Optical detection system

Abstract

The utility model provides an optical detection system, and relates to the technical field of optical detection. The optical detection system comprises a distance reducing element, an image acquisition device and an upper computer, the distance reducing element is used for being arranged on the light emitting side of a projection module to be detected, the distance reducing element comprises a light-transmitting area and a light-proof area, the light-proof area surrounds the light-transmitting area, and the light-transmitting area is used for transmitting light beams emitted by the projection module to be detected. And the image acquisition device is used for acquiring an image formed by the light beams passing through the light-transmitting area. The upper computer is electrically connected with the image acquisition device, receives the image acquired by the image acquisition device, and is used for detecting and analyzing the received image to judge whether the image is qualified or not. The optical detection system can test the projection reliability of the projection module, and occupies a small space.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of optical detection technology, and in particular, to an optical detection system. Background Art

[0002] At present, cars are equipped with smart headlight modules with image projection functions. In order to ensure the image projection reliability of the smart headlight modules, it is necessary to conduct projection reliability tests on the smart headlight modules. In related technologies, the smart headlight module projects an imaging beam onto a projection screen, and then judges the projection reliability of the smart headlight module based on the image on the projection screen. Among them, the focal length of the smart headlight projection module is usually around 10m, and the smart headlight module is about 10m away from the projection screen, so the image is clear. However, the distance between the smart headlight module and the projection screen is too large, and the space occupied is large. Utility Model Content

[0003] An embodiment of the present application provides an optical detection system, which can perform projection reliability testing on a projection module and occupies a small space.

[0004] An embodiment of the present application provides an optical detection system, which includes: a telescoping element, an image acquisition device, and a host computer, wherein the telescoping element is used to be arranged on the light-emitting side of the projection module to be tested, and the telescoping element includes a light-transmitting area and a light-impermeable area, the light-impermeable area surrounds the light-transmitting area, and the light-transmitting area is used to pass a portion of the light beam emitted by the projection module to be tested. The image acquisition device is used to acquire an image formed by the light beam passing through the light-transmitting area. The host computer is electrically connected to the image acquisition device, and the host computer receives the image acquired by the image acquisition device. The host computer is used to detect and analyze the received image to determine whether the image is qualified.

[0005] By setting a distance reduction element on the light-emitting side of the projection module to be tested, the distance reduction element can allow part of the light beam to pass through, shorten the imaging distance of the projection module to be tested, achieve close-range imaging, and occupy less space. In addition, the host computer detects and analyzes the image collected by the image acquisition device to determine whether the image is qualified, realize automatic detection, and improve detection efficiency and detection accuracy.

[0006] In some possible implementations, the shortening element is located at a light-emitting side of a projection lens of the projection module to be tested, and is fixedly connected to the projection lens.

[0007] In this implementation, the shortening element is fixedly connected to the projection lens, further reducing the space occupied by the optical detection system.

[0008] In some possible implementations, the shortening element has a receiving groove and a light-transmitting through hole, the receiving groove is used to receive a portion of the projection lens, and the light-transmitting through hole penetrates the bottom of the receiving groove and forms a light-transmitting area.

[0009] In this implementation, while reducing the space occupied by the optical detection system, it is ensured that the distance reduction element filters out part of the light beam to achieve close-range imaging.

[0010] In some possible implementations, the accommodating groove is spaced apart from the projection lens along a direction perpendicular to the optical axis of the projection lens.

[0011] In this implementation, the distance reducing element can match projection lenses of different specifications, and dissipate heat for the projection lens through the gap between the projection lens and the distance reducing element.

[0012] In some possible implementations, the distance reducing element is made of metal.

[0013] In this implementation, metal has high thermal conductivity and can dissipate heat from the projection lens.

[0014] In some possible implementations, the distance reducing element further has a plurality of fastening through holes, which are arranged at intervals along the circumference of the accommodating groove, and the fastening through holes connect the inside and the outside of the accommodating groove. The optical detection system also includes a plurality of fasteners, which correspond to the fastening through holes one by one, each fastener is inserted into the inside of the corresponding fastening through hole and fixedly connected to the distance reducing element, and each fastener abuts against the projection lens along the axial direction of the fastening through hole.

