Laser array detection method and device

Abstract

The invention discloses a laser array detection method and device, and relates to the technical field of laser. According to the laser array detection method, image detection and power detection are combined together, firstly, dark spots are screened out to determine a part of light-emitting chips with relatively high abnormal risks, and then targeted power detection is carried out on the dark spots, so that the detection efficiency can be improved; whether the light-emitting chip is abnormal or not is judged through power detection, and the detection accuracy can be guaranteed. Furthermore, by judging whether the distribution state of the dark spots is decentralized distribution or centralized distribution, the difference of the positions of the dark spots can be determined to a certain extent. The dark spots are determined, the distribution state of the dark spots is judged, and different detection strategies are adopted in different distribution states, so that the detection efficiency is relatively high, and the detection accuracy is also relatively high. The laser array detection equipment provided by the embodiment of the invention can realize the detection method.

Description

Technical Field

[0001] The present application relates to the field of laser technology, and in particular to a laser array detection method and device. Background Art

[0002] Existing semiconductor lasers consist of multiple light-emitting chips arranged in an array. To detect abnormalities in the light-emitting chips in a laser array, conventional methods can use a power meter to test each chip. Alternatively, a charge-coupled device (CCD) with high-resolution imaging capabilities can be used to capture 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, conventional laser array detection methods struggle to achieve both high efficiency and high accuracy. Summary of the Invention

[0003] The purpose of this application includes providing a laser array detection method and device, which can achieve both high detection efficiency and detection accuracy.

[0004] The embodiments of the present application can be implemented as follows: In a first aspect, the present application provides a laser array detection method, wherein the laser array includes a plurality of light-emitting chips arranged in an array, and the laser array detection method includes: Acquire a grayscale image of the laser array in a light-emitting state, and determine the grayscale value of each grayscale block in the grayscale image, wherein the grayscale blocks correspond one-to-one to the light-emitting chips; Determine a grayscale block in a grayscale image whose grayscale value is less than a preset threshold as a dark spot; Determine whether the distribution of dark spots is concentrated or dispersed; When the distribution state of the dark spots is concentrated, the power of the light-emitting chips corresponding to the grayscale blocks is tested in order from low to high grayscale values, and whether they are qualified is determined until a qualified light-emitting chip is detected; When the distribution of dark spots is dispersed, the grayscale image is divided into multiple sub-areas, and the light-emitting chip corresponding to the grayscale block with the lowest grayscale value in each sub-area is subjected to power detection and judged whether it is qualified. If the light-emitting chips corresponding to the grayscale block with the lowest grayscale value in each sub-area are all qualified, the detection is stopped.

[0005] In an optional embodiment, the step of acquiring a grayscale image of the laser array in a light-emitting state includes: Using a grid plate to cover the laser array in a light-emitting state, wherein the grid plate includes avoidance holes and shielding portions that are alternately arranged, the avoidance holes exposing a first portion of the light-emitting chips, and the shielding portions shielding a second portion of the light-emitting chips; Acquire a first image, where the first image includes grayscale blocks corresponding to a first portion of light-emitting chips; Move the grid plate so that the avoidance hole exposes the second part of the light-emitting chips and the shielding portion shields the first part of the light-emitting chips; Acquire a second image, where the second image includes grayscale blocks corresponding to the second portion of light-emitting chips; The first image and the second image are combined into a grayscale image of the laser array.

[0006] In an optional embodiment, the step of determining whether the distribution state of the dark spots is concentrated or dispersed includes: Divide the grayscale image into multiple matrix units and count the number of dark spots in each matrix unit; Determining whether there is a matrix unit in which 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; If the number of dark dots in a matrix unit exceeds a second preset ratio of the total number of dark dots, and the number of matrix units containing dark dots is less than a third preset ratio of the total number of matrix units, then the distribution state of the dark dots is determined to be a concentrated distribution; If the number of dark spots in no matrix unit exceeds the second preset proportion of the total number of dark spots, or the number of matrix units containing dark spots is not less than the third preset proportion of the total number of matrix units, it is determined that the distribution state of the dark spots is a dispersed distribution.

[0007] In an optional embodiment, the step of determining whether the distribution state of the dark spots is concentrated or dispersed includes: Calculate the nearest neighbor distance of each dark point, where the nearest neighbor distance of a dark point is the distance between the dark point and the nearest dark point; Determine whether the average value of the nearest neighbor distances of all dark spots is less than a preset distance value; If the average value of the nearest neighbor distances of all dark spots is less than the preset distance value, the distribution state of the dark spots is determined to be a concentrated distribution; If the average value of the nearest neighbor distances of all dark spots is not less than the preset distance value, it is determined that the distribution state of the dark spots is a dispersed distribution.

[0008] In an optional embodiment, 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: Determine the sub-region corresponding to the unqualified light-emitting chip as an abnormal sub-region; Determining whether the number of grayscale blocks in the abnormal sub-region is greater than a second preset number; If the number of grayscale blocks in the abnormal sub-region is greater than a second preset number, the abnormal sub-region is divided into multiple new sub-regions, and the steps of power detection and judging whether the light-emitting chip corresponding to the grayscale block with the lowest grayscale value in each sub-region is qualified are cyclically performed; If the number of grayscale blocks in the abnormal sub-area is not greater than the second preset number, the light-emitting chips corresponding to the grayscale blocks in the abnormal sub-area are power-tested in order from low to high grayscale values ​​and judged to be qualified until a qualified light-emitting chip is detected.

