Optical element inspection system, inspection method and application

Abstract

The application provides an optical element detection system, a detection method and application. The optical element detection system comprises: an analysis component, configured to obtain a head-up display real vehicle light path of a to-be-tested optical element, set an equivalent virtual image plane according to an actual virtual image plane in the head-up display real vehicle light path, and design a head-up display equivalent light path according to the equivalent virtual image plane; a standard image source, configured to project a preset pattern to the to-be-tested optical element according to the head-up display equivalent light path to form an equivalent projection image; and a camera component, configured to capture the equivalent projection image; wherein the camera component has a standard depth of field DOF0, the equivalent virtual image plane has an equivalent depth of view DOF2, and DOF2≤DOF0; and the analysis component can obtain the equivalent projection image and determine the imaging quality of the to-be-tested optical element according to the equivalent projection image. The optical element detection system, the detection method and the application provided by the application can efficiently and accurately detect a HUD image with a large depth of view.

Description

Technical Field

[0001] This application relates to the field of vehicle head-up displays, specifically to optical component testing systems, testing methods, and applications. Background Technology

[0002] Vehicles are one of the most important means of transportation for humans. The application of automotive head-up display (HUD) systems can reduce the time drivers spend looking down at the dashboard or related information, facilitate the switching of the driver's eyes between near and far objects, maximize the driver's attention while driving, improve driving safety, and provide richer driving information.

[0003] With the evolution of the era of intelligent connected vehicles, Augmented Reality HUD (AR-HUD) systems combine AR technology with HUD functionality, changing the way information is displayed independently on a virtual screen. This not only allows the vehicle to convey more information but also integrates image information with the real-world scene. To provide drivers with a more realistic AR experience, the optimal approach is to set the HUD image to a forward-tilted position, so that the image seen by the driver is approximately flat on the ground, providing a better sense of ground contact.

[0004] However, when inspecting head-up display (HUD) glass, the camera is used to simulate the human eye to capture HUD images. If the HUD image is tilted forward significantly, some parts of the HUD image will exceed the camera's depth of field. As a result, there will be some blurry areas in the actual projected image, which will affect the pattern pixel processing based on this projected image and the subsequent analysis and judgment of HUD test items. The final test results will have defects such as insufficient detection accuracy or even misjudgment. Summary of the Invention

[0005] In a first aspect, this application provides an optical element inspection system, the optical element inspection system comprising:

[0006] An analysis component is used to acquire the actual optical path of the head-up display of the optical element under test, set an equivalent virtual image surface according to the actual virtual image surface in the actual optical path of the head-up display, and design an equivalent optical path of the head-up display according to the equivalent virtual image surface.

[0007] A standard image source, wherein the standard image source projects a preset pattern onto the optical element under test according to the equivalent optical path of the head-up display to form an equivalent projection image;

[0008] A camera assembly for capturing the equivalent projected image;

[0009] The camera assembly has a standard depth of field DOF0, and the equivalent virtual image plane has an equivalent distance depth DOF2, where DOF2≤DOF0;

[0010] The analysis component is able to acquire the equivalent projection image and determine the imaging quality of the optical element under test based on the equivalent projection image.

[0011] Wherein, the actual virtual image plane has an actual viewing distance depth DOF1, wherein the actual viewing distance depth DOF1 is ≥3 meters, or the actual viewing distance depth DOF1 is ≥5 meters, or the actual viewing distance depth DOF1 is ≥7.5 meters, or the actual viewing distance depth DOF1 is ≥10 meters.

[0012] Wherein, DOF2 / DOF1≤0.5, or DOF2 / DOF1≤0.3, or DOF2 / DOF1≤0.1.

[0013] Wherein, the equivalent line-of-sight depth DOF2 = 0 to 3 meters, or the equivalent line-of-sight depth DOF2 = 0 to 2 meters, or the equivalent line-of-sight depth DOF2 = 0 to 1 meter.

[0014] Wherein, the forward tilt angle of the actual virtual image surface is ≥45°, or the forward tilt angle of the actual virtual image surface is ≥60°, or the forward tilt angle of the actual virtual image surface is ≥75°.

[0015] Wherein, the forward tilt angle of the equivalent virtual image surface is ≤20°, or the forward tilt angle of the equivalent virtual image surface is ≤10°, or the forward tilt angle of the equivalent virtual image surface is ≤5°.

[0016] The head-up display (HUD) optical path includes the position and specifications of the actual eye box, the position and specifications of the actual virtual image surface, the specifications of the HUD glass, and the position of its display area. The actual eye box has an actual eye box surface through which the actual virtual image surface can be observed. The actual eye box surface includes multiple sub-actual eye box surfaces. The actual virtual image surface includes multiple sub-actual virtual image surfaces that correspond one-to-one with the multiple sub-actual eye box surfaces. The line connecting the center point of any sub-actual eye box surface and the center point of the corresponding sub-actual virtual image surface is the main optical axis. The plane passing through the main optical axis and perpendicular to the ground is the main optical axis plane.

[0017] The line of intersection between the principal optical axis plane and the corresponding sub-actual virtual image plane has an actual far point and an actual near point. The projection point of the actual far point on the principal optical axis is the first point, and the projection point of the actual near point on the principal optical axis is the second point.

[0018] A point is selected on the principal optical axis as a weighting point, which is located between the first point and the second point. An equivalent virtual image surface is set through the weighting point, which is perpendicular to the principal optical axis plane. The weighting point is the center point of the equivalent virtual image surface.

[0019] Wherein, the actual virtual image surface has an actual vertical field of view VFOV1, which is the angle between the center point of the sub-actual eye box surface and the line connecting the upper and lower boundaries of the corresponding sub-actual virtual image surface in the principal optical axis plane.

[0020] The equivalent virtual image surface has an equivalent vertical field of view VFOV2. The equivalent virtual image surface includes a plurality of sub-equivalent virtual image surfaces that correspond one-to-one with the plurality of sub-actual eye box surfaces. The equivalent vertical field of view VFOV2 is the angle between the center point of the sub-actual eye box surface and the line connecting the upper and lower boundaries of the corresponding sub-equivalent virtual image surface in the principal optical axis plane.

[0021] Among them, VFOV2 / VFOV1 = 0.8 to 1.2.

[0022] Wherein, the line connecting the upper and lower boundaries of the sub-actual virtual image surface within the principal optical axis plane is the first connecting line, and the line connecting the upper and lower boundaries of the sub-equivalent virtual image surface within the principal optical axis plane is the second connecting line. The first connecting line and the second connecting line have an intersection point, and the angle between the center point of the sub-actual eye box surface and the two connecting lines of the intersection point and the weight point has a first angle β.

[0023] Where β / VFOV1≤1 / 3, or β / VFOV1≤1 / 5, or β / VFOV1≤1 / 10.

[0024] The standard image source is a standard lightbox or display screen;

[0025] The standard light box includes a light source and a pattern. The pattern is disposed between the light source and the optical element under test. The pattern has a light-transmitting area, which is used to transmit light emitted by the light source to form a preset pattern.

[0026] The display screen is used to emit preset patterns.

[0027] The preset pattern includes multiple detection marks, wherein the detection marks include at least one of dots and lines.

[0028] The optical element detection system further includes:

[0029] A mirror assembly, wherein the mirror assembly is disposed between the standard image source and the optical element under test, the mirror assembly comprising at least one of a plane mirror and an aspherical mirror.

[0030] The optical element detection system further includes:

[0031] A carrier assembly, wherein the carrier assembly carries and supports the standard image source, the camera assembly, and the optical element under test; and

[0032] An adjustment component is provided for adjusting the position of the camera component to move between multiple shooting points.

[0033] The analysis component can obtain a standard image with the center point of the actual eye box surface as the shooting point based on the standard optical element and the equivalent optical path of the head-up display. i*j detection points are taken on the standard image, and m*n shooting points are taken on the actual eye box surface, where i, j, m, and n are all positive integers greater than or equal to 2.

[0034] Take any detection point P on the standard image k The coordinates are (Y) k0 Z k0 ), 1≤k≤i*j;

[0035] Observe the detection point P on the standard image k The coordinates of the detection point corresponding to the t-th shooting point are (Y) kt Z kt ), 1≤t≤m*n;

[0036] Then the detection point P on the standard image k The correction value for the detection point corresponding to the t-th shooting point is (△Y) kt , △Z kt ), △Y kt =Y kt -Y k0 , △Z kt =Z kt -Z k0 .

