An auto-collimation adjustment system and method for a near-eye display device

Abstract

The present invention relates to an auto - collimation adjustment system and method for a near - eye display device. The system includes: an adjustment platform, on which an industrial camera and a corner reflector are successively fixed; a waveguide device to be adjusted, which is arranged on the adjustment platform and at least includes a projection optical machine and a waveguide plate. The waveguide plate is arranged between the industrial camera and the corner reflector, and the waveguide plate includes a light - emitting side, which is arranged facing the direction of the industrial camera; a semi - transparent and semi - reflective mirror, which is arranged on the adjustment platform, between the industrial camera and the waveguide plate and is close to the waveguide plate. Among them, the center points of the industrial camera, the waveguide plate, the semi - transparent and semi - reflective mirror, and the corner reflector are on the same horizontal line, with high adjustment efficiency, meeting the high - precision adjustment requirements at the same time and improving the product quality.

Description

Technical Field

[0001] The present invention relates to the technical field of augmented reality, and particularly to an auto-collimation adjustment system and method for a near-eye display device. Background Art

[0002] The adjustment and assembly of a near-eye display device requires a precise assembly and adjustment platform. Usually, an industrial camera is used to take pictures of the imaging, and the direction that the projection optical machine needs to be adjusted is judged according to the real-time picture captured by the industrial camera, and finally the adjustment is completed. The main difficulties in the implementation process are the calibration of the camera and the accuracy maintenance of the calibrated camera during use. According to Figures 1-4 , the calibration process of the existing solution is as follows:

[0003] 1. Keep the adjustment platform in a fixed position, install a waveguide plate 20' on the adjustment platform and keep it firm; 2. Place a laser 11' on the light-emitting side of the waveguide plate, so that the emitted laser light is approximately perpendicular to the waveguide plate 20'. Observe and adjust the attitude of the laser 11' so that the reflected light can return to the light-emitting port of the laser 11'. In this way, the accuracy of the laser irradiation direction perpendicular to the waveguide plate 20' is improved, as shown in Figures 1-2 ; 3. On the optical path after the laser light passes through the waveguide plate 20', place two sets of semi-transparent light screens 21' and fix them. At the same time, mark the incident points where the laser passes through the semi-transparent light screens 21'. At this time, the connection line between the two marked points is parallel to the normal direction of the waveguide plate 20', as shown in Figure 3 ; 4. Turn off the laser 11', put an industrial camera on the adjustment platform to take pictures, as shown in Figure 4 , by adjusting the attitude of the industrial camera, make the marked points on the two light screens 21' all overlap with the center of the crosshair in the picture, as shown in Figure 5 . At this time, the optical axis of the camera is collinear with the connection line between the two marked points, that is, parallel to the normal direction of the waveguide plate 20', and the calibration is completed.

[0004] However, the above technical solution is very likely to have the following problems:

[0005] 1. Using the laser to reflect back to the light-emitting port of the laser 11' to determine the direction reference, considering the laser beam diameter, there will be an alignment error. Subsequently, using the two-point positioning method to transfer the direction reference to the camera, a lot of alignment and mechanical adjustment are involved in the process, which will further increase the error;

[0006] 2. When using an industrial camera to judge the overlap of the two marked points and the center of the crosshair in the picture, for a camera with a limited depth of field, it is impossible to simultaneously see the clear images of the two marked points. It can only adjust different depths of field successively and repeatedly to find the target attitude, and the adjustment process is not efficient;

[0007] 3. During the use process, once there is a deviation in the positions of the adjustment platform and the industrial camera, the reference will be lost. In addition, the process of determining whether the reference is lost is the same as the process of optical axis alignment, which is rather cumbersome and cannot achieve the purpose of monitoring at any time. Summary of the Invention

[0008] According to the problems existing in the prior art, the present invention provides an auto - collimation adjustment system and method for a near - eye display device.

