction grating of the first optical waveguide by the projector, further comprising: pre-fixing the first diffraction grating with an adhesive an optical waveguide and the second optical waveguide;

Wherein, fixing the first optical waveguide and the second optical waveguide together based on the installation position relationship includes: curing all the optical waveguides disposed between the first optical waveguide and the second optical waveguide. the adhesive.
The assembling method according to claim 5 or 7, wherein the thickness of the adhesive is in the range of 50 μm to 150 μm, and the width of the adhesive is in the range of 1 mm to 3 mm.
The assembling method according to any one of claims 5 to 7, wherein the adhesive is provided on the peripheral regions of the first optical waveguide and the second optical waveguide.
The assembling method of claim 9, wherein the adhesive has a non-closed shape.
The assembling method according to claim 10, wherein the shape of the adhesive is a ring shape with at least one notch.
The assembling method of claim 9, wherein the adhesive is provided at four corner regions of the peripheral region.
The assembly method according to any one of claims 5 to 7, wherein the adhesive comprises a plurality of particles embedded therein and uniformly distributed, and the diameter of the particles is smaller than or equal to the first optical waveguide and the The size of the gap between the second optical waveguides.
The assembly method of claim 13, wherein the diameter of the particles ranges from 50 μm to 150 μm.
The assembling method of claim 1, wherein before providing the first optical waveguide, the second optical waveguide, the projector and the imaging device, further comprising: determining that the first optical waveguide and the second optical waveguide are the same category of optical waveguides.
The assembling method according to claim 15, wherein determining that the first optical waveguide and the second optical waveguide are the same type of optical waveguide, comprising:

obtaining the first offset required when the first optical waveguide is actively calibrated relative to the standard second optical waveguide;

obtaining a second offset required for active calibration of the second optical waveguide relative to the standard first optical waveguide; and

It is determined that the first offset amount and the second offset amount satisfy a preset range, so as to determine that the first optical waveguide and the second optical waveguide are optical waveguides of the same type.
The assembling method according to claim 1, further comprising: arranging a light shielding layer on the side of the first optical waveguide and/or the side of the second optical waveguide.
An optical structure suitable for a near-eye display device, characterized in that it includes:

a first optical waveguide having a first diffraction grating;

A second optical waveguide with a second diffraction grating, the first optical waveguide and the second optical waveguide have a preset installation position relationship, the first optical waveguide and the second optical waveguide are relative to the projection by the projection The projection directions of the instrument toward the first optical waveguide are staggered from each other with a preset gap therebetween; and

The adhesive disposed between the first optical waveguide and the second optical waveguide, wherein the gap between the first optical waveguide and the second optical waveguide ranges from 50 μm to 150 μm.
The optical structure according to claim 18, wherein the thickness of the adhesive is in the range of 50 μm to 150 μm, and the width of the adhesive is in the range of 1 mm to 3 mm.
19. The optical structure of claim 18, wherein the installation positional relationship between the first optical waveguide and the second optical waveguide is confirmed by an active calibration process.
19. The optical structure of claim 19, wherein the adhesive includes a plurality of particles embedded therein and uniformly distributed, the particles having a diameter range less than or equal to the first optical waveguide and the second optical waveguide gap between.
21. The optical structure of claim 21, wherein the particles have a diameter in the range of 50 [mu]m to 150 [mu]m.
The optical structure according to claim 18, further comprising a light shielding layer provided on the side of the first optical waveguide and/or the side of the second optical waveguide.
19. The optical structure of claim 18, wherein the first optical waveguide and the second optical waveguide are the same type of optical waveguide, wherein the same type of optical waveguide indicates that the first optical waveguide is relative to a standard first optical waveguide The first offset required when the two optical waveguides are actively calibrated and the second offset required when the second optical waveguide is actively calibrated relative to the standard first optical waveguide meet a preset range.
The optical structure according to claim 18, wherein the degree of parallelism between the first optical waveguide and the second optical waveguide is less than or equal to 2'.
A near-eye display device, comprising:

The optical structure of any of claims 18-25; and

A projector configured to project a projected image onto the optical structure.