[0037] The process of determining the imaging quality of the tested optical element based on the equivalent projection image includes calculating the evaluation index of the equivalent projection image to obtain a first evaluation parameter, and determining the imaging quality based on the evaluation parameter corresponding to the evaluation index and the evaluation standard corresponding to the preset evaluation index.

[0038] The evaluation indicators include at least one of the following: horizontal straightness, vertical straightness, horizontal ghosting, vertical ghosting, image rotation, center of gravity shift, image tilt, trapezoidal shape, scaling factor, image brightness, sharpness, image color, binocular horizontal parallax, binocular vertical parallax, virtual image plane dynamic distortion, and eyebox plane dynamic distortion.

[0039] Determining the imaging quality of the inspected optical element based on the equivalent projected image further includes calculating detection correlation, which includes:

[0040] The analysis component can obtain an equivalent test image located on the equivalent virtual image plane based on the optical element under test and the optical path of the head-up display vehicle. It calculates the evaluation index of the equivalent test image to obtain a second evaluation parameter. It calculates the detection correlation based on the first evaluation parameter and the second evaluation parameter. The detection correlation is equal to the difference between the first evaluation parameter and the second evaluation parameter. If the detection correlation is less than or equal to 20% of the evaluation standard, preferably less than or equal to 10% of the evaluation standard, then the imaging quality is determined.

[0041] Secondly, this application also provides a method for detecting optical components, the method comprising:

[0042] Obtain the actual optical path of the head-up display of the inspected optical component;

[0043] An equivalent virtual image surface is set according to the actual virtual image surface in the optical path of the real vehicle in the head-up display;

[0044] Design the equivalent optical path for the head-up display based on the aforementioned equivalent virtual image surface;

[0045] A preset pattern is projected onto the tested optical element according to the equivalent optical path of the head-up display to form an equivalent projection image;

[0046] The equivalent projection image is captured, wherein the camera assembly capturing the equivalent projection image has a standard depth of field DOF0, and the equivalent virtual image plane has an equivalent viewing distance depth DOF2, where DOF2 ≤ DOF0; and

[0047] The equivalent projection image is acquired, and the imaging quality of the optical element under test is determined based on the equivalent projection image.

[0048] The head-up display optical path includes the position and specifications of the actual eye box, the position and specifications of the actual virtual image surface, the specifications of the head-up display glass and the position of its display area. The actual eye box has an actual eye box surface through which the actual virtual image surface can be observed. The actual eye box surface includes multiple sub-actual eye box surfaces, and the actual virtual image surface includes multiple sub-actual virtual image surfaces that correspond one-to-one with the multiple sub-actual eye box surfaces.

[0049] The step of setting an equivalent virtual image surface based on the actual virtual image surface in the optical path of the head-up display vehicle includes:

[0050] The line connecting the center point of any sub-actual eye box surface and the center point of the corresponding sub-actual virtual image surface is taken as the main optical axis. The plane passing through the main optical axis and perpendicular to the ground is taken as the main optical axis plane. The line of intersection between the main optical axis plane and the corresponding sub-actual virtual image surface has an actual far point and an actual near point. The projection point of the actual far point on the main optical axis is the first point, and the projection point of the actual near point on the main optical axis is the second point.

[0051] A point is selected on the main optical axis as the weighting point, wherein the weighting point is located between the first point and the second point;

[0052] An equivalent virtual image surface is set through the weighting point, wherein the equivalent virtual image surface is perpendicular to the principal optical axis plane, and the weighting point is the center point of the equivalent virtual image surface.

[0053] Thirdly, this application also provides an optical element inspection application, which uses the optical element inspection system described in the first aspect to inspect the head-up display image quality of the head-up display glass, the size of the reflection ghosting, or the head-up display image quality of the mirror assembly.

[0054] The head-up display glass has a wedge-shaped cross-sectional profile, and the wedge-shaped cross-sectional profile has at least one wedge angle. The size of the reflected ghost image and the wedge angle satisfy a functional relationship: Y = KX + B, where Y is the size of the reflected ghost image, K is the slope of the change of the reflected ghost image and the wedge angle, X is the wedge angle, and B is the size of the reflected ghost image when the wedge angle X = 0.

[0055] In the actual vehicle optical path of the head-up display, the size of the reflected ghost image and the wedge angle satisfy a functional relationship Yp; in the equivalent optical path of the head-up display, the size of the reflected ghost image and the wedge angle satisfy a functional relationship Yt.

[0056] Functional relations Yp and Yt can be converted into each other.

[0057] The optical element detection system is used to detect the head-up display glass or mirror assembly in a head-up display system with a projection distance of ≥6 meters.

[0058] The optical element detection system is used to detect the head-up display glass or mirror assembly in a head-up display system having at least two projection distances.

[0059] The optical component inspection system, method, and application provided in this application overcome the problem of a large depth of field caused by the excessive forward tilt angle of the actual virtual image surface in the head-up display (HUD) system by setting an equivalent virtual image surface that is equivalent to the actual virtual image surface. This results in a clearer equivalent projection image, which facilitates subsequent analysis of the equivalent projection image to determine the HUD quality of the inspected optical component and whether the HUD optical path conforms to the design. Therefore, the optical component inspection system, method, and application provided in this application can achieve efficient and accurate inspection of HUD images with large viewing depths. Attached Figure Description

[0060] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the implementation will be briefly introduced below. Obviously, the drawings described below are some implementations of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0061] Figure 1 This is a schematic diagram of the structure of an optical element detection system provided in one embodiment of this application.

[0062] Figure 2 for Figure 1 A schematic diagram of the optical path for imaging inspection of the optical components under test by the optical component inspection system.

[0063] Figure 3 for Figure 1 A schematic diagram of the optical path of the actual vehicle and the equivalent optical path of the head-up display in the optical component inspection system.

[0064] Figure 4 for Figure 1 A schematic diagram of the structure of a standard image source.

[0065] Figure 5 for Figure 4 A schematic diagram of the preset pattern formed by the light-transmitting area of ​​the case.

[0066] Figure 6 for Figure 1 A schematic diagram of the structure of the load-bearing component and the adjustment component.

[0067] Figure 7 for Figure 1 A schematic diagram of the structure of the center correction component.

[0068] Figure 8 for Figure 3 A schematic diagram showing the corresponding setup of the shooting points and detection points.

[0069] Figure 9This is a flowchart of an optical element detection method provided in one embodiment of this application.

[0070] Figure 10 A comparative simulation diagram of the image rotation of the two HUD optical paths corresponding to the embodiments provided in this application.

[0071] Figure 11 A comparative simulation diagram of the horizontal offset of the two HUD optical paths corresponding to the embodiments provided in this application.

[0072] Reference numerals: Optical Component Inspection System 1; Analysis Component 11; Standard Image Source 12; Light Source 121; Pattern 122; Transmitting Area 1221; Inspection Mark 1222; Camera Component 13; Equivalent Virtual Image Plane 14; Sub-Equivalent Virtual Image Plane 141; Intersection Point 142; Inspection Point 143; Mirror Group 15; Support Component 16; Adjustment Component 17; Correction Component 18; Optical Component Under Inspection 2; Display Area 21; Actual Eye Box Surface 22; Sub-Actual Eye Box Surface 221; Shooting Point 222; Actual Virtual Image Plane 23; Principal Axis 231; First Point 2311; Second Point 2312; Weighting Point 2313; Sub-Actual Virtual Image Plane 232. Detailed Implementation

[0073] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0074] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0075] In this document, references to "embodiment" or "implementation" mean that a particular feature, structure, or characteristic described in connection with an embodiment or implementation may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0076] This application provides an optical element inspection system 1. Please refer to... Figure 1 , Figure 2 and Figure 3 , Figure 1 This is a schematic diagram of the structure of an optical element detection system provided in one embodiment of this application; Figure 2 for Figure 1 A schematic diagram of the optical path for imaging inspection of the optical components under test by the optical component inspection system. Figure 3 for Figure 1 A schematic diagram of the actual optical path and the equivalent optical path of the head-up display (HUD) in the optical component inspection system. In this embodiment, the optical component inspection system 1 includes an analysis component 11, a standard image source 12, and a camera component 13. The analysis component 11 is used to acquire the actual optical path of the optical component under test (HUD) in the actual vehicle, and to set an equivalent virtual image surface 14 according to the actual virtual image surface 23 in the actual vehicle optical path, and to design an equivalent optical path for the HUD according to the equivalent virtual image surface 14. The standard image source 12 projects a preset pattern onto the optical component under test (HUD) according to the equivalent optical path to form an equivalent projection image. The camera component 13 is used to capture the equivalent projection image. The camera component 13 has a standard depth of field (DOF0), and the equivalent virtual image surface 14 has an equivalent depth of view (DOF2), where DOF2 ≤ DOF0. The analysis component 11 can acquire the equivalent projection image and determine the imaging quality of the optical component under test (HUD) based on the equivalent projection image.

