Chromatic aberration on-line measurement method and system

Abstract

The invention discloses a color difference on-line measurement method which specifically comprises the following steps: (1) receiving the product color of a next product, detecting whether the received product color exists in a color database, and if so, directly executing a step (2); (2) the online colorimeter calls the standard color chromaticity of the next product color and the current joint calibration coefficient of the standard color chromaticity; (3) detecting the chromaticity L1, the chromaticity A1 and the chromaticity B1 of the product in real time by the online colorimeter, and calculating color chromaticity difference values delta L1, delta A1 and delta B1 between the chromaticity L1, the chromaticity A1 and the chromaticity B1 of the product and the corresponding standard color chromaticity after the chromaticity detection of the next product is started; and (4) correcting the color chromaticity difference values deltaL1, deltaA1 and deltaB1 based on the latest joint correction coefficient of the current product color, and outputting the corrected color chromaticity difference values deltaL1 ', deltaA1' and deltaB1 '. In the production process, a production line does not need to be stopped, joint calibration of the online colorimeter and the offline colorimeter can be directly carried out, instrument errors of the online colorimeter and the offline colorimeter are eliminated, the joint calibration process is simplified, personnel operation is reduced, and production efficiency is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of color coating, and more specifically, the present invention relates to a color difference online measurement method and system. Background Art

[0002] Color difference is of great significance in the color-coated plate industry, especially the color difference between the manufacturer's products and the standard samples is a core indicator of quality management.

[0003] At present, the color difference detection of color coated plates is carried out offline by using a colorimeter through local sampling. The local sampling method is also the color difference standard release and arbitration method defined in various standards in the world. However, its defect is that the sampling is poorly representative and cannot reflect the color difference indicators of all products. Therefore, it is necessary to install an online colorimeter on the production line to detect the color difference of products online in real time.

[0004] However, since all non-contact colorimeter have a large time drift problem, before each color switch in production, the corresponding color standard sample needs to be placed in the online colorimeter and the offline colorimeter for joint calibration. This process is very cumbersome and inconvenient for production operations; when the color of the production line is switched frequently, it seriously affects production efficiency. Summary of the invention

[0005] The present invention provides a color difference online measurement method, aiming to improve the above problem.

[0006] The present invention is implemented as follows: a method for measuring color difference online.

[0007] (1) receiving the product color of the next product, and checking whether the received product color already exists in the color database. If so, directly executing step (2);

[0008] (2) The online colorimeter retrieves the standard color chromaticity of the next product color and its current joint calibration coefficient;

[0009] (3) The online colorimeter detects the product color chromaticity L1, A1, B1 in real time, and after starting the color difference detection of the next product, calculates the color chromaticity difference ΔL1, ΔA1, ΔB1 ​​between the product color chromaticity L1, A1, B1 and the corresponding standard color chromaticity;

[0010] (4) Correct the color chromaticity difference values ​​ΔL1, ΔA1, and ΔB1 based on the latest joint calibration coefficient of the current product color, and output the corrected color chromaticity difference values ​​ΔL1′, ΔA1′, and ΔB1′.

[0011] Furthermore, if the product color does not exist in the color database, the color information of the next product color is entered into the color database, and the initial joint calibration coefficient of the product color is calculated;

[0012] The color database stores color information of products of different colors and their joint calibration coefficients, wherein the color information includes: color identification and its corresponding standard color chromaticity L, A, B.

[0013] Furthermore, the method for determining the initial joint calibration coefficient of the product color is as follows:

[0014] (11) Before production, enter the standard color chromaticity L, A, B of the next product into the online colorimeter;

[0015] (12) placing the color standard sample into the sample slot of the online colorimeter for measurement to obtain the color chromaticity measurement values ​​L0, A0, and B0 of the color standard sample;

[0016] (13) The difference between the color chromaticity measurement values ​​L0, A0, B0 of the color standard sample and the standard color chromaticity L, A, B is used as the initial joint calibration coefficient of the product color.

