Laser array detection method and apparatus

Abstract

The application discloses a laser array detection method and device, and relates to the technical field of lasers. The laser array detection method combines image detection and power detection together, first determines part of the light-emitting chips with higher abnormality risk by screening out dark spots, and then carries out targeted power detection on the dark spots, so that the detection efficiency can be improved; whether the light-emitting chips are abnormal is judged by the power detection, and the detection accuracy can be ensured. Further, by judging whether the distribution state of the dark spots is a scattered distribution or a concentrated distribution, the differentiation of the positions of the dark spots can be determined to a certain extent. By determining the dark spots and judging the distribution state of the dark spots, different detection strategies are adopted under different distribution states, so that the detection efficiency is higher, and the detection accuracy is also higher. The laser array detection device provided in the application examples can realize the detection method.

Description

Technical Field

[0001] This application relates to the field of laser technology, and more specifically, to a laser array detection method and device. Background Technology

[0002] Existing semiconductor lasers consist of multiple light-emitting chips arranged in an array. In related technologies, to detect whether there are abnormalities in the light-emitting chips within a laser array, a power meter can be used to inspect each chip individually; alternatively, a charge-coupled device (CCD) with high-resolution imaging capabilities can be used to acquire images and perform image analysis to determine which light-emitting chips are abnormal. However, when the number of light-emitting chips is large, the former method has low detection efficiency, while the latter method has low detection accuracy. Therefore, the laser array detection methods in related technologies struggle to simultaneously achieve high efficiency and high accuracy. Summary of the Invention

[0003] The purpose of this application is to provide a laser array detection method and device that can balance high detection efficiency and detection accuracy.

[0004] The embodiments of this application can be implemented as follows:

[0005] In a first aspect, this application provides a laser array detection method, wherein the laser array includes multiple light-emitting chips arranged in an array, and the laser array detection method includes:

[0006] Acquire a grayscale image of the laser array in the emitting state, and determine the grayscale value of each grayscale block in the grayscale image, wherein each grayscale block corresponds one-to-one with a light-emitting chip;

[0007] Gray blocks in a grayscale image whose grayscale values ​​are less than a preset threshold are identified as dark spots.

[0008] Determine whether the distribution of dark spots is concentrated or dispersed;

[0009] When the distribution of dark spots is concentrated, the power of the light-emitting chips corresponding to the gray-scale blocks is detected and judged to be qualified in order of gray-scale value from low to high, until a qualified light-emitting chip is detected.

[0010] When the distribution of dark spots is dispersed, the grayscale image is divided into multiple sub-regions. The power of the light-emitting chip corresponding to the grayscale block with the lowest grayscale value in each sub-region is detected and its qualification is determined. If the light-emitting chips corresponding to the grayscale blocks with the lowest grayscale values ​​in each sub-region are all qualified, the detection is stopped.

[0011] In an optional implementation, the step of acquiring a grayscale image of the laser array in the emitting state includes:

[0012] A grid plate is used to cover the laser array in the emitting state. The grid plate includes alternately arranged clearance holes and blocking parts. The clearance holes expose the first part of the light-emitting chip, and the blocking parts block the second part of the light-emitting chip.

[0013] Acquire a first image, which contains grayscale blocks corresponding to the first portion of the light-emitting chips;

[0014] Move the grid plate to expose the second part of the light-emitting chip through the clearance hole, while the blocking part blocks the first part of the light-emitting chip.

[0015] Acquire a second image, which contains grayscale blocks corresponding to the second part of the light-emitting chip;

[0016] The first and second images are combined into a grayscale image of the laser array.

[0017] In an optional implementation, the step of determining whether the distribution of dark spots is a concentrated or dispersed distribution includes:

[0018] The grayscale image is divided into multiple matrix units, and the number of dark points in each matrix unit is counted.

[0019] Determine whether there exists a matrix unit where the number of dark spots exceeds a second preset ratio of the total number of dark spots, and the number of matrix units containing dark spot chips is less than a third preset ratio of the total number of matrix units, wherein the third preset ratio is greater than the reciprocal of the number of matrix units;

[0020] If the number of dark points in a matrix cell exceeds the second preset proportion of the total number of dark points, and the number of matrix cells containing dark points is less than the third preset proportion of the total number of matrix cells, then the distribution of dark points is determined to be a concentrated distribution.

[0021] If the number of dark points in a single matrix cell does not exceed a second preset proportion of the total number of dark points, or if the number of matrix cells containing dark points is not less than a third preset proportion of the total number of matrix cells, then the distribution of dark points is determined to be a dispersed distribution.

[0022] In an optional implementation, the step of determining whether the distribution of dark spots is a concentrated or dispersed distribution includes:

[0023] Calculate the nearest neighbor distance for each dark spot, where the nearest neighbor distance of a dark spot is the distance between the dark spot and its nearest other dark spot;

[0024] Determine if the average nearest neighbor distance of all dark spots is less than a preset distance value;

[0025] If the average of the nearest neighbor distances of all dark spots is less than the preset distance value, then the distribution of dark spots is determined to be a concentrated distribution.

[0026] If the average of the nearest neighbor distances of all dark spots is not less than a preset distance value, the distribution of dark spots is determined to be a dispersed distribution.

[0027] In an optional implementation, after performing power detection on the light-emitting chip corresponding to the grayscale block with the lowest grayscale value in each sub-region and determining whether it is qualified, the laser array detection method further includes:

[0028] The sub-region corresponding to the defective light-emitting chip is identified as the abnormal sub-region;

[0029] Determine whether the number of grayscale blocks in the abnormal sub-region is greater than the second preset number;

[0030] If the number of gray blocks in the abnormal sub-region is greater than the second preset number, the abnormal sub-region is divided into multiple new sub-regions, and the power detection and determination of whether the light-emitting chip corresponding to the gray block with the lowest gray value in each sub-region is performed in a loop.