[0015] In this implementation, the fastener is inserted into the fastening through hole and abuts against the projection lens, thereby fixing the shortening element on the projection lens.

[0016] In some possible implementations, the distance reducing element includes a light-transmitting through hole and a light-impermeable body, and the light-transmitting through hole penetrates the light-impermeable body to form a light-transmitting area.

[0017] In this implementation, the distance reducing element transmits a portion of the light beam emitted by the projection module to be tested through the light-transmitting through hole, and blocks another portion of the light beam emitted by the projection module to be tested through the light-impermeable body, so as to shorten the imaging distance of the projection module to be tested.

[0018] In some possible implementations, the spacing reduction element includes a light-transmitting through hole, a light-transmitting substrate and an opaque layer, wherein the light-opaque layer is disposed on the surface of the light-transmitting substrate, the light-transmitting through hole penetrates the light-opaque layer, and the light-transmitting through hole is used to form a light-transmitting area.

[0019] In this implementation, the distance reducing element blocks a portion of the light beam emitted by the projection module to be tested through the opaque layer, and transmits another portion of the light beam emitted by the projection module to be tested through the light-transmitting through hole, thereby shortening the imaging distance of the projection module to be tested.

[0020] In some possible implementations, the image acquisition device is a camera, and the camera is used to capture an image formed by a light beam passing through the light-transmitting area.

[0021] In this implementation, images are captured by a camera, which meets the image capture requirements while reducing the cost of the image capture device, thereby reducing the cost of the optical detection system and facilitating the batch deployment of the optical detection system.

[0022] In some possible implementations, the optical detection system also includes a projection board, which is arranged on the light-emitting side of the reduction element, and the light beam passing through the light-transmitting area forms an image on the projection board, and the image acquisition device is used to acquire the image on the projection board.

[0023] In this implementation, a projection plate is used to carry the image formed by the light beam, which helps to improve the clarity of the image.

[0024] In some possible implementations, the optical detection system further includes a cabinet, and the host computer, the image acquisition device, the zoom element, the projection board and the projection module to be tested are all located in the cabinet, and the projection board is fixedly connected to the cabinet.

[0025] In this implementation, the optical detection system can be arranged at a corresponding position according to application requirements.

[0026] In some possible implementations, the host computer is also used to be electrically connected to the projection module to be tested, and the host computer controls the projection module to be tested to emit a light beam toward the shortening element.

[0027] In this implementation, the application scope of the host computer is increased, and the structure of the optical detection system can be simplified. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram of the structure of a projection module provided in an embodiment of the present application;

[0029] Figure 2 It is a schematic diagram of performing projection reliability test on a projection module in the related art;

[0030] Figure 3 A schematic diagram of the structure of an optical detection system provided in an embodiment of the present application;

[0031] Figure 4 A schematic diagram of the structure of a distance reduction element and a projection module provided in an embodiment of the present application;

[0032] Figure 5 A schematic diagram of the structure of another distance reduction element and a projection module provided in an embodiment of the present application;

[0033] Figure 6 for Figure 5A schematic diagram of the three-dimensional structure of the middle shortening element;

[0034] Figure 7 for Figure 6 A bottom view schematic diagram of the shortening element shown;

[0035] Figure 8 for Figure 7 Cross-section view in the AA direction;

[0036] Fig. 9 A cross-sectional schematic diagram of another distance reduction element provided in an embodiment of the present application;

[0037] Fig.10 A schematic diagram of a flow chart of an image detection method provided in an embodiment of the present application;

[0038] Fig.11 for Fig.10 Schematic diagram of the process of step S3 and step S4;

[0039] Fig.12 A schematic diagram of a reference image preparation process provided in an embodiment of the present application.