[0077] In this embodiment, the optical element testing system 1 is used to simulate a head-up display (HUD) system on a real vehicle. The optical element under test 2 is set according to the actual vehicle installation angle. The standard image source 12 projects test projection light onto the display area 21 of the optical element under test 2. The camera assembly 13 simulates the human eye to capture the HUD image at the predetermined observation position to obtain an equivalent projection image. By performing pixel processing on the pattern in the equivalent projection image, various HUD test items are analyzed, and it is determined whether the optical element under test 2 meets the set requirements. The optical element under test 2 is typically a head-up display (HUD) glass, which can be used as the windshield of a vehicle.

[0078] Optionally, the analysis component 11 stores the actual optical path of the head-up display vehicle, or the analysis component 11 has the function of acquiring the actual optical path of the head-up display vehicle from the outside.

[0079] Optionally, the equivalent optical path of the head-up display adopts the optical path under the standard lightbox testing mode (Testing in standard Testgrid). This mode uses a standard test pattern of a lightbox for imaging, and evaluates the quality of the tested optical element 2 by capturing and analyzing the quality of the equivalent projection image of the HUD image. This results in high detection accuracy, short development cycle, and more targeted detection for the optical element detection system 1. The standard image source 12 can be a standard lightbox made of a metal plate with a certain hollow pattern, or it can be a display screen, such as a thin-film transistor display (TFT), an organic light-emitting diode display (OLED), a liquid crystal on silicon (LCOS), a digital light processing display (DLP), a sub-millimeter light-emitting diode display (Mini LED), a micro light-emitting diode display (Micro LED), etc. One standard image source 12 can be set, or two, three, or even more can be set to meet the detection needs of multiple different detection indicators.

[0080] In this embodiment, the head-up display (HUD) optical path includes the position and specifications of the actual eye box, the position and specifications of the actual virtual image surface 23, the specifications of the HUD glass, and the position of its display area 21. The actual eye box has an actual eye box surface 22 through which the actual virtual image surface 23 can be observed. The actual eye box surface 22 includes multiple sub-actual eye box surfaces 221. The actual virtual image surface 23 includes multiple sub-actual virtual image surfaces 232 corresponding one-to-one with the multiple sub-actual eye box surfaces 221. The line connecting the center point of any sub-actual eye box surface 221 to the center point of the corresponding sub-actual virtual image surface 232 is taken as the main optical axis 231, and the plane passing through the main optical axis 231 and perpendicular to the ground is taken as the main optical axis plane. The intersection line of the main optical axis plane and the corresponding sub-actual virtual image surface 232 has an actual far point and an actual near point. The projection point of the actual far point on the main optical axis 231 is the first point 2311. The projection point of the actual near point on the main optical axis 231 is the second point 2312. A point is selected on the principal optical axis 231 as a weighting point 2313, located between the first point 2311 and the second point 2312. An equivalent virtual image surface 14 is established through the weighting point 2313. The equivalent virtual image surface 14 is perpendicular to the principal optical axis plane. The weighting point 2313 is the center point of the equivalent virtual image surface. The equivalent virtual image surface 14 includes multiple sub-equivalent virtual image surfaces 141 corresponding one-to-one with the multiple sub-actual eyepiece surfaces 221. The intersection line between the principal optical axis plane and the corresponding sub-equivalent virtual image surface 141 has an equivalent far point and an equivalent near point.

[0081] The eye box simulates a human eye. Specifically, the actual eye box surface 22 is a rectangular area that just encloses the eye ellipse. Its plane passes perpendicularly through the centroid of the eye ellipse, and its boundary is always parallel to the XY and YZ planes of the vehicle's coordinate system. The X direction is the opposite direction of the vehicle's forward movement, the Z direction is perpendicular to the ground, and the Y direction is perpendicular to both the X and Z directions. Depending on the height of the human eye within the driver's cab, the actual eye box surface 22 has multiple sub-actual eye box surfaces 221 at different Z-direction positions.

[0082] Furthermore, by adjusting the position of the weight point 2313 between the first point 2311 and the second point 2312, the emphasis on detecting the equivalent projection image can be adjusted. Specifically, near the weight point 2313, the correlation between the equivalent virtual image surface 14 and the actual virtual image surface 23 is good. When the weight point 2313 is close to the first point 2311, the detection of the equivalent projection image is biased towards the top of the equivalent projection image. When the weight point 2313 is close to the second point 2312, the detection of the equivalent projection image is biased towards the bottom of the projection image under test. When the weight point 2313 is close to the center of the actual virtual image surface 23, the detection of the equivalent projection image is biased towards the middle of the equivalent projection image. Therefore, the weight point 2313 can be designed according to the area on the actual virtual image surface 23 that has important information in practical applications to achieve more accurate detection.

[0083] Optionally, the actual virtual image surface 23 has an actual depth of view (DOF1), wherein the actual depth of view (DOF1) is ≥3 meters, ≥5 meters, ≥7.5 meters, or ≥10 meters. Because the actual depth of view of the actual virtual image surface 23 is relatively large, the standard depth of field (DOF0) of the camera assembly 13 cannot meet the requirements, resulting in a blurry image obtained from the actual virtual image surface 23, which is detrimental to detection. In this embodiment, the equivalent depth of view (DOF2) of the equivalent virtual image surface 14 is designed to be small, such that DOF2 ≤ DOF0, thereby making the equivalent projection image captured by the camera assembly 13 clear. This facilitates subsequent analysis of the equivalent projection image to determine the head-up display quality of the inspected optical element 2 and whether the actual vehicle optical path of the head-up display conforms to the design. Specifically, the equivalent viewing distance depth DOF2 = 0-3 meters, or the equivalent viewing distance depth DOF2 = 0-2 meters, or the equivalent viewing distance depth DOF2 = 0-1 meter, enables the equivalent projected image captured by the camera assembly 13 to be clear. For example, the equivalent viewing distance depth DOF2 can be, but is not limited to, 0 meters, 0.3 meters, 0.6 meters, 1.0 meters, 1.2 meters, 1.4 meters, 1.8 meters, 2.0 meters, 2.4 meters, 2.8 meters, or 3.0 meters, etc.

[0084] Furthermore, DOF2 / DOF1≤0.5, or DOF2 / DOF1≤0.3, or DOF2 / DOF1≤0.1 can effectively improve the problem of large viewing distance depth of the virtual image plane. The actual virtual image plane 23 with large viewing distance depth is equivalently set as the equivalent virtual image plane 14 with small viewing distance depth, so that the equivalent virtual image plane 14 can be clearly captured.

[0085] Wherein, the actual viewing distance depth DOF1 refers to the distance between the first point 2311 and the second point 2312. The equivalent viewing distance depth DOF2 refers to the distance between the projection point of the equivalent far point on the principal optical axis 231 and the projection point of the equivalent near point on the principal optical axis 231.

[0086] Optionally, in the head-up display (HUD) real-vehicle optical path, the HUD image has a virtual image surface with a large forward tilt angle, giving the driver a better sense of ground contact when observing the HUD image. Specifically, the forward tilt angle of the actual virtual image surface 23 is ≥45°, ≥60°, or ≥75°, ensuring good ground contact and improving the user's driving experience. However, because the forward tilt angle of the actual virtual image surface 23 is too large, some areas are blurred when the camera assembly 13 captures the actual virtual image surface 23. In this embodiment, by setting the forward tilt angle of the equivalent virtual image surface 14 to be smaller, the camera assembly 13 captures the equivalent virtual image surface 14 more clearly. Specifically, the forward tilt angle of the equivalent virtual image surface 14 is ≤20°, ≤10°, or ≤5°. For example, the forward tilt angle of the equivalent virtual image plane 14 can be, but is not limited to, 0°, 2°, 4°, 5°, 7°, 9°, 10°, 12°, 14°, 16°, 18°, or 20°.

[0087] The forward tilt angle of the actual virtual image plane 23 refers to the angle between the line connecting the actual far point and the actual near point, which is inclined towards the direction of the actual virtual image plane 23 as viewed from the actual eyelid plane 22, and the YZ plane. The forward tilt angle of the equivalent virtual image plane 14 refers to the angle between the line connecting the equivalent far point and the equivalent near point, which is inclined towards the direction of the equivalent virtual image plane 14 as viewed from the actual eyelid plane 22, and the YZ plane.

