Optical waveguide, detection module and near-to-eye display module

Abstract

The embodiment of the utility model discloses an optical waveguide, a detection module and a near-to-eye display module, the optical waveguide comprises a waveguide substrate, a coupling-in area, a coupling-out area, a first detection coupling-out area and a second detection coupling-out area, the coupling-in area enables image light to be coupled into the optical waveguide and transmits the image light to the coupling-out area, and the coupling-out area enables the image light to be coupled to the coupling-out area. The coupling-out area is used for expanding and propagating the image light and coupling out part of the expanded image light, and the first detection coupling-out area is arranged on a light path of the image light which passes through the coupling-out area and continues to be propagated in the waveguide substrate; the first detection coupling-out area deflects a part of image light to the second detection coupling-out area, and the second detection coupling-out area is arranged on a light path of the image light deflected by the first detection coupling-out area. The first detection out-coupling area and the second detection out-coupling area are respectively used for coupling out part of the image light for detection.

Description

Technical Field

[0001] The present application relates to the field of scanning display technology, and specifically to an optical waveguide, a detection module and a near-eye display module. Background Art

[0002] Augmented Reality (AR) devices (such as AR glasses) have become a research hotspot in the display industry. Light engines combined with optical waveguides have become a more mainstream optical solution for AR glasses.

[0003] Some existing solutions will add corresponding detection devices to AR glasses to detect whether the image output by the light engine is abnormal. For example, the detection device is set opposite to the light output position of the light engine (located outside the waveguide lens), and part of the light is transmitted through the waveguide and received by the detection device, or a corresponding spectroscopic structure is set to deflect part of the light output by the light engine to the target surface of the detection device. However, the above methods will lead to an increase in the local size of the AR glasses (such as: frame thickness, temple diameter); and in order to ensure the accuracy of the detection results, especially for scanning light engines, the detection device will usually amplify the difference in motion amplitude and phase as much as possible. Amplifying the difference often requires the detection device to have a larger volume, which is also not conducive to the local miniaturization design of AR glasses. Utility Model Content

[0004] Based on the above content, the present application provides an optical waveguide, a detection module and a near-eye display module, which are used to facilitate the miniaturization of the local volume of AR glasses while providing detection functions.

[0005] Based on the first aspect of the present application, an embodiment of the present application provides an optical waveguide, the optical waveguide comprising a waveguide substrate, an incoupling region, an outcoupling region, a first detection outcoupling region and a second detection outcoupling region; wherein,

[0006] The coupling-in region couples the image light into the optical waveguide and propagates a portion of the image light toward the coupling-out region;

[0007] The outcoupling region is used to expand and propagate the image light, and to couple out a portion of the expanded image light;

[0008] The first detection outcoupling region is arranged on the optical path of the image light that continues to propagate in the waveguide matrix after passing through the outcoupling region, and the first detection outcoupling region deflects a portion of the image light to the second detection outcoupling region;

[0009] The second detection outcoupling region is arranged on the optical path of the image light deflected by the first detection outcoupling region;

[0010] The first detection outcoupling region and the second detection outcoupling region are respectively used to couple out a portion of the image light for detection.

[0011] Optionally, the first detection decoupling region is located on an optical path of image light corresponding to a lateral image central field of view among image light rays that continue to propagate through the decoupling region in the waveguide matrix.

[0012] Optionally, the first detection outcoupling area is symmetrically arranged based on the optical path of the image light corresponding to the lateral direction of the image central field of view.

[0013] Optionally, the second detection outcoupling region is located on an optical path of image light corresponding to a longitudinal direction of a central field of view of the image, among image light deflected by the first detection outcoupling region.

[0014] Optionally, the second detection outcoupling area is symmetrically arranged based on the optical path of the image light corresponding to the longitudinal direction of the image central field of view.

[0015] Optionally, the first detection outcoupling area and the second detection outcoupling area are independent areas.

[0016] Optionally, grating structures are provided in both the first detection outcoupling region and the second detection outcoupling region.

[0017] Optionally, the first detection outcoupling region and the second detection outcoupling region are located on different side surfaces of the optical waveguide.

[0018] Based on the second aspect of the present application, an embodiment of the present application provides a detection module, the detection module comprising a first detection unit, a second detection unit and the aforementioned optical waveguide, wherein the first detection unit is matched with the first detection outcoupling region in the optical waveguide, and the second detection unit is matched with the second detection outcoupling region in the optical waveguide;

[0019] The first detection unit and the second detection unit are used to respectively receive the light coupled out from the two detection outcoupling areas for detection.

