Online detection system for optical element production

Abstract

The invention discloses an on-line detection system for optical element production, and relates to the technical field of optical element production and manufacture, a laser gradienter irradiates a test target plate to form light spots, a thermal imager is used for shooting eight different angles of the light spots at four different time points and the light spot at the first time point, and the light spots at four different time points and the light spots at the second time point are obtained. And obtaining a thermal imaging picture. And carrying out temperature interval area change calculation on the obtained thermal imaging pictures of the adjacent time points, and judging the temperature stability of the laser level meter according to the temperature interval area total change rate Stotal. And if the temperature stability of the laser gradienter reaches the standard, color and area consistency judgment is carried out on the thermal imaging images at the eight angles collected at the time point t. If the temperature stability and the energy uniformity of the laser gradienter all reach the standard, it can be judged that the laser gradienter is detected to be qualified, otherwise, it is judged that the laser gradienter is detected to be unqualified, unqualified products can be effectively found, and the product quality and the actual user experience are guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of optical element production and manufacturing, and specifically relates to an on-line detection system for optical element production. Background Art

[0002] In the production process of optical elements, quality control is a crucial link. As a common optical instrument widely used in fields such as construction, decoration, and engineering surveying, the performance of a laser level directly affects the quality of measurement work. Most of the existing detection methods for laser levels are off-line detection, which has many drawbacks. It not only greatly reduces production efficiency, increases labor and time costs, but also makes it difficult to discover problems that occur during the production process in real time, resulting in the possible production of a batch of unqualified products, causing waste of resources and increased costs. In addition, the existing detection methods have problems of incomplete detection and low accuracy when evaluating key performance indicators such as the stability and energy uniformity of laser levels. Some detection means can only detect some performances of the laser level and cannot comprehensively consider its performance under different working conditions. Therefore, some potential quality problems are difficult to be discovered in time, leading to unqualified products flowing into the market, bringing inconvenience in use and potential safety hazards to users. Summary of the Invention

[0003] Aiming at the deficiencies of the prior art, the present invention provides an on-line detection system for optical element production, which solves the problems of incomplete detection and low accuracy of existing laser levels in the production stage.

[0004] To achieve the above objectives, the present invention is realized through the following technical solutions: An on-line detection system for optical element production, comprising:

[0005] Energy uniformity analysis module: This module pre-divides RGB values into certain intervals, with each interval corresponding to a specific color. For each thermal imaging picture, all pixels are traversed to count the number of pixels in each color interval, thereby obtaining the color set of the picture. Calculate the intersection C12 = C1 ∩ C2 and union C12u = C1 ∪ C2 of the color sets of two thermal imaging pictures, and obtain the cross-color ratio mixture. If mixture >= 0.8, it means the colors of the two pictures are the same. Compare the 8 pictures pairwise and record the number of times Num when the colors are the same. If Num >= 27, the color consistency meets the standard; otherwise, the color consistency does not meet the standard. For each color area in the thermal imaging picture, calculate its area by counting the number of pixels of that color. If the actual area of each pixel is area, then the area A of the color area = n × area, where n is the number of pixels of that color. Confirm the intersection color of the two pictures, calculate the sum Q1 and Q2 of the areas occupied by the intersection of Picture 1 and Picture 2 respectively, and then calculate the sum Q3 of the areas occupied by the difference set color of Picture 1 and Picture 2. If (Q1 / Q2) > 0.9 and Q3 < Qth, it means the areas of the two pictures are the same. Record the number of times Num1 when the areas are the same. If Num1 >= 27, the area consistency meets the standard; otherwise, the area consistency does not meet the standard.

[0006] Detection result determination module: If the temperature stability and energy uniformity of the laser level are all up to standard, it can be determined that the laser level passes the detection; otherwise, it is determined that the detection fails.