[0009] The technical solution of the present invention is as follows:

[0010] In the first aspect, the present invention provides an auto - collimation adjustment system for a near - eye display device, including:

[0011] An adjustment platform, on which an industrial camera and a corner reflector are successively fixed;

[0012] A waveguide device to be adjusted, which is arranged on the adjustment platform. The waveguide device to be adjusted at least includes a projection optical machine and a waveguide sheet. The waveguide sheet is arranged between the industrial camera and the corner reflector, and the waveguide sheet includes an outgoing light side, and the outgoing light side is arranged towards the direction of the industrial camera;

[0013] A semi - transparent and semi - reflective mirror, which is arranged on the adjustment platform, between the industrial camera and the waveguide sheet, and is adjacent to the waveguide sheet;

[0014] Among them, the center points of the industrial camera, the waveguide sheet, the semi - transparent and semi - reflective mirror, and the corner reflector are on the same horizontal line; the light rays emitted by the projection optical machine are coupled and emitted through the waveguide sheet. A part of the light rays passes through the semi - transparent and semi - reflective mirror and enters the industrial camera, and another part of the light is reflected by the semi - transparent and semi - reflective mirror, then passes through the waveguide sheet, and then enters the industrial camera successively through the corner reflector, the waveguide sheet, and the semi - transparent and semi - reflective mirror.

[0015] As a preferred technical solution, the semi - transparent and semi - reflective mirror, the waveguide sheet, and the corner reflector are parallel to each other.

[0016] As a preferred technical solution, the distance between the semi - transparent and semi - reflective mirror and the waveguide sheet is a first distance, and the first distance is greater than or equal to zero.

[0017] As a preferred technical solution, the distance between the waveguide sheet and the corner reflector is a second distance, and the second distance is greater than the first distance.

[0018] As a preferred technical solution, the corner reflector is an array corner reflector.

[0019] As a preferred technical solution, the waveguide sheet is a geometric array optical waveguide sheet or a grating optical waveguide sheet.

[0020] In the second aspect, the present invention provides a collimation adjustment method for using the above - mentioned auto - collimation adjustment system for a near - eye display device, including:

[0021] An angle reflector, a semi-transparent and semi-reflective mirror, and an industrial camera are sequentially arranged on an adjustment platform;

[0022] The optical waveguide device to be adjusted is arranged between the angle reflector and the semi-transparent and semi-reflective mirror;

[0023] Turn on the projection optical machine, and the light is coupled and emitted through the waveguide sheet. A part of the light is projected through the semi-transparent and semi-reflective mirror into the industrial camera, and the industrial camera obtains the crosshair image 1, denoted as Cross 1; the other part of the light is reflected by the semi-transparent and semi-reflective mirror, and the light after passing through the waveguide sheet is reflected N times by the angle reflector and then passes through the waveguide sheet and the semi-transparent and semi-reflective mirror into the industrial camera in sequence. The industrial camera obtains the crosshair image 2, denoted as Cross 2, where N≥2;

[0024] Judge whether Cross 1 coincides with Cross 2. If they coincide, the collimation adjustment is completed; otherwise, adjust the position and / or angle of the projection optical machine until Cross 1 coincides with Cross 2.

[0025] As a preferred technical solution, adjust the angle reflector and the semi-transparent and semi-reflective mirror to be in a parallel state, and adjust the industrial camera and the semi-transparent and semi-reflective mirror to be in a perpendicular state.

[0026] As a preferred technical solution, the light-emitting side of the waveguide sheet faces the direction of the industrial camera, and the waveguide sheet is arranged parallel to and adjacent to the semi-transparent and semi-reflective mirror.

[0027] As a preferred technical solution, when Cross 1 coincides with Cross 2, denoted as Cross 3, judge whether the crosshair reference line in the industrial camera coincides with Cross 3. If they coincide, the optical axis direction of the industrial camera, the normal direction of the waveguide sheet, and the central light ray direction of Cross 3 are in a parallel state; otherwise, continue to adjust the position and / or angle of the industrial camera until the crosshair reference line in the industrial camera coincides with Cross 3.

