Optical waveguide, detection module and near-to-eye display module
By setting the first and second detection coupling areas in the optical waveguide, and deflecting and coupling image light by the grating structure, the volume increase problem caused by the detection device in the AR glasses is solved, and the miniaturization design of the AR glasses and the accuracy of image abnormality detection is achieved.
Patent Information
- Application Number
- CN202410231019.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-02-29
- Publication Date
- 2025-08-29
AI Technical Summary
The arrangement of detection devices in existing AR glasses leads to an increase in local size and large size of the detection device, which is not conducive to the miniaturization design of AR glasses. In particular, the detection devices of scanning light engines require a larger volume to amplify motion amplitude and phase differences.
The first and second detection coupling areas are arranged in the optical waveguide, which are used to detect the difference in the horizontal and vertical lights of the center of the image, and deflect and coupling the image lights through the grating structure, and realize image abnormality detection with the detection unit, avoiding the additional detection light path and detection device occupation.
The detection of image abnormalities in AR glasses is realized, which avoids the increase in the volume of the detection device, promotes the local miniaturization design of AR glasses, and improves the accuracy of detection.
Smart Images
Figure CN120559784A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of scanning display technology, and in particular 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 mainstream optical solution for AR glasses.
[0003] Some existing solutions 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 placed opposite the light engine's light output position (located outside the waveguide lens), so that some 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 from the light engine to the detection device's target surface. However, these methods will increase the local dimensions of the AR glasses (such as the thickness of the frame and the diameter of the temples). Moreover, to ensure the accuracy of the detection results, especially for scanning light engines, the detection device usually amplifies the differences in motion amplitude and phase as much as possible. Amplifying the differences often requires a larger detection device, which is also not conducive to the local miniaturization of AR glasses. Summary of the Invention
[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 provide detection functions while facilitating the miniaturization of the local volume of AR glasses.
[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 base, 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 couple out a portion of the expanded image light;
[0008] The first detection outcoupling region is arranged on an 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 area and the second detection outcoupling area are respectively used to couple out a portion of the image light for detection.
[0011] Optionally, the first detection outcoupling region is located on an optical path of an image light ray that continues to propagate through the outcoupling region in the waveguide matrix and corresponds to an image light ray that is transverse to the image center field of view.
[0012] Optionally, the first detection outcoupling area is symmetrically arranged based on the optical path of the image light corresponding to the horizontal direction of the image central field of view.
[0013] Optionally, the second detection outcoupling region is located on an optical path of an image light corresponding to a longitudinal direction of the image central field of view, among the 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 center field of view.
[0015] Optionally, the first detection outcoupling area and the second detection outcoupling area are independent areas.
[0016] Optionally, both the first detection outcoupling region and the second detection outcoupling region are provided with grating structures.
[0017] Optionally, the first detection outcoupling region and the second detection outcoupling region are located on different side surfaces of the optical waveguide.
[0018] According to the second aspect of the present application, an embodiment of the present application provides a 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, wherein 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 following description and, in part, will become apparent from the description or be understood through implementation of the technical solutions of the present application. The objectives and other advantages of the present application can be achieved 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 upon reading the detailed description of non-limiting embodiments made with reference to the following drawings:
[0023] Figure 1 Schematic diagram of the propagation of light entering the optical waveguide provided by 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 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 optical path schematic diagram;
[0027] Figure 4 Schematic diagram of the structure of the detection module provided in the embodiment of the present application;
[0028] Figure 5a This is a schematic diagram of detecting a normal state of an image provided by an embodiment of the present application;
[0029] Figure 5b This is a schematic diagram of detecting an abnormal state of an image provided by an embodiment of the present application; Figure 5c This is a schematic diagram of detecting the same image abnormality using different test pattern areas, as provided in an embodiment of the present application;
[0030] Figure 6 is a schematic structural diagram of another optical waveguide provided in an embodiment of the present application;
[0031] Figure 7a Schematic diagram of the structure of an optical waveguide provided in an embodiment of the present application;
[0032] Figure 7b It is a schematic structural diagram of another optical waveguide provided in an embodiment of the present application. DETAILED DESCRIPTION
[0033] The present application will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the relevant invention and are not intended to limit the invention. It should also be noted that, for ease of description, only portions relevant to the relevant invention are shown in the accompanying drawings.