[0007] As a further solution of the present invention, before the energy uniformity analysis module, there also include a picture data acquisition module and a temperature stability analysis module. The picture data acquisition module aims at the light spot formed by the laser level irradiating the test target board, and uses a thermal imager to perform thermal imaging shooting of the light spot at 4 time points: t minutes, t + △t minutes, t + 2△t minutes, and t + 3△t minutes, and at time point t, perform thermal imaging shooting from 8 angles respectively, and transmit the collected picture data to the temperature stability analysis module and the energy uniformity analysis module; the temperature stability analysis module calculates the change in the area of the temperature interval for each adjacent time point of the obtained thermal imaging pictures, and judges the temperature stability of the laser level according to the total change rate S of the temperature interval area 总 Judge the temperature stability of the laser level.

[0008] As a further solution of the present invention, the resolution of the thermal imager is not less than 640×480 pixels, the accuracy reaches ±0.1°C, and the response wavelength range is 2.5 - 8.5μm.

[0009] As a further solution of the present invention, the material of the selected test target board is copper alloy, the thermal conductivity is maintained in the range of 300 - 400 W / m·K, and the surface roughness does not exceed Ra0.8μm.

[0010] As a further solution of the present invention, the value range of t is [3, 5], and the value range of △t is [2, 3].

[0011] As a further solution of the present invention, the specific steps for calculating the area change of the temperature range in the thermal imaging pictures at adjacent time points are as follows:

[0012] Based on all the temperature data at two time points of p minutes and q minutes, take the lowest temperature and the highest temperature at the two time points to determine a total range that includes all temperature values, and then perform equally spaced division within this total range;

[0013] For each uniformly divided temperature range, calculate its area proportion in the thermal imaging pictures at p minutes and q minutes respectively. The area proportion = (the area of this range ÷ the total area of the thermal imaging picture) × 100%;

[0014] Subtract the area proportion of a certain temperature range at p minutes from the area proportion of this range at q minutes to obtain the change amount of the area proportion;

[0015] Add up the absolute values of the change amounts of the area proportions of all temperature ranges to obtain the comprehensive value Spq of the area change of the temperature range.

[0016] As a further solution of the present invention, the comprehensive value of the area change of the temperature range from time point t minutes to t + △t minutes is S t,t+△t , the comprehensive change value of the area of the temperature range from time point t + △t to t + 2△t minutes is S t+△t,t+2△t , the comprehensive change value of the area of the temperature range from time point t + 2△t to t + 3△t minutes is S t+2△t,t+3△t , combine the comprehensive change values of the area of the temperature range at the 4 time points, and according to the formula S 总 = a1 × S t,t+△t + a2 × S t+△t,t+2△t + a3 × S t+2△t,t+3△t Calculate the total change rate of the area of the temperature range, where a1, a2, and a3 are the weights of the comprehensive change values of the area of the temperature range at different time points.

[0017] As a further solution of the present invention, calculate the proportion of cross colors according to the formula mixture = |C12| / |C12u|, where |C12| and |C12u| represent the number of elements in C12 and C12u respectively.

[0018] As a further solution of the present invention, the difference set colors between Picture One and Picture Two specifically include the colors that belong to Picture One but not Picture Two and the colors that belong to Picture Two but not Picture One.

[0019] As a further solution of the present invention, in the detection result determination module, the specific detection conclusions can be displayed through indicator lights, display screens, sound prompts, printouts, and mobile devices.

[0020] The present invention provides an on-line detection system for optical element production. Compared with the prior art, it has the following beneficial effects:

[0021] (1) The present invention can directly perform real-time detection on the laser level production line without removing the products from the production line for off-line detection, greatly shortening the detection time, improving the production efficiency, facilitating the timely discovery of quality problems during the production process and making adjustments, and effectively avoiding batch unqualified products;

[0022] (2) By comprehensively detecting and analyzing the temperature changes of the laser level at different time points and the energy distribution from multiple angles, the present invention can accurately evaluate its long-term working stability and energy uniformity. This multi-dimensional detection method greatly improves the accuracy and reliability of the detection, effectively prevents unqualified products from entering the market, and ensures the product quality and the actual user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a block diagram of the system principle of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0025] As Figure 1 , the present invention provides an on-line detection system for optical element production, including:

[0026] An image data acquisition module, when the laser level irradiates the test target board, uses a thermal imager to perform thermal imaging shooting at 4 time points of t minutes, t + △t minutes, t + 2△t minutes, and t + 3△t minutes, and continues to perform thermal imaging shooting from 8 angles at time point t. For example, it can be selected to shoot at 0°, 45°, 90°, 135°, 180°, 225°, 270°, and 315° to ensure that relatively clear thermal imaging pictures of the light spot can be captured at different angles;

[0027] In order to accurately capture the minute temperature changes of the light spot when the laser level irradiates the test target board, the selected thermal imager needs to have high resolution and high precision. For the resolution requirement, it should be no less than 640×480 pixels. This resolution can relatively clearly reflect the fine features of the laser light spot, ensuring that the captured thermal imaging pictures contain sufficient valid information. For example, when there is an uneven temperature distribution in the laser light spot, the high resolution can clearly display these subtle differences in the picture;

[0028] For the precision requirement, the error reaches ±0.1℃. Because during the working process of the laser level, the laser energy it emits may have minute fluctuations, resulting in corresponding subtle changes in the temperature of the light spot. The high-precision thermal imager can accurately measure the specific changes in the temperature of each area, providing a reliable basis for subsequent data analysis;

[0029] The response band range should match the thermal radiation band generated by the laser emitted by the laser level. In this case, the thermal imager can more effectively obtain the temperature information of the laser light spot. Within this band, the thermal radiation generated by the laser can be efficiently captured by the thermal imager and converted into accurate temperature data. For example, the energy of infrared laser is relatively high, and the thermal radiation band generated after interacting with the object is relatively wide, mainly concentrated in the mid-infrared band, approximately between 3 - 8μm. At this time, an infrared thermal imager with a response band of 2.5 - 8.5μm can be selected;

[0030] Before using the thermal imager, it needs to be calibrated through a standard blackbody furnace. First, aim the thermal imager at the standard blackbody furnace and set the temperature of the standard blackbody furnace to multiple different values, such as 20℃, 30℃, 40℃, etc.; the thermal imager measures the standard blackbody furnace at each set temperature and records the measured values; compare the measured values with the temperature previously set by the standard blackbody furnace to obtain the error between the two data; adjust the thermal imager according to the error and correct the measurement results through a calibration algorithm until the error between the measured temperature and the set temperature is maintained within ±0.1℃;

[0031] For the selected test target board, it is necessary to start from two aspects: thermal conductivity and surface flatness. The material can be selected as copper alloy. This material has good thermal conductivity and uniformity. In practical applications, the copper alloy also needs to be specially proportioned and processed to maintain its thermal conductivity coefficient within the range of 300 - 400 W / m·K. This range can enable the heat generated by the laser irradiation to spread quickly and evenly. For example, when the laser level emits a laser beam and irradiates the test target board, the heat will be evenly distributed on the surface of the target board in a short time, avoiding large local temperature deviations caused by uneven heat conduction, thereby effectively ensuring that the thermal imager can accurately measure the temperature distribution of the laser light spot;

[0032] The surface roughness of the test target plate should not exceed Ra 0.8 μm. A flat surface can ensure that the laser can irradiate the target plate evenly, avoiding laser reflection or scattering caused by surface unevenness, which may affect the temperature measurement of each part. At the same time, the size of the test target plate should be maintained at approximately 200 mm × 200 mm × 10 mm. This size range can not only meet the coverage range of the laser spot emitted by the laser level, but also take into account issues such as heat conductivity and manufacturing cost;

[0033] The starting value of t should ensure the preheating of the laser level and the production rhythm of the products on the production line. If t is set too small, the laser level will start detection before it is fully preheated, and the obtained thermal imaging data cannot reflect its performance under normal working conditions; if t is set too large, the production rhythm will be slowed down, affecting production efficiency;

[0034] In an embodiment of the present invention, the value range of t is [3, 5];

[0035] If △t is too large, the performance change information of the laser level in a short period of time will be missed, and its stability cannot be comprehensively and accurately evaluated. If △t is too small, it will not work well for a laser level that requires long-term observation to obtain effective information;

[0036] In an embodiment of the present invention, the value range of △t is [2, 3].