[0088] In summary, the optical element inspection system 1 provided in this application can overcome the problem of a large depth of field caused by the large forward tilt angle of the actual virtual image surface 23 in the head-up display system by setting an equivalent virtual image surface 14 that is equivalent to the actual virtual image surface 23. This makes the equivalent viewing distance depth of the equivalent virtual image surface 14 smaller than the standard depth of field of the camera assembly 13, resulting in a clear equivalent projection image. This facilitates subsequent analysis of the equivalent projection image to determine the head-up display quality of the inspected optical element 2 and whether the head-up display optical path conforms to the design. Therefore, the optical element inspection system 1 provided in this application can achieve efficient and accurate inspection of HUD images with a strong sense of ground contact.

[0089] Please refer to this again. Figure 1 , Figure 2 and Figure 3In this embodiment, the actual virtual image surface 23 has a vertical field of view (VFOV1), which is the angle between the center point of the sub-actual eyepiece surface 221 and the lines connecting the upper and lower boundaries of the corresponding sub-actual virtual image surface 232 within the principal optical axis plane. The equivalent virtual image surface 14 has an equivalent vertical field of view (VFOV2), comprising multiple sub-equivalent virtual image surfaces 141 corresponding one-to-one with the multiple sub-actual eyepiece surfaces 221. The equivalent vertical field of view (VFOV2) is the angle between the center point of the sub-actual eyepiece surface 221 and the lines connecting the upper and lower boundaries of the corresponding sub-equivalent virtual image surface 141 within the principal optical axis plane. Wherein, VFOV2 / VFOV1 = 0.8 to 1.2.

[0090] In some specific embodiments, the corresponding sub-actual virtual image plane 232 is located on the line connecting its upper and lower boundaries within the principal optical axis plane, i.e., the intersection line between the principal optical axis plane and the corresponding sub-actual virtual image plane 232, which has an actual far point and an actual near point; the corresponding sub-equivalent virtual image plane 141 is located on the line connecting its upper and lower boundaries within the principal optical axis plane, i.e., the intersection line between the principal optical axis plane and the corresponding sub-equivalent virtual image plane 141, which has an equivalent far point and an equivalent near point.

[0091] For example, the ratio of VFOV2 to VFOV1 can be, but is not limited to, 0.8, 0.85, 0.9, 0.95, 1, 1.05, 1.1, 1.15, 1.2, or other values ​​between 0.8 and 1.2.

[0092] When the effective usable area of ​​the actual virtual image surface 23 is small, VFOV2 / VFOV1 < 1, so as to save detection costs.

[0093] When the effective usable area of ​​the actual virtual image surface 23 is large, VFOV2 / VFOV1 > 1, so as to provide a detection margin.

[0094] When the equivalence requirements between the actual vehicle optical path and the equivalent optical path of the head-up display are high, VFOV2 / VFOV1 = 1 can be designed so that the deviation between the equivalent virtual image surface 14 and the theoretical design and the deviation between the actual virtual image surface 23 and the theoretical design are more consistent, which is beneficial for evaluating the optical element 2 under test.

[0095] Please refer to this again. Figure 1 , Figure 2 and Figure 3In this embodiment, the line connecting the upper and lower boundaries of the sub-actual virtual image plane within the principal optical axis plane is taken as the first connecting line, that is, the line connecting the actual far point and the actual near point is taken as the first connecting line; the line connecting the upper and lower boundaries of the sub-equivalent virtual image plane within the principal optical axis plane is taken as the second connecting line, that is, the line connecting the equivalent far point and the equivalent near point is taken as the second connecting line; the first connecting line and the second connecting line have an intersection point 142. The angle between the center point of the sub-actual eye box surface 221 and the two connecting lines of the intersection point 142 and the weight point 2313 has a first angle β. Wherein, β / VFOV1≤1 / 3, or β / VFOV1≤1 / 5, or β / VFOV1≤1 / 10.

[0096] In this embodiment, when the display information level is consistent across all parts of the actual virtual image surface 23, if β / VFOV1≤1 / 3, or β / VFOV1≤1 / 5, or β / VFOV1≤1 / 10, the weight point 2313 can be made closer to the center of the actual virtual image surface 23, thereby making the clarity level of each part in the captured equivalent projection image more consistent, which is beneficial for analyzing the equivalent projection image.

[0097] Please refer to Figure 1 , Figure 2 and Figure 4 , Figure 4 for Figure 1 A schematic diagram of the structure of a standard image source. In this embodiment, the standard image source 12 is a standard lightbox or a display screen. The standard lightbox includes a light source 121 and a pattern 122. The pattern 122 is disposed between the light source 121 and the optical element under test 2. The pattern 122 has a light-transmitting area 1221. The light-transmitting area 1221 is used to transmit light emitted from the light source 121 to form a preset pattern. The display screen is used to emit the preset pattern.

[0098] In this embodiment, when the standard image source 12 is a standard lightbox, the preset pattern is formed by providing a light-transmitting area 1221 on the pattern 122 through which light emitted from the light source 121 passes, making the formation of the preset pattern convenient and stable. Furthermore, the preset pattern can be designed by shaping the contour of the light-transmitting area 1221.

[0099] Optionally, the light-transmitting area 1221 is a hollow structure on the pattern 122, or a light-transmitting film with a corresponding pattern on the pattern 122.

[0100] Further, please refer to Figure 1 , Figure 2 ,and Figure 5 , Figure 5 for Figure 4A schematic diagram of a preset pattern formed by the light-transmitting area of ​​a transparent pattern. In this embodiment, the preset pattern includes multiple detection marks 1222. The detection marks 1222 include at least one of dots and lines. It should be noted that dots or lines actually refer to visually appearing as dot-shaped or line-shaped graphics occupying a certain spatial area; the lines can be straight segments or curved segments.

[0101] When the detection identifier 1222 includes the dots, a plurality of the dots are distributed in an array. The dots are used to evaluate the display quality of the equivalent projected image, such as image distortion, positional offset, etc.

[0102] When the detection identifier 1222 includes the lines, multiple lines are distributed in an array. The lines are used to evaluate the degree of projection ghosting in the equivalent projection image, and the direction of the offset of the equivalent projection image is determined according to the offset direction of the lines.

[0103] Specifically, the analysis component 11 stores a standard virtual image pattern. By comparing the equivalent projection image with the standard virtual image pattern, the image distortion, offset direction, sharpness, offset distance, and offset angle of the multiple detection marks 1222 in the equivalent projection image are compared with those of the multiple detection marks 1222 in the standard virtual image pattern. This allows the determination of whether the equivalent projection image meets the requirements, and consequently, whether the inspected optical element 2 meets the design requirements.

[0104] Please refer to this again. Figure 1 , Figure 2 and Figure 4 In this embodiment, the optical element inspection system 1 further includes a mirror assembly 15. The mirror assembly 15 is disposed between the standard image source 12 and the optical element under inspection 2. The mirror assembly 15 includes at least one of a plane mirror and an aspherical mirror.

[0105] In this embodiment, the standard image source 12 is reflected and folded by the mirror group 15 to the optical path emitted from the standard image source 12 to the optical element under test 2, thereby shortening the distance between the standard image source 12 and the optical element under test 2, thereby reducing the space occupied by the optical element detection system 1, which is beneficial to the construction of the optical element detection system 1 and the detection cost.

[0106] Optionally, the mirror assembly 15 includes at least one of a plane mirror and an aspherical mirror. When the mirror assembly 15 includes the aspherical mirror, the aspherical mirror is also used to scale the size of the projected image to be measured for flexible adjustment.

[0107] Please refer to this again. Figure 2 , Figure 3 and Figure 6 , Figure 6 for Figure 1 A schematic diagram of the structure of the carrier component and the adjustment component. In this embodiment, the optical element inspection system 1 further includes a carrier component 16 and an adjustment component 17. The carrier component 16 is used to carry and support the standard image source 12, the camera component 13, and the optical element under inspection 2. The adjustment component 17 is used to adjust the position of the camera component 13 to move it between multiple shooting points 222.

[0108] In this embodiment, the support assembly 16 serves as the basic framework of the optical element inspection system 1, providing fundamental support for the standard image source 12, the camera assembly 13, and the optical element under test 2. The support assembly 16 is also referred to as a device stand. The support assembly 16 includes a glass positioning system for placing, supporting, and positioning the optical element under test 2 at a predetermined position. Furthermore, the adjustment assembly 17 is used to adjust the position of the camera assembly 13, enabling it to move between the plurality of shooting points 222. For example, a robotic arm can be used to move the camera assembly 13.