[0017] Furthermore, the calculation formulas of the corrected color chromaticity differences ΔL1′, ΔA1′, and ΔB1′ are as follows:

[0018] ΔL1′=ΔL1-L * ;

[0019] ΔA1′=ΔA1-A * ;

[0020] ΔB1′=ΔB1-B * ;

[0021] Among them, L * , A * , B * is the current joint coefficient in the product color.

[0022] Furthermore, after step (4), the current joint calibration coefficient of the product color is updated.

[0023] Furthermore, the update process of the joint school coefficient is as follows:

[0024] (5) Enter the standard color chromaticity L, A, and B of the next product into the offline colorimeter, place the color standard sample in the sample slot of the offline colorimeter, and calibrate the offline colorimeter based on the standard color chromaticity L, A, and B;

[0025] (6) Extracting samples from products undergoing color difference testing, testing the samples with an offline colorimeter, and detecting the color chromaticity L2, A2, and B2 of the products in real time by the offline colorimeter, and calculating the color chromaticity differences ΔL2, ΔA2, and ΔB2 with the corresponding standard color chromaticity L, A, and B;

[0026] (7) Calculate the current joint calibration coefficient L of the product color * , A * , B * , update the joint calibration coefficient corresponding to the color identifier of the current product color in the color database to the current joint calibration coefficient L * , A * , B * .

[0027] Furthermore, the current joint coefficient L of the product color * , A * , B * The calculation formula is as follows:

[0028] L * =ΔL′1-ΔL2;

[0029] A * =ΔA′1-ΔA2;

[0030] B*=ΔB′1-ΔB2.

[0031] The present invention is implemented as follows: a color difference online measurement system, the system comprising:

[0032] Online colorimeter, connected with input unit and color database;

[0033] The input unit is used to input the product identification of the next product and send it to the online colorimeter;

[0034] The online colorimeter detects whether the product color of the next product exists in the color database. If not, the user is prompted to enter the color information corresponding to the product color and its initial joint calibration coefficient. If it exists, the standard color chromaticity of the current product color and its current joint calibration coefficient are read from the color data.

[0035] The online colorimeter detects the product color chromaticity L1, A1, B1 online and in real time, and calculates the color chromaticity difference ΔL1, ΔA1, ΔB1 ​​between the product color chromaticity L1, A1, B1 and the corresponding standard color chromaticity, and corrects the color chromaticity difference ΔL1, ΔA1, ΔB1 ​​based on the current joint calibration coefficient of the product color, and outputs the corrected color chromaticity difference ΔL1′, ΔA1′, ΔB1′.

[0036] Furthermore, the system also includes:

[0037] Online colorimeter, connected with input unit and color database;

[0038] The input unit is used to input the color identification of the currently tested product and the corresponding standard color chromaticity L, A, B, and send them to the offline colorimeter;

[0039] Place the color standard sample in the sample slot of the offline colorimeter, and calibrate the offline colorimeter based on the standard color chromaticity L, A, B; extract the tested sample from the product undergoing color difference detection, and use the offline colorimeter to detect the tested sample. The offline colorimeter detects the product color chromaticity L2, A2, B2 in real time, and calculates the color chromaticity difference ΔL2, ΔA2, ΔB2 with the corresponding standard color chromaticity L, A, B; calculate the current joint calibration coefficient L of the product color * , A * , B * , and sent to the color database, the color database updates the joint calibration coefficient corresponding to the color identifier of the current product color to the current joint calibration coefficient L * , A * , B * .

[0040] During the production process, the online colorimeter and the offline colorimeter can be directly calibrated without stopping the production line, eliminating the instrument errors of the online colorimeter and the offline colorimeter, simplifying the joint calibration process, reducing personnel operations, and improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 A flow chart of the color difference online measurement method provided by an embodiment of the present invention;

[0042] Figure 2 A schematic diagram of the structure of a color difference online measurement system provided in an embodiment of the present invention. Implementation

[0044] The specific implementation modes of the present invention are further explained in detail below by describing the embodiments with reference to the accompanying drawings, so as to help those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention.