[0031] If the number of grayscale blocks in the abnormal sub-region is not greater than the second preset number, then the power of the light-emitting chips corresponding to the grayscale blocks in the abnormal sub-region will be detected and judged to be qualified in order of grayscale value from low to high, until a qualified light-emitting chip is detected.

[0032] In an optional implementation, the preset threshold is the standard grayscale value of the light-emitting chip;

[0033] Alternatively, the preset threshold can be the average gray value of all gray blocks in the grayscale image.

[0034] In an optional implementation, after the step of identifying grayscale blocks with grayscale values ​​less than a preset threshold as dark spots in a grayscale image, and before the step of determining whether the distribution of dark spots is a concentrated or dispersed distribution, the laser array detection method further includes:

[0035] Determine if the number of dark spots is greater than the first preset number;

[0036] If the number of dark spots is greater than the first preset number, then the step of determining whether the distribution of dark spots is a concentrated distribution or a dispersed distribution is executed;

[0037] If the number of dark spots is not greater than the first preset number, then the power of the light-emitting chips corresponding to all dark spots is detected and it is determined whether they are qualified.

[0038] In an optional implementation, the first preset quantity is a first preset proportion of the total number of grayscale blocks; or, the first preset quantity is a preset quantity value.

[0039] In an optional implementation, the step of power detection of the light-emitting chip includes:

[0040] The laser emitted by the light-emitting chip to be tested is passed through an aperture, and a power meter is used to detect the power of the laser emitted by the light-emitting chip on the side of the aperture away from the light-emitting chip.

[0041] Secondly, this application provides a laser array detection device, including an image acquisition device, a power detection device, and a controller. The image acquisition device and the power detection device are both electrically connected to the controller. The image acquisition device is used to detect the grayscale image of the laser array in the light-emitting state, and the power detection device is used to measure the power of the light-emitting chip.

[0042] The controller is used to execute executable instructions to implement the laser array detection method of any of the foregoing embodiments.

[0043] In an optional embodiment, the laser array detection device further includes a grid plate and a driving component, the driving component being connected to the grid plate in a transmission manner, and the driving component being used to drive the grid plate to move.

[0044] The beneficial effects of the laser array detection method and device provided in this application include:

[0045] The laser array detection method provided in this application includes: acquiring a grayscale image of the laser array in an emitting state; determining the grayscale value of each grayscale block in the grayscale image, wherein each grayscale block corresponds one-to-one with a light-emitting chip; identifying grayscale blocks in the grayscale image with grayscale values ​​less than a preset threshold as dark spots; determining whether the distribution of dark spots is a concentrated or dispersed distribution; if the distribution of dark spots is a concentrated distribution, sequentially performing power detection on the light-emitting chips corresponding to the grayscale blocks from low to high grayscale values ​​and determining whether they are qualified, until a qualified light-emitting chip is detected; if the distribution of dark spots is a dispersed distribution, dividing the grayscale image into multiple sub-regions, performing power detection on the light-emitting chip corresponding to the grayscale block with the lowest grayscale value in each sub-region and determining whether it is qualified, and stopping the detection if all the light-emitting chips corresponding to the grayscale blocks with the lowest grayscale values ​​in each sub-region are qualified. In this application, abnormal light-emitting chips have low power or do not emit light, and will show low grayscale values ​​in the grayscale image. Therefore, combining image detection and power detection involves first identifying high-risk LEDs by filtering out dark spots, and then performing targeted power detection on these dark spots, thus improving detection efficiency. The accuracy of detection is ensured by determining whether an LED is abnormal through power detection. Furthermore, determining whether the dark spots are distributed in a dispersed or concentrated manner can help identify the differences in their locations. When dark spots are concentrated, the positional differences between them are relatively small; therefore, the order of grayscale values ​​of the dark spots represents their power order—the lower the grayscale value, the lower the power. Thus, when dark spots are concentrated, power detection can be performed on the LEDs corresponding to grayscale blocks sequentially from low to high grayscale values. Once an LED corresponding to a grayscale block is found to be qualified, LEDs corresponding to other grayscale blocks with higher grayscale values ​​do not require further power detection and can be directly identified as qualified LEDs. When dark spots are distributed in a scattered manner, it means that their positions vary greatly. The grayscale value of the light-emitting chip will be affected by the interference of adjacent light-emitting chips. Therefore, the grayscale value of a dark spot surrounded by bright spots will be different from that of a dark spot surrounded by dark spots. This demonstrates the difference in grayscale value representation between scattered and concentrated dark spots. If the grayscale image of the entire light-emitting chip array is treated as a single region for grayscale value sorting and detection, the results may be inaccurate. Therefore, when dark spots are distributed in a scattered manner, the grayscale image is divided into multiple sub-regions. Power detection is performed on the light-emitting chip corresponding to the lowest grayscale block in each sub-region, rather than sorting the grayscale values ​​of all dark spots and detecting them sequentially. This ensures the accuracy of the detection.If the light-emitting chip corresponding to the grayscale block with the lowest grayscale value in a sub-region is normal, then the light-emitting chips corresponding to other grayscale blocks in the entire sub-region do not need to undergo power detection. If the light-emitting chip corresponding to the grayscale block with the lowest grayscale value in a sub-region is abnormal, then the light-emitting chips corresponding to other grayscale blocks in that sub-region can be further detected, thus balancing detection efficiency and accuracy. It is evident that the laser array detection method provided in this application, by identifying dark spots and determining their distribution state, employs different detection strategies under different distribution states, resulting in high detection efficiency and high detection accuracy.