[0109] Please refer to Figure 1 , Figure 2 and Figure 7 , Figure 7 for Figure 1 A schematic diagram of the correction component is shown. In this embodiment, the standard image source 12 further includes a correction component 18. Before testing the optical element under test 2, the correction component 18 is located at the equivalent virtual image plane 14 to correct the position of the camera component 13.

[0110] In this embodiment, the correction component 18 is used to correct the position of the camera component 13. Specifically, before testing the optical element under test 2, the correction component 18 is positioned at the equivalent virtual image surface 14, and the correction component 18 has the same pattern as the equivalent projected image, and within the XYZ space, the correction component 18 has the same physical spatial position as the equivalent virtual image surface 14. The detection projection light is projected onto the display area 21 through the standard image source 12, and the camera component 13 captures an image towards the display area 21. When the equivalent projected image captured by the camera component 13 coincides with the pattern on the correction component 18, the adjustment of the position, attitude angle, and optical axis direction of the camera component 13 is completed. Optionally, the correction component 18 is a correction plate or correction sheet, etc.

[0111] Optionally, the optical element detection system 1 further includes a display unit, which is used to display the captured equivalent projection image, test results, analysis reports, etc.

[0112] Optionally, the optical element testing system 1 further includes a correction mirror, which is located at the theoretical surface of the optical element under test 2 that reflects the projected light to be tested, and is used to correct the projected light path.

[0113] Optionally, the optical element inspection system 1 further includes a label printer, which marks "qualified" or "unqualified" on the inspected optical element 2 after the analysis component 11 determines whether the inspected optical element 2 is qualified. In addition, the label printer can also mark information such as the inspection time, the number of shooting points 222, and the equivalent viewing distance depth of the equivalent virtual image plane 14 on the inspected optical element 2.

[0114] Optionally, the optical component inspection system 1 further includes an online auxiliary production line, which includes a conveyor belt and a robotic arm. The conveyor belt includes a loading conveyor belt and an unloading conveyor belt. The loading conveyor belt is used to transport the completed optical components 2 to the side of the carrier assembly 16. The processor in the analysis assembly 11 controls the robotic arm to transfer the optical components 2 from the loading conveyor belt to a preset position on the carrier assembly 16, so that the position of the optical components 2 relative to the camera assembly 13 and the standard image source 12 conforms to the equivalent optical path of the head-up display. After the optical components 2 are inspected, the processor in the analysis assembly 11 controls the robotic arm to transfer the optical components 2 from the carrier assembly 16 to the unloading conveyor belt, which is used to transfer the optical components 2. Further, the unloading conveyor belt includes a first conveyor belt and a second conveyor belt. The first conveyor belt is used to transport qualified optical components 2, and the second conveyor belt is used to transport unqualified optical components 2. After the inspection of the optical element 2 is completed, the processor in the analysis component 11 is used to control the robot to transfer the optical element 2 to the first or second conveyor belt according to whether the optical element 2 is qualified.

[0115] Optionally, the optical element inspection system 1 also includes a safety alarm system, which is used to provide early warning of external interference or to provide an alarm for abnormal detection of the inspected optical element 2.

[0116] Please refer to Figure 1 , Figure 2 and Figure 8 , Figure 8 for Figure 3A schematic diagram showing the corresponding setup of the shooting points and detection points. In this embodiment, the analysis component 11 can obtain a standard image with the center point of the actual eye box surface 221 as the shooting point 222 based on the standard optical elements and the equivalent optical path of the head-up display. i*j detection points 143 are selected on the standard image. m*n shooting points 222 are selected on the actual eye box surface 221, where i, j, m, and n are all positive integers greater than or equal to 2. The coordinate value of any detection point 143 on the standard image is P. k (Y k0 Z k0 ), 1≤k≤i*j. Observe the coordinates of the detection point corresponding to the t-th shooting point of detection point 143 on the standard image (Y). kt Z kt ), 1≤t≤m*n. Then the detection point P on the standard image. k The correction value for the detection point corresponding to the t-th shooting point is (△Y) kt , △Z kt ), △Y kt =Y kt -Y k0 , △Z kt =Z kt -Z k0 .

[0117] In this embodiment, in the XYZ coordinate system, the analysis component 11 stores multiple correction values ​​under the theoretical design. Each shooting point 222 has a corresponding correction value for each detection point 143.

[0118] In this embodiment, before analyzing the equivalent projection image, the analysis component 11 corrects and compensates the coordinates of multiple detection points 143 in the equivalent projection image according to the correction value, and then performs image quality analysis on the corrected equivalent projection image, so that the analysis results of the equivalent projection image can more reasonably or accurately reflect the head-up display image quality in the actual vehicle optical path of the head-up display.

[0119] Furthermore, in this embodiment, determining the imaging quality of the tested optical element 2 based on the equivalent projected image includes calculating an evaluation index of the equivalent projected image to obtain a first evaluation parameter. The imaging quality is then determined based on the evaluation parameter corresponding to the evaluation index and the preset evaluation criteria corresponding to the evaluation index.

[0120] Specifically, the evaluation metrics include at least one of the following: horizontal straightness, vertical straightness, horizontal ghosting, vertical ghosting, image rotation, focus shift, image tilt, trapezoidal shape, scaling factor, image brightness, sharpness, image color, binocular horizontal parallax, binocular vertical parallax, virtual image plane dynamic distortion, and eyebox plane dynamic distortion.

[0121] In this embodiment, different evaluation indicators have different evaluation standards, and the weight of each evaluation indicator corresponding to the image quality is different. Specifically, the weight is set according to the product focus of the optical element under test 2. For example, if the horizontal ghosting and vertical ghosting of the optical element under test 2 are the product focus, then the evaluation standards for horizontal ghosting and vertical ghosting in the evaluation indicators are higher than those for other evaluation indicators. Furthermore, when determining the image quality, the weight of horizontal ghosting and vertical ghosting in the first evaluation parameter is also higher than the weight of other evaluation indicators in the first evaluation parameter.

[0122] Furthermore, determining the imaging quality of the tested optical element 2 based on the equivalent projected image also includes calculating detection correlation. The calculation of detection correlation involves the analysis component 11 obtaining an equivalent test image located on the equivalent virtual image plane 14 based on the tested optical element 2 and the actual optical path of the head-up display, calculating an evaluation index of the equivalent test image to obtain a second evaluation parameter, and calculating the detection correlation based on the first and second evaluation parameters. The detection correlation is equal to the difference between the first and second evaluation parameters. If the detection correlation is less than or equal to 20% of the evaluation standard, preferably less than or equal to 10% of the evaluation standard, then the imaging quality is determined.

[0123] In this embodiment, it is necessary to first determine the correlation between the equivalent optical path of the head-up display (HUD) and the actual optical path of the HUD in the vehicle, and then determine the imaging quality. Specifically, a first evaluation parameter of the equivalent projected image in the equivalent optical path of the HUD and a second evaluation parameter of the equivalent tested image in the actual optical path of the HUD are calculated, and the difference between the first evaluation parameter and the second evaluation parameter is calculated. The smaller the difference between the first evaluation parameter and the second evaluation parameter, the higher the correlation between the equivalent optical path of the HUD and the actual optical path of the HUD. If the detected correlation is less than or equal to 20% of the evaluation standard, preferably less than or equal to 10% of the evaluation standard, it indicates that the correlation between the equivalent optical path of the HUD and the actual optical path of the HUD is relatively high, also referred to as the equivalent optical path of the HUD and the actual optical path of the HUD being equivalent. Therefore, evaluating the equivalent optical path of the HUD is equivalent to evaluating the actual optical path of the HUD. Thus, if the detected correlation is less than or equal to 20% of the evaluation standard, preferably less than or equal to 10% of the evaluation standard, the imaging quality is determined. For example, the detection correlation can be, but is not limited to, 0, 2%, 4%, 6%, 8%, 10%, 12%, 14%, 16%, 18%, or 20%.

[0124] This application also provides a method for detecting optical components. Please refer to... Figure 1 , Figure 2 and Figure 9 , Figure 9 This is a flowchart of an optical element detection method provided in one embodiment of the present application. In this embodiment, the optical element detection method includes steps S10, S20, S30, S40, S50, and S60.

[0125] S10, acquire the actual optical path of the head-up display of the inspected optical element 2.

[0126] In this embodiment, the actual eye box has a position and specifications, the actual virtual image surface 23 has a position and specifications, the head-up display glass has specifications and the position of its display area 21, the actual eye box has an actual eye box surface 22 through which the actual virtual image surface 23 can be observed, the actual eye box surface 22 includes a plurality of sub-actual eye box surfaces 221, and the actual virtual image surface 23 includes a plurality of sub-actual virtual image surfaces 232 that correspond one-to-one with the plurality of sub-actual eye box surfaces 221.