[0037] The temperature stability analysis module judges the change of the temperature interval area of the thermal imaging pictures at each time point obtained by the image data acquisition module, so as to illustrate the stability of the long-term operation of the laser level:

[0038] The specific operation method for calculating the area change of the temperature range between two time points is as follows: (1) Unify the temperature range division. To avoid the difficulty of comparison caused by differences in range division, based on all temperature data at two time points of p minutes and q minutes, re-divide a unified temperature range. Take the lowest and highest temperatures at the two time points to determine a total range that includes all temperature values, and then perform equally spaced division within this total range; (2) Calculate the actual area ratio of each unified range at different time points. For each uniformly divided temperature range, calculate its area ratio in the thermal imaging pictures at p minutes and q minutes respectively. The area ratio = (the area of this range ÷ the total area of the thermal imaging picture) × 100%. Through the area ratio, the measurement error that may exist in the total area of the thermal imaging picture can be eliminated, making the data at different time points more comparable; (3) Calculate the change amount of the area ratio. Subtract the area ratio of a certain temperature range at p minutes from the area ratio of this range at q minutes to obtain the change amount of the area ratio. The change amount of the area ratio reflects the actual change situation of this temperature range during this period. A positive value indicates an increase in the area ratio, and a negative value indicates a decrease in the area ratio; (4) Add up the absolute values of the change amounts of the area ratios of all temperature ranges to obtain the comprehensive value Spq of the area change of the temperature range;

[0039] The comprehensive value of the area change of the temperature range from time point t minutes to t + △t minutes is calculated as S t,t+△t , and the comprehensive value of the area change of the temperature range from time point t + △t to t + 2△t minutes is S t+△t,t+2△t , and the comprehensive value of the area change of the temperature range from time point t + 2△t to t + 3△t minutes is S t+2△t,t+3△t , Combine the comprehensive values of the area changes of the temperature ranges at the 4 time points. According to the formula S 总 = a1×S t,t+△t + a2×S t+△t,t+2△t + a3×S t+2△t,t+3△t Calculate the total change rate of the area of the temperature range, where a1, a2, and a3 are the weights of the comprehensive values of the area changes of the temperature ranges at different time points.

[0040] Energy uniformity analysis module. If S 总 < Sth, it is necessary to perform color consistency judgment and area consistency judgment on the thermal imaging images at 8 angles collected at time point t;

[0041] The specific steps for color consistency judgment are as follows:

[0042] Since the colors in thermal imaging pictures are essentially determined by the RGB or HSV values of pixels, it is necessary to quantify these continuous numerical values, that is, to convert them into a countable discrete color set. For example, the RGB values can be divided into certain intervals, and each interval corresponds to a specific color. For each thermal imaging picture, all pixels are traversed, and the number of pixels in each color interval is counted to obtain the color set of the picture. If the color set C1 of Picture 1 after quantization is {red, blue, green, gray}, and the color set C2 of Picture 2 is {red, blue, green, gray, orange}; calculate the intersection C12 = C1 ∩ C2 and the union C12u = C1 ∪ C2 of the color sets of the two pictures. According to the above example, the intersection C12 = {red, blue, green, gray}, and the union C12u = {red, blue, green, gray, orange}; calculate the proportion of cross colors according to the formula mixture = |C12| / |C12u|, where |C12| and |C12u| represent the number of elements in C12 and C12u respectively. In the above example, mixture = 4 / 5 = 0.8; if mixture >= 0.8, it means that the colors of the two pictures are the same; for pairwise comparison of 8 pictures, a total of 28 comparisons are required. After each comparison, record the number of times Num when the colors are the same, that is, mixture >= 0.8. If Num >= [28 × 0.95] = 27, the color consistency meets the standard;