[0020] Based on the third aspect of the present application, an embodiment of the present application provides a near-eye display module, which includes a light engine and the aforementioned detection module, the light engine is used to generate image light, and the detection module performs display and detection based on the image light.

[0021] Other features and advantages of the present application will be described in the subsequent description, and partly become apparent from the description, or understood by implementing the technical solution of the present application. The purpose and other advantages of the present application can be realized and obtained through the structures and / or processes specifically pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0023] Figure 1 is a schematic diagram of the propagation of light entering an optical waveguide provided in an embodiment of the present application;

[0024] Figure 2 is a schematic diagram of a test image 20 provided in an embodiment of the present application;

[0025] Figure 3a is a schematic diagram of the structure of an optical waveguide provided in an embodiment of the present application;

[0026] Figure 3b yes Figure 3a The optical waveguide shown is prepared into a lens-shaped structure and a schematic diagram of the optical path;

[0027] Figure 4 is a schematic diagram of the structure of the detection module provided in the embodiment of the present application;

[0028] Figure 5a is a schematic diagram of a normal state detection of an image provided by an embodiment of the present application;

[0029] Figure 5b is a schematic diagram of detecting an abnormal state of an image provided by an embodiment of the present application;

[0030] Figure 5c is a schematic diagram of another abnormal state detection of an image provided by an embodiment of the present application;

[0031] Figure 6 is a schematic diagram of the structure of another optical waveguide provided in an embodiment of the present application;

[0032] Figure 7a is a schematic structural diagram of an optical waveguide 700 provided in an embodiment of the present application;

[0033] Figure 7b It is a schematic diagram of the structure of an optical waveguide 700 ′ provided in an embodiment of the present application. DETAILED DESCRIPTION

[0034] The present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant utility model, rather than to limit the utility model. It is also necessary to explain that, for ease of description, only the parts related to the relevant utility model are shown in the accompanying drawings.

[0035] In the embodiment of the present application, the light engine can be based on at least one display technology or device suitable for the field of AR glasses, such as LCOS, MicroLED, MicroOLED, Micro-Electro-Mechanical Systems (MEMS) scanning mirror, and fiber scanner.

[0036] In actual applications, AR glasses face bending of temples when users put them on or take them off, as well as vibration and rotation during wearing and use, which may cause abnormal images output by the light engine. Especially for scanning light engines (such as light engines composed of scanning devices such as MEMS scanning mirrors and fiber scanners), two-dimensional scanning is usually used for scanning and display, that is, the scanning trajectory is coupled by motion in the longitudinal and lateral directions. However, in the actual scanning process, due to factors such as manufacturing / installation deviations and vibration nonlinearity, the motion amplitude and phase of the scanning device in two directions will not match, causing the scanning trajectory to deviate from the ideal trajectory, resulting in abnormal display.

[0037] It should be noted that the image anomaly / difference described in the embodiments of the present application can be considered as an anomaly in the image displayed / output by the corresponding light engine. For example, for a scanning light engine, when raster scanning is used, unexpected image anomalies may occur. Detecting the image anomaly / difference becomes the key to subsequent image correction.

[0038] refer to Figure 1 , which shows the propagation of the image light 14 entering the optical waveguide 100. Specifically, the image light 14 is coupled from the coupling region 102 at a set propagation angle and azimuth angle (in the embodiment of the present application, the propagation angle is recorded as θ and the azimuth angle is recorded as ψ). In this example, the coupling grating in the coupling region 102 is a two-dimensional diffraction grating. Under the action of the two-dimensional diffraction grating, the image light 14 will form an extended image light. The corresponding optical path is as follows: Figure 1 140, 141 and 142 shown in FIG. Of course, after the decoupling region ( Figure 1 After that, part of the image light will be coupled out from the optical waveguide 100 through the outcoupling region, and part of the image light will continue to be transmitted in the optical waveguide 100 while maintaining the propagation angle θ and the azimuth angle ψ.