[0028] The beneficial effects achieved by the technical solution adopted in the present invention: The present invention provides a self-collimation adjustment system and method for a near-eye display device. The system includes an industrial camera, a semi-transparent and semi-reflective mirror, and an angle reflector sequentially arranged on an adjustment platform. The optical waveguide device to be adjusted is fixedly arranged between the semi-transparent and semi-reflective mirror and the angle reflector, which can achieve high-precision adjustment and high adjustment efficiency. The system can also integrate the adjustment platform, the industrial camera, the semi-transparent and semi-reflective mirror, and the angle reflector into one body, which is convenient for detecting at any time whether the optical axis of the projection system coincides with the normal direction of the waveguide sheet, helps to monitor at any time, and improves the product quality. Description of the Drawings

[0029] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the accompanying drawings required for the description of the embodiments. These drawings form a part of the present invention. The schematic embodiments of the present invention and their descriptions explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0030] Figure 1 Schematic diagram of a collimation adjustment system in the prior art;

[0031] Figure 2 Schematic diagram of a collimation adjustment system in the prior art;

[0032] Figure 3 Schematic diagram of a collimation adjustment system in the prior art;

[0033] Figure 4 Schematic diagram of a collimation adjustment system in the prior art;

[0034] Figure 5 Schematic diagram of a collimation adjustment system in the prior art;

[0035] Figure 6 Schematic diagram of a self-collimation adjustment system for a near-eye display device disclosed in this embodiment.

[0036] Explanation of reference numerals:

[0037] Industrial camera 10; waveguide 20; corner reflector 30; semi-transmissive semi-reflective mirror 40. Detailed implementation manners

[0038] To make the objectives, technical solutions, and advantages of the present invention clearer, the following will clearly and completely describe the technical solutions of the present invention in combination with specific embodiments of the present invention and the corresponding drawings. In the description of the present invention, it should be noted that the term "or" is usually used in the sense of including "and / or" unless otherwise clearly specified in the context.

[0039] In the description of the present invention, it should be understood that terms such as "first", "second", "Cross 1", "Cross 2", "Cross 3", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance. In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, terms such as "connected" and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through a medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] In addition, those skilled in the art should understand that in the disclosure of the present invention, the orientation or positional relationship indicated by terms such as "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limiting the present invention.

[0041] Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0042] Embodiment

[0043] According to Figure 2 , an auto-collimation adjustment system for a near-eye display device provided by an embodiment of the present invention includes:

[0044] An adjustment platform, on which an industrial camera 10 and a corner reflector 30 are sequentially fixed;

[0045] A waveguide device to be adjusted, disposed on the adjustment platform. The waveguide device to be adjusted at least includes a projection optical machine and a waveguide sheet 20. The waveguide sheet 20 is disposed between the industrial camera 10 and the corner reflector 30. The waveguide sheet 20 includes a light-emitting side, and the light-emitting side is disposed towards the direction of the industrial camera 10;

[0046] A semi-transmissive and semi-reflective mirror 40, disposed on the adjustment platform. The semi-transmissive and semi-reflective mirror 40 is disposed between the industrial camera 10 and the waveguide sheet 20 and is adjacent to the waveguide sheet 20;

[0047] Wherein, the center points of the industrial camera 10, the waveguide sheet 20, the semi-transmissive and semi-reflective mirror 40, and the corner reflector 30 are on the same horizontal line; the light rays emitted by the projection optical machine are coupled and emitted through the waveguide sheet 20. A part of the light rays pass through the semi-transmissive and semi-reflective mirror 40 and enter the industrial camera 10, and the other part of the light is reflected by the semi-transmissive and semi-reflective mirror 40, then passes through the waveguide sheet 20, and then enters the industrial camera 10 through the corner reflector 30, the waveguide sheet 20, and the semi-transmissive and semi-reflective mirror 40 in sequence.

[0048] Based on the problems of large errors caused by the existing collimation adjustment device method, low efficiency in the adjustment process, and inability to monitor at any time, this embodiment proposes a self-collimation adjustment system for a near-eye display device, which mainly includes an adjustment platform, and an industrial camera 10, a semi-transparent semi-reflective mirror 40, and a corner reflector 30 are sequentially arranged on the adjustment platform. The optical waveguide device to be adjusted is fixedly arranged between the semi-transparent semi-reflective mirror 40 and the corner reflector 30, which can accurately achieve the purpose of collimation adjustment, has high-precision adjustment and high adjustment efficiency. This system can also integrate the adjustment platform, industrial camera 10, semi-transparent semi-reflective mirror 40, and corner reflector 30 into one body, which is convenient for detecting at any time whether the optical axis of the projection system overlaps with the normal line of the waveguide sheet 20, and helps to monitor at any time to improve product quality.