[0045] Figure 1 The present invention provides a flowchart of a method for measuring color difference online, which specifically includes the following steps:

[0046] (1) After receiving the product color of the next product, check whether the current product color already exists in the color database. If not, enter the next product color into the color database, calculate the initial joint calibration coefficient of the product color, and execute step (3). If it exists, directly execute step (2);

[0047] In the embodiment of the present invention, the colors of all color-coated plates are identified by color identification, and the color database stores the color information of different product colors and their current joint calibration coefficients. The color information includes: color identification and its corresponding standard color chromaticity L, A, B. When the color identification of the next product does not exist in the color database, the color identification of the next product is formed based on the set rules, and the standard color chromaticity L, A, B of the next product is entered; the joint calibration coefficient of the color chromaticity collected by the online colorimeter relative to the standard color chromaticity is calculated, and the joint calibration coefficient is the initial joint calibration coefficient of the current color. The method for determining the initial joint calibration coefficient of the current color is as follows:

[0048] (11) Before production, enter the standard color chromaticity L, A, B of the next product into the online colorimeter;

[0049] (12) placing the color standard sample into the sample slot of the online colorimeter for measurement to obtain the color chromaticity measurement value of the color standard sample;

[0050] (13) The difference between the color chromaticity measurement value of the color standard sample and the standard color chromaticity L, A, B is used as the initial joint calibration coefficient of the next product color.

[0051] (2) The online colorimeter retrieves the standard color chromaticity of the next product color and its current joint calibration coefficient;

[0052] (3) The online colorimeter detects the product color chromaticity L1, A1, B1 of the product in real time online, and after starting the color detection of the next product, calculates the color chromaticity difference ΔL1, ΔA1, ΔB1 ​​between the detected product color chromaticity L1, A1, B1 and the corresponding standard color chromaticity;

[0053] (4) Correct the color chromaticity difference values ​​ΔL1, ΔA1, and ΔB1 based on the current joint calibration coefficient of the product color, and output the corrected color chromaticity difference values ​​ΔL1′, ΔA1′, and ΔB1′.

[0054] In the embodiment of the present invention, the calculation formulas of the corrected color chromaticity differences ΔL1′, ΔA1′, and ΔB1′ are specifically as follows:

[0055] ΔL1′=ΔL1-L * ;

[0056] ΔA1′=ΔA1-A * ;

[0057] ΔB1′=ΔB1-B * ;

[0058] Among them, L * , A * , B *is the current joint coefficient in the product color.

[0059] In the embodiment of the present invention, after step (4), the joint calibration coefficient of the current product color needs to be updated. The updating process of the joint calibration coefficient is as follows:

[0060] (5) Enter the standard color chromaticity L, A, and B of the next product into the offline colorimeter, place the color standard sample in the sample slot of the offline colorimeter, and calibrate the offline colorimeter based on the standard color chromaticity L, A, and B;

[0061] (6) Extracting samples from products undergoing color difference testing, testing the samples with an offline colorimeter, and calculating the color chromaticity differences ΔL2, ΔA2, ΔB2 between the product color chromaticity L2, A2, B2 detected in real time by the offline colorimeter and the corresponding standard color chromaticity;

[0062] (7) Calculate the current joint coefficient L of the product color * , A * , B * , update the joint calibration coefficient corresponding to the color identifier of the product color in the color database to the current joint calibration coefficient L * , A * , B * .

[0063] In the embodiment of the present invention, since the use environment of the offline colorimeter is more stable than that of the online colorimeter, the color chromaticity difference between the product color chromaticity and the standard color chromaticity collected by the offline colorimeter is relatively more accurate. Therefore, the color chromaticity difference values ​​ΔL2, ΔA2, and ΔB2 of the product color chromaticity detected by the offline colorimeter and the corresponding standard color chromaticity are used as standard color chromaticity differences, and the color chromaticity difference values ​​ΔL1′, ΔA1′, and ΔB1′ obtained in real time through detection by the online colorimeter are used as measurement values ​​to calculate the current joint calibration coefficient L of the product color. * , A * , B * , the current joint coefficient L of the product color * , A * , B * The calculation formula is as follows:

[0064] L * =ΔL′1-ΔL2;

[0065] A * = ΔA′1-ΔA2;

[0066] B * =ΔB′1-ΔB2.