[0127] S20, an equivalent virtual image surface 14 is set according to the actual virtual image surface 23 in the head-up display vehicle optical path.

[0128] In this embodiment, the line connecting the center point of any sub-actual eye-box surface 221 to the center point of the corresponding sub-actual virtual image surface 232 is taken as the principal optical axis 231. A plane passing through the principal optical axis 231 and perpendicular to the ground is taken as the principal optical axis plane. The intersection line between the principal optical axis plane and the corresponding sub-actual virtual image surface 232 has an actual far point and an actual near point. The projection point of the actual far point on the principal optical axis 231 is a first point 2311, and the projection point of the actual near point on the principal optical axis 231 is a second point 2312. A point is selected on the principal optical axis 231 as a weighting point 2313, located between the first point 2311 and the second point 2312. An equivalent virtual image surface 14 is set through the weighting point 2313, perpendicular to the principal optical axis plane, and the weighting point 2313 is the center point of the equivalent virtual image surface.

[0129] S30, design the equivalent optical path for the head-up display based on the equivalent virtual image surface 14.

[0130] S40, a preset pattern is projected onto the tested optical element 2 according to the equivalent optical path of the head-up display to form an equivalent projection image.

[0131] S50, capture the equivalent projection image, wherein the camera assembly 13 capturing the equivalent projection image has a standard depth of field DOF0, and the equivalent virtual image plane 14 has an equivalent viewing distance depth DOF2, where DOF2≤DOF0.

[0132] S60, acquire the equivalent projection image, and determine the imaging quality of the optical element under test 2 based on the equivalent projection image.

[0133] The optical element testing method provided in this application can overcome the problem of a large depth of field caused by the large forward tilt angle of the actual virtual image surface 23 in the head-up display system by setting an equivalent virtual image surface 14 that is equivalent to the actual virtual image surface 23. This makes the equivalent viewing distance depth of the equivalent virtual image surface 14 less than the standard depth of field of the camera assembly 13, resulting in a clear equivalent projection image. This facilitates subsequent analysis of the equivalent projection image to determine the head-up display quality of the tested optical element 2 and whether the head-up display optical path conforms to the design. Therefore, the optical element testing method provided in this application can achieve efficient and accurate testing of HUD images with a strong sense of ground contact.

[0134] This application also provides an optical component inspection application. In this embodiment, the optical component inspection application uses the optical component inspection system 1 provided in any of the foregoing embodiments to inspect the head-up display image quality of the head-up display glass, the size of the reflection ghosting, or the head-up display image quality of the mirror assembly 15.

[0135] In this embodiment, the optical element detection system 1 described in the above embodiments can be specifically implemented by the optical element detection application. The optical element detection application can be, but is not limited to, a computer chip, a physical object, or a product with a certain function.

[0136] For example, a typical application for optical component inspection is computer equipment, which can be a personal computer, laptop computer, cellular phone, camera phone, smartphone, personal digital assistant, media player, navigation device, email device, game console, tablet computer, wearable device, or any combination of these devices.

[0137] Specifically, a computer device includes a central processing unit (CPU), which performs various appropriate tasks and processes based on programs stored in read-only memory (ROM) or loaded from storage into random access memory (RAM). RAM also stores various programs and data required for the operation of the computer device. The CPU, ROM, and RAM are interconnected via a bus. Input / output (I / O) interfaces are also connected to the bus. The following components are connected to the I / O interface: input sections including keyboards, mice, etc.; output sections including cathode ray tubes (CRTs), liquid crystal display (LCDs), and speakers; storage sections including hard disks, etc.; and communication sections including network interface cards such as LAN cards and modems. The communication sections perform communication processing via networks such as the Internet. Drives are also connected to the I / O interface as needed. Removable media, such as disks, optical disks, magneto-optical disks, semiconductor memories, etc., are installed on the drives as needed so that computer programs read from them can be installed into the storage section as needed. In particular, the processes described above can be implemented as computer software programs. For example, a computer program product includes a computer program tangibly contained on a machine-readable medium, the computer program including program code for the optical element detection system 1 to detect the head-up display image quality of the head-up display glass, the size of the reflection ghosting, or the head-up display image quality of the mirror assembly 15. Optionally, the computer program can be downloaded and installed from a network via a communication component, and / or installed from a removable medium.

[0138] Optionally, computer-readable media, including permanent and non-permanent, removable and non-removable media, can be used to store information by any method or technology. The information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transfer medium that can be used to store information accessible by a computing device.

[0139] Further, in this embodiment, the head-up display glass has a wedge-shaped cross-sectional profile. The wedge-shaped cross-sectional profile has at least one wedge angle. The size of the reflected ghost image and the wedge angle satisfy a functional relationship: Y = KX + B. Y is the size of the reflected ghost image, K is the slope of the change in the reflected ghost image relative to the wedge angle, X is the wedge angle, and B is the size of the reflected ghost image when the wedge angle X = 0. In the actual optical path of the head-up display, the size of the reflected ghost image and the wedge angle satisfy the above functional relationship Yp. In the equivalent optical path of the head-up display, the size of the reflected ghost image and the wedge angle satisfy the above functional relationship Yt.

[0140] In some specific embodiments, K can be negative, indicating that as the wedge angle increases, the reflection ghosting decreases or even increases in the opposite direction. In some specific embodiments, at a certain local position of the head-up display glass, the wedge angle corresponding to the actual vehicle optical path of the head-up display at different projection distances is the same. Using the above functional relationships Yp and Yt, the numerical conversion of the reflection ghosting from the equivalent optical path of the head-up display to the actual vehicle optical path of the head-up display at that local position can be realized.

[0141] In some specific embodiments, the head-up display glass has a horizontal wedge angle and a vertical wedge angle, which satisfy the above-mentioned functional relationship in both the horizontal and vertical directions, thereby realizing the numerical conversion of reflection ghosting in the horizontal direction and reflection ghosting in the vertical direction.

[0142] Furthermore, the optical element detection system 1 is used to detect the head-up display glass or reflector group 15 in a head-up display system with a projection distance of ≥6 meters, so as to meet the detection requirements of head-up display images that are better integrated with the external environment of the vehicle, such as augmented reality head-up display systems (AR-HUD), whose projection distance is preferably ≥10 meters, or even ≥20 meters.

[0143] Furthermore, the optical element detection system 1 is used to detect the head-up display glass or mirror assembly 15 in a head-up display system with at least two projection distances, so as to meet the detection requirements of the head-up display system using multifocal imaging technology. In the head-up display system using multifocal imaging technology, multiple head-up display images have different projection distances. For example, the driver can observe a first HUD image with a projection distance of 3 meters, a second HUD image with a projection distance of 7.5 meters, a third HUD image with a projection distance of 10 meters, etc.

[0144] Example

[0145] Please refer to the above as well. Figure 1 , Figure 2 , Figure 3 and Figure 4 In this embodiment, the steps of the optical element detection system 1 include steps S100, S200, S300, S400 and S500.

[0146] S100, Obtain the actual vehicle optical path of the head-up display.

[0147] The head-up display optical path is the actual head-up display optical path on the vehicle. The specific information of the head-up display optical path is as follows: the optical element under test 2 is laminated glass, wherein the thicknesses of the outer glass, intermediate adhesive layer, and inner glass of the optical element under test 2 are 1.8mm, 0.76mm, and 1.8mm, respectively. The mounting angle of the optical element under test 2 is 27 degrees. The vertical curvature of the optical element under test 2 in the display area 21 is 5225mm, and the horizontal curvature is 3830mm. The size of the eye box used to observe the head-up display image displayed in the head-up display area 21 is 120mm*50mm, and the projection distance (VID) is 11500mm. The lower angle of view (LDA) of the middle eye box is -2 degrees, the horizontal angle of view (LOA) is 0 degrees, and the field of view (FOV) is 10°×4°. The actual virtual image surface 23 is tilted forward at an angle of 88.3 degrees, meaning that the angle between the actual virtual image surface 23 and the ground is 1.7 degrees.

[0148] The head-up display optical path includes one concave mirror and one plane mirror. The concave mirror is a freeform surface with a lateral radius of curvature of 690mm to 730mm. Following the optical path direction of the standard image source 12, i.e., the forward optical path, the light emitted from the image generation unit (PGU) plane is reflected sequentially by the plane mirror and the concave mirror onto the inner surface of the display area 21 of the optical element under test 2 and then onto the actual eye box surface 22.