[0049] Preferably, the semi-transparent semi-reflective mirror 40, the waveguide sheet 20, and the corner reflector 30 are parallel to each other.

[0050] Specifically, according to Figure 2 , on the adjustment platform, the industrial camera 10, the semi-transparent semi-reflective mirror 40, and the corner reflector 30 are fixedly arranged in sequence from right to left. The optical waveguide device to be adjusted is fixedly arranged between the semi-transparent semi-reflective mirror 40 and the corner reflector 30. The optical waveguide device to be adjusted at least includes a waveguide sheet 20 and a projection optical machine. The waveguide sheet 20 is in a parallel state with both the semi-transparent semi-reflective mirror 40 and the corner reflector 30, so that the industrial camera 10 is perpendicular to the waveguide sheet 20, and the center point of the industrial camera 10, the center point of the waveguide sheet 20, the center point of the semi-transparent semi-reflective mirror 40, and the center point of the corner reflector 30 are on the same horizontal line, which helps the industrial camera 10 to completely and clearly capture the projection image.

[0051] The above-mentioned industrial camera 10, semi-transparent semi-reflective mirror 40, corner reflector 30, and optical waveguide device to be adjusted can all be fixed on the adjustment platform in a plug-in manner. For example, one end of the industrial camera 10, semi-transparent semi-reflective mirror 40, and corner reflector 30 is provided with a plug-in rack, and the adjustment platform is provided with a fixed position matching one end of the plug-in rack, etc. This is not limited to this. The plug-in fixation is convenient for installation and disassembly; the industrial camera 10, semi-transparent semi-reflective mirror 40, and corner reflector 30 can also be firmly set on the adjustment platform, such as by welding, gluing, etc. This is not limited to this, which can achieve a firm fixation effect. The firm setting method is convenient for strictly maintaining the reference during the subsequent adjustment process, improving the adjustment accuracy, and further improving the product quality.

[0052] Preferably, the distance between the semi-transparent semi-reflective mirror 40 and the waveguide sheet 20 is a first distance, and the first distance is greater than or equal to zero.

[0053] Preferably, the distance between the waveguide sheet 20 and the corner reflector 30 is a second distance, and the second distance is greater than the first distance.

[0054] Specifically, there is a certain distance between the industrial camera 10 and the semi-transmissive and semi-reflective mirror 40 in the system. The value of this distance is not specifically limited. As long as the industrial camera 10 can observe and / or capture the projection screen completely and clearly, it can also be set by those skilled in the art according to actual needs. The semi-transmissive and semi-reflective mirror 40 and the waveguide plate 20 need to be kept parallel, which helps the light to maintain normal reflection and transmission after passing through the semi-transmissive and semi-reflective mirror 40, reduces the system adjustment error, and thus improves the accuracy of adjustment.

[0055] The semi-transmissive and semi-reflective mirror 40 and the waveguide plate 20 are parallel to each other and have a distance, and the distance is greater than zero. It can be a glass plate with a coating on one side, and the coated surface is placed close to the light-emitting surface of the waveguide plate 20. It can also be that the semi-transmissive and semi-reflective film is directly attached to the light-emitting surface of the waveguide plate 20. In this case, the distance is zero, which improves the accuracy of parallel alignment between the semi-transmissive and semi-reflective mirror 40 and the waveguide plate 20, and can also shorten the adjustment distance faster and improve the adjustment efficiency. No matter which of the above methods, as long as the semi-transmissive and semi-reflective mirror 40 and the waveguide plate 20 can be kept parallel, it is not specifically limited here.

[0056] Specifically, the corner reflector 30 is a device that reflects light multiple times and returns the light along the original path. Different specifications and types of corner reflectors 30 are selected according to actual needs to ensure that the light can return along the original path intact. In this embodiment, an array corner reflector 30 is preferably used. The array corner reflector 30 is a series of arrayed triangular pyramids, and the three internal reflection surfaces of each unit are perpendicular to each other, which can well reflect the light multiple times and return it along the original path.