[0009] In an optional embodiment, the preset threshold is a standard grayscale value of the light-emitting chip; Alternatively, the preset threshold is the average grayscale value of all grayscale blocks in the grayscale image.

[0010] In an optional embodiment, after the step of determining a grayscale block having a grayscale value less than a preset threshold in the grayscale image as a dark spot and before the step of determining whether the distribution state of the dark spots is concentrated or dispersed, the laser array detection method further includes: Determining whether the number of dark spots is greater than a first preset number; If the number of dark spots is greater than the first preset number, performing the step of determining whether the distribution state of the dark spots is a concentrated distribution or a dispersed distribution; If the number of the dark spots is not greater than the first preset number, power detection is performed on the light-emitting chips corresponding to all the dark spots to determine whether they are qualified.

[0011] In an optional implementation, the first preset number is a first preset proportion of the total number of grayscale blocks; or, the first preset number is a preset quantity value.

[0012] In an optional embodiment, the step of performing power detection on the light-emitting chip includes: The laser light emitted by the light emitting chip to be tested is passed through the aperture, and the power of the laser light emitted by the light emitting chip is tested using a power meter on the side of the aperture away from the light emitting chip.

[0013] In a second aspect, the present 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 a grayscale image of the laser array in a light-emitting state, and the power detection device is used to power the light-emitting chip. The controller is used to execute executable instructions to implement the laser array detection method of any one of the aforementioned embodiments.

[0014] In an optional embodiment, the laser array detection device further includes a grid plate and a driving member, wherein the driving member is in transmission connection with the grid plate, and the driving member is used to drive the grid plate to move.

[0015] The beneficial effects of the laser array detection method and device provided by the embodiments of the present application include: The laser array detection method provided by the embodiment of the present application includes: obtaining a grayscale image of the laser array in a light-emitting state, determining the grayscale value of each grayscale block in the grayscale image, wherein the grayscale block corresponds to the light-emitting chip one-to-one; determining the grayscale block in the grayscale image whose grayscale value is less than a preset threshold as a dark spot; judging whether the distribution state of the dark spot is concentrated or dispersed; if the distribution state of the dark spot is concentrated, performing power detection on the light-emitting chips corresponding to the grayscale blocks in order from low to high grayscale values ​​and judging whether they are qualified until a qualified light-emitting chip is detected; if the distribution state of the dark spot is dispersed, dividing the grayscale image into multiple sub-areas, performing power detection on the light-emitting chips corresponding to the grayscale blocks with the lowest grayscale value in each sub-area and judging whether they are qualified, and stopping the detection if the light-emitting chips corresponding to the grayscale blocks with the lowest grayscale value in each sub-area are all qualified. In the present application, the abnormal light-emitting chip has low power or does not emit light, and the grayscale value displayed in the grayscale image will be low. Therefore, combining image detection and power testing can improve detection efficiency. First, dark spots are screened out to identify the light-emitting chips with a higher risk of abnormality. Targeted power testing is then performed on these dark spots. Power testing is then used to determine whether a light-emitting chip is abnormal, ensuring detection accuracy. Furthermore, by determining whether the dark spots are distributed or concentrated, the location of the dark spots can be differentiated to a certain extent. When the dark spots are concentrated, the positional differences between the dark spots are relatively small. Therefore, the ranking of the grayscale values ​​of the dark spots can represent their power ranking: the lower the grayscale value, the lower the power. Therefore, when the dark spots are concentrated, power testing can be performed on the light-emitting chips corresponding to the grayscale blocks, starting from low to high grayscale values. If a light-emitting chip corresponding to a grayscale block is found to be qualified, the light-emitting chips corresponding to the grayscale blocks with higher grayscale values ​​do not need to undergo power testing and can be directly determined as qualified. When dark spots are dispersed, their locations vary widely, and the grayscale values ​​of the light-emitting chips are affected by interference from neighboring light-emitting chips. Therefore, the grayscale values ​​of a dark spot surrounded by bright spots will differ from those of a dark spot surrounded by dark spots. This demonstrates the difference in grayscale values ​​between dispersed and concentrated dark spots. If the grayscale image of the entire light-emitting chip array is treated as a single area and then tested, the results may be inaccurate. Therefore, when dark spots are dispersed, the grayscale image is divided into multiple sub-areas. Power testing is performed on the light-emitting chip corresponding to the grayscale block with the lowest grayscale value in each sub-area, rather than sorting the grayscale values ​​of all dark spots and testing them sequentially. This ensures accurate testing.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 the other grayscale blocks in the entire sub-region do not need to undergo power testing; 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 the other grayscale blocks in the sub-region can be further tested, thus balancing detection efficiency and accuracy. It can be seen that the laser array detection method provided in the embodiments of the present application, by determining dark spots and judging their distribution state, adopts different detection strategies under different distribution states, resulting in high detection efficiency and high detection accuracy.