[0040] Description of reference numerals:

[0041] 100, projection module; 110, three-color light source; 120, collimation component; 130, light modulation device; 140, reflector; 150, projection lens; 160, projection screen;

[0042] 200. Optical detection system;

[0043] 210, shortening element; 211, light-transmitting area; 212, opaque area; 213, accommodating groove; 214, light-transmitting through hole; 215, opaque body; 216, light-transmitting substrate; 217, opaque layer; 218, fastening through hole;

[0044] 220, image acquisition device; 230, host computer; 240, projection board; 250, cabinet; 260, CAN box; 270, ETH converter; 280, DC power supply; 290, fasteners. DETAILED DESCRIPTION

[0045] The terms used in the implementation section of this application are only used to explain the specific embodiments of this application and are not intended to limit this application.

[0046] At present, the intelligent vehicle lamp module includes a lamp housing and a projection module 100 . The projection module 100 is installed in the lamp housing, and the projection module 100 is used to generate a light beam that forms an image.

[0047] Figure 1 A schematic diagram of the structure of a projection module provided in an embodiment of the present application.

[0048] In one embodiment, if Figure 1 As shown, the projection module 100 includes: a three-color light source 110, a collimating component 120, a light modulator 130, a reflector 140 and a projection lens 150. The three-color light source 110 is used to generate three-color light beams, including red light, blue light and green light, and send the three-color light beams to the collimating component 120. The three-color light beams are then collimated by the collimating component 120, and the collimated three-color light beams are sent to the light modulator 130, wherein the collimating component 120 can be a collimating lens or a collimating lens group composed of multiple lenses, which is not limited in this embodiment. The reflector 140 reflects the three-color light beams from the collimating component 120 to the light modulator 130, and the light modulator 130 is used to phase modulate the received three-color light beams and converge the modulated light beams to the focal plane of the projection lens 150. The projection lens 150 may project the received light beam to the front of the vehicle to form an image in front of the vehicle. Here, the projection lens 150 may be a combination of one or more lenses, prisms, apertures, etc.

[0049] The light modulator 130 may be a liquid crystal on silicon (LCoS), a digital micromirror device (DMD), a liquid crystal display (LCD), etc. Figure 1 In the embodiment, the optical modulation device 130 is a DMD.

[0050] The three-color light source 110 may include: at least one red light source, at least one green light source and at least one blue light source; or, the three-color light source 110 may include at least one tunable light source, which can send red light, green light and blue light in different time periods. The above monochromatic light source and tunable light source may be any one of coherent or partially coherent light sources such as fiber lasers, solid-state lasers, semiconductor lasers, or even light-emitting diodes (LEDs). Figure 1 As shown, taking the three-color light source 110 as three different monochromatic light sources as an example, the three colors of light are input to the light modulator 130 in a time-sharing manner; at this time, the collimating component 120 can be three collimating lenses or three collimating lens groups, which are used to collimate the three monochromatic light sources respectively; or it can be a collimating lens or a collimating lens group, which can achieve the collimation effect on the three monochromatic light sources, and this application does not limit it.

[0051] Figure 2 It is a schematic diagram of performing projection reliability test on a projection module in the related art.

[0052] After the projection module 100 is assembled, it is necessary to perform a projection reliability test on the projection module 100 to ensure the image quality. Figure 2 As shown, the projection module 100 is placed at a certain distance from the projection screen 160. The projection module 100 projects a light beam to the projection screen 160, and the light beam forms an image on the projection screen 160, and whether the image is qualified is judged by visual inspection. The focal length of the projection module 100 is usually 10m, so the distance between the projection screen 160 and the projection module 100 is 10m, so as to form a clear image on the projection screen 160 and ensure the reliability of the test. However, the distance between the projection screen 160 and the projection module 100 is too large, and the space occupied is relatively large. In addition, the method of visually judging the image has the problems of low efficiency and low detection accuracy.

[0053] In view of this, the embodiment of the present application provides an optical detection system 200, which shortens the imaging distance of the projection module 100 to be tested by the distance reduction element 210, realizes close-range imaging, and occupies less space. In addition, the optical detection system 200 can also automatically detect the image projected by the projection module 100 to be tested, and can automatically identify whether the image is qualified, thereby improving the detection efficiency and detection accuracy.