[0039] Further references Figure 2 ,exist Figure 1 Based on the example of the propagation of the image light 14 shown, for the test image 20, a number of measurement points D are set therein. ij(Specifically, it is a 5*5 dot matrix, that is, i, j=1~5), the test image 20 can be output to the optical waveguide 100 by the corresponding light engine, and the propagation angle and azimuth angle of the image light at the corresponding measurement point coupled into the optical waveguide 100 are measured. The propagation angle θ and azimuth angle ψ data corresponding to the image light at each measurement point can be referred to Table 1 and Table 2 respectively.

[0040] θ 1 2 3 4 5 1 44.85 41.30 37.86 34.56 31.47 2 44.77 41.20 37.74 34.43 31.32 3 44.74 41.16 37.69 34.38 31.27 4 44.77 41.20 37.74 34.43 31.32 5 44.85 41.30 37.86 34.56 31.47

[0041] Table 1

[0042]

[0043] Table 2

[0044] It can be seen from Table 2 above that the azimuth angle ψ of the image light emitted from each measuring point in the upper and lower fields of view of the test image 20 is not 0. As the lateral propagation distance increases, the degree of separation of the image light in the upper and lower fields of view will gradually increase.

[0045] By utilizing the above-mentioned propagation characteristics, a corresponding detection decoupling area can be set at a specific position on the waveguide 100 to couple the image light corresponding to the upper and lower fields of view and the left and right fields of view to the detection device respectively, thereby realizing abnormal detection of the image.

[0046] refer to Figure 3a , an optical waveguide 300 provided in an embodiment of the present application, comprising: a waveguide substrate 301, an incoupling region 302, an outcoupling region 303, a first detection outcoupling region 304, and a second detection outcoupling region 305. The incoupling region 302, the outcoupling region 303, the first detection outcoupling region 304, and the second detection outcoupling region 305 are all arranged on the waveguide substrate 301, and a grating structure is arranged therein, and the grating structure can be realized by processes such as imprinting, coating, and etching, which are not limited here. In addition, Figure 3a The outlines, shapes, sizes, and relative positions of the coupling-in region 302, the coupling-out region 303, the first detection coupling-out region 304, and the second detection coupling-out region 305 shown in the figure are exemplary and are not limited to Figure 3a For example, in practical applications, the profile of the coupling region 302 may not be Figure 3a The circular outline shown in the figure may be a rounded rectangle, a trapezoid, etc.; the outlines of the first detection decoupling area 304 and the second detection decoupling area 305 may also be a rounded rectangle, a square, etc.

[0047] In this embodiment, the first detection outcoupling region 304, the second detection outcoupling region 305, the coupling-in region 302, and the coupling-out region 303 are on the same side surface of the waveguide matrix 301 (the side surface faces the user's eyes when used as AR glasses). In some embodiments, the first detection outcoupling region 304, the second detection outcoupling region 305, the coupling-in region 302, and the coupling-out region 303 are not on the same side surface of the waveguide matrix 301, wherein the first detection outcoupling region 304 and the second detection outcoupling region 305 may not be on the same side surface of the waveguide matrix 301.

[0048] In the embodiment of the present application, the grating structure provided in the coupling-in region 302 may be referred to as a coupling-in grating, and the specific grating type may be a one-dimensional grating or a two-dimensional diffraction grating; the grating structure provided in the coupling-out region 303 may be referred to as a coupling-out grating, and the specific grating type may be a two-dimensional diffraction grating (in the subsequent description, the two-dimensional diffraction grating may be referred to as a two-dimensional grating). The grating type provided in the first detection coupling-out region 304 may be a two-dimensional grating, and the grating type in the second detection coupling-out region 305 may be a one-dimensional grating or a two-dimensional grating.

[0049] The grating types in each region may be the same or different. When the same grating type is used, the specific grating structures may be different. In some embodiments, the same grating structure may be used, which will be determined according to actual needs.

[0050] exist Figure 3a In the example shown, the grating types set in the coupling-in region 302 , the coupling-out region 303 and the first detection region 304 are all two-dimensional gratings, and the grating type set in the second detection region 305 is a one-dimensional grating.

[0051] In the embodiments of the present application, the direction parallel to the y-axis may also be referred to as the first direction, the vertical direction or the longitudinal direction; the direction parallel to the x-axis may also be referred to as the second direction, the horizontal direction or the transverse direction; the direction perpendicular to the xy plane may be considered as the z-axis direction, and may also be referred to as the third direction. In the subsequent embodiments, different viewing angles will be used in some views, but unless otherwise specified, this coordinate system will still be used, and the description of the corresponding direction names also applies throughout the text.