[0016] The laser array detection device provided in the embodiment of the present application can implement the above-mentioned detection method, and thus has the above-mentioned corresponding beneficial effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 This is a schematic diagram of a laser array in one embodiment of the present application; Figure 2 This is a flow chart of a laser array detection method in one embodiment of the present application; Figure 3 This is a schematic diagram of a grayscale image in one embodiment of the present application; Figure 4 This is a flowchart of obtaining a grayscale image in one embodiment of the present application; Figure 5 This is a schematic diagram of a grid plate in one embodiment of the present application; Figure 6 This is a schematic diagram showing concentrated distribution of dark spots in one embodiment of the present application; Figure 7 This is a detection flow chart for a case where dark spots are dispersed in one embodiment of the present application; Figure 8 This is a schematic diagram of a laser array detection device in one embodiment of the present application; Figure 9 The following is a schematic diagram of the arrangement of the grid plate in an embodiment of the present invention.

[0019] Icons: 100 - image acquisition device; 200 - power detection device; 300 - grid plate; 310 - avoidance hole; 320 - shielding part; 330 - window; 400 - rack; 410 - top plate; 500 - driving part; 10 - laser array; 11 - light-emitting chip; 12 - grayscale block; 12a - dark spot; 12b - bright spot. DETAILED DESCRIPTION

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Generally, the components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0021] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0022] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0023] In the description of this application, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, or is the orientation or position relationship in which the invented product is usually placed when in use. It is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on this application.

[0024] In addition, the terms "first", "second", etc., if used, are merely used to distinguish and describe, and should not be understood as indicating or implying relative importance.

[0025] It should be noted that, in the absence of conflict, the features in the embodiments of this application can be combined with each other.

[0026] In related technologies, laser array testing typically involves measuring power using a high-precision power meter, or using a charge-coupled device (CCD) to capture images, then performing image processing to determine if any light-emitting chips in the laser array are abnormal. However, while using a power meter to scan each light-emitting chip offers high accuracy, it is inefficient. Similarly, using image processing to determine if a light-emitting chip is abnormal also suffers from poor accuracy. Therefore, image processing and power metering can be combined. Image analysis can be used to first determine the risk of abnormality in each light-emitting chip, and then power testing can be performed on light-emitting chips with higher risk, thereby improving testing efficiency. Specifically, power testing can be performed on each light-emitting chip sequentially, from low to high grayscale values. Once a light-emitting chip is detected to be normal, testing of the light-emitting chips with higher grayscale values ​​is discontinued, thus saving testing time. However, this approach still presents the problem of inaccuracy. Because grayscale blocks in a grayscale image vary in location—some at the edge, some at the corner, and some in the center—and some surrounded by darker blocks, while others are surrounded by brighter blocks, the light-emitting chips interact with each other, and grayscale values ​​are also affected by location and environment. Therefore, it's possible for a light-emitting chip corresponding to a certain grayscale block to be normal, while a light-emitting chip corresponding to a grayscale block with a higher grayscale value is abnormal. When this happens, the aforementioned method of inspecting light-emitting chips from low to high grayscale values ​​can lead to missing abnormal chips.

[0027] To this end, an embodiment of the present application provides a laser array detection method, which first determines the distribution state of the dark spots by judging the discrete degree of the dark spots through image analysis, and then executes different power detection strategies according to the different types of dark spot distribution, so as to achieve the purpose of balancing efficiency and detection accuracy.

[0028] The laser array detection method provided in the embodiment of the present application can be used to detect whether the light-emitting chip 11 in the laser array 10 has an abnormality, so as to repair the abnormal light-emitting chip 11. Figure 1 FIG. 1 is a schematic diagram of a laser array 10 in one embodiment of the present application. Figure 1 As shown, the laser array 10 includes a plurality of light emitting chips 11 arranged in an array, each light emitting chip 11 is used to generate laser light. Optionally, the plurality of light emitting chips 11 are arranged in a rectangular array, and the laser array 10 is rectangular as a whole. Figure 2 This is a flow chart of a laser array detection method in one embodiment of the present application. Figure 2 As shown, the laser array detection method provided in the embodiment of the present application includes the following steps: Step S100 , obtaining a grayscale image of the laser array 10 in a light-emitting state, and determining the grayscale value of each grayscale block 12 in the grayscale image, wherein the grayscale blocks 12 correspond one-to-one to the light-emitting chips 11 .

[0029] Grayscale images can be acquired using a high-precision charge-coupled device (CCD). Figure 3 Schematic diagram of a grayscale image in one embodiment of the present application. Figure 3 As shown, the grayscale image includes a plurality of grayscale blocks 12 arranged in an array, and one grayscale block 12 represents one light-emitting chip 11. The grayscale value ranges from 0 to 255, where a grayscale value of 0 represents pure black, i.e., the darkest; and a grayscale value of 255 represents pure white, i.e., the brightest. The grayscale value of a grayscale block 12 is usually 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, that is, the brighter the grayscale block 12. An abnormal light-emitting chip 11 usually has insufficient luminous power, which is generally manifested as a lower grayscale value of its corresponding grayscale block 12, that is, the grayscale block 12 is darker. However, the different positions of the light-emitting chip 11 may affect its grayscale performance in the grayscale image. For example, if two light-emitting chips 11 of equal power are surrounded by brighter light-emitting chips 11, and the other is surrounded by darker light-emitting chips 11, the grayscale representation of the former in the grayscale image may be better than that of the latter. Specifically, the grayscale blocks 12 corresponding to the former are brighter (higher grayscale values) than those corresponding to the latter. Therefore, the grayscale value ranking of each grayscale block 12 in the grayscale image obtained in step S100 does not necessarily accurately represent the power ranking of the corresponding light-emitting chips 11.