[0046] The laser array detection device provided in this application embodiment can implement the above-described detection method, and therefore has the corresponding beneficial effects. Attached Figure Description

[0047] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1 This is a schematic diagram of a laser array in one embodiment of this application;

[0049] Figure 2 This is a flowchart of a laser array detection method in one embodiment of this application;

[0050] Figure 3 This is a schematic diagram of a grayscale image in one embodiment of this application;

[0051] Figure 4 This is a flowchart of obtaining a grayscale image in one embodiment of this application;

[0052] Figure 5 This is a schematic diagram of a grid plate in one embodiment of this application;

[0053] Figure 6 This is a schematic diagram showing a concentrated distribution of dark spots in one embodiment of this application;

[0054] Figure 7 This is a flowchart illustrating the detection process when dark spots are distributed in a dispersed manner, as described in one embodiment of this application.

[0055] Figure 8 This is a schematic diagram of a laser array detection device in one embodiment of this application;

[0056] Figure 9 This is a schematic diagram of the grid plate arrangement in one embodiment.

[0057] Icons: 100-Image acquisition device; 200-Power detection device; 300-Grid plate; 310-Avoidance hole; 320-Obscuration part; 330-Window; 400-Rack; 410-Top plate; 500-Driver; 10-Laser array; 11-Light emission chip; 12-Grayscale block; 12a-Dark spot; 12b-Bright spot. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, 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. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0059] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0060] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0061] In the description of this application, it should be noted that if the terms "upper", "lower", "inner", "outer", etc. appear to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, they are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0062] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0063] It should be noted that, where there is no conflict, the features in the embodiments of this application can be combined with each other.

[0064] In related technologies, the detection of laser arrays typically involves measuring power using a high-precision power meter, or acquiring images using a charge-coupled device (CCD) and then processing the images to determine whether the light-emitting chips in the laser array are abnormal based on grayscale values. However, while traversing each light-emitting chip with a power meter offers high accuracy, it is inefficient; and relying solely on image processing to determine chip abnormalities also suffers from poor accuracy. Therefore, image processing and power metering can be combined. Image analysis can be used to assess the risk of abnormalities in each light-emitting chip, and power testing can be performed on chips with higher risk, thus improving detection efficiency. Specifically, power testing can be performed on the light-emitting chips sequentially from low to high grayscale values. Once a chip is found to be normal, testing of chips with higher grayscale values ​​is stopped, saving testing time. However, this approach still suffers from inaccuracies. Because the grayscale blocks in a grayscale image are located in different positions—some at the edges, some at the corners, and some in the center—and because some grayscale blocks are surrounded by darker grayscale blocks while others are surrounded by brighter grayscale blocks, the light-emitting chips (LEDs) influence each other, and grayscale values ​​are also affected by position and environment. Therefore, it's possible that the LED corresponding to a certain grayscale block is normal, while the LED corresponding to a grayscale block with a higher grayscale value is abnormal. When this happens, the method described above for detecting LEDs from low to high grayscale values ​​may result in missing abnormal LEDs.

[0065] Therefore, this application provides a laser array detection method. First, image analysis is used to determine the dispersion of dark spots to identify their distribution. Then, different power detection strategies are executed based on the different types of dark spot distribution, thereby achieving a balance between efficiency and detection accuracy.

[0066] The laser array detection method provided in this application embodiment can be used to detect whether there is any abnormality in the light-emitting chip 11 in the laser array 10, so as to repair the abnormal light-emitting chip 11. Figure 1 This is a schematic diagram of a laser array 10 in one embodiment of this application. Figure 1 As shown, the laser array 10 includes multiple light-emitting chips 11 arranged in an array, each of which is used to generate laser light. Optionally, the multiple light-emitting chips 11 are arranged in a rectangular array, and the laser array 10 as a whole is rectangular. Figure 2 This is a flowchart of a laser array detection method in one embodiment of this application. Figure 2 As shown, the laser array detection method provided in this application includes the following steps:

[0067] Step S100: Obtain a grayscale image of the laser array 10 in the light-emitting state, and determine the grayscale value of each grayscale block 12 in the grayscale image, wherein the grayscale block 12 corresponds one-to-one with the light-emitting chip 11.

[0068] Grayscale images can be acquired using high-precision charge-coupled devices (CCDs). Figure 3 This is a schematic diagram of a grayscale image in one embodiment of this application. Figure 3 As shown, the grayscale image includes multiple grayscale blocks 12 arranged in an array, with each grayscale block 12 representing a light-emitting chip 11. The grayscale value ranges from 0 to 255, where a grayscale value of 0 represents pure black (the darkest) and a grayscale value of 255 represents pure white (the brightest). The grayscale value of a grayscale block 12 is generally positively correlated with the luminous power of the corresponding light-emitting chip 11; the higher the power of the light-emitting chip 11, the higher the grayscale value of the corresponding grayscale block 12, meaning the grayscale block 12 is brighter. Abnormal light-emitting chips 11 usually have insufficient luminous power, generally manifested as a lower grayscale value for their corresponding grayscale block 12, meaning the grayscale block 12 is darker. However, the different positions of the light-emitting chips 11 may affect their grayscale representation in the grayscale image. For example, given two light-emitting chips 11 with equal power, one surrounded by brighter light-emitting chips 11 and the other surrounded by darker light-emitting chips 11, the former may have better grayscale performance in a grayscale image than the latter. Specifically, the grayscale block 12 corresponding to the former will be brighter (higher grayscale value) than the grayscale block 12 corresponding to the latter. Therefore, the grayscale value order of each grayscale block 12 in the grayscale image obtained in step S100 may not accurately represent the power order of the corresponding light-emitting chips 11.

[0069] Figure 4 This is a flowchart illustrating the acquisition of a grayscale image in one embodiment of this application. Figure 4 As shown, optionally, a grayscale image can be obtained through the following steps:

[0070] In step S110, a grid plate 300 is used to cover the laser array 10 in the light-emitting state. The grid plate 300 includes alternately arranged clearance holes 310 and blocking portions 320. The clearance holes 310 expose the first part of the light-emitting chip 11, and the blocking portions 320 block the second part of the light-emitting chip 11.