[0054] Figure 3 A schematic diagram of the structure of an optical detection system provided in an embodiment of the present application is shown in FIG. Figure 4 A schematic diagram of the structure of a distance reduction element and a projection module provided in an embodiment of the present application.

[0055] like Figure 3 As shown, the optical detection system 200 includes a distance reduction element 210, an image acquisition device 220 and a host computer 230. Figure 4 As shown, the distance reduction element 210 is used to be arranged on the light-emitting side of the projection module 100 to be tested. The distance reduction element 210 includes a light-transmitting area 211 and a light-impermeable area 212. The light-impermeable area 212 is an annular area. The light-impermeable area 212 surrounds the light-transmitting area 211. The light-transmitting area 211 is used to pass through part of the light beam emitted by the projection module 100 to be tested. The light beam emitted by the projection module 100 to be tested cannot pass through the light-impermeable area 212. It can be seen that the distance reduction element 210 can filter out part of the light emitted by the projection module 100 to be tested, and allow the other part of the light to pass through the light-transmitting area 211 of the distance reduction element 210. The image acquisition device 220 is used to acquire an image formed by the light beam passing through the light-transmitting area 211. The host computer 230 is electrically connected to the image acquisition device 220, and the host computer 230 receives the image acquired by the image acquisition device 220. The host computer 230 is used to detect and analyze the received image to determine whether the image is qualified.

[0056] like Figure 4As shown, by setting a distance reduction element 210 on the light-emitting side of the projection module 100 to be tested, the distance reduction element 210 can allow part of the light beam to pass through, shorten the imaging distance of the projection module 100 to be tested, achieve close-range imaging, and occupy less space. In addition, the image collected by the image acquisition device 220 is detected and analyzed by the host computer 230 to determine whether the image is qualified, automatically detect the image, automatically identify the reliability of the projection, and improve the detection efficiency and detection accuracy.

[0057] In some possible implementations, such as Figure 4 As shown, the optical detection system 200 further includes a projection board 240, which is disposed on the light-emitting side of the shortening element 210. The light beam transmitted through the light-transmitting area 211 forms an image on the projection board 240. At this time, the image acquisition device 220 is used to acquire the image on the projection board 240. In this way, the image formed by the light beam carried by the projection board 240 is helpful to improve the clarity of the image, so as to improve the detection accuracy.

[0058] It should be noted that, in addition to forming an image on the projection board 240 , the light beam passing through the shortening element 210 may also form an image on a projection image surface such as a wall surface or a cabinet surface in some scenarios.

[0059] In some possible implementations, such as Figure 3 As shown, the optical detection system 200 also includes a cabinet 250, and the host computer 230, the image acquisition device 220, the distance reduction element 210, the projection board 240 and the projection module 100 to be tested are all located in the cabinet 250, and the projection board 240 is fixedly connected to the cabinet 250. In this way, the optical detection system 200 constitutes a whole and can be arranged in a corresponding position. In addition, the optical detection system 200 is also movable.

[0060] In one possible implementation, in order to support the projection module 100 to be tested, the optical detection system 200 may further include a support member (not shown in the figure) located in the cabinet 250, the support member is fixedly connected to the cabinet 250, and the projection module 100 to be tested is fixed to the support member to support the projection module 100 to be tested.

[0061] In one possible implementation, Figure 3 As shown, the optical detection system 200 further includes a DC power supply 280 , which is disposed in the cabinet 250 . The DC power supply 280 is used to receive AC power and transmit DC power to the projection module 100 to ensure the operation of the projection module 100 to be tested.

[0062] In one embodiment, the image acquisition device 220 may be a camera, which is used to capture an image formed by a light beam passing through the light-transmitting area 211. In this way, by acquiring images through the camera, the image acquisition requirements are met while reducing the cost of the image acquisition device 220, thereby reducing the cost of the optical detection system 200, which is conducive to the mass deployment of the optical detection system 200.

[0063] Of course, in addition to being a camera, in another embodiment, the image acquisition device 220 may also be a camera, which is used to capture the image on the projection board 240 and send the image to the host computer 230.