[0030] Figure 4 This is a flow chart for obtaining a grayscale image in one embodiment of the present application. Figure 4 As shown, optionally, the grayscale image can be obtained by the following steps: In step S110 , a grid plate 300 is used to cover the laser array 10 in the light-emitting state, wherein the grid plate 300 includes alternately arranged avoidance holes 310 and shielding portions 320 , the avoidance holes 310 expose a first portion of the light-emitting chips 11 , and the shielding portions 320 shield a second portion of the light-emitting chips 11 .

[0031] Figure 5 FIG. 3 is a schematic diagram of a grid plate 300 in one embodiment of the present application. Figure 5As shown, the grid plate 300 includes alternating avoidance holes 310 and shielding portions 320. The avoidance holes 310 and shielding portions 320 are arranged in a rectangular array. Each avoidance hole 310 and shielding portion 320 matches the size of a single light-emitting chip 11 on the laser array 10. Specifically, the avoidance holes 310 and shielding portions 320 are both rectangular in shape. Furthermore, the edges of the shielding portions 320 are adjacent to the edges of the avoidance holes 310, and the corners of the shielding portions 320 are at opposite angles to the corners of another shielding portion 320. When the grid plate 300 is placed over the laser array 10, a first portion of the light-emitting chips 11 is exposed, while a second portion of the light-emitting chips 11 is shielded by the shielding portions 320. It should be understood that the matrix formed by the avoidance holes 310 and shielding portions 320 can be slightly larger than the laser array 10 so that it can still cover the laser array 10 after the grid plate 300 is subsequently moved.

[0032] Step S120 : acquiring a first image, wherein the first image includes grayscale blocks 12 corresponding to a first portion of light-emitting chips 11 .

[0033] Since the second portion of the light-emitting chips 11 is blocked by the blocking portion 320 , the first image does not include the grayscale blocks 12 corresponding to the second portion of the light-emitting chips 11 .

[0034] In step S130 , the grid plate 300 is moved so that the avoidance holes 310 expose the second portion of the light emitting chips 11 and the shielding portions 320 shield the first portion of the light emitting chips 11 .

[0035] By moving the grid plate 300 , the first portion of the light emitting chips 11 originally exposed by the avoidance hole 310 can be shielded by the shielding portion 320 , and the second portion of the light emitting chips 11 originally shielded by the shielding portion 320 can be exposed by the avoidance hole 310 .

[0036] Step S140 : Acquire a second image, where the second image includes grayscale blocks 12 corresponding to the second portion of light-emitting chips 11 .

[0037] Since the first portion of the light-emitting chips 11 is blocked by the blocking portion 320 , the second image does not include the grayscale blocks 12 corresponding to the first portion of the light-emitting chips 11 .

[0038] Step S150 : synthesizing the first image and the second image into a grayscale image of the laser array 10 .

[0039] By means of image synthesis, the first image and the second image can be synthesized into a grayscale image, which includes grayscale blocks 12 corresponding to all the light-emitting chips 11 on a one-to-one basis.

[0040] Since the grayscale performance of a light-emitting chip 11 may be affected by the adjacent light-emitting chip 11 when acquiring a grayscale image, the light-emitting chip 11 is shielded by the grid plate 300 320 so that the four sides of the exposed light-emitting chip 11 and the adjacent light-emitting chips 11 are all shielded. This can reduce the influence of the light-emitting chip 11 on the adjacent light-emitting chips 11, thereby improving the accuracy of the acquired grayscale image.

[0041] Step S200 : determining a grayscale block 12 in the grayscale image whose grayscale value is less than a preset threshold as a dark spot 12 a .

[0042] In this application, a dark spot 12a is a grayscale block 12 with a low grayscale value, which means that the corresponding light-emitting chip 11 has a high risk of abnormality. For ease of description, the grayscale blocks 12 other than the dark spot 12a are named bright spots 12b.

[0043] Optionally, the preset threshold is the standard grayscale value of the light-emitting chip 11. The standard grayscale value can range from 40 to 50, for example, 45. It will be appreciated that a larger preset threshold value results in a greater number of dark spots 12a, a greater detection volume, and higher detection accuracy (making it less likely that abnormal light-emitting chips 11 will be missed). A smaller preset threshold value results in a smaller number of dark spots 12a, a smaller detection volume, and higher efficiency, but with relatively lower detection accuracy. In other optional embodiments, the preset threshold value can also be the average grayscale value of all grayscale blocks 12 in the grayscale image.

[0044] Step S300 , determining whether the distribution state of the dark spots 12 a is concentrated or dispersed.

[0045] Adjacent light-emitting chips 11 will have a certain degree of influence. For example, when a light-emitting chip 11 is surrounded by lower-power light-emitting chips 11, it may appear darker in the grayscale image. However, when a light-emitting chip 11 of the same power is surrounded by higher-power light-emitting chips 11, it may appear brighter in the grayscale image. Similarly, the position of the light-emitting chip 11 may also affect its grayscale performance. For example, the grayscale value-power relationship between a light-emitting chip 11 at the edge of a grayscale image and a light-emitting chip 11 in the middle, or between a light-emitting chip 11 in the upper left corner and a light-emitting chip 11 in the lower right corner, may differ. This shows that the environmental conditions in which the light-emitting chip 11 is located have an impact on its grayscale performance. Therefore, in this application, the distribution of dark spots 12a is determined to be concentrated. This means that the environmental conditions of the dark spots 12a are similar. Similar environmental conditions here can mean that the positions of the multiple dark spots 12a in the grayscale image are relatively close, and / or 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). If the distribution of dark spots 12a is dispersed, this means that the positions of different dark spots 12a in the image vary significantly, and one dark spot 12a may be surrounded by dark spots 12a, while another dark spot 12a may be surrounded by bright spots 12b.