[0034] 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.
[0035] In actual applications, AR glasses face the risk of bending temples when users put them on and take them off, as well as vibration and rotation during use, which can cause abnormal images output by the light engine. In particular, scanning light engines (such as those composed of scanning devices such as MEMS scanning mirrors and fiber scanners) typically use two-dimensional scanning for scanning and display. That is, the scanning trajectory is formed by coupling motion in the longitudinal and lateral directions. However, during the actual scanning process, due to factors such as manufacturing / installation deviations and vibration nonlinearity, the amplitude and phase of the scanning device's motion in the two directions may not match, causing the scanning trajectory to deviate from the ideal trajectory and resulting in display anomalies.
[0036] It should be noted that the image anomalies / differences described in the embodiments of this application can be considered to be abnormalities in the image displayed / output by the corresponding light engine. For example, in a scanning light engine, raster scanning may cause unexpected image anomalies. Detecting these image anomalies / differences is crucial for subsequent image correction.
[0037] 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 into the coupling region 102 at a set propagation angle and azimuth angle (in this embodiment, the propagation angle is denoted as θ and the azimuth angle is denoted 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 expanded image light. The corresponding optical path is shown as follows: Figure 1 140, 141 and 142 shown in FIG. Of course, after the coupling 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.
[0038] 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, several measuring points D are set therein. ij(Specifically, a 5*5 dot matrix, i.e., i, j = 1 to 5). The test pattern 20 can be output by the corresponding light engine to the optical waveguide 100, and the propagation angle and azimuth angle of the image light coupled into the optical waveguide 100 at the corresponding measurement points are measured. The propagation angle θ and azimuth angle ψ corresponding to the image light at each measurement point can be referred to in Tables 1 and 2, respectively.
[0039] 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
[0040] Table 1
[0041]
[0042] Table 2
[0043] As can be seen from Table 2 above, the azimuth angle ψ of the image light emitted from each measuring point in the upper and lower parts of the field 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 parts of the field of view will gradually increase.
[0044] By utilizing the above-mentioned propagation characteristics, corresponding detection decoupling areas can be set at specific positions 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 abnormality detection of the image.
[0045] 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 disposed on the waveguide substrate 301, and are each provided with a grating structure. The grating structure can be implemented by processes such as imprinting, coating, and etching, which are not limited here. In addition, Figure 3a The outline, size, and relative position 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 FIG 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 can be a rounded rectangle, a trapezoid, etc.; the outline morphology of the first detection outcoupling area 304 and the second detection outcoupling area 305 can also be a rounded rectangle, a square, etc.
[0046] In this embodiment, the first detection outcoupling region 304, the second detection outcoupling region 305, the coupling-in region 302, and the outcoupling region 303 are on the same side surface of the waveguide matrix 301 (this 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 outcoupling 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.
[0047] In the embodiment of the present application, the grating structure provided in the coupling-in region 302 may be referred to as an 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 an 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 simply 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.
[0048] 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 also be used. The specific decision will be based on actual needs.
[0049] 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.
[0050] In the embodiments of this application, the direction parallel to the y-axis may also be referred to as the first direction, vertical direction, or longitudinal direction; the direction parallel to the x-axis may also be referred to as the second direction, horizontal direction, or transverse direction; and the direction perpendicular to the xy plane may be considered the z-axis direction and may also be referred to as the third direction. In subsequent embodiments, some views will use different perspectives, but unless otherwise specified, this coordinate system will be used throughout, and the corresponding direction names will apply throughout.
[0051] Continue to refer Figure 3a In this embodiment, the first detection outcoupling region 304 and the second detection outcoupling region 305 are both located on one side of the outcoupling region 303 (at Figure 3a, located on the right side of the outcoupling region 303), which is the other side opposite to the incoupling region 302. The positions of the first detection outcoupling region 304 and the second detection outcoupling region 305 are related to the image light corresponding to the image center field of view. Specifically, the first detection outcoupling region 304 is located on the optical path of the image light that continues to propagate within the waveguide matrix 301. In addition, the image light corresponding to the image center field of view that continues to propagate within 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 portion of the image light passing through the first detection outcoupling region 304 will be deflected. Accordingly, the second detection outcoupling region 305 is located on the optical path of the deflected image light.