[0052] Continue to refer Figure 3a In this embodiment, the first detection decoupling region 304 and the second detection decoupling region 305 are both located on one side of the decoupling region 303 (at Figure 3a, located on the right side of the outcoupling region 303), which side is the other side opposite to the coupling-in region 302. Among them, the positions at which the first detection outcoupling region 304 and the second detection outcoupling region 305 are arranged are related to the image light corresponding to the central field of view of the image. Specifically, the first detection outcoupling region 304 is located on the optical path of the image light that continues to propagate in the waveguide matrix 301. In addition, the image light corresponding to the central field of view of the image that continues to propagate in the waveguide matrix 301 passes through the first detection outcoupling region 304. Under the action of the grating in the first detection outcoupling region 304, a part of the image light passing through the first detection outcoupling region 304 will be deflected, and accordingly, the second detection outcoupling region 305 is located on the optical path of the deflected image light.

[0053] refer to Figure 3b , the waveguide matrix 301 of the optical waveguide 300 is prepared into a lens morphology (in this example, the lens corresponds to the user's left eye), Figure 3b 3 shows the optical path of the image light propagating in the optical waveguide 300. After being coupled into the optical waveguide 300 via the coupling-in region 302, a certain image light is expanded and propagated in the optical waveguide 300, and the expanded image light forms corresponding optical paths 34 and 35, and the optical paths 34 and 35 pass through the coupling-out region 303 and further pass through the first detection coupling-out region 304.

[0054] Figure 3b Taking the optical path 34 as an example, when passing through the first detection outcoupling region 304, a portion of the image light propagating along the optical path 34 will be deflected by the grating in the first detection outcoupling region 304, and the deflected image light forms optical paths 340 and 341. The optical paths 340 and 341 pass through the second detection outcoupling region 305.

[0055] Of course, when the image light passes through the outcoupling region 303, the first detection outcoupling region 304 and the second detection outcoupling region 305, a portion of the image light is outcoupled under the action of the grating structure therein ( Figure 3b The out-coupling efficiency depends on the grating structure, which is not specifically limited in the present application. It should be noted that when the image light passes through the first detection out-coupling region 304, a portion of the image light will continue to propagate in the waveguide matrix 301 according to the original propagation angle and azimuth angle; when the deflected image light passes through the second detection out-coupling region 305, a portion of the image light will continue to propagate in the waveguide matrix 301 according to the propagation angle and azimuth angle after the deflection.

[0056] The above-mentioned setting method can make the image light corresponding to the upper and lower fields of view of the image and having a sufficient degree of separation pass through the first detection outcoupling area 304, wherein a part of the image light is coupled outward under the action of the grating structure, and after being deflected by the first detection outcoupling area 304, a part of the image light corresponding to the left and right fields of view of the image and having a sufficient degree of separation propagates to the second detection outcoupling area 305, and a part of these image light is coupled outward under the action of the grating in the second detection outcoupling area 305. Based on the image light coupled outward by the two detection areas, in cooperation with the corresponding detection units, the differences in the horizontal and vertical directions on the image can be detected.

[0057] In a preferred embodiment, the first detection outcoupling area 304 is arranged axially symmetrically with the optical path of the lateral image light corresponding to the image center field of view in the optical waveguide 300 (in the subsequent description, the light may be referred to as the lateral image center field of view light; the corresponding optical path may be referred to as the lateral image center field of view optical path). The image light corresponding to the upper and lower fields of view of the image will pass through the first detection outcoupling area 304 and be coupled out. Since the first detection outcoupling area 304 is arranged in a symmetrical distribution, the difference between the upper and lower fields of view of the image can be detected more obviously.

[0058] Accordingly, the second detection outcoupling area 305 is arranged axially symmetrically with the optical path of the longitudinal image light corresponding to the image center field of view deflected by the first detection outcoupling area 304 (in the subsequent description, the light may be referred to as: longitudinal image center field of view light; its corresponding optical path may be referred to as: longitudinal image center field of view optical path). The image light corresponding to the left and right fields of view of the image will pass through the second detection outcoupling area 305 and be coupled out. Since the second detection outcoupling area 305 is arranged in a symmetrical distribution, the difference between the left and right fields of view of the image can also be detected more clearly.