[0046] When the dark spots 12a are distributed in a concentrated manner, the grayscale value ranking of the dark spots 12a is most likely to be the same as the actual power ranking, because the environmental conditions of the dark spots 12a are similar, so the grayscale value-power relationship is similar; while in the case of a dispersed distribution, the grayscale value ranking of the dark spots 12a is likely to be different from the actual power ranking, because the environmental conditions of different dark spots 12a are quite different, so the grayscale value-power relationship may be different.

[0047] Optionally, step S300 may specifically include the following steps: Step S301, dividing the grayscale image into a plurality of matrix units, and counting the number of dark spots 12a in each matrix unit; Step S302, determining whether there is a matrix unit in which 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 chips with dark spots 12a 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; If the number of dark dots 12a within a matrix unit exceeds the second preset ratio of the total number of dark dots 12a, and the number of matrix units containing dark dots 12a is less than the third preset ratio of the total number of matrix units, step S320 is executed to determine that the distribution of the dark dots 12a is concentrated. If the number of dark dots 12a within a matrix unit does not exceed the second preset ratio of the total number of dark dots 12a, or the number of matrix units containing dark dots 12a is not less than the third preset ratio of the total number of matrix units, step S330 is executed to determine that the distribution of the dark dots 12a is dispersed.

[0048] For example, if a grayscale image includes a 9×9 matrix of grayscale blocks 12, the grayscale image can be divided into 3×3 matrix units, i.e., each matrix unit includes 9 grayscale blocks 12, for a total of 9 matrix units. The number of dark spots 12a in each matrix unit is counted. If the number of dark spots 12a in a particular matrix unit exceeds a second predetermined ratio of the total number of dark spots 12a, and the number of matrix units containing chips with dark spot 12a is less than a third predetermined ratio of the total number of matrix units, the dark spots 12a are considered to be concentrated in a small number of matrix units, and the distribution of the dark spots 12a is determined to be concentrated. Conversely, if dark spots 12a are distributed in most matrix units, and no particular matrix unit has a large number of dark spots 12a, the distribution of the dark spots 12a is considered to be dispersed. It is understood that the third preset ratio should be set based on the number of matrix units, but should at least be greater than the inverse of the number of matrix units (if the third preset ratio is less than or equal to the inverse of the number of matrix units, then the number of matrix units containing dark spots 12a must not be less than the third preset ratio of the total number of matrix units, and the judgment result must be a dispersed distribution). Optionally, the third preset ratio is 20%.

[0049] In other optional embodiments, step S300 may specifically include the following steps: Step S311, calculating the nearest neighbor distance of each dark point 12a, wherein the nearest neighbor distance of the dark point 12a is the distance between the dark point 12a and the nearest other dark point 12a; Step S312, determining whether the average value of the nearest neighbor distances of all dark spots 12a is less than a preset distance value; If the average value of the nearest neighbor distances of all dark spots 12a is less than the preset distance value, step S320 is executed: determining that the distribution state of the dark spots 12a is a concentrated distribution; if the average value of the nearest neighbor distances of all dark spots 12a is not less than the preset distance value, step S330 is executed: determining that the distribution state of the dark spots 12a is a dispersed distribution.

[0050] It is understood that if the dark spots 12a are concentrated, the nearest-neighbor distances of each dark spot 12a are short, and the average of the nearest-neighbor distances of all dark spots 12a is also small. If the dark spots 12a are dispersed, the nearest-neighbor distances of each dark spot 12a are long, and the average of the nearest-neighbor distances of all dark spots 12a is also large. Optionally, the preset distance value can be a fixed value or determined based on 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.

[0051] In other optional embodiments, it is also possible to determine whether the distribution state of the dark spots 12a is concentrated or dispersed through manual observation. Figure 3 As shown, the dark spots 12a are distributed in a dispersed manner; Figure 6 This is a schematic diagram showing that dark spots 12a are distributed in a concentrated manner in one embodiment of the present application.

[0052] Optionally, after the step of determining the grayscale blocks 12 having grayscale values ​​less than a preset threshold in the grayscale image as dark spots, and before the step of determining whether the distribution state of the dark spots 12a is concentrated or dispersed (i.e., step S300), the laser array detection method further includes: Step S210, determining whether the number of 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, the step of determining whether the distribution state of the dark spots 12a is a concentrated distribution or a dispersed distribution is performed (ie, step S300); If the number of the dark spots 12a is not greater than the first preset number, it is not necessary to determine the distribution of the dark spots 12a, and step S600 is directly executed: power detection is performed on the light-emitting chips 11 corresponding to all the dark spots 12a to determine whether they are qualified.