[0064] It should be understood that the host computer 230 refers to a computer that can directly issue operation control commands. For example, the host computer 230 can be a personal computer (PC).

[0065] In one embodiment, if Figure 3 As shown, the host computer 230 is also used to be electrically connected to the projection module 100 to be tested, and the host computer 230 controls the projection module 100 to be tested to emit a light beam to the distance reduction element 210. In this way, the application scope of the host computer 230 is increased, and the structure of the optical detection system 200 can be simplified.

[0066] Specifically, if Figure 3 As shown, the optical detection system 200 also includes a controller area network (CAN) box and an Ethernet (ETH) converter. The host computer 230 is connected to the projection module 100 to be tested via the CAN box 260 and the ETH converter 270. The host computer 230 controls the CAN box 260 and the ETH converter 270 to send signals to control the projection module 100 to be tested to project a light beam toward the shortening element 210 to form an image on the projection board 240.

[0067] Figure 5 A schematic diagram of the structure of another distance reduction element and a projection module provided in an embodiment of the present application.

[0068] In some possible implementations, such as Figure 5 As shown, the shortening element 210 is located at the light-emitting side of the projection lens 150 of the projection module 100 to be tested, and is fixedly connected to the projection lens 150. In this way, the shortening element 210 is fixedly connected to the projection lens 150, further reducing the space occupied by the optical detection system 200.

[0069] Of course, in addition to being fixed to the projection lens 150 , in some embodiments, the shortening element 210 may also be arranged side by side and at intervals with the projection lens 150 along the optical axis of the projection lens 150 .

[0070] Figure 6 for Figure 5 Schematic diagram of the three-dimensional structure of the middle-reduction element. Figure 7 for Figure 6 A bottom view of the shortening element shown, Figure 8 for Figure 7 Cross-section view along the AA direction.

[0071] In some possible implementations, combined with Figures 6 to 8 It can be seen that the shortening element 210 has a receiving groove 213 and a light-transmitting through hole 214. Figure 5 As shown, the receiving groove 213 is used to receive part of the projection lens 150, and the light-transmitting through hole 214 penetrates the groove bottom of the receiving groove 213 to form a light-transmitting area 211. In this way, while reducing the space occupied by the optical detection system 200, the light-blocking effect of the distance reduction element 210 on the light beam emitted by the projection lens 150 is improved, ensuring that the distance reduction element 210 filters out part of the light beam to achieve close-range imaging.

[0072] It is understandable that the area of ​​the shortening element 210 other than the light-transmitting through hole 214 is a light-proof area 212 that does not transmit the light beam emitted by the projection lens 150 , so that part of the light beam passes through the light-transmitting through hole 214 .

[0073] In some possible implementations, such as Figure 5 As shown, the accommodating groove 213 is spaced apart from the projection lens 150 in a direction perpendicular to the optical axis of the projection lens 150. In the process of the projection module 100 to be tested emitting a light beam, the shortening element 210 blocks part of the light beam, which causes the temperature of the projection lens 150 to rise. By setting a gap between the projection lens 150 and the shortening element 210, the projection lens 150 can be cooled, so that the temperature of the projection lens 150 is within a suitable range, thereby ensuring the image quality. In addition, the shortening element 210 can match projection lenses 150 of different specifications, thereby improving the application range of the optical detection system 200.

[0074] In some possible implementations, the material of the distance reducing element 210 may be metal, for example, the material of the distance reducing element 210 may be copper or aluminum, etc. Since metal has high thermal conductivity, the distance reducing element 210 can transfer the heat on the projection lens 150 to the air in time to dissipate the heat of the projection lens 150.