[0057] A semi-transmissive and semi-reflective mirror 40 is arranged on one side of the waveguide plate 20, and an array corner reflector 30 is placed on the other side of the waveguide plate 20. The waveguide plate 20 is placed and fixed approximately parallel. The distance between the array corner reflector 30 and the waveguide plate 20 is the second distance. The second distance is greater than the distance between the semi-transmissive and semi-reflective mirror 40 and the waveguide plate 20 mentioned above. The second distance is preferably in the range of 5 - 10 cm, which can meet the best adjustment and collimation requirements. The specific distance of the second distance can also be set by those skilled in the art according to actual needs.

[0058] Preferably, the waveguide plate 20 is a geometric array optical waveguide plate 20 or a grating optical waveguide plate 20.

[0059] Specifically, the optical waveguide device to be adjusted mentioned in this embodiment can be a geometric array optical waveguide device or a grating optical waveguide device. Taking the geometric array optical waveguide device as an example, it includes a projection optical machine and a waveguide plate 20. With this system, the optical axis of the projection system and the normal direction of the waveguide plate 20 can be accurately made consistent.

[0060] The embodiment of the present invention also provides a collimation adjustment method using the above self-collimation adjustment system for a near-eye display device, including:

[0061] Step S101: sequentially set a corner reflector 30, a semi-transparent and semi-reflective mirror 40, and an industrial camera 10 on an adjustment platform.

[0062] Step S102: place the optical waveguide device to be adjusted between the corner reflector 30 and the semi-transparent and semi-reflective mirror 40.

[0063] Step S103: turn on the projection optical machine, the light is coupled and emitted through the waveguide sheet 20, a part of the light is projected into the industrial camera 10 through the semi-transparent and semi-reflective mirror 40, and the industrial camera 10 obtains a crosshair image 1, denoted as Cross 1; another part of the light is reflected by the semi-transparent and semi-reflective mirror 40, and then passes through the waveguide sheet 20, and then after being reflected N times by the corner reflector 30, passes through the waveguide sheet 20 and the semi-transparent and semi-reflective mirror 40 in sequence and enters the industrial camera 10, and the industrial camera 10 obtains a crosshair image 2, denoted as Cross 2, where N≥1;

[0064] Step S104: determine whether Cross 1 coincides with Cross 2.

[0065] Step S105: if they coincide, the collimation adjustment is completed; otherwise, execute Step S106.

[0066] Step S106: adjust the position and / or angle of the projection optical machine until Cross 1 coincides with Cross 2.

[0067] In the collimation adjustment method of this embodiment, the optical axis of the projection device of the waveguide sheet 20 is mainly self-collimated through the semi-transparent and semi-reflective mirror 40 and the corner reflector 30, and the adjustment efficiency is high and the accuracy is high.

[0068] In some embodiments of the present invention, Step S101 includes: adjusting the corner reflector 30 and the semi-transparent and semi-reflective mirror 40 to be in a parallel state, and adjusting the industrial camera 10 and the semi-transparent and semi-reflective mirror 40 to be in a perpendicular state.

[0069] Specifically, sequentially set the industrial camera 10, the semi-transparent and semi-reflective mirror 40, and the corner reflector 30 on the adjustment platform, adjust the corner reflector 30 and the semi-transparent and semi-reflective mirror 40 to be in a parallel state, and the industrial camera 10 and the semi-transparent and semi-reflective mirror 40 to be in a perpendicular state. There is a spaced arrangement between the industrial camera 10, the semi-transparent and semi-reflective mirror 40, and the corner reflector 30 in pairs. Preferably, the distance between the semi-transparent and semi-reflective mirror 40 and the corner reflector 30 is greater than the distance between the industrial camera 10 and the semi-transparent and semi-reflective mirror 40. It is also possible that the distance between the semi-transparent and semi-reflective mirror 40 and the corner reflector 30 is equal to the distance between the industrial camera 10 and the semi-transparent and semi-reflective mirror 40. Select according to the actual situation, maintain the current state and fix it. It is also possible to make the above-mentioned components and the adjustment platform into an integrated body for convenient real-time detection.