[0149] Furthermore, in this embodiment, the weights of the observation point on the actual eye box surface 22 and the detection point 143 on the actual virtual image surface 23 are both set to be equal.

[0150] S200, set the equivalent virtual image plane 14 and its specifications.

[0151] The equivalent virtual image surface 14 is set perpendicular to the line connecting the center point of the middle eye box and the center of the actual virtual image surface 23, so that the forward tilt angle of the equivalent virtual image surface 14 is 2 degrees, that is, the angle between the equivalent virtual image surface 14 and the ground is 88 degrees, and the corresponding equivalent viewing distance depth of the equivalent virtual image surface 14 is 0 mm. The equivalent optical path of the head-up display is set to have the same field of view (FOV) as the actual optical path of the head-up display.

[0152] S300, design the HUD detection optical path and complete the HUD detection optical path data.

[0153] The acquired head-up display optical path of the actual vehicle is inspected to ensure accuracy and completeness.

[0154] The standard virtual image pattern is set as a standard dot matrix grid pattern. The standard dot matrix grid pattern includes multiple dots arranged in an array, and lines arranged between two adjacent dots.

[0155] Design mirror assembly 15.

[0156] Set the plane where the pattern 122 is located. Set the relative position between the standard image source 12 and the optical element under test 2, so that the virtual image plane of the projected image formed by the standard image source 12 in the display area 21 is located at the equivalent virtual image plane 14.

[0157] A standard detection pattern is set. Assuming that the camera assembly 13 emits light in a reversible manner, the light is reflected by the inner surface of the optical element under test 2 to obtain a standard detection pattern located on the plane of the pattern 122, also known as a pre-deformed detection pattern, that is, the light-transmitting area 1221 constitutes the standard detection pattern.

[0158] Multiple shooting points 222 are set. Several shooting points 222 are selected on the actual eye box surface 22 to set the camera assembly 13 to capture equivalent projected images.

[0159] S400, calculate the correction value.

[0160] Sampling and shooting points 222 are taken on the actual eye box surface 22, consisting of 3 rows × 3 columns, corresponding to the positions of 3 rows × 3 columns of camera components 13. Sampling and detection points 143 are taken on the actual virtual image surface 23, consisting of 5 rows × 9 columns, corresponding to the sampling and detection points 143 on the equivalent virtual image surface 14, i.e., sampling and detection points 143 on the standard image. The correction values ​​for each detection point 143 corresponding to each shooting point 222 are calculated in both the actual vehicle optical path and the equivalent optical path of the head-up display, totaling 3 × 3 × 5 × 9 = 405.

[0161] For example, a point on the actual eye box surface 22 is selected as the shooting point 222 to obtain an equivalent projection image. Multiple detection points 143 in the equivalent projection image are taken, and the correction value of the detection point 143 corresponding to the fitting point on the standard image is calculated. Please refer to Table 1 below. Table 1 below shows the correction value of each detection point 143 in the Y-axis direction and the correction value in the Z-axis direction.

[0162] Table 1 shows the correction values ​​for detection point 143 in the standard image along the Y-axis and Z-axis.

[0163]

[0164]

[0165] Where RiCj represents the j-th point in the i-th row among the i*j detection points 143 on the standard image.

[0166] S500, apply correction value.

[0167] Given the above-mentioned head-up display (HUD) actual vehicle optical path and equivalent optical path settings, the surface shape data of the actual product glass is used, and through simulation, the direct coordinate values ​​of each detection point 143 under the actual eye box surface 22 on the equivalent virtual image surface 14 are obtained. Corresponding correction values ​​are then applied, i.e., the equivalent projection image captured by the camera assembly 13 is compensated using these correction values. Finally, the image quality of the compensated equivalent projection image is evaluated. The surface shape of the actual product glass is obtained by scanning the reflective surface of the actual product glass, reflecting a glass surface shape with tolerances.

[0168] Next, we will use evaluation metrics to demonstrate the correlation between the actual optical path of the head-up display (HUD) and the equivalent optical path of the HUD. Please refer to... Figure 10 and Figure 11 , Figure 10 A comparative simulation diagram of the image rotation of the two HUD optical paths corresponding to the embodiments provided in this application; Figure 11 A comparative simulation diagram of the horizontal offset of the two HUD optical paths corresponding to the embodiments provided in this application.

[0169] Two metrics are provided. Metric 1 is image rotation α, which is used to evaluate the angular deviation of multiple detection points 143 relative to the ideal position. It is defined as the mean of the angles between the three horizontal regression lines of the top / middle / bottom edges of multiple detection points 143 and their corresponding ideal lines.

[0170] Index 2 is the horizontal offset Y_offset, which is used to evaluate the displacement deviation of multiple detection points 143 relative to the ideal position. It is defined as the offset of the center of multiple detection points 143 along the horizontal Y direction.

[0171] exist Figure 10 and Figure 11 In this context, CamN represents the equivalent virtual image surface 14 observed at the shooting point 222, and also the actual virtual image surface 23 observed at the shooting point 222 on the corresponding actual eye box surface, where N = 1, 2, ..., 9. Figure 10 The solid line represents the image rotation of the equivalent measured image, and the dashed line represents the image rotation of the equivalent projected image. Figure 11 The solid line represents the horizontal offset of the equivalent measured image, and the virtual image represents the horizontal offset of the equivalent projected image. Figure 10 and Figure 11It can be seen that, under the same conditions, the detection correlation of image rotation and horizontal offset of the actual vehicle optical path and the equivalent optical path of the head-up display at 9 shooting points 222 is very close or even consistent. The equivalent tested image and the equivalent projected image are highly correlated. The equivalent optical path of the head-up display and the actual vehicle optical path of the head-up display can be regarded as equivalent.

[0172] Therefore, in this application, by setting an equivalent virtual image plane 14 and constructing a head-up display equivalent optical path, the head-up display equivalent optical path can represent the deviation index under the actual vehicle optical path of the head-up display.

[0173] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application, and such improvements and refinements are also considered to be within the protection scope of this application.

Claims

1. An optical element inspection system, characterized in that, The optical component detection system includes: An analysis component is used to acquire the actual optical path of the head-up display of the optical element under test, set an equivalent virtual image surface according to the actual virtual image surface in the actual optical path of the head-up display, and design an equivalent optical path of the head-up display according to the equivalent virtual image surface. A standard image source, wherein the standard image source projects a preset pattern onto the optical element under test according to the equivalent optical path of the head-up display to form an equivalent projection image; A camera assembly for capturing the equivalent projected image; The camera assembly has a standard depth of field DOF0, and the equivalent virtual image plane has an equivalent distance depth DOF2, where DOF2≤DOF0; The analysis component is able to acquire the equivalent projection image and determine the imaging quality of the optical element under test based on the equivalent projection image; The head-up display (HUD) optical path includes the position and specifications of the actual eye box, the position and specifications of the actual virtual image surface, the specifications of the HUD glass, and the position of its display area. The actual eye box has an actual eye box surface through which the actual virtual image surface can be observed. The actual eye box surface includes multiple sub-actual eye box surfaces. The actual virtual image surface includes multiple sub-actual virtual image surfaces that correspond one-to-one with the multiple sub-actual eye box surfaces. The line connecting the center point of any sub-actual eye box surface and the center point of the corresponding sub-actual virtual image surface is the main optical axis. The plane passing through the main optical axis and perpendicular to the ground is the main optical axis plane. The line of intersection between the principal optical axis plane and the corresponding sub-actual virtual image plane has an actual far point and an actual near point. The projection point of the actual far point on the principal optical axis is the first point, and the projection point of the actual near point on the principal optical axis is the second point. A point is selected on the principal optical axis as a weighting point, which is located between the first point and the second point. An equivalent virtual image surface is set through the weighting point, which is perpendicular to the principal optical axis plane. The weighting point is the center point of the equivalent virtual image surface.

2. The optical element inspection system as described in claim 1, characterized in that, The actual virtual image plane has an actual viewing distance depth (DOF1) of ≥3 meters, ≥5 meters, ≥7.5 meters, or ≥10 meters.

3. The optical element inspection system as described in claim 2, characterized in that, DOF2 / DOF1≤0.5, or DOF2 / DOF1≤0.3, or DOF2 / DOF1≤0.

1.

4. The optical element inspection system as described in claim 1, characterized in that, The equivalent line-of-sight depth (DOF2) is 0 to 3 meters, or the equivalent line-of-sight depth (DOF2) is 0 to 2 meters, or the equivalent line-of-sight depth (DOF2) is 0 to 1 meter.