[0071] Figure 5 This is a schematic diagram of a grid plate 300 in one embodiment of this application. Figure 5As shown, the grid plate 300 includes alternating clearance holes 310 and blocking portions 320. The clearance holes 310 and blocking portions 320 are arranged in a rectangular array, and the size of each clearance hole 310 and blocking portion 320 matches that of a single light-emitting chip 11 on the laser array 10. Specifically, both the clearance holes 310 and the blocking portions 320 are rectangular in shape; and the edges of the blocking portions 320 are adjacent to the edges of the clearance holes 310, and the corners of the blocking portions 320 are perpendicular to the corners of another blocking portion 320. When the grid plate 300 covers the laser array 10, the first portion of the light-emitting chips 11 is exposed, and the second portion of the light-emitting chips 11 is blocked by the blocking portions 320. It should be understood that the matrix formed by the clearance holes 310 and the blocking portions 320 can be slightly larger than the laser array 10 so that the grid plate 300 still covers the laser array 10 after subsequent movement of the grid plate 300.

[0072] Step S120: Obtain a first image, which contains grayscale blocks 12 corresponding to the first part of the light-emitting chip 11.

[0073] Since the second part of the light-emitting chip 11 is blocked by the blocking part 320, the first image does not contain the gray block 12 corresponding to the second part of the light-emitting chip 11.

[0074] In step S130, the grid plate 300 is moved so that the clearance hole 310 exposes the second part of the light-emitting chip 11, and the blocking part 320 blocks the first part of the light-emitting chip 11.

[0075] By moving the grid plate 300, the first part of the light-emitting chip 11 that was originally exposed by the clearance hole 310 can be blocked by the blocking part 320, and the second part of the light-emitting chip 11 that was originally blocked by the blocking part 320 can be exposed by the clearance hole 310.

[0076] Step S140: Obtain the second image, which contains the grayscale block 12 corresponding to the second part of the light-emitting chip 11.

[0077] Since the first part of the light-emitting chip 11 is blocked by the blocking part 320, the second image does not contain the gray block 12 corresponding to the first part of the light-emitting chip 11.

[0078] Step S150: Combine the first image and the second image into a grayscale image of the laser array 10.

[0079] By means of image synthesis, the first image and the second image can be combined into a grayscale image, which includes grayscale blocks 12 that correspond one-to-one with all the light-emitting chips 11.

[0080] Since the grayscale performance of a light-emitting chip 11 may be affected by adjacent light-emitting chips 11 when acquiring a grayscale image, the grid plate 300 is used to block part 320 of the light-emitting chips 11 so that the four sides of the exposed light-emitting chip 11 are blocked by the adjacent light-emitting chips 11. This can reduce the influence of adjacent light-emitting chips 11 on the light-emitting chip 11, thereby improving the accuracy of the acquired grayscale image.

[0081] Step S200: The gray block 12 in the grayscale image whose grayscale value is less than a preset threshold is identified as dark spot 12a.

[0082] In this application, dark spot 12a is a grayscale block 12 with a low grayscale value, which means that the corresponding light-emitting chip 11 has a higher risk of abnormality. For ease of description, the other grayscale blocks 12 besides dark spot 12a are named bright spots 12b.

[0083] Optionally, the preset threshold is the standard grayscale value of the light-emitting chip 11, and the standard grayscale value can range from 40 to 50, for example, 45. It can be understood that a larger preset threshold value results in more dark spots 12a, a larger detection volume, and higher detection accuracy (less likely to miss abnormal light-emitting chips 11); a smaller preset threshold value results in fewer dark spots 12a, a smaller detection volume, higher efficiency, but relatively lower detection accuracy. In other optional embodiments, the preset threshold can also be the average grayscale value of all grayscale blocks 12 in the grayscale image.

[0084] Step S300: Determine whether the distribution of dark spot 12a is a concentrated distribution or a dispersed distribution.

[0085] Adjacent light-emitting chips 11 can have a certain degree of influence. For example, when a light-emitting chip 11 is surrounded by low-power light-emitting chips 11, it may appear darker in a grayscale image; conversely, when a light-emitting chip 11 of the same power is surrounded by high-power light-emitting chips 11, it may appear brighter in a grayscale image. Similarly, the position of the light-emitting chip 11 can also affect its grayscale performance. For instance, the grayscale value-power relationship may differ between a light-emitting chip 11 located at the edge of a grayscale image and one located in the middle, or between a light-emitting chip 11 in the upper left corner and one in the lower right corner. Therefore, the environmental conditions surrounding the light-emitting chip 11 influence its grayscale performance. Therefore, this application judges the distribution state of dark spots 12a. When it is determined to be a concentrated distribution, it means that the environmental conditions of each dark spot 12a are similar. The similar environmental conditions mentioned here can mean that the positions of multiple dark spots 12a in the grayscale image are relatively close, and / or that the distribution of dark spots 12a around each dark spot 12a is relatively similar (for example, each dark spot 12a is surrounded by one or more dark spots 12a). When the distribution state of dark spots 12a is a dispersed distribution, it means that the positions of different dark spots 12a in the image are very different, and there may be a situation where one dark spot 12a is surrounded by dark spots 12a, while another dark spot 12a is surrounded by bright spots 12b.

[0086] When dark spots 12a are concentrated, the gray value ranking of dark spots 12a is likely to be the same as the actual power ranking, because the environmental conditions of each dark spot 12a are similar, so the relationship between their gray value and power is similar. However, when they are dispersed, the gray value ranking of dark spots 12a is likely to differ from the actual power ranking, because the environmental conditions of different dark spots 12a are quite different, so the relationship between their gray value and power may differ.

[0087] Optionally, step S300 may specifically include the following steps:

[0088] Step S301: Divide the grayscale image into multiple matrix units and count the number of dark points 12a in each matrix unit;

[0089] Step S302: Determine whether there exists a matrix unit where the number of dark spots 12a exceeds a second preset ratio of the total number of dark spots 12a, and the number of matrix units containing dark spot 12a chips is less than a third preset ratio of the total number of matrix units, wherein the third preset ratio is greater than the reciprocal of the number of matrix units.