[0070] All components set on the adjustment platform need to be cleaned before assembly or adjustment to ensure that there is no dust attached to the surface of the components.

[0071] In some embodiments of the present invention, step S102 includes: orienting the light-emitting side of the waveguide sheet 20 towards the industrial camera 10, and arranging the waveguide sheet 20 parallel to and adjacent to the semi-transparent semi-reflective mirror 40.

[0072] Specifically, after the above components and the adjustment platform are set up, the waveguide sheet 20 of the optical waveguide device to be adjusted is placed between the semi-transparent semi-reflective mirror 40 and the corner reflector 30, and the light-emitting side of the waveguide sheet 20 faces and is adjacent to the semi-transparent semi-reflective mirror 40, and this position is maintained and fixed. In another embodiment, the semi-transparent semi-reflective mirror 40 is replaced with a semi-transparent semi-reflective film, and the semi-transparent semi-reflective film is attached to the surface of the light-emitting side of the waveguide sheet 20.

[0073] In the above, step S101 and step S102 can be swapped or executed simultaneously. In another embodiment, the semi-transparent semi-reflective mirror 40 and the waveguide sheet 20 can be first fixed on the adjustment platform and the two are in a parallel state, and then the corner reflector 30 is set on the other side of the waveguide sheet 20, that is, the side away from the semi-transparent semi-reflective mirror 40, and at the same time, the industrial camera 10 is set on the other side of the semi-transparent semi-reflective mirror 40, that is, the side away from the waveguide sheet 20. This method is more convenient for operation.

[0074] Further, turn on the projection optical machine to display a black background with a white cross reference line passing through the center of the screen. At the same time, use the industrial camera 10 to observe the screen. At this time, in the screen, the cross line screen that the waveguide sheet 20 couples out and transmits through the semi-transparent semi-reflective mirror 40 and enters the industrial camera 10 can be seen, denoted as cross 1. At the same time, it can also be seen that the waveguide sheet 20 couples out and is reflected by the semi-transparent semi-reflective mirror 40, and then is reflected by the array corner reflector 30 and then passes through the waveguide sheet 20 and the semi-transparent semi-reflective mirror 40 and enters the cross screen of the camera, denoted as cross 2. There may also be higher-order multiple reflection screens, all of which are denoted as cross 2, because the intensity of higher-order multiple reflections is relatively weak.

[0075] Further, after the industrial camera 10 obtains cross 1 and cross 2, adjust the attitude of the projection optical machine, that is, the position and / or angle, that is, adjust the position of the projection optical machine screen so that cross 1 and cross 2 coincide. The coincidence of cross 1 and cross 2 indicates that the light at the center point of the screen is consistent with the normal direction of the waveguide sheet 20.

[0076] The image projected by the near-eye display device is a virtual image at infinity, that is, each pixel point (x, y) on the screen, and a certain field of view angle emitted by the near-eye display device The parallel light rays are in one-to-one correspondence. For the sake of intuitive understanding, we make the following definitions: (x, y) are the horizontal and vertical coordinates of a certain pixel point in the picture with the center of the picture as the origin (0, 0), and the value is the number of pixels deviating from the origin. Define the right direction as positive and the left direction as negative for the x-axis facing the virtual image direction, and the up direction as positive and the down direction as negative for the y-axis, then are the horizontal and vertical angles between the light ray and the normal of the waveguide sheet 20. Define the right direction as positive and the left direction as negative for the θ-axis facing the virtual image direction (opposite to the light output direction), and the up direction as positive and the down direction as negative.

[0077] Actually, if the pixel size of the display is P x ×P y , and the focal length of the projection system is f, then there is:

[0078]

[0079]

[0080] In the coordinate axes of the projection optical machine, the origin (0, 0) of the projection optical machine picture corresponds to the light output optical axis (0°, 0°) of the projection optical machine.