[0053] It is understood that if the number of dark spots 12a is small, then even if the power detection is performed on the light-emitting chips 11 corresponding to all dark spots 12a, the workload is relatively small. Therefore, the detection strategy is no longer formulated based on the distribution state. Instead, the 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, then the workload of performing power detection on each dark spot 12a is large. Therefore, it is necessary to formulate a corresponding detection strategy based on the distribution state of the dark spots 12a (such as steps S400 and S500 described below) to improve detection efficiency while ensuring accuracy as much as possible.

[0054] Optionally, the first preset number is a first preset proportion of the total number of grayscale blocks 12, such as the first preset proportion is 5% to 15%; or, the first preset number is a preset quantity value, such as the first preset number is 5 to 15.

[0055] In the present application, when the distribution state of the dark spot 12a is a concentrated distribution, step S400 is executed: the light-emitting chip 11 corresponding to the grayscale block 12 is power-tested in order from low to high grayscale values ​​and judged whether it is qualified until a qualified light-emitting chip 11 is detected.

[0056] Because the grayscale value ranking of the dark spots 12a is highly likely to match the actual power ranking when the dark spots 12a are distributed in a concentrated pattern, power testing can be performed on each light-emitting chip 11, sorted by the grayscale values ​​of the grayscale blocks 12, from darkest to brightest. Each light-emitting chip 11 tested is the darkest among all untested light-emitting chips 11 (the one with the lowest grayscale value in the corresponding grayscale block 12). Once a light-emitting chip 11 is found to be qualified, power testing can be stopped, and the remaining untested light-emitting chips 11 can be assumed to be qualified.

[0057] In some cases (especially when the preset threshold is high), if a qualified light-emitting chip 11 exists among the light-emitting chips 11 corresponding to the dark spot 12a, the qualified light-emitting chip 11 will be detected before all the light-emitting chips 11 corresponding to the dark spot 12a are fully tested, thus terminating the test. In some extreme cases, all the light-emitting chips 11 corresponding to the dark spots 12a are detected as abnormal, meaning that an abnormal light-emitting chip 11 may still exist in the bright spot 12b. In this case, power testing can continue for the light-emitting chips 11 corresponding to the remaining grayscale blocks 12 (i.e., bright spots 12b), sequentially from low to high grayscale values. Once a light-emitting chip 11 is found to be qualified, power testing can be stopped, and the remaining untested light-emitting chips 11 can be assumed to be qualified.

[0058] When the distribution state of the dark spots 12a is dispersed, step S510 is executed: the grayscale image is divided into multiple sub-regions, and the light-emitting chip 11 corresponding to the grayscale block 12 with the lowest grayscale value in each sub-region is subjected to power detection to determine whether it is qualified.

[0059] Because the grayscale value ranking of dark spots 12a is likely to differ from the actual power ranking when the dark spots 12a are dispersed, testing is performed on a region-by-region basis. Power testing is performed on the light-emitting chip 11 corresponding to the grayscale block 12 with the lowest grayscale value in each subregion. If a light-emitting chip 11 is found to be qualified, it can be assumed that the light-emitting chips 11 corresponding to the other grayscale blocks 12 in the subregion are also qualified, thereby improving testing efficiency. Testing can be stopped if the light-emitting chips 11 corresponding to the grayscale block 12 with the lowest grayscale value in each subregion are all qualified.

[0060] Figure 7 This is a detection flow chart for an embodiment of the present application when the dark spots 12a are distributed in a dispersed manner. Figure 7As shown, after 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 and whether it is qualified is determined, if the light-emitting chip 11 corresponding to the grayscale block 12 with the lowest grayscale value in a sub-region is detected to be unqualified, the detection method of the laser array 10 may optionally further include: Step S520: determining the sub-region corresponding to the unqualified light-emitting chip 11 as an abnormal sub-region; Step S530, determining whether the number of grayscale blocks 12 in the abnormal sub-region is greater than a second preset number; If the number of grayscale blocks 12 in the abnormal sub-region is greater than the second preset number, step S540 is executed: the abnormal sub-region is divided into multiple new sub-regions. Then, the steps of power testing 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 are executed in a loop; If the number of grayscale blocks 12 in the abnormal sub-area is not greater than the second preset number, step S550 is executed, and power detection is performed on the light-emitting chips 11 corresponding to the grayscale blocks 12 in the abnormal sub-area in order from low to high grayscale values, and whether they are qualified is determined until a qualified light-emitting chip 11 is detected.

[0061] 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 a power test 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 executing step S540, the process returns to step S512.

[0062] It can be understood that if the number of grayscale blocks 12 in an abnormal sub-region is no greater than a second preset number (e.g., 4-10), then the power ranking and grayscale ranking of each light-emitting chip 11 within the small area are likely the same. Therefore, power testing can be performed on the light-emitting chips 11 corresponding to the grayscale blocks 12 in the abnormal sub-region, sequentially from low to high grayscale values. Once a qualified light-emitting chip 11 is detected, testing ceases, and the remaining light-emitting chips 11 in the abnormal sub-region are considered qualified. Furthermore, if the number of grayscale blocks 12 in the abnormal sub-region is less than the second preset number, even performing a full test will not be very laborious, and further dividing the sub-region into new sub-regions is less meaningful. 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 the larger area are likely different. Testing based on grayscale value ranking may miss the abnormal light-emitting chip 11. Therefore, the abnormal sub-region is further divided into multiple sub-regions, and power testing is continued for 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 the recursive idea to achieve a balance between accuracy and efficiency.