[0090] If the number of dark points 12a in a matrix unit exceeds a second preset proportion of the total number of dark points 12a, and the number of matrix units containing dark points 12a is less than a third preset proportion of the total number of matrix units, then proceed to step S320: determine that the distribution of dark points 12a is a concentrated distribution. If the number of dark points 12a in no matrix unit exceeds a second preset proportion of the total number of dark points 12a, or the number of matrix units containing dark points 12a is not less than a third preset proportion of the total number of matrix units, then proceed to step S330: determine that the distribution of dark points 12a is a dispersed distribution.

[0091] For example, if a grayscale image consists of a 9×9 grayscale block matrix, then the grayscale image can be divided into 3×3 matrix units, meaning each matrix unit contains 9 grayscale blocks, for a total of 9 matrix units. The number of dark points 12a in each matrix unit is counted. If the number of dark points 12a in a particular matrix unit exceeds a second preset proportion of the total number of dark points 12a, and the number of matrix units containing dark point 12a chips is less than a third preset proportion of the total number of matrix units, then the dark points 12a are considered concentrated in a small number of matrix units, and the distribution of dark points 12a is determined to be a concentrated distribution. Conversely, if dark points 12a are distributed in most matrix units, and no particular matrix unit has a large number of dark points 12a, then the distribution of dark points 12a is considered to be a dispersed distribution. It is understandable that the third preset ratio should be set according to the number of matrix units, but it should be at least greater than the reciprocal of the number of matrix units (if the third preset ratio is less than or equal to the reciprocal of the number of matrix units, then the number of matrix units containing dark spot 12a will definitely not be less than the third preset ratio of the total number of matrix units, and the judgment result will definitely be a dispersed distribution). Optionally, the third preset ratio is 20%.

[0092] In other optional embodiments, step S300 may specifically include the following steps:

[0093] Step S311: Calculate the nearest neighbor distance for each dark spot 12a, where the nearest neighbor distance for dark spot 12a is the distance between dark spot 12a and its nearest other dark spot 12a;

[0094] Step S312: Determine whether the average of the nearest neighbor distances of all dark spots 12a is less than a preset distance value;

[0095] If the average of the nearest neighbor distances of all dark spots 12a is less than the preset distance value, then proceed to step S320: determine that the distribution state of dark spots 12a belongs to a concentrated distribution; if the average of the nearest neighbor distances of all dark spots 12a is not less than the preset distance value, then proceed to step S330: determine that the distribution state of dark spots 12a belongs to a dispersed distribution.

[0096] It is understandable that if the dark spots 12a are concentrated, then the nearest neighbor distance of each dark spot 12a is shorter, and the average nearest neighbor distance of all dark spots 12a is also smaller; if the dark spots 12a are dispersed, then the nearest neighbor distance of each dark spot 12a is longer, and the average nearest neighbor distance of all dark spots 12a is also larger. Optionally, the preset distance value can be a fixed value, or it can be determined according to the size of the grayscale block 12 matrix, for example, set to 5% to 15% of the diagonal length of the grayscale block 12 matrix.

[0097] In other alternative embodiments, the distribution of dark spots 12a can also be determined by manual observation as either a concentrated or dispersed distribution. Figure 3 The image shows that dark spot 12a is distributed in a scattered manner. Figure 6 This is a schematic diagram showing the concentrated distribution of dark spots 12a in one embodiment of this application.

[0098] Optionally, after determining grayscale blocks 12 with grayscale values ​​less than a preset threshold as dark spots in the grayscale image, and before determining whether the distribution of dark spots 12a is a concentrated or dispersed distribution (i.e., step S300), the laser array detection method further includes:

[0099] Step S210: Determine whether the number of dark spots 12a is greater than the first preset number;

[0100] If the number of dark spots 12a is greater than the first preset number, then the step of determining whether the distribution state of dark spots 12a is a concentrated distribution or a dispersed distribution is executed (i.e., step S300).

[0101] If the number of dark spots 12a is not greater than the first preset number, it is not necessary to judge the distribution state of dark spots 12a, and directly execute step S600: perform power detection on the light-emitting chip 11 corresponding to all dark spots 12a and determine whether it is qualified.

[0102] It is understandable that if the number of dark spots 12a is small, the workload of power detection for all the light-emitting chips 11 corresponding to the dark spots 12a is relatively small. Therefore, instead of formulating a detection strategy based on the distribution, power detection is performed on the light-emitting chip 11 corresponding to each dark spot 12a to ensure detection accuracy. If the number of dark spots 12a is large, the workload of power detection for each dark spot 12a is large. In this case, it is necessary to formulate a corresponding detection strategy based on the distribution of the dark spots 12a (such as steps S400 and S500 below) to improve detection efficiency while ensuring accuracy as much as possible.

[0103] Optionally, the first preset quantity is a first preset ratio of the total number of grayscale blocks 12, such as 5% to 15%; or, the first preset quantity is a preset quantity value, such as 5 to 15.

[0104] In this application, when the distribution of dark spot 12a is a concentrated distribution, step S400 is executed: power detection is performed on the light-emitting chip 11 corresponding to gray block 12 in order of gray value from low to high, and it is determined whether it is qualified, until a qualified light-emitting chip 11 is detected.

[0105] Since the dark spots 12a are concentrated in one area, the probability that their grayscale value order is the same as the actual power order is high. Therefore, power detection can be performed on each light-emitting chip 11 sequentially from darkest to brightest, according to the grayscale value order of grayscale block 12. Each light-emitting chip 11 detected is the darkest among all the undetected light-emitting chips 11 (the one with the lowest grayscale value in the corresponding grayscale block 12). Power detection can be stopped when a light-emitting chip 11 is detected as qualified, at which point all other undetected light-emitting chips 11 can be considered qualified.