[0059] It should be noted that, in a feasible implementation mode, not all image light in the upper and lower fields of view of the image passes through the first detection outcoupling area 304. Correspondingly, the image light deflected by the first detection outcoupling area 304 is not all image light passing through the first detection outcoupling area 304. It can be understood that in the scheme of the present application, the number of image light passing through the first detection outcoupling area 304 and the second detection outcoupling area 305 is sufficient for detection.

[0060] Based on the above content, a detection module 30 is provided in the embodiment of the present application, referring to Figure 4 The detection module 30 includes: the aforementioned optical waveguide 300, and detection units 400 and 500 respectively arranged in cooperation with the detection outcoupling regions 304 and 305 in the optical waveguide 300.

[0061] refer to Figure 4The detection unit 400 arranged in cooperation with the first detection outcoupling area 304 includes two detection areas 400a and 400b, and the detection unit 400 is arranged in a manner that the detection areas are distributed in the first direction, that is, one detection area 400a of the detection unit 400 is mainly used to receive image light in the upper half of the field of view in the image, and the other detection area 400b is mainly used to receive image light in the lower half of the field of view in the image. Thus, the detection unit 400 can detect image anomalies (such as scanning track anomalies) based on the difference in image light corresponding to the upper and lower fields of view.

[0062] The detection unit 500 arranged in cooperation with the second detection coupling-out region 305 includes two detection regions 500a and 500b, and the detection unit 500 is arranged in a manner that the detection regions are distributed in the second direction, that is, one detection region 500a of the detection unit 500 is mainly used to receive image light of the left half of the field of view in the image, and the other detection region 500b is mainly used to receive image light of the right half of the field of view in the image. Thus, the detection unit 500 can detect image anomalies (such as scanning track anomalies) based on the difference in image light corresponding to the left and right fields of view.

[0063] In some embodiments, the detection unit 400 and the detection unit 500 can fully receive the image light coupled out by the first detection coupling-out area 304 and the second detection coupling-out area 305, but it should be understood that in some embodiments, affected by factors such as the installation position of the detection unit and the size of the target surface, it is feasible for the detection unit to receive a portion of the image light, and the amount of image light received can be sufficient to detect image abnormalities.

[0064] In the embodiment of the present application, the detection units 400 and 500 may be photoelectric detectors, such as multi-quadrant detectors, or other detection devices with the function of collecting light differences. In the present embodiment, the detection units 400 and 500 are dual-quadrant detectors. Of course, in different embodiments, the detection units 400 and / or 500 may be in different forms. Taking the detection unit 400 as an example, in some embodiments, the detection unit 400 may include two detectors for detecting target surfaces, each of which corresponds to a detection area (400a or 400b) of the detection unit 400; in other embodiments, the detection unit 400 may include more than two detection areas or detection target surfaces. Usually, when setting, multiple detection areas or detection target surfaces may be distributed on both sides of the transverse symmetry axis of the first detection coupling-out area 304, so as to fully receive the image light corresponding to the upper half of the field of view and the lower half of the field of view in the image. The specific will be determined according to the actual application needs, and there is no limitation on this.

[0065] It should be noted that the above Figure 4In order to illustrate the relative position relationship between the detection units 400, 500 and the detection coupling units 304, 305 of the waveguide 300 and the light propagation between the two, Figure 4 There is a certain distance between the detection units 400, 500 and the optical waveguide 300, and Figure 4 The black arrows in the figure represent the image light coupled out from the detection outcoupling units 304 and 305. In fact, as a preferred implementation, the detection units 400 and 500 can be fixed to the first detection outcoupling area 304 and the second detection outcoupling area 305 respectively by attaching.

[0066] Of course, the aforementioned detection units 400 and 500 can be arranged on the side surface of the optical waveguide 300 where the coupling-in area 302 and the coupling-out area 303 are located (when used as AR glasses, the side facing the human eye), or can be arranged on the opposite side surface (when used as AR glasses, the side away from the human eye), or the detection units 400 and 500 are respectively arranged on the two side surfaces of the optical waveguide 300. Accordingly, the grating structures in the first detection coupling-out area 304 and the second detection coupling-out area 305 will be designed accordingly so that the image light can be coupled out in the corresponding direction, which will be determined according to the needs of the actual application and is not limited here.