[0081] For the alignment of the waveguide near-eye display system, it is necessary to determine the relative relationship between the coordinate system of the reference projection picture and the coordinate system of the normal of the reference waveguide sheet 20, and perform adjustments with consistent standards in the same batch of products. For the sake of understanding, define the coordinate system of the reference projection picture as the picture coordinate system, and the coordinate system of the normal of the reference waveguide sheet 20 is called the waveguide sheet 20 coordinate system. Define the offset angle of the picture coordinate system relative to the waveguide sheet 20 coordinate system as

[0082] According to different product designs, this offset angle will have different set values. The most common one is that is, the picture coordinate system and the waveguide sheet 20 coordinate system overlap, i.e., the light direction at the center of the picture is perpendicular to the waveguide sheet 20. The distance in this embodiment is also assumed according to .

[0083] When the light ray is reflected by the array corner reflector 30, the reflected light will return along the direction of the incident light ray. In the reference system of the waveguide sheet 20, for the light ray propagating along the direction , its reflected light is converted to According to the linear relationship between the picture pixel (x, y) and the light direction mentioned above, if corresponds to the point (x1, y1) on the picture, then the reflected light The point (-x1, -y1) on the corresponding screen, that is, the points corresponding to the original light ray and the reflected light ray, are centrosymmetric with respect to the origin (0, 0) of the reference system of the waveguide plate 20.

[0084] Furthermore, for the industrial camera 10 that has not been calibrated with the waveguide plate 20, there is a linear transformation relationship between its camera reference system and the reference system of the waveguide plate 20. During the linear transformation process, the symmetric relationship remains unchanged: the original light ray and the reflected light ray are still centrosymmetric, and the center of symmetry is the origin of the reference system of the waveguide plate 20.

[0085] Therefore, in this embodiment, the origin of the reference system of the waveguide plate 20 can be determined in the image of the industrial camera 10, effectively saving the adjustment process and improving the adjustment efficiency. In other words, directly adjust the projection light machine image without the need for the calibration process.

[0086] In some embodiments of the present invention, after step S106, steps S107, S108, and S109 may further be included:

[0087] Step S107: Coincide cross 1 and cross 2, denoted as cross 3, and determine whether the cross reference line in the industrial camera 10 coincides with cross 3.

[0088] Step S108: If the cross reference line in the industrial camera 10 coincides with cross 3, then the optical axis direction of the industrial camera 10, the normal direction of the waveguide plate 20, and the central light ray direction of cross 3 are in a parallel state. Otherwise, execute step S109.

[0089] Step S109: Continue to adjust the position and / or angle of the industrial camera 10 until the cross reference line in the industrial camera 10 coincides with cross 3.

[0090] Steps S107 - S109 can be combined according to actual needs. If it is necessary to calibrate the parallelism between the optical axis of the industrial camera 10 and the normal of the waveguide plate 20, coincide cross 1 and cross 2, denoted as cross 3, and then further adjust the posture of the industrial camera 10 to make the cross reference line of the industrial camera 10 coincide with cross 3, that is, the cross reference line of the industrial camera 10 coincides with the coincided cross 1 and cross 2 again. At this time, the central light ray direction, the camera optical axis direction, and the normal direction of the waveguide plate 20 are in a parallel relationship, further improving the accuracy of the overall system collimation adjustment and precise maintenance.

[0091] The above has introduced in detail a self-collimation adjustment system and method for a near-eye display device according to an embodiment of the present application. Specific examples are used in this article to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea; at the same time, for those of ordinary skill in the art, according to the idea of the present application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. A self-collimation adjustment system for a near-eye display device, characterized in that: include: An adjustment platform is provided, on which an industrial camera and a corner reflector are fixed in sequence; the corner reflector is an array corner reflector, and three internal reflection surfaces of the corner reflector of each unit in the array corner reflector are perpendicular to each other; The optical waveguide device to be adjusted is arranged on the adjustment platform, and the optical waveguide device to be adjusted at least includes a projection optical machine and a waveguide plate, and the waveguide plate is arranged between the industrial camera and the corner reflector, and the waveguide plate includes a light emitting side, and the light emitting side is arranged toward the direction of the industrial camera; A semi-transparent and semi-reflective mirror is arranged on the adjustment platform, wherein the semi-transparent and semi-reflective mirror is arranged between the industrial camera and the waveguide sheet and is arranged adjacent to the waveguide sheet; Among them, the center point of the industrial camera, the center point of the waveguide plate, the center point of the semi-transparent and semi-reflective mirror, and the center point of the corner reflector are on the same horizontal line; the outgoing light of the projection optical machine is coupled and emitted through the waveguide plate, a part of the light passes through the semi-transparent and semi-reflective mirror to enter the industrial camera, and the other part of the light is reflected by the semi-transparent and semi-reflective mirror and then passes through the waveguide plate, and then passes through the corner reflector, the waveguide plate, and the semi-transparent and semi-reflective mirror in sequence to enter the industrial camera; when the light is reflected by the array corner reflector, the reflected light will return along the original direction of the incident light, and the reference system of the industrial camera is in a linear conversion relationship with respect to the reference system of the waveguide plate, with the origin of the reference system of the waveguide plate as the center of symmetry, and the incident light and the reflected light are in a centrally symmetrical relationship.