[0106] In some cases (especially when the preset threshold value is high), if there is a qualified light-emitting chip 11 among the light-emitting chips 11 corresponding to dark spot 12a, then a qualified light-emitting chip 11 will be detected before all the light-emitting chips 11 corresponding to dark spot 12a are detected, thus ending the detection. In some extreme cases, all light-emitting chips 11 corresponding to dark spot 12a are detected as abnormal, meaning that there may still be abnormal light-emitting chips 11 among bright spot 12b. In this case, the power detection can continue to be performed on the light-emitting chips 11 corresponding to the remaining grayscale blocks 12 (i.e., bright spot 12b) in order of increasing grayscale value; when a qualified light-emitting chip 11 is detected, the power detection can be stopped, and at this time, the other undetected light-emitting chips 11 can be considered as qualified.

[0107] If the distribution of dark spot 12a is a dispersed distribution, step S510 is executed: the grayscale image is divided into multiple sub-regions, and the power of the light-emitting chip 11 corresponding to the grayscale block 12 with the lowest grayscale value in each sub-region is detected and it is determined whether it is qualified.

[0108] Since the dark spots 12a are distributed in a dispersed manner, the grayscale value order of the dark spots 12a may differ from the actual power order. Therefore, it is necessary to perform detection by region. Power detection is performed on the light-emitting chip 11 corresponding to the grayscale block 12 with the lowest grayscale value in each sub-region. If the light-emitting chip 11 is found to be qualified, then the light-emitting chips 11 corresponding to the other grayscale blocks 12 in that sub-region can be considered qualified, thereby improving detection efficiency. If the light-emitting chips 11 corresponding to the grayscale block 12 with the lowest grayscale value in each sub-region are all qualified, the detection can be stopped.

[0109] Figure 7 This is a flowchart illustrating the detection process when dark spots 12a are distributed in a dispersed manner, according to one embodiment of this application. Figure 7 As shown, after power detection and determination of whether the light-emitting chip 11 corresponding to the grayscale block 12 with the lowest grayscale value in each sub-region is qualified, if the light-emitting chip 11 corresponding to the grayscale block 12 with the lowest grayscale value in a certain sub-region is found to be unqualified, optionally, the detection method of the laser array 10 further includes:

[0110] Step S520: The sub-region corresponding to the unqualified light-emitting chip 11 is identified as an abnormal sub-region;

[0111] Step S530: Determine whether the number of grayscale blocks 12 in the abnormal sub-region is greater than the second preset number;

[0112] If the number of grayscale blocks 12 in the abnormal sub-region is greater than the second preset number, then step S540 is executed: the abnormal sub-region is divided into multiple new sub-regions. Then, the step of performing power detection on the light-emitting chip 11 corresponding to the grayscale block 12 with the lowest grayscale value in each sub-region and determining whether it is qualified is executed cyclically.

[0113] If the number of grayscale blocks 12 in the abnormal sub-region is not greater than the second preset number, then step S550 is executed, and the power of the light-emitting chips 11 corresponding to the grayscale blocks 12 in the abnormal sub-region is detected and judged to be qualified in order of grayscale value from low to high, until a qualified light-emitting chip 11 is detected.

[0114] It should be noted that step S510 can be further divided into step S511 (dividing the grayscale image into multiple sub-regions) and step S512 (performing power detection on the light-emitting chip 11 corresponding to the grayscale block 12 with the lowest grayscale value in each sub-region and determining whether it is qualified). After step S540 is completed, return to step S512.

[0115] It is understandable that if the number of grayscale blocks 12 in the abnormal sub-region is no greater than the second preset number (e.g., 4-10), then the power ranking and grayscale ranking of each light-emitting chip 11 within a small area are likely to be the same. Therefore, power detection can be performed on the light-emitting chips 11 corresponding to the grayscale blocks 12 in the abnormal sub-region in order of grayscale value from low to high. Once a qualified light-emitting chip 11 is detected, the detection stops, and the other light-emitting chips 11 in the abnormal sub-region can be considered qualified. Furthermore, if the number of grayscale blocks 12 in the abnormal sub-region is less than the second preset number, the workload of detecting all of them will not be too large, and further dividing into new sub-regions is of little significance. However, if the number of grayscale blocks 12 in the abnormal sub-region is greater than the second preset number, then the power ranking and grayscale ranking of each light-emitting chip 11 within a larger area may be different. If detection is performed by grayscale value ranking, abnormal light-emitting chips 11 may be missed. Therefore, the abnormal sub-region is further divided into multiple new sub-regions, and power detection is performed on the light-emitting chip 11 corresponding to the grayscale block 12 with the lowest grayscale value in each sub-region. The above detection method utilizes recursion to achieve a balance between accuracy and efficiency.

[0116] In this embodiment, the step of power detection of the light-emitting chip 11 may specifically include: passing the laser emitted by the light-emitting chip 11 to be tested through an aperture, and using a power meter to detect the power of the laser emitted by the light-emitting chip 11 on the side of the aperture away from the light-emitting chip 11. The aperture can block the light emitted by other light-emitting chips 11, allowing only the laser emitted by the light-emitting chip 11 to pass through, thus ensuring the accuracy of the detection. Furthermore, a variable aperture aperture can be used to improve the adaptability to light-emitting chips 11 of different sizes.

[0117] Furthermore, such as Figure 5 As shown, the grid plate 300 is also provided with a window 330. By moving the grid plate 300, the window 330 can expose all the light-emitting chips 11 on the laser array 10, which makes it convenient to perform power detection on any light-emitting chip 11.

[0118] Figure 8 This is a schematic diagram of a laser array detection device in one embodiment of this application. Figure 8 As shown in the figure, this application embodiment also provides a laser array detection device, including an image acquisition device 100, a power detection device 200 and a controller (not shown in the figure). The image acquisition device 100 and the power detection device 200 are both electrically connected to the controller, which is used to execute executable instructions to implement the laser array detection method provided in the above embodiment.