[0075] In some possible implementations, the shortening element 210 further has a plurality of fastening through holes 218, and the plurality of fastening through holes 218 are arranged at intervals along the circumference of the accommodating groove 213, for example Figure 6As shown, the shortening element 210 has four fastening through holes 218, which are arranged at equal intervals along the circumference of the receiving groove 213. The fastening through holes 218 connect the inside and the outside of the receiving groove 213. Figure 5 As shown, the optical detection system 200 also includes a plurality of fasteners 290, and the fasteners 290 correspond one-to-one to the fastening through holes 218. Each fastener 290 is passed through the interior of the corresponding fastening through hole 218 and is fixedly connected to the distance reducing element 210. Each fastener 290 abuts against the projection lens 150 along the axial direction of the fastening through hole 218 to fix the distance reducing element 210 on the projection lens 150.

[0076] In one embodiment, the fastening through hole 218 may be a threaded hole, and the fastener 290 may be a screw member, and the fastener 290 is threadedly connected to the distance reducing element 210 to achieve a fixed connection between the fastener 290 and the distance reducing element 210. In another embodiment, the fastener 290 may include a screw member and a nut, the screw member is inserted into the fastening through hole 218 and abuts against the projection lens 150, and the nut is sleeved on the outer wall of the screw member, the nut abuts against the distance reducing element 210 and is threadedly connected to the screw member.

[0077] The specific shape of the light-transmitting through hole 214 is not specifically limited here. Figure 6 As shown, the light-transmitting through hole 214 may be a circular hole.

[0078] The larger the aperture of the light-transmitting through hole 214, the more light beams are transmitted, the brighter the image is, and the more blurred the image is. The smaller the aperture of the light-transmitting through hole 214, the fewer light beams are transmitted, the darker the image is, and the clearer the image is. It can be seen that by controlling the aperture size of the light-transmitting through hole 214, the accuracy and brightness of the image can be controlled. Therefore, there is no limitation on the diameter of the light-transmitting through hole 214. By way of example, the diameter of the light-transmitting through hole 214 can be 1.5 mm.

[0079] In some possible implementations, such as Figure 8 As shown, the distance reducing element 210 includes a light-transmitting through hole 214 and a light-impermeable body 215, wherein the light-transmitting through hole 214 penetrates the light-impermeable body 215 and forms a light-transmitting area 211. In this way, the distance reducing element 210 transmits a portion of the light beam emitted by the projection module 100 to be tested through the light-transmitting through hole 214, and blocks another portion of the light beam emitted by the projection module 100 to be tested through the light-impermeable body 215, so as to shorten the imaging distance of the projection module 100 to be tested.

[0080] The specific structure of the opaque body 215 is not limited here. Figure 6 and Figure 8As shown, the light-proof body 215 includes a cylindrical portion and an annular portion, the annular portion is sleeved on the open end of the cylindrical portion, the annular portion and the cylindrical portion are an integral structure, the cylindrical portion has the above-mentioned accommodating groove 213, and the above-mentioned fastening through hole 218 passes through the annular portion and the cylindrical portion. In another embodiment, the light-proof body 215 can also be a flat plate structure (for example Figure 4 In this case, the opaque body 215 covers the field of view of the projection lens 150, ensuring that the light beam emitted by the projection lens 150 only passes through the light-transmitting area 211.

[0081] Fig. 9 A cross-sectional schematic diagram of another distance reduction element provided in an embodiment of the present application.

[0082] In some other possible implementations, such as Fig. 9 As shown, the distance reducing element 210 includes a light-transmitting through hole 214, a light-transmitting substrate 216 and an opaque layer 217. The opaque layer 217 is arranged on the surface of the light-transmitting substrate 216, and the light-transmitting through hole 214 penetrates the opaque layer 217, and the light-transmitting through hole 214 is used to form a light-transmitting area 211. In this way, the distance reducing element 210 blocks a part of the light beam emitted by the projection module 100 to be tested through the opaque layer 217, and transmits another part of the light beam emitted by the projection module 100 to be tested through the light-transmitting through hole 214, so as to achieve the purpose of shortening the imaging distance of the projection module 100 to be tested.

[0083] The light-transmitting substrate 216 is made of a light-transmitting material, such as glass, and the light-impermeable layer 217 is made of a light-impermeable material, such as light-shielding ink.