[0052] refer to Figure 3b The waveguide base 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 image light propagating in optical waveguide 300. After being coupled into optical waveguide 300 via coupling-in region 302, an image light beam expands and propagates within optical waveguide 300. The expanded image light beam forms corresponding optical paths 34 and 35. Optical paths 34 and 35 pass through coupling-out region 303 and then through first detection coupling-out region 304.
[0053] Figure 3b Taking optical path 34 as an example, when passing through the first detection outcoupling region 304, a portion of the image light propagating along optical path 34 will be deflected by the grating in the first detection outcoupling region 304. The deflected image light forms optical paths 340 and 341. Optical paths 340 and 341 pass through the second detection outcoupling region 305.
[0054] 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 outcoupling efficiency depends on the grating structure and is not specifically limited in this application. It should be noted that when the image light passes through the first detection outcoupling region 304, a portion of the image light continues to propagate within the waveguide matrix 301 at its original propagation angle and azimuth. When the deflected image light passes through the second detection outcoupling region 305, a portion of the image light also continues to propagate within the waveguide matrix 301 at its deflected propagation angle and azimuth.
[0055] The aforementioned configuration allows image light rays corresponding to the upper and lower fields of view, with sufficient separation, to pass through first detection outcoupling region 304. A portion of these image rays are outcoupled due to the grating structure. Furthermore, after being deflected by first detection outcoupling region 304, a portion of image light rays corresponding to the left and right fields of view, with sufficient separation, propagate to second detection outcoupling region 305. A portion of these image light rays are outcoupled due to the grating in second detection outcoupling region 305. Based on the image light rays outcoupled from the two detection regions and in conjunction with the corresponding detection units, both horizontal and vertical differences in the image can be detected.
[0056] In a preferred embodiment, first detection outcoupling regions 304 are arranged axially symmetrically with respect to the optical path of the transverse image light corresponding to the image's central field of view (hereinafter referred to as the "transverse image central field of view light" and its corresponding optical path as the "transverse image central field of view optical path"). Image light corresponding to the upper and lower image fields of view pass through and are coupled out of the first detection outcoupling regions 304. The symmetrical arrangement of first detection outcoupling regions 304 allows for more distinct detection of differences between the upper and lower image fields of view.
[0057] Accordingly, second detection outcoupling region 305 is arranged axially symmetrically about the optical path of the longitudinal image light corresponding to the image's central field of view, deflected by first detection outcoupling region 304 (in the subsequent description, this light may be referred to as the longitudinal image central field of view light; its corresponding optical path may be referred to as the longitudinal image central field of view optical path). Image light corresponding to the left and right image fields will pass through second detection outcoupling region 305 and be coupled out. Because second detection outcoupling region 305 is arranged in a symmetrical distribution, the difference between the left and right image fields of view can also be more clearly detected.
[0058] It should be noted that, in a feasible embodiment, not all image light in the upper and lower fields of view of the image passes through the first detection outcoupling area 304. Accordingly, 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 solution 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.
[0059] 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 conjunction with the detection outcoupling regions 304 and 305 in the optical waveguide 300.
[0060] refer to Figure 4The detection unit 400, configured in conjunction with the first detection outcoupling region 304, includes two detection regions 400a and 400b. The detection units 400 are arranged such that the detection regions are distributed along a first direction. That is, one detection region 400a of the detection unit 400 primarily receives image light from the upper half of the field of view, while the other detection region 400b primarily receives image light from the lower half of the field of view. This allows the detection unit 400 to detect image anomalies (e.g., scanning trajectory anomalies) based on the difference in image light corresponding to the upper and lower fields of view.
[0061] The detection unit 500, configured in conjunction with the second detection outcoupling region 305, includes two detection regions 500a and 500b. The detection unit 500 is arranged such that the detection regions are distributed in the second direction. That is, one detection region 500a of the detection unit 500 is primarily configured to receive image light from the left half of the field of view, while the other detection region 500b is primarily configured to receive image light from the right half of the field of view. This allows the detection unit 500 to detect image anomalies (e.g., scanning trajectory anomalies) based on the difference in image light corresponding to the left and right fields of view.