[0119] Specifically, the image acquisition device 100 may include a CCD, and the power detection device 200 may include a high-precision power meter and an aperture. Optionally, the aperture of the aperture is variable, so that the aperture of the aperture can be adaptively adjusted according to the size of the light-emitting chip 11 to be detected, thereby better shielding other light-emitting chips around it. The laser array detection equipment includes a frame 400, and the image acquisition device 100 and the power detection device 200 are both disposed on the frame 400. In this embodiment, the image acquisition device 100 and the power detection device 200 can be driven to move relative to the frame 400, thereby adjusting their positions relative to the laser array 10, thereby accurately acquiring images and performing power detection. Optionally, the power detection device 200 is configured to be height-adjustable, thereby adjusting its distance from the laser array 10 in the vertical direction.

[0120] Figure 9 This is a schematic diagram illustrating the arrangement of the grid plate 300 in one embodiment. Figure 9 As shown, in this embodiment, the laser array detection device may further include a grid plate 300 and a driving component 500. The driving component 500 is connected to the grid plate 300 and is used to drive the grid plate 300 to move. The frame 400 also includes a top plate 410, which is disposed above the image acquisition device 100 and the power detection device 200. The top plate 410 is provided with a fixing port for fixing the laser array 10, which penetrates through the top plate 410. When detecting the laser array 10, the light-emitting surface of the laser array 10 faces downward. The grid plate 300 is slidably engaged with the top plate 410. The grid plate 300 can be moved under the drive of the driving component 500 to selectively block a portion of the light-emitting chips 11 and expose another portion of the light-emitting chips 11. Alternatively, by moving the grid plate 300, the window 330 of the grid plate 300 can expose all the light-emitting chips 11, thereby facilitating the power detection device 200 to perform power detection on any one of the light-emitting chips 11.

[0121] In summary, the laser array detection method provided in this application includes: acquiring a grayscale image of the laser array 10 under emission conditions; determining the grayscale value of each grayscale block 12 in the grayscale image, wherein each grayscale block 12 corresponds to a light-emitting chip 11; identifying grayscale blocks 12 in the grayscale image with grayscale values ​​less than a preset threshold as dark spots 12a; determining whether the distribution of dark spots 12a is a concentrated distribution or a dispersed distribution; if the distribution of dark spots 12a is a concentrated distribution, sequentially performing power detection on the light-emitting chips 11 corresponding to grayscale blocks 12 from low to high grayscale values ​​and determining whether they are qualified, until a qualified light-emitting chip 11 is detected; if the distribution of dark spots 12a is a dispersed distribution, dividing the grayscale image into multiple sub-regions, performing power detection on the light-emitting chip 11 corresponding to the grayscale block 12 with the lowest grayscale value in each sub-region and determining whether it is qualified, and stopping the detection if all the light-emitting chips 11 corresponding to the grayscale block 12 with the lowest grayscale value in each sub-region are qualified. In this application, image detection and power detection are combined. First, dark spots 12a are screened to identify the light-emitting chips 11 with a high risk of anomalies. Then, targeted power detection is performed on the dark spots 12a, which improves detection efficiency. Whether the light-emitting chip 11 is abnormal is determined by power detection, ensuring detection accuracy. Furthermore, by determining whether the distribution of dark spots 12a is dispersed or concentrated, the differences in the location of dark spots 12a can be determined to a certain extent. When dark spots 12a are concentrated, power detection can be performed on the light-emitting chips 11 corresponding to grayscale blocks 12 in ascending order of grayscale value. When a light-emitting chip 11 corresponding to a certain grayscale block 12 is found to be normal, the light-emitting chips 11 corresponding to other grayscale blocks 12 with higher grayscale values ​​do not need to undergo further power detection and can be directly identified as normal light-emitting chips 11. When the dark spots 12a are distributed in a dispersed manner, the differences in the positions of each dark spot 12a are significant. Therefore, the grayscale image is divided into multiple sub-regions, and power detection is performed on the light-emitting chip 11 corresponding to the grayscale block 12 with the lowest grayscale value in each sub-region. This ensures the accuracy of the detection. If the light-emitting chip 11 corresponding to the grayscale block 12 with the lowest grayscale value in a sub-region is normal, then power detection is not required for the light-emitting chips 11 corresponding to other grayscale blocks 12 in the entire sub-region. If the light-emitting chip 11 corresponding to the grayscale block 12 with the lowest grayscale value in a sub-region is abnormal, then further detection can be performed on the light-emitting chips 11 corresponding to other grayscale blocks 12 in that sub-region. This balances detection efficiency and detection accuracy. It can be seen that the laser array detection method provided in this application embodiment, by determining the dark spots 12a and judging the distribution state of the dark spots 12a, adopts different detection strategies under different distribution states, resulting in high detection efficiency and high detection accuracy.

[0122] The laser array detection device provided in this application embodiment can implement the above-described detection method, and therefore has the corresponding beneficial effects.

[0123] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A method of detecting a laser array, characterized by, The laser array (10) comprises a plurality of light emitting chips (11) arranged in an array, and the laser array detection method comprises: acquiring a gray image of the laser array (10) in a light emitting state, and determining a gray value of each gray block (12) in the gray image, wherein the gray block (12) corresponds to the light emitting chip (11) one by one; determining the gray block (12) with a gray value less than a preset threshold in the gray image as a dark point (12a); judging whether the distribution state of the dark point (12a) belongs to a concentrated distribution or a scattered distribution; in the case that the distribution state of the dark point (12a) belongs to the concentrated distribution, sequentially detecting the power of the light emitting chip (11) corresponding to the gray block (12) from low to high in terms of the gray value and judging whether it is qualified until a qualified light emitting chip (11) is detected; in the case that the distribution state of the dark point (12a) belongs to the scattered distribution, dividing the gray image into a plurality of sub-regions, detecting the power of the light emitting chip (11) corresponding to the gray block (12) with the lowest gray value in each sub-region and judging whether it is qualified, and if the light emitting chip (11) corresponding to the gray block (12) with the lowest gray value in each sub-region is qualified, stopping the detection.