5. The optical element inspection system as described in claim 1, characterized in that, The forward tilt angle of the actual virtual image plane is ≥45°, or the forward tilt angle of the actual virtual image plane is ≥60°, or the forward tilt angle of the actual virtual image plane is ≥75°.

6. The optical element inspection system as described in claim 1, characterized in that, The forward tilt angle of the equivalent virtual image surface is ≤20°, or the forward tilt angle of the equivalent virtual image surface is ≤10°, or the forward tilt angle of the equivalent virtual image surface is ≤5°.

7. The optical element inspection system as described in any one of claims 1 to 6, characterized in that, The actual virtual image surface has an actual vertical field of view VFOV1, which is the angle between the center point of the sub-actual eye box surface and the line connecting the upper and lower boundaries of the corresponding sub-actual virtual image surface in the principal optical axis plane. The equivalent virtual image surface has an equivalent vertical field of view VFOV2. The equivalent virtual image surface includes a plurality of sub-equivalent virtual image surfaces that correspond one-to-one with the plurality of sub-actual eye box surfaces. The equivalent vertical field of view VFOV2 is the angle between the center point of the sub-actual eye box surface and the line connecting the upper and lower boundaries of the corresponding sub-equivalent virtual image surface in the principal optical axis plane. Among them, VFOV2 / VFOV1 = 0.8 to 1.

2.

8. The optical element inspection system as described in claim 7, characterized in that, The first line is the line connecting the upper and lower boundaries of the sub-actual virtual image surface within the principal optical axis plane, and the second line is the line connecting the upper and lower boundaries of the sub-equivalent virtual image surface within the principal optical axis plane. The first line and the second line have an intersection point, and the angle between the center point of the sub-actual eye box surface and the two lines connecting the intersection point and the weight point has a first angle β. Where β / VFOV1≤1 / 3, or β / VFOV1≤1 / 5, or β / VFOV1≤1 / 10.

9. The optical element inspection system as described in claim 1, characterized in that, The standard image source is a standard lightbox or display screen; The standard light box includes a light source and a pattern. The pattern is disposed between the light source and the optical element under test. The pattern has a light-transmitting area, which is used to transmit light emitted by the light source to form a preset pattern. The display screen is used to emit preset patterns.

10. The optical element inspection system as described in claim 9, characterized in that, The preset pattern includes multiple detection marks, wherein the detection marks include at least one of dots and lines.

11. The optical element inspection system as described in claim 1, characterized in that, The optical component detection system also includes: A mirror assembly, wherein the mirror assembly is disposed between the standard image source and the optical element under test, the mirror assembly comprising at least one of a plane mirror and an aspherical mirror.

12. The optical element inspection system as described in claim 1, characterized in that, The optical component detection system also includes: A carrier assembly, wherein the carrier assembly carries and supports the standard image source, the camera assembly, and the optical element under test; and An adjustment component is provided for adjusting the position of the camera component to move between multiple shooting points.

13. The optical element inspection system as described in claim 1, characterized in that, The analysis component can obtain a standard image with the center point of the actual eye box surface as the shooting point based on the standard optical element and the equivalent optical path of the head-up display. i*j detection points are taken on the standard image, and m*n shooting points are taken on the actual eye box surface, where i, j, m, and n are all positive integers greater than or equal to 2. Take any detection point P on the standard image k The coordinates are (Y) k0 Z k0 ), 1≤k≤i*j; Observe the detection point P on the standard image k The coordinates of the detection point corresponding to the t-th shooting point are (Y) kt Z kt ), 1≤t≤m*n; Then the detection point P on the standard image k The correction value for the detection point corresponding to the t-th shooting point is (△Y) kt , △Z kt ), △Y kt = Y kt - Y k0 , △Z kt = Z kt - Z k0 .

14. The optical element inspection system as described in claim 1, characterized in that, Determining the imaging quality of the tested optical element based on the equivalent projection image includes calculating the evaluation index of the equivalent projection image to obtain a first evaluation parameter, and determining the imaging quality based on the evaluation parameter corresponding to the evaluation index and the evaluation standard corresponding to the preset evaluation index.

15. The optical element inspection system as described in claim 14, characterized in that, The evaluation metrics include at least one of the following: horizontal straightness, vertical straightness, horizontal ghosting, vertical ghosting, image rotation, center of gravity shift, image tilt, trapezoidal shape, scaling factor, image brightness, sharpness, image color, binocular horizontal parallax, binocular vertical parallax, virtual image plane dynamic distortion, and eyebox plane dynamic distortion.

16. The optical element inspection system as described in claim 14, characterized in that, Determining the imaging quality of the inspected optical element based on the equivalent projected image also includes calculating detection correlation, which includes: The analysis component can obtain an equivalent test image located on the equivalent virtual image plane based on the optical element under test and the optical path of the head-up display vehicle. It calculates the evaluation index of the equivalent test image to obtain a second evaluation parameter. It calculates the detection correlation based on the first evaluation parameter and the second evaluation parameter. The detection correlation is equal to the difference between the first evaluation parameter and the second evaluation parameter. If the detection correlation is less than or equal to 20% of the evaluation standard, preferably less than or equal to 10% of the evaluation standard, then the imaging quality is determined.

17. A method for detecting optical elements, characterized in that, The optical element detection method includes: Obtain the actual optical path of the head-up display of the inspected optical component; An equivalent virtual image surface is set according to the actual virtual image surface in the optical path of the real vehicle in the head-up display; Design the equivalent optical path for the head-up display based on the aforementioned equivalent virtual image surface; A preset pattern is projected onto the tested optical element according to the equivalent optical path of the head-up display to form an equivalent projection image; The equivalent projection image is captured, wherein the camera assembly capturing the equivalent projection image has a standard depth of field DOF0, and the equivalent virtual image plane has an equivalent viewing distance depth DOF2, where DOF2 ≤ DOF0; and The equivalent projection image is acquired, and the imaging quality of the optical element under test is determined based on the equivalent projection image. The head-up display optical path includes the position and specifications of the actual eye box, the position and specifications of the actual virtual image surface, the specifications of the head-up display glass and the position of its display area. The actual eye box has an actual eye box surface through which the actual virtual image surface can be observed. The actual eye box surface includes multiple sub-actual eye box surfaces, and the actual virtual image surface includes multiple sub-actual virtual image surfaces that correspond one-to-one with the multiple sub-actual eye box surfaces. The step of setting an equivalent virtual image surface based on the actual virtual image surface in the optical path of the head-up display vehicle includes: The line connecting the center point of any sub-actual eye box surface and the center point of the corresponding sub-actual virtual image surface is taken as the main optical axis. The plane passing through the main optical axis and perpendicular to the ground is taken as the main optical axis plane. The line of intersection between the main optical axis plane and the corresponding sub-actual virtual image surface has an actual far point and an actual near point. The projection point of the actual far point on the main optical axis is the first point, and the projection point of the actual near point on the main optical axis is the second point. A point is selected on the main optical axis as the weighting point, wherein the weighting point is located between the first point and the second point; An equivalent virtual image surface is set through the weighting point, wherein the equivalent virtual image surface is perpendicular to the principal optical axis plane, and the weighting point is the center point of the equivalent virtual image surface.

18. An application for detecting optical components, characterized in that, The optical element inspection system according to any one of claims 1-16 is used to inspect the head-up display image quality of the head-up display glass, the size of the reflection ghosting, or the head-up display image quality of the mirror assembly.

19. The optical element inspection application as described in claim 18, characterized in that, The head-up display glass has a wedge-shaped cross-sectional profile, the wedge-shaped cross-sectional profile has at least one wedge angle, and the size of the reflected ghost image and the wedge angle satisfy a functional relationship: Y=KX+B, where Y is the size of the reflected ghost image, K is the slope of the change of the reflected ghost image and the wedge angle, X is the wedge angle, and B is the size of the reflected ghost image when the wedge angle X=0. In the head-up display's actual vehicle optical path, the size of the reflected ghost image and the wedge angle satisfy a functional relationship Yp; In the equivalent optical path of a head-up display, the size of the reflected ghost image and the wedge angle satisfy a functional relationship Yt. Functional relations Yp and Yt can be converted into each other.

20. The optical element inspection application as described in claim 18, characterized in that, The optical element inspection system is used to inspect the head-up display glass or mirror assembly in a head-up display system with a projection distance of ≥6 meters.

21. The optical element inspection application as described in claim 18, characterized in that, The optical element inspection system is used to inspect the head-up display glass or mirror assembly in a head-up display system having at least two projection distances.

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