[0067] For the solution of the present application, after the image light entering the optical waveguide 300 propagates a certain distance, the image light corresponding to the upper and lower parts of the image field of view will gradually separate. By setting the first detection coupling area 304 at a specific position on the optical waveguide 300 and coordinating with the corresponding detection unit, the transmission characteristics of the diffraction optical waveguide can be used to detect the light in the upper and lower parts of the image field of view; the first detection coupling area 304 can further deflect the image light, so that the image light corresponding to the left and right parts of the image field of view gradually separates after deflection. Then, by setting the second detection coupling area 305 at a specific position on the optical waveguide 300 and coordinating with the corresponding detection unit, the light in the left and right parts of the image field of view can be detected.

[0068] Based on the aforementioned detection module 30, it is possible to detect the differences in the horizontal and vertical directions of the image. Figure 5a to Figure 5c, showing an image 21 in a normal state and images 22 and 23 in an abnormal state of tilt, as well as the detection states of the detection unit 400 in these states. Among them, the test pattern area 210 in the image 21 displays a red solid color pattern, and the color and / or brightness displayed in this area are significantly different from the rest of the area in the image 21, so that the detection unit 400 can more effectively capture the light difference. It should be understood that in the actual display process, the content displayed in the test pattern area 210 is not limited to a red solid color pattern, and may also be a test pattern containing other colors and filling content (such as: grid lines); and the range of the test pattern area 210 is not limited to Figure 5a As shown in , a larger range can be used, or even the entire image can be used as the test pattern area.

[0069] The horizontal dotted line in the figure represents the dividing line between the upper and lower fields of view of the image when the image is in a normal state, and the dotted line also corresponds to the light with an azimuth angle ψ of 0 in the central field of view of the image. The detection unit 400 is symmetrically arranged based on the horizontal dotted line, so that the two detection areas 400a and 400b will respectively receive the light corresponding to the upper and lower fields of view of the image 21. The vertical dotted line represents the dividing line between the left and right fields of view of the image when the image is in a normal state, and the detection unit 500 is symmetrically arranged based on the vertical dotted line, so that the two detection areas 500a and 500b will respectively receive the light corresponding to the left and right fields of view of the image 21.

[0070] Figure 5a In the figure, the image 21 is in a normal state. Since the test pattern area 210 is located in the upper half of the image 21, the light of the test pattern collected by the detection unit 400 is distributed on the detection target surface 400a of the detection unit 400. For the detection unit 500, the light of the test pattern collected by it is evenly distributed on the detection target surfaces 500a and 500b of the detection unit 500.

[0071] Figure 5b , an image 22 in an abnormal tilt state is shown, that is, the image 22 is tilted and deformed to the right along the X-axis direction. At this time, the light of the test pattern collected by the detection unit 400 does not change significantly and is still distributed on the detection target surface 400a, but the light of the test pattern collected by the detection unit 500 is unevenly distributed on the two detection target surfaces 500a and 500b. Specifically, the detection target surface 500b can receive more red light, while the detection target surface 500a receives less red light.

[0072] In some embodiments, the location of the test pattern area is not limited to Figure 5b As shown, it can be located elsewhere in the image, see Figure 5c , the tilt state of image 23 is Figure 5bThe tilt state of the image 22 is the same, and the test pattern area 230 is located on the right side of the image 23. At this time, the detection target surfaces 400a and 400b of the detection unit 400 can both collect red light. The detection target surface 500b of the detection unit 500 can collect red light.

[0073] Obviously, the detection unit 400 is symmetrically arranged based on the optical path of the central field of view of the horizontal image, so that the image light of the upper and lower fields of view of the image (coupled out by the first detection coupling area 304) can be received by the detection areas 400a and 400b respectively, so that when the image is abnormally tilted, the abnormal tilt state can be detected more accurately through the specific light received and accumulated by the two detection areas 400a and 400b. Correspondingly, the detection unit 500 is symmetrically arranged based on the deflected, longitudinal image central field of view optical path, so that the image light of the left and right fields of view of the image (coupled out by the second detection coupling area 305) can be received by the detection areas 500a and 500b respectively, so that when the image is abnormally tilted, the abnormal tilt state can be detected more accurately through the specific light received and accumulated by the two detection areas 500a and 500b.

[0074] Of course, for the solution of the present application, in addition to detecting the abnormal tilt state produced by the above-mentioned image, it is also possible to detect other abnormal morphological states produced by the image, such as: bending deformation of the image, image differences caused by scanning delays of the scanning light engine, etc., which will not be repeated here.