[0062] 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 area 304 and the second detection coupling 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 also 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.
[0063] In the embodiment of the present application, the detection units 400 and 500 can be photodetectors, such as multi-quadrant detectors, or other detection devices with the function of collecting light differences. In this embodiment, the detection units 400 and 500 are dual-quadrant detectors. Of course, in different embodiments, the detection units 400 and / or 500 can take different forms. Taking the detection unit 400 as an example, in some embodiments, the detection unit 400 can include two detectors for detection target surfaces, each detection target surface corresponding to a detection area (400a or 400b) of the detection unit 400; in other embodiments, the detection unit 400 can include more than two detection areas or detection target surfaces. Usually, when setting up, multiple detection areas or detection target surfaces can be distributed on both sides of the transverse symmetry axis of the first detection coupling-out region 304 so as to fully receive the image light corresponding to the upper and lower fields of view in the image. The specific form will be determined according to the actual application needs and is not limited to this.
[0064] It should be noted that the aforementioned 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 FIG. 3 represent the image light coupled out from the detection outcoupling units 304 and 305. In fact, as a preferred embodiment, 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 attachment.
[0065] Of course, the aforementioned detection units 400 and 500 can be disposed on the surface of the optical waveguide 300 on the side where the coupling-in region 302 and the coupling-out region 303 are located (the side facing the human eye when used as AR glasses), or on the opposite side (the side away from the human eye when used as AR glasses). Alternatively, the detection units 400 and 500 can be disposed on both side surfaces of the optical waveguide 300. Accordingly, the grating structures in the first detection coupling-out region 304 and the second detection coupling-out region 305 will be designed accordingly to enable the image light to be coupled out in the corresponding directions. The specific design will depend on the needs of the actual application and is not limited here.
[0066] 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 a first detection decoupling 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 decoupling 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 a second detection decoupling 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.
[0067] Based on the aforementioned detection module 30, it is possible to detect differences in both 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 in which tilt occurs, as well as the detection states of the detection unit 400 under 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, 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.
[0068] The horizontal dashed line in the figure represents the boundary between the upper and lower fields of view of the image when it is in a normal state. This dashed line also corresponds to light rays with an azimuth angle ψ of 0 within the image's central field of view. Detection unit 400 is symmetrically arranged about this horizontal dashed line, so that the two detection areas 400a and 400b will respectively receive light rays corresponding to the upper and lower fields of view of image 21. The vertical dashed line represents the boundary between the left and right fields of view of the image when it is in a normal state. Detection unit 500 is symmetrically arranged about this vertical dashed line, so that the two detection areas 500a and 500b will respectively receive light rays corresponding to the left and right fields of view of image 21.
[0069] Figure 5a In the figure, image 21 is in a normal state. Since the test pattern area 210 is located in the upper half of 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 the detection unit 500 is evenly distributed on the detection target surfaces 500a and 500b of the detection unit 500.
[0070] Figure 5b , shows image 22 in an abnormal tilt state, i.e., image 22 is tilted to the right along the X-axis. At this point, the light from the test pattern captured by detection unit 400 has not changed significantly and is still distributed on detection target surface 400a. However, the light from the test pattern captured by detection unit 500 is unevenly distributed across detection target surfaces 500a and 500b. Specifically, detection target surface 500b receives more red light, while detection target surface 500a receives less red light.
[0071] 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 also collect red light.
[0072] 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 more accurately detected 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 more accurately detected through the specific light received and accumulated by the two detection areas 500a and 500b.
[0073] Of course, for the solution of the present application, in addition to detecting the tilt abnormality generated by the above-mentioned image, it is also possible to detect other types of morphological abnormalities generated 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.