[0043] The specific steps for judging area consistency are as follows:

[0044] For each color region in the thermal imaging image, its area can be calculated by counting the number of pixels of that color. If the actual area of ​​each pixel is area, then the area of ​​the color region is A=n×area, where n is the number of pixels of that color. For example, the number of red pixels in the above-mentioned image 1 is n1, then the area of ​​the red region is A1=n1×area. Similarly, the area occupied by each color in image 1 can be calculated as A1-red, A2-blue, A3-green, A4-gray, and the area occupied by each color in image 2 can be calculated as B1-red, B2-blue, B3-green, B4-gray. Gray, B5-orange; confirm the intersection color of the two pictures, and then calculate the sum of the areas occupied by the intersection of picture one and picture two as Q1=A1+A2+A3+A4 and Q2=B1+B2+B3+B4, and then calculate the sum of the areas occupied by the difference sets of picture one and picture two as Q3=B5. The difference set mentioned above is actually the color difference set that combines the colors that belong to picture one but not to picture two with the colors that belong to picture two but not to picture one. Since there is only one difference set between the two in the above example, its area can be directly obtained; if (Q1 / Q2)>0.9 and Q3 <Qth,则表示两张图片的面积一致;对8张图片进行两两对比,总共需要进行28次对比,每次对比后,记录面积一致的次数Num1,若Num1> =[28×0.95]=27, the area consistency meets the standard.

[0045] The test result judgment module comprehensively judges whether the laser level is qualified according to the stability and energy stability of the laser level when it is continuously working obtained by the temperature stability analysis module and the energy uniformity analysis module, that is, whether the total change rate of the area in the temperature interval S is met. 总 <Sth、颜色一致性和面积一致性达标,才能判定该激光水平仪检测合格,否则,则判定为检测不合格,检测结果判定模块会将最终的检测结果以直观的方式显示出来,如通过指示灯:绿灯表示合格,红灯表示不合格;显示屏上显示具体的检测结论;声音提示:利用扬声器或蜂鸣器发出不同频率、节奏的声音来表示不同检测结果;打印输出:连接打印机,将检测结果以纸质报告形式打印出来;移动设备:借助蓝牙、Wi-Fi或移动网络,将检测结果推送到操作人员的手机、平板电脑等移动设备上,方便操作人员及时了解产品的质量情况。

[0046] Some of the data in the above formulas are dimensionless and numerically calculated. Meanwhile, the contents not described in detail in this specification belong to the prior art known to those skilled in the art.

[0047] The above embodiments are only used to illustrate the technical method of the present invention and not to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical method of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical method of the present invention.

Claims

1. An online detection system for optical component production, characterized in that: Including: An energy uniformity analysis module that pre-divides RGB values into certain intervals, with each interval corresponding to a specific color. For each thermal imaging picture, all pixels are traversed to count the number of pixels in each color interval, thereby obtaining the color set of the picture. Calculate the intersection C12 = C1 ∩ C2 and union C12u = C1 ∪ C2 of the color sets of two thermal imaging pictures, and obtain the cross-color ratio mixture. If mixture >= 0.8, it means the colors of the two pictures are the same. Compare the 8 pictures pairwise and record the number of times Num when the colors are the same. If Num >= 27, the color consistency meets the standard; otherwise, the color consistency does not meet the standard. For each color area in the thermal imaging picture, calculate its area by counting the number of pixels of that color. If the actual area of each pixel is area, then the area A of the color area = n × area, where n is the number of pixels of that color. Confirm the intersection color of the two pictures, and calculate the sum Q1 and Q2 of the areas occupied by the intersection of Picture 1 and Picture 2 respectively, and then find the sum Q3 of the areas occupied by the difference-set colors of Picture 1 and Picture 2. If (Q1 / Q2) > 0.9 and Q3 < Qth, it means the areas of the two pictures are the same. Record the number of times Num1 when the areas are the same. If Num1 >= 27, the area consistency meets the standard; otherwise, the area consistency does not meet the standard. A detection result determination module. If the temperature stability and energy uniformity of the laser level are all up to standard, it can be determined that the laser level passes the detection; otherwise, it is determined that the detection fails.