[0075] In addition to the above-described contents, in other embodiments of the present application, the detection outcoupling area in the present application solution may also be set in different forms. Figure 6 , shows an optical waveguide 600, including: a waveguide substrate 601, a coupling-in region 602, a coupling-out region 603, a first detection coupling-out region 604, and a second detection coupling-out region 605. The second detection coupling-out region 605 in this embodiment further includes two independent sub-regions 605a and 605b, each of which is provided with a grating structure. Usually, the grating structures provided in the two sub-regions 605a and 605b are the same. Of course, in some embodiments, the grating structures provided in the two sub-regions 605a and 605b may be different, for example, the coupling-out directions are different, one coupling-out direction is toward the side of the human eye, and the other coupling-out direction is toward the side away from the human eye; accordingly, when arranged in conjunction with the detection unit, the detection unit will also be respectively arranged on both sides of the optical waveguide 600 based on the direction of the coupling-out direction.

[0076] Figure 6, the optical paths of the image light deflected by the first detection outcoupling region 604 are shown, and these optical paths respectively pass through the two sub-regions 605a and 605b of the second detection outcoupling region 605. In the present embodiment, the two sub-regions 605a and 605b of the second detection outcoupling region 605 are symmetrically arranged based on the longitudinal image central field of view optical path deflected by the first detection outcoupling region 604.

[0077] refer to Figure 7a , shows an optical waveguide 700, including: a waveguide base 701, a coupling-in region 702, a coupling-out region 703, a first detection coupling-out region 704, and a second detection coupling-out region 705. The arrangement position of the second detection coupling-out region 705 is arranged obliquely to the first detection coupling-out region 704. Specifically, Figure 7a As shown in FIG. 1 , the second detection outcoupling region 705 is located at the upper left of the first detection outcoupling region 704. Accordingly, in this example, the grating structure arranged in the first detection outcoupling region 704 makes the optical path of the deflected image light (given by Figure 7a The image light beams (indicated by the gray line between the first detection outcoupling region 704 and the second detection outcoupling region 705) propagate obliquely to the second detection outcoupling region 705. In this manner, part of the image light beams passing through the first detection outcoupling region 704 and the second detection outcoupling region 705 are also coupled out of the optical waveguide 700 ( Figure 7a (shown by the black arrow in the

[0078] Figure 7b Another optical waveguide 700' is shown, in which the second detection outcoupling region 705' is located above and to the right of the first detection outcoupling region 704'. Figure 7b In the manner shown, the grating structure arranged in the first detection outcoupling region 704' makes the optical path of the deflected image light (by Figure 7b The gray line between the first detection outcoupling region 704' and the second detection outcoupling region 705' indicates that the ion propagates obliquely to the second detection outcoupling region 705'.

[0079] Of course, the arrangement of the coupling-in region and the coupling-out region in the optical waveguide is not limited to that shown in the aforementioned embodiment, and other arrangements may be adopted, such as: the coupling-in region and the coupling-out region are arranged obliquely to each other. Correspondingly, for the first detection coupling-out region and the second coupling-out region, their arrangement also changes accordingly. Specifically, the position of the first detection coupling-out region is related to the optical path of the image center field of view light, and the position of the second detection coupling-out region is related to the optical path of the image center field of view light deflected by the first detection coupling-out region. That is, under the premise that the coupling-in region and the coupling-out region are arranged obliquely to each other, the position of the first detection coupling-out region can be set on the optical path of the image light passing through the coupling-out region and continuing to be transmitted in the optical waveguide; the position of the second detection region can be set on the optical path of the image light deflected by the first detection coupling-out region and continuing to be transmitted in the optical waveguide. Also as a preferred embodiment, the first detection coupling-out region and the second detection coupling-out region are still arranged symmetrically with the corresponding image center field of view optical path as the axis.

[0080] Based on the optical waveguide and detection module described above, a near-eye display module is also provided in an embodiment of the present application, which can be applied to AR glasses. The near-eye display module includes: a light engine and the aforementioned detection module, the light engine is used to generate image light and project it to the corresponding coupling-in area on the optical waveguide in the detection module, the image light can be transmitted in the optical waveguide and coupled out through the coupling-out area, thereby realizing display; in addition, a part of the image light will continue to propagate in the optical waveguide, and when these image light rays propagate to the first detection coupling-out area in the optical waveguide, a part of the image light rays are coupled out for detection, and a part of the image light rays are deflected to the second detection coupling-out area and coupled out by the second detection coupling-out area, also for detection; the image light used for detection can be received by the detection unit in the detection module, thereby realizing detection.