[0074] In addition to the above description, in other embodiments of the present application, the detection outcoupling area in the present application solution can also be set in different forms. Figure 6 , shows an optical waveguide 600, comprising: a waveguide base 601, an incoupling region 602, an outcoupling region 603, a first detection outcoupling region 604, and a second detection outcoupling region 605. In this embodiment, the second detection outcoupling region 605 further comprises two independent sub-regions 605a and 605b, each of which is provided with a grating structure. Typically, the grating structures provided in the two sub-regions 605a and 605b are identical. Of course, in some embodiments, the grating structures provided in the two sub-regions 605a and 605b may be different, for example, with different outcoupling directions, one outcoupling direction toward the human eye and the other outcoupling direction toward the side away from the human eye; accordingly, when configured in conjunction with a detection unit, the detection unit will also be provided on both sides of the optical waveguide 600 based on the orientation of the outcoupling direction.
[0075] Figure 66 shows the optical paths of the image light deflected by the first detection outcoupling region 604, which pass through the two sub-regions 605a and 605b of the second detection outcoupling region 605. In this embodiment, the two sub-regions 605a and 605b of the second detection outcoupling region 605 are symmetrically arranged based on the longitudinal image center field of view optical path deflected by the first detection outcoupling region 604.
[0076] refer to Figure 7a , shows an optical waveguide 700, comprising: a waveguide base 701, an incoupling region 702, an outcoupling region 703, a first detection outcoupling region 704, and a second detection outcoupling region 705. The second detection outcoupling region 705 is arranged obliquely to the first detection outcoupling region 704. Specifically, Figure 7a As shown in FIG, 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 provided in the first detection outcoupling region 704 makes the optical path of the deflected image light (given by Figure 7a The gray line between the first detection outcoupling region 704 and the second detection outcoupling region 705 in FIG2 is shown) propagates obliquely to the second detection outcoupling region 705. In this way, part of the image light passing through the first detection outcoupling region 704 and the second detection outcoupling region 705 is also coupled out of the optical waveguide 700 ( Figure 7a (shown by the black arrow in the
[0077] Figure 7b Another optical waveguide 700' is shown, wherein 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 provided 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 light propagates obliquely to the second detection outcoupling region 705'.
[0078] Of course, the arrangement of the incoupling and outcoupling regions in the optical waveguide is not limited to that shown in the aforementioned embodiment; other arrangements are possible, such as positioning the incoupling and outcoupling regions at an angle to each other. Accordingly, the arrangement of the first and second detection outcoupling regions also varies accordingly. Specifically, the position of the first detection outcoupling region is related to the optical path of the image's central field of view light, while the position of the second detection outcoupling region is related to the optical path of the image's central field of view light after being deflected by the first detection outcoupling region. That is, if the incoupling and outcoupling regions are positioned at an angle to each other, the first detection outcoupling region can be positioned on the optical path of the image light that passes through the outcoupling region and continues to propagate through the optical waveguide; the second detection region can be positioned on the optical path of the image light that continues to propagate through the optical waveguide after being deflected by the first detection outcoupling region. Similarly, as a preferred embodiment, the first and second detection outcoupling regions are still arranged symmetrically about the corresponding image's central field of view optical path.
[0079] 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. The near-eye display module 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 onto 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 to achieve display; in addition, a part of the image light will continue to propagate in the optical waveguide. When these image light rays propagate to the first detection coupling-out area in the optical waveguide, a part of the image light rays is coupled out for detection, and a part of the image light rays is deflected to the second detection coupling-out area and coupled out by the second detection coupling-out area, also for detection; the image light rays used for detection can be received by the detection unit in the detection module to achieve detection.
[0080] For the solution 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 a 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 a 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 also no need to expand the detection target surface of the detection device.
[0081] In addition, this method allows the detection process to occur entirely 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.
[0082] 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.
[0083] The above description is merely a preferred embodiment of the present application and an illustration of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to the technical solutions formed by the specific combination of the above-mentioned technical features, but also encompasses other technical solutions formed by any combination of the above-mentioned technical features or their equivalents without departing from the above-mentioned inventive concept. For example, a technical solution formed by replacing the above-mentioned features with (but not limited to) technical features with similar functions disclosed in this application.
Claims
1. An optical waveguide, characterized in that The optical waveguide includes a waveguide base, 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 couple out a portion of the expanded image light; The first detection outcoupling region is arranged on an 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 area and the second detection outcoupling area 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 outcoupling region is located on an optical path of an image light ray that continues to propagate through the outcoupling region 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 horizontal 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 an image light corresponding to a 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 center 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 provided 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 the optical waveguide according to 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.