[0084] The light-impermeable layer 217 may be disposed on the light-incoming side of the light-transmitting substrate 216 , or the light-impermeable layer 217 may be disposed on the light-emitting side of the light-transmitting substrate 216 .

[0085] Fig.10 A schematic diagram of a flow chart of an image detection method provided in an embodiment of the present application, Fig.11 for Fig.10 Schematic diagram of the process of step S3 and step S4.

[0086] The present application also provides an image detection method, through which the optical detection system 200 can detect and analyze the image projected by the projection module 100 to be tested, so as to determine whether the image is qualified. Fig.10 As shown, the image detection method comprises the following steps:

[0087] S1. The image acquisition device 220 acquires an image formed by the light beam emitted by the projection module 100 to be tested.

[0088] Specifically, the host computer 230 controls the projection module 100 to emit a light beam toward the distance reducing element 210, and the light beam passing through the distance reducing element 210 forms an image on the projection board 240. Then, the image acquisition device 220 captures the image on the projection board 240 and sends the captured image to the host computer 230.

[0089] The image acquisition device 220 may be a camera. At this time, the camera captures the image on the projection board 240 to achieve image acquisition.

[0090] S2. The host computer 230 performs image optimization processing on the collected image to obtain an image to be tested.

[0091] Specifically, the image optimization process may include the following steps: S21, grayscale processing. S22, binarization processing. Among them, the grayscale processing can refer to any method for implementing grayscale processing in the prior art, which is not described in detail here. Similarly, the binarization processing can also refer to any method for implementing binarization processing in the prior art, which is not described in detail here.

[0092] The purpose of the binarization process is to remove noise, remove stray light at the edge of the image, highlight the outline and shape of the image, and improve the clarity of the image. In addition, the execution order of step S21 and step S22 can be reversed.

[0093] S3. The host computer 230 calculates the pixel difference between the image to be tested and the reference image.

[0094] Specifically, Fig.11 As shown, the host computer 230 subtracts the image to be tested from the reference image to obtain the pixel difference between the image to be tested and the reference image, and then calculates the number b of pixels whose difference is not 0 to obtain the pixel difference between the image to be tested and the reference image.

[0095] S4. The host computer 230 calculates whether the image to be tested is qualified according to the pixel difference between the image to be tested and the reference image and a preset threshold.

[0096] Specifically, Fig.11 As shown, the pixel difference between the image to be tested and the reference image is calculated, and the pixel difference is represented by the value of b / a, where a is the number of pixels in the reference image whose grayscale value is greater than 0. The larger the ratio of b / a, the greater the difference between the image to be tested and the reference image, and vice versa. At the same time, the calculation result can be squared according to the characteristics of the image, and the overall trend remains unchanged.

[0097] Then, it is determined whether the value of b / a is less than a preset threshold. If the value of b / a is less than the preset threshold, the image to be tested is qualified. If the value of b / a is greater than or equal to the preset threshold, the image to be tested is unqualified.

[0098] The size of the preset threshold can be set according to the difference of actual imaging.

[0099] Fig.12 A schematic diagram of a reference image preparation process provided in an embodiment of the present application.

[0100] It should be noted that the reference image is pre-installed in the host computer 230. Fig.12 As shown, the preparation of the reference image can refer to the following steps: 1. After the host computer 230 controls the projection module 100 to be tested to project an image on the projection board 240, manually confirm the image qualification. 2. After the image is qualified, the image acquisition device 220 is used to acquire the image on the projection board 240. 3. Grayscale processing is performed on the acquired image. 4. A grayscale threshold is set according to the ambient light intensity to perform binarization processing on the image, so as to extract the pattern projected by the projection module 100 to be tested from the image and obtain a reference image. 5. Then calculate the number of pixels with grayscale values ​​greater than 0 in the reference image, which is recorded as a.