[0081] For the scheme of the present application, after the image light entering the optical waveguide propagates a certain distance, the image light corresponding to the upper and lower parts of the image field of view will gradually separate. By setting the first detection coupling area at a specific position on the optical waveguide and coordinating with the corresponding detection unit, the transmission characteristics of the diffraction optical waveguide can be used to detect the light in the upper and lower parts of the image field of view without expanding the target surface of the detection device; the first detection coupling area can further deflect the image light, so that the image light corresponding to the left and right parts of the image field of view gradually separates after deflection. Then, by setting the second detection coupling area at a specific position on the optical waveguide and coordinating with the corresponding detection unit, the light in the left and right parts of the image field of view can be detected, and there is no need to expand the detection target surface of the detection device.

[0082] In addition, this method allows the detection process to occur on the optical waveguide. When applied to AR glasses, it can further avoid designing additional detection optical paths at other locations of the AR glasses, and also avoid the detection unit occupying other locations of the AR glasses, thereby facilitating the local miniaturization design of the AR glasses.

[0083] The expressions "first", "second", "the first" or "the second" used in various embodiments of the present disclosure may modify various components regardless of order and / or importance, but these expressions do not limit the corresponding components. The above expressions are only configured for the purpose of distinguishing an element from other elements.

[0084] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the utility model involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the above utility model concept. For example, the above features are replaced with the technical features with similar functions disclosed in this application (but not limited to) by each other.

Claims

1. An optical waveguide, characterized in that: The optical waveguide comprises a waveguide substrate, an incoupling region, an outcoupling region, a first detection outcoupling region and a second detection outcoupling region; The coupling-in region couples the image light into the optical waveguide and propagates a portion of the image light toward the coupling-out region; The outcoupling region is used to expand and propagate the image light, and to couple out a portion of the expanded image light; The first detection outcoupling region is arranged on the optical path of the image light that continues to propagate in the waveguide matrix after passing through the outcoupling region, and the first detection outcoupling region deflects a portion of the image light to the second detection outcoupling region; The second detection outcoupling region is arranged on the optical path of the image light deflected by the first detection outcoupling region; The first detection outcoupling region and the second detection outcoupling region are respectively used to couple out a portion of the image light for detection.

2. The optical waveguide according to claim 1, wherein The first detection decoupling region is located on an optical path of an image light ray that continues to propagate through the decoupling region in the waveguide matrix and corresponds to an image light ray that is transverse to the image center field of view.

3. The optical waveguide according to claim 2, wherein: The first detection outcoupling area is symmetrically arranged based on the optical path of the image light corresponding to the lateral direction of the image central field of view.

4. The optical waveguide according to claim 1, wherein The second detection outcoupling region is located on an optical path of image light corresponding to the longitudinal direction of the image central field of view, among the image light deflected by the first detection outcoupling region.

5. The optical waveguide according to claim 4, wherein: The second detection outcoupling area is symmetrically arranged based on the optical path of the image light corresponding to the longitudinal direction of the image central field of view.

6. The optical waveguide according to claim 1, wherein The first detection outcoupling area and the second detection outcoupling area are independent areas.

7. The optical waveguide according to claim 1, wherein Grating structures are disposed in both the first detection outcoupling region and the second detection outcoupling region.

8. The optical waveguide according to claim 1, wherein The first detection outcoupling region and the second detection outcoupling region are located on different side surfaces of the optical waveguide.

9. A detection module, characterized in that: The detection module comprises a first detection unit, a second detection unit and an optical waveguide as claimed in any one of claims 1 to 8, wherein the first detection unit is matched with the first detection outcoupling region in the optical waveguide, and the second detection unit is matched with the second detection outcoupling region in the optical waveguide; The first detection unit and the second detection unit are used to respectively receive the light coupled out from the two detection outcoupling areas for detection.

10. A near-eye display module, characterized in that: The near-eye display module includes a light engine and the detection module described in claim 9, wherein the light engine is used to generate image light, and the detection module performs display and detection based on the image light.

Images