[0067] Figure 2The schematic diagram of the structure of the color difference online measurement system provided by the embodiment of the present invention, for the convenience of description, only the part related to the embodiment of the present invention is shown, and the system includes:

[0068] Online colorimeter, connected with input unit and color database;

[0069] The input unit is used to input the product color of the next product and send it to the online colorimeter;

[0070] The online colorimeter detects whether the product color of the next product exists in the color database. If not, the user is prompted to enter the color information corresponding to the product color and its initial joint calibration coefficient. If it exists, the standard color chromaticity of the current product color and its current joint calibration coefficient are read from the color data.

[0071] The online colorimeter detects the product color chromaticity L1, A1, B1 online and in real time, and calculates the color chromaticity difference ΔL1, ΔA1, ΔB1 ​​between the product color chromaticity L1, A1, B1 and the corresponding standard color chromaticity, and corrects the color chromaticity difference ΔL1, ΔA1, ΔB1 ​​based on the current joint calibration coefficient of the product color, and outputs the corrected color chromaticity difference ΔL1′, ΔA1′, ΔB1′.

[0072] In an embodiment of the present invention, the system further includes:

[0073] Online colorimeter, connected with input unit and color database;

[0074] The input unit is used to input the color identification of the currently tested product and the corresponding standard color chromaticity L, A, B, and send them to the offline colorimeter;

[0075] Place the color standard sample in the sample slot of the offline colorimeter, and calibrate the offline colorimeter based on the standard color chromaticity L, A, B; extract the tested sample from the product undergoing color difference detection, and use the offline colorimeter to detect the tested sample. The offline colorimeter detects the product color chromaticity L2, A2, B2 in real time, and calculates the color chromaticity difference ΔL2, ΔA2, ΔB2 with the corresponding standard color chromaticity L, A, B; calculate the current joint calibration coefficient L of the product color * , A * , B * , and sent to the color database, the color database updates the joint calibration coefficient corresponding to the color identifier of the current product color to the current joint calibration coefficient L * , A * , B * The current joint coefficient L of this product color * , A * , B * The calculation formula is as follows:

[0076] L* =ΔL′1-ΔL2;

[0077] A * = ΔA′1-ΔA2;

[0078] B * =ΔB′1-ΔB2.

[0079] In an embodiment of the present invention, when the color identification of the next product does not exist in the color database, the color identification of the next product is formed based on the set rules, and the standard color chromaticity L, A, B of the next product is entered; the joint calibration coefficient of the color chromaticity collected by the online colorimeter relative to the standard color chromaticity is calculated, and the joint calibration coefficient is the initial joint calibration coefficient of the current color. The method for determining the initial joint calibration coefficient of the current color is as follows: before production, the standard color chromaticity L, A, B of the next product is entered into the online colorimeter; the color standard sample is placed in the sample slot of the online colorimeter for measurement to obtain the color chromaticity measurement value of the color standard sample; the difference between the color chromaticity measurement value of the color standard sample and the standard color chromaticity L, A, B is used as the initial joint calibration coefficient of the next product color.

[0080] The present invention has been described exemplarily. Obviously, the specific implementation of the present invention is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A color difference online measurement method, characterized in that: The method is specifically as follows: (1) receiving the product color of the next product, and checking whether the received product color already exists in the color database. If so, directly executing step (2); (2) The online colorimeter retrieves the standard color chromaticity of the next product color and its current joint calibration coefficient; (3) The online colorimeter detects the product color chromaticity L1, A1, B1 in real time, and after starting the color difference detection of the next product, calculates the color chromaticity difference ΔL1, ΔA1, ΔB1 ​​between the product color chromaticity L1, A1, B1 and the corresponding standard color chromaticity; (4) Correct the color chromaticity difference values ​​ΔL1, ΔA1, and ΔB1 based on the latest joint calibration coefficient of the current product color, and output the corrected color chromaticity difference values ​​ΔL1′, ΔA1′, and ΔB1′.

2. The color difference online measurement method according to claim 1, characterized in that: If the product color does not exist in the color database, the color information of the next product color is entered into the color database, and the initial joint calibration coefficient of the product color is calculated; The color database stores color information of products of different colors and their joint calibration coefficients, wherein the color information includes: color identification and its corresponding standard color chromaticity L, A, B.