2. An online detection system for optical component production according to claim 1, characterized in that: The energy uniformity analysis module also includes an image data acquisition module and a temperature stability analysis module. The image data acquisition module uses a thermal imager to perform thermal imaging of the light spot at four time points, namely, t minute, t+△t minute, t+2△t minute, and t+3△t minute, for the light spot formed by the laser level irradiating the test target plate. The thermal imaging is continued at the time point t from eight angles, and the collected image data is transmitted to the temperature stability analysis module and the energy uniformity analysis module. The temperature stability analysis module calculates the temperature interval area change of the thermal imaging images obtained at each adjacent time point, and calculates the total temperature interval area change rate S according to the total temperature interval area change rate S. 总 Determine the temperature stability of a laser level.

3. An online detection system for optical component production according to claim 2, characterized in that: The resolution of the thermal imager is not less than 640 × 480 pixels, the accuracy reaches ±0.1 °C, and the response wavelength range is 2.5 - 8.5 μm.

4. The online detection system for optical component production according to claim 2, characterized in that: The material of the selected test target board is copper alloy, the thermal conductivity is maintained in the range of 300 - 400 W / m·K, and the surface roughness does not exceed Ra0.8 μm.

5. The online detection system for optical component production according to claim 2, characterized in that: The value range of t is [3, 5], and the value range of △t is [2, 3].

6. The online detection system for optical component production according to claim 2, characterized in that: The specific steps for calculating the area change of the temperature interval of thermal imaging pictures at adjacent time points are as follows: Based on all the temperature data at two time points of p minutes and q minutes, take the lowest temperature and the highest temperature at the two time points to determine a total interval that includes all temperature values, and then make equally spaced divisions within this total interval; For each uniformly divided temperature interval, calculate its area proportion in the thermal imaging pictures at p minutes and q minutes respectively. The area proportion = (the area of this interval ÷ the total area of the thermal imaging picture) × 100%; Subtract the area proportion of a certain temperature interval at p minutes from the area proportion of this interval at q minutes to obtain the area proportion change amount; Add up the absolute values of the area proportion change amounts of all temperature intervals to obtain the comprehensive value Spq of the area change of the temperature interval.

7. The online detection system for optical component production according to claim 3, characterized in that: The comprehensive value of the temperature area change from time point t minutes to t+△t minutes is S t,t+△t The comprehensive change value of the temperature interval area from time point t+△t to t+2△t minutes is S t+△t,t+2△t The comprehensive change value of the temperature interval area from time point t+2△t to t+3△t minutes is S t+2△t,t+3△t , combine the comprehensive change values ​​of the temperature interval area at the four time points, and according to the formula S 总 =a1×S t,t+△t +a2×S t+△t,t+2△t +a3×S t+2△t,t+3△t Calculate the total change rate of the temperature interval area, where a1, a2, and a3 are the weights of the comprehensive change values ​​of the temperature interval area at different time points.

8. The online detection system for optical component production according to claim 1, characterized in that: Calculate the cross-color proportion according to the formula mixture = |C12| / |C12u|, where |C12| and |C12u| represent the number of elements in C12 and C12u respectively.

9. The online detection system for optical component production according to claim 1, characterized in that: The difference-set colors of Picture 1 and Picture 2 specifically include the colors that belong to Picture 1 but not to Picture 2 and the colors that belong to Picture 2 but not to Picture 1.

10. The online detection system for optical component production according to claim 1, characterized in that: In the test result determination module, the specific test conclusions can be displayed through indicator lights, display screens, sound prompts, printouts, and mobile devices.

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