[0063] In the embodiment of the present application, the step of performing power detection on the light-emitting chip 11 may specifically include passing the laser light emitted by the light-emitting chip 11 to be detected through an aperture, and then detecting the power of the laser light emitted by the light-emitting chip 11 using a power meter on the side of the aperture facing away from the light-emitting chip 11. The aperture can shield light emitted by other light-emitting chips 11, allowing only the laser light emitted by the light-emitting chip 11 to pass through, thereby ensuring detection accuracy. Furthermore, a variable aperture can be used to improve adaptability to light-emitting chips 11 of different sizes.

[0064] Further, such as Figure 5 As shown, a window 330 is further provided on the grid plate 300 . By moving the grid plate 300 , the window 330 can expose all the light-emitting chips 11 on the laser array 10 , thereby facilitating power detection of any light-emitting chip 11 .

[0065] Figure 8 This is a schematic diagram of a laser array detection device in one embodiment of the present application. Figure 8 As shown, an embodiment of the present application further 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, and the controller is used to execute executable instructions to implement the laser array detection method provided in the above embodiment.

[0066] 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 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 device includes a frame 400, and the image acquisition device 100 and the power detection device 200 are both arranged 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, so that their positions relative to the laser array 10 can be adjusted, thereby accurately acquiring images and performing power detection. Optionally, the power detection device 200 is configured to be liftable, so that its distance in the vertical direction relative to the laser array 10 can be adjusted.

[0067] Figure 9 The following is a schematic diagram of the arrangement of the grid plate 300 in one embodiment. Figure 9As shown, in this embodiment, the laser array detection device may further include a grid plate 300 and a driver 500. The driver 500 is in driving connection with 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 opening for securing the laser array 10, which extends through the top plate 410. During detection of the laser array 10, the light-emitting surface of the laser array 10 faces downward. The grid plate 300 slidably engages with the top plate 410. Driven by the driver 500, the grid plate 300 can move to selectively block a portion of the light-emitting chips 11 and expose another portion. Furthermore, the grid plate 300 can be moved to expose all the light-emitting chips 11 through its window 330, thereby facilitating power detection of any light-emitting chip 11 by the power detection device 200.

[0068] In summary, the laser array detection method provided in the embodiment of the present application includes: obtaining a grayscale image of the laser array 10 in a light-emitting state, determining the grayscale value of each grayscale block 12 in the grayscale image, wherein the grayscale block 12 corresponds to the light-emitting chip 11 one-to-one; determining the grayscale block 12 in the grayscale image whose grayscale value is less than a preset threshold as a dark spot 12a; judging whether the distribution state of the dark spot 12a is concentrated or dispersed; when the distribution state of the dark spot 12a is concentrated, performing power detection on the light-emitting chips 11 corresponding to the grayscale blocks 12 in order from low to high grayscale values ​​and judging whether they are qualified until a qualified light-emitting chip 11 is detected; when the distribution state of the dark spot 12a is dispersed, dividing the grayscale image into multiple sub-areas, performing power detection on the light-emitting chip 11 corresponding to the grayscale block 12 with the lowest grayscale value in each sub-area and judging whether they are qualified; if the light-emitting chips 11 corresponding to the grayscale block 12 with the lowest grayscale value in each sub-area are all qualified, stopping the detection. In this application, image detection and power detection are combined. First, by screening out dark spots 12a, the light-emitting chips 11 with a higher risk of abnormality are determined. Then, targeted power detection is performed on the dark spots 12a. This can improve detection efficiency. Whether the light-emitting chip 11 is abnormal is determined by power detection, which can ensure detection accuracy. Furthermore, by determining whether the distribution state of the dark spots 12a is dispersed or concentrated, the location of the dark spots 12a can be differentiated to a certain extent. When the dark spots 12a are concentrated, the light-emitting chips 11 corresponding to the grayscale blocks 12 can be power-tested in order from low to high grayscale values. When it is detected that the light-emitting chip 11 corresponding to a certain grayscale block 12 is normal, the light-emitting chips 11 corresponding to other grayscale blocks 12 with higher grayscale values ​​do not need to be power-tested again and can be directly determined as normal light-emitting chips 11. When the dark spots 12a are distributed in a dispersed manner, the positions of the dark spots 12a vary greatly. 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 the sub-region is normal, then the light-emitting chips 11 corresponding to the other grayscale blocks 12 in the entire sub-region do not need to be power-detected; if the light-emitting chip 11 corresponding to the grayscale block 12 with the lowest grayscale value in the sub-region is abnormal, the light-emitting chips 11 corresponding to the other grayscale blocks 12 in the sub-region can be further detected. This balances detection efficiency and detection accuracy. It can be seen that the laser array detection method provided in the embodiment of the present application, 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.

[0069] The laser array detection device provided in the embodiment of the present application can implement the above-mentioned detection method, and thus has the above-mentioned corresponding beneficial effects.

[0070] The above is only a specific implementation method of the present application, but the scope of protection of the present application is not limited thereto. Any changes or replacements that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed in this application should be covered by the scope of protection of the present application.