2. The laser array detection method of claim 1, wherein, The step of acquiring a gray image of the laser array (10) in a light emitting state comprises: covering the laser array (10) with a grid plate (300), wherein the grid plate (300) comprises alternatingly arranged avoiding holes (310) and shielding portions (320), the avoiding holes (310) expose a first part of the light emitting chips (11), and the shielding portions (320) shield a second part of the light emitting chips (11); acquiring a first image, wherein the first image comprises the gray blocks (12) corresponding to the first part of the light emitting chips (11); moving the grid plate (300) so that the avoiding holes (310) expose the second part of the light emitting chips (11) and the shielding portions (320) shield the first part of the light emitting chips (11); acquiring a second image, wherein the second image comprises the gray blocks (12) corresponding to the second part of the light emitting chips (11); combining the first image and the second image into the gray image of the laser array (10).

3. The laser array detection method of claim 1, wherein, The step of judging whether the distribution state of the dark point (12a) belongs to a concentrated distribution or a scattered distribution comprises: dividing the gray image into a plurality of matrix units and counting the number of dark points (12a) in each matrix unit; judging whether the number of dark points (12a) in one matrix unit exceeds a second preset proportion of the total number of dark points (12a), and the number of matrix units containing the dark points (12a) is less than a third preset proportion of the total number of matrix units, wherein the third preset proportion is greater than the inverse of the number of matrix units; If the number of the dark spots (12a) in one of the matrix units exceeds the second preset proportion of the total number of the dark spots (12a), and the number of the matrix units containing the dark spots (12a) is less than the third preset proportion of the total number of the matrix units, it is determined that the distribution state of the dark spots (12a) belongs to the concentrated distribution; If the number of the dark spots (12a) in one of the matrix units does not exceed the second preset proportion of the total number of the dark spots (12a), or the number of the matrix units containing the dark spots (12a) is not less than the third preset proportion of the total number of the matrix units, it is determined that the distribution state of the dark spots (12a) belongs to the dispersed distribution.

4. The laser array detection method of claim 1, wherein, The step of determining whether the distribution state of the dark spots (12a) belongs to the concentrated distribution or the dispersed distribution includes: calculating the nearest distance of each of the dark spots (12a), wherein the nearest distance of the dark spot (12a) is the distance between the dark spot (12a) and the nearest other dark spot (12a); determining whether the average value of the nearest distances of all the dark spots (12a) is less than a preset distance value; If the average value of the nearest distances of all the dark spots (12a) is less than the preset distance value, it is determined that the distribution state of the dark spots (12a) belongs to the concentrated distribution; If the average value of the nearest distances of all the dark spots (12a) is not less than the preset distance value, it is determined that the distribution state of the dark spots (12a) belongs to the dispersed distribution.

5. The laser array detection method of claim 1, wherein, After the power detection and qualification of the light emitting chip (11) corresponding to the gray block (12) with the lowest gray value in each of the sub-regions, the laser array detection method further includes: determining the sub-region corresponding to the unqualified light emitting chip (11) as an abnormal sub-region; determining whether the number of the gray blocks (12) in the abnormal sub-region is greater than a second preset number; If the number of the gray blocks (12) in the abnormal sub-region is greater than the second preset number, the abnormal sub-region is divided into a plurality of new sub-regions, and the step of performing power detection and qualification of the light emitting chip (11) corresponding to the gray block (12) with the lowest gray value in each of the sub-regions is repeatedly executed; If the number of the gray blocks (12) in the abnormal sub-region is not greater than the second preset number, the power detection and qualification of the light emitting chip (11) corresponding to the gray block (12) in the abnormal sub-region are sequentially performed from low to high in terms of gray value until a qualified light emitting chip (11) is detected.

6. The laser array detection method according to any one of claims 1-5, wherein, The preset threshold value is a standard gray value of the light emitting chip (11); Or, the preset threshold value is an average gray value of all the gray blocks (12) in the gray image.

7. The laser array detection method according to any one of claims 1-5, wherein, After the step of determining the gray blocks (12) with a gray value less than a preset threshold in the gray image as dark spots (12a), before the step of judging whether the distribution state of the dark spots (12a) belongs to a concentrated distribution or a scattered distribution, the laser array detection method further comprises: judging whether the number of the dark spots (12a) is greater than a first preset number; if the number of the dark spots (12a) is greater than the first preset number, performing the step of judging whether the distribution state of the dark spots (12a) belongs to a concentrated distribution or a scattered distribution; if the number of the dark spots (12a) is not greater than the first preset number, performing power detection on the light emitting chip (11) corresponding to all the dark spots (12a) and judging whether it is qualified.

8. The laser array detection method of any one of claims 1-5, wherein, The step of performing power detection on the light emitting chip (11) comprises: making the laser emitted by the light emitting chip (11) to be detected pass through an aperture, and using a power meter on the side of the aperture away from the light emitting chip (11) to perform power detection on the laser emitted by the light emitting chip (11).

9. A laser array detection apparatus, characterized by, The laser array detection device comprises an image acquisition device (100), a power detection device (200) and a controller, the image acquisition device (100) and the power detection device (200) are electrically connected with the controller, the image acquisition device (100) is used for detecting the gray image of the laser array (10) in a light emitting state, and the power detection device (200) is used for performing power detection on the light emitting chip (11). The controller is used for executing executable instructions to realize the laser array detection method in any one of claims 1-8.

10. The laser array detection device of claim 9, wherein, The laser array detection device further comprises a grid plate (300) and a driving member (500), the driving member (500) is in transmission connection with the grid plate (300), and the driving member (500) is used for driving the grid plate (300) to move.

Images