3. The color difference online measurement method according to claim 2, characterized in that: The method for determining the initial joint calibration coefficient of product color is as follows: (11) Before production, enter the standard color chromaticity L, A, B of the next product into the online colorimeter; (12) placing the color standard sample into the sample slot of the online colorimeter for measurement to obtain the color chromaticity measurement values ​​L0, A0, and B0 of the color standard sample; (13) The difference between the color chromaticity measurement values ​​L0, A0, B0 of the color standard sample and the standard color chromaticity L, A, B is used as the initial joint calibration coefficient of the product color.

4. The color difference online measurement method according to claim 1, characterized in that: The calculation formulas for the corrected color chromaticity differences ΔL1′, ΔA1′, and ΔB1′ are as follows: ΔL1′=ΔL1-L * ; ΔA1′=ΔA1-A * ; ΔB1′=ΔB1-B * ; Among them, L * , A * , B * is the current joint coefficient in the product color.

5. The color difference online measurement method according to claim 1, characterized in that: After step (4), the current joint calibration coefficient of the product color is updated.

6. The color difference online measurement method according to claim 5, characterized in that: The update process of the joint school coefficient is as follows: (5) Enter the standard color chromaticity L, A, and B of the next product into the offline colorimeter, place the color standard sample in the sample slot of the offline colorimeter, and calibrate the offline colorimeter based on the standard color chromaticity L, A, and B; (6) Extracting samples from products undergoing color difference testing, testing the samples with an offline colorimeter, and detecting the color chromaticity L2, A2, and B2 of the products in real time by the offline colorimeter, and calculating the color chromaticity differences ΔL2, ΔA2, and ΔB2 with the corresponding standard color chromaticity L, A, and B; (7) Calculate the current joint coefficient L of the product color * , A * , B * , update the joint calibration coefficient corresponding to the color identifier of the current product color in the color database to the current joint calibration coefficient L * , A * , B * .

7. The color difference online measurement method according to claim 6, characterized in that: The current joint coefficient L of this product color * , A * , B * The calculation formula is as follows: L * =ΔL′1-ΔL2; A * =ΔA′1-ΔA2; B * = ΔB′1-ΔB2.

8. A color difference online measurement system, characterized in that: The system comprises: Online colorimeter, connected with input unit and color database; The input unit is used to input the color identification of the next product and send it to the online colorimeter; The online colorimeter detects whether the product color of the next product exists in the color database. If not, the user is prompted to enter the color information corresponding to the product color and its initial joint calibration coefficient. If it exists, the standard color chromaticity of the current product color and its current joint calibration coefficient are read from the color data. The online colorimeter detects the product color chromaticity L1, A1, B1 online and in real time, and calculates the color chromaticity difference ΔL1, ΔA1, ΔB1 ​​between the product color chromaticity L1, A1, B1 and the corresponding standard color chromaticity, and corrects the color chromaticity difference ΔL1, ΔA1, ΔB1 ​​based on the current joint calibration coefficient of the product color, and outputs the corrected color chromaticity difference ΔL1′, ΔA1′, ΔB1′.

9. The color difference online measurement system according to claim 8, characterized in that: The system further comprises: Offline colorimeter, connected with input unit and color database; The input unit is used to input the color identification of the currently tested product and the corresponding standard color chromaticity L, A, B, and send them to the offline colorimeter; Place the color standard sample in the sample slot of the offline colorimeter, and calibrate the offline colorimeter based on the standard color chromaticity L, A, B; extract the tested sample from the product undergoing color difference detection, and detect the tested sample using the offline colorimeter. The offline colorimeter detects the product color chromaticity L2, A2, B2 in real time, and calculates the color chromaticity difference ΔL2, ΔA2, ΔB2 with the corresponding standard color chromaticity L, A, B; calculate the current joint calibration coefficient L of the product color * , A * , B * , and sent to the color database, the color database updates the joint calibration coefficient corresponding to the color identifier of the current product color to the current joint calibration coefficient L * , A * , B * .

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