Claims

1. A laser array detection method, characterized in that: 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 grayscale image of the laser array (10) in a light-emitting state, and determining the grayscale value of each grayscale block (12) in the grayscale image, wherein the grayscale blocks (12) correspond one-to-one to the light-emitting chips (11); Determining the grayscale block (12) in the grayscale image whose grayscale value is less than a preset threshold as a dark spot (12a); Determining whether the distribution state of the dark spots (12a) is a concentrated distribution or a dispersed distribution; When the distribution state of the dark spots (12a) belongs to the concentrated distribution, power detection is performed on the light-emitting chips (11) corresponding to the grayscale blocks (12) in order from low to high grayscale values, and whether they are qualified is determined until a qualified light-emitting chip (11) is detected; When the distribution state of the dark spots (12a) belongs to the dispersed distribution, the grayscale image is divided into a plurality of 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 tested and judged to be qualified. If the light-emitting chip (11) corresponding to the grayscale block (12) with the lowest grayscale value in each sub-region is qualified, the test is stopped.

2. The laser array detection method according to claim 1, characterized in that: The step of obtaining a grayscale image of the laser array (10) in a light-emitting state comprises: Using a grid plate (300) to cover the laser array (10), wherein the grid plate (300) comprises alternately arranged avoidance holes (310) and shielding portions (320), the avoidance holes (310) exposing a first portion of the light-emitting chips (11), and the shielding portions (320) shielding a second portion of the light-emitting chips (11); Acquire a first image, wherein the first image includes the grayscale block (12) corresponding to the first portion of the light-emitting chip (11); The grid plate (300) is moved so that the avoidance hole (310) exposes the second portion of the light-emitting chip (11), and the shielding portion (320) shields the first portion of the light-emitting chip (11); Acquire a second image, wherein the second image includes the grayscale block (12) corresponding to the second portion of the light-emitting chip (11); The first image and the second image are synthesized into the grayscale image of the laser array (10).

3. The laser array detection method according to claim 1, wherein: The step of determining whether the distribution state of the dark spots (12a) is a concentrated distribution or a dispersed distribution comprises: Dividing the grayscale image into a plurality of matrix units, and counting the number of the dark spots (12a) in each matrix unit; Determining whether there is a matrix unit in which the number of the dark dots (12a) exceeds a second preset ratio of the total number of the dark dots (12a), and the number of the matrix units containing the dark dots (12a) is less than a third preset ratio of the total number of the matrix units, wherein the third preset ratio is greater than the inverse of the number of the matrix units; If there is a matrix unit in which the number of the dark spots (12a) exceeds the second preset ratio 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 ratio of the total number of the matrix units, then it is determined that the distribution state of the dark spots (12a) belongs to the concentrated distribution; If there is no matrix unit in which the number of the dark spots (12a) exceeds the second preset proportion of the total number of the dark spots (12a), or if 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 according to claim 1, wherein: The step of determining whether the distribution state of the dark spots (12a) is a concentrated distribution or a dispersed distribution comprises: Calculating the nearest neighbor distance of each dark point (12a), wherein the nearest neighbor distance of the dark point (12a) is the distance between the dark point (12a) and another nearest dark point (12a); Determining whether an average value of the nearest neighbor distances of all the dark spots (12a) is less than a preset distance value; If the average value of the nearest neighbor 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 neighbor 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 according to claim 1, wherein: After 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, the laser array detection method further comprises: Determining the sub-region corresponding to the unqualified light-emitting chip (11) as an abnormal sub-region; Determining whether the number of the grayscale blocks (12) in the abnormal sub-region is greater than a second preset number; If the number of the grayscale 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 steps 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 judging whether the light-emitting chip (11) is qualified are cyclically performed; If the number of the grayscale blocks (12) in the abnormal sub-region is not greater than the second preset number, power detection is performed on the light-emitting chips (11) corresponding to the grayscale blocks (12) in the abnormal sub-region in order from low to high grayscale values, and whether they are qualified is determined until a qualified light-emitting chip (11) is detected.

6. The laser array detection method according to any one of claims 1 to 5, characterized in that: The preset threshold is the standard grayscale value of the light-emitting chip (11); Alternatively, the preset threshold is the average grayscale value of all the grayscale blocks (12) in the grayscale image.

7. The laser array detection method according to any one of claims 1 to 5, characterized in that: After the step of determining the grayscale block (12) having a grayscale value less than a preset threshold in the grayscale image as a dark spot (12a), and before the step of determining whether the distribution state of the dark spot (12a) is a concentrated distribution or a dispersed distribution, the laser array detection method further comprises: Determining 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, executing the step of determining whether the distribution state of the dark spots (12a) is a concentrated distribution or a dispersed distribution; If the number of the dark spots (12a) is not greater than the first preset number, power detection is performed on the light-emitting chips (11) corresponding to all the dark spots (12a) to determine whether they are qualified.

8. The laser array detection method according to any one of claims 1 to 5, characterized in that: The step of performing power detection on the light-emitting chip (11) comprises: The laser light emitted by the light emitting chip (11) to be detected is passed through an aperture, and a power meter is used on a side of the aperture facing away from the light emitting chip (11) to detect the power of the laser light emitted by the light emitting chip (11).

9. A laser array detection device, characterized in that: The invention comprises an image acquisition device (100), a power detection device (200) and a controller, wherein the image acquisition device (100) and the power detection device (200) are both electrically connected to the controller, the image acquisition device (100) is used to detect a grayscale image of the laser array (10) in a light-emitting state, and the power detection device (200) is used to perform power detection on the light-emitting chip (11); The controller is configured to execute executable instructions to implement the laser array detection method according to any one of claims 1 to 8.

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

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