[0101] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, or it can be an indirect connection through an intermediate medium, it can be the internal connection of two components or the interaction relationship between two components. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances. The terms "first", "second", "third", "fourth", etc. (if any) are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0102] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of the present application, rather than to limit them. Although the embodiments of the present application have been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. An optical detection system (200), characterized in that: include: A shortening element (210), the shortening element (210) being arranged on a light-emitting side of a projection module (100) to be tested, the shortening element (210) comprising a light-transmitting area (211) and a light-impermeable area (212), the light-impermeable area (212) surrounding the light-transmitting area (211), the light-transmitting area (211) being used to transmit a portion of the light beam emitted by the projection module (100) to be tested; An image acquisition device (220), the image acquisition device (220) being used to acquire an image formed by the light beam passing through the light-transmitting area (211); A host computer (230), the host computer (230) being electrically connected to the image acquisition device (220), the host computer (230) receiving the image acquired by the image acquisition device (220), and the host computer (230) being used to perform detection and analysis on the received image to determine whether the image is qualified.

2. The optical detection system (200) according to claim 1, characterized in that: The shortening element (210) is located on the light-emitting side of the projection lens (150) of the projection module (100) to be tested, and is fixedly connected to the projection lens (150).

3. The optical detection system (200) according to claim 2, characterized in that: The shortening element (210) comprises a receiving groove (213) and a light-transmitting through hole (214); the receiving groove (213) is used to receive part of the projection lens (150); and the light-transmitting through hole (214) penetrates the groove bottom of the receiving groove (213) and forms the light-transmitting area (211).

4. The optical detection system (200) according to claim 3, characterized in that: Along a direction perpendicular to the optical axis of the projection lens (150), the accommodating groove (213) and the projection lens (150) are arranged at a distance.

5. The optical detection system (200) according to claim 3, characterized in that: The material of the shortening element (210) is metal.

6. The optical detection system (200) according to claim 3, characterized in that: The shortening element (210) further comprises a plurality of fastening through holes (218), the plurality of fastening through holes (218) being arranged at intervals along the circumference of the accommodating groove (213), the fastening through holes (218) communicating the inside and the outside of the accommodating groove (213); The optical detection system (200) further comprises a plurality of fasteners (290), wherein the fasteners (290) correspond to the fastening through holes (218) one by one, each of the fasteners (290) being inserted into the interior of the corresponding fastening through hole (218) and fixedly connected to the distance reducing element (210), and each of the fasteners (290) being in contact with the projection lens (150) along the axial direction of the fastening through hole (218).

7. The optical detection system (200) according to claim 1, characterized in that The shortening element (210) comprises a light-transmitting through hole (214) and a light-impermeable body (215); the light-transmitting through hole (214) penetrates the light-impermeable body (215) and forms the light-transmitting area (211).

8. The optical detection system (200) according to claim 1, characterized in that: The shortening element (210) comprises a light-transmitting through hole (214), a light-transmitting substrate (216) and a light-impermeable layer (217); the light-impermeable layer (217) is arranged on the surface of the light-transmitting substrate (216); the light-transmitting through hole (214) penetrates the light-impermeable layer (217); and the light-transmitting through hole (214) is used to form a light-transmitting area (211).

9. The optical detection system (200) according to any one of claims 1 to 8, characterized in that: The image acquisition device (220) is a camera, and the camera is used to capture an image formed by the light beam passing through the light-transmitting area (211).

10. The optical detection system (200) according to any one of claims 1 to 8, characterized in that: The optical detection system (200) further comprises a projection plate (240), the projection plate (240) being arranged on the light-emitting side of the shortening element (210), the light beam transmitted through the light-transmitting area (211) forming an image on the projection plate (240), and the image acquisition device (220) being used for acquiring the image on the projection plate (240).

11. The optical detection system (200) according to claim 10, characterized in that: The optical detection system (200) further comprises a cabinet (250), wherein the host computer (230), the image acquisition device (220), the distance reduction element (210), the projection board (240) and the projection module to be tested (100) are all located in the cabinet (250), and the projection board (240) is fixedly connected to the cabinet (250).

12. The optical detection system (200) according to any one of claims 1 to 8, characterized in that: The host computer (230) is also used to be electrically connected to the projection module (100) to be tested, and the host computer (230) controls the projection module (100) to be tested to emit a light beam toward the shortening element (210).

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