2. The self-collimation adjustment system according to claim 1, characterized in that: The semi-transparent and semi-reflective mirror, the waveguide plate, and the corner reflector are parallel to each other.

3. The self-collimation adjustment system according to claim 2, characterized in that: The semi-transparent and semi-reflective mirror is spaced from the waveguide plate by a first spacing, and the first spacing is greater than or equal to zero.

4. The self-collimation adjustment system according to claim 3, characterized in that: The waveguide plate and the corner reflector are spaced apart by a second spacing, and the second spacing is greater than the first spacing.

5. The self-collimation adjustment system according to any one of claims 1 to 4, characterized in that: The waveguide plate is a geometric array optical waveguide plate or a grating waveguide plate.

6. A collimation adjustment method using the self-collimation adjustment system for a near-eye display device according to any one of claims 1 to 5, characterized in that: include: A corner reflector, a semi-transparent and semi-reflective mirror, and an industrial camera are sequentially arranged on the adjustment platform; The optical waveguide device to be adjusted is arranged between the corner reflector and the semi-transparent and semi-reflective mirror; The projection optical machine is turned on, and the light is coupled and emitted through the waveguide plate. A part of the light is projected through the semi-transparent and semi-reflective mirror into the industrial camera, and the industrial camera obtains a cross-line image 1, which is recorded as Cross 1; another part of the light is reflected by the semi-transparent and semi-reflective mirror, and then passes through the waveguide plate, and then reflects N times through the corner reflector, and then passes through the waveguide plate and the semi-transparent and semi-reflective mirror in sequence into the industrial camera, and the industrial camera obtains a cross-line image 2, which is recorded as Cross 2, where N≥1; It is determined whether the cross 1 and the cross 2 coincide with each other. If so, the collimation adjustment is completed; otherwise, the position and / or angle of the projection optical machine is adjusted until the cross 1 and the cross 2 coincide with each other.

7. The method according to claim 6, characterized in that A corner reflector, a semi-transparent and semi-reflective mirror, and an industrial camera are sequentially arranged on the adjustment platform, including: The corner reflector is adjusted to be parallel to the semi-transparent and semi-reflective mirror, and the industrial camera is adjusted to be vertical to the semi-transparent and semi-reflective mirror.

8. The method according to claim 6, characterized in that The optical waveguide device to be adjusted is arranged between the corner reflector and the semi-transparent and semi-reflective mirror, comprising: The light emitting side of the waveguide plate is oriented toward the industrial camera, and the waveguide plate is arranged parallel to and adjacent to the semi-transparent and semi-reflective mirror.

9. The method according to claim 6, characterized in that Determine whether the cross 1 and the cross 2 coincide with each other, if so, the collimation adjustment is completed; otherwise, adjust the position and / or angle of the projection optical machine until the cross 1 and the cross 2 coincide with each other, and further include: The cross 1 coincides with the cross 2, which is recorded as cross 3. It is determined whether the cross reference line inside the industrial camera coincides with the cross 3. If so, the optical axis direction of the industrial camera, the normal direction of the waveguide plate, and the central light direction of the cross 3 are parallel to each other; otherwise, the position and / or angle of the industrial camera is continuously adjusted until the cross reference line inside the industrial camera coincides with the cross 3.

Images