A repeated positioning precision detection method for a CCD automatic screen printing machine

Abstract

The application provides a detection method for the repeated positioning accuracy of a CCD automatic screen printing machine. The method is characterized in that three test points are arranged on a detection plate, and measurement inserts are arranged at the corresponding positions of the test points to realize the height difference matching of the test points. The method comprises the following steps: first, calibrate the device and the test origin; then, place the detection plate into the CCD target grabbing area of the screen printing machine; after the detection plate is automatically conveyed to the printing area, the measurement values of the three test points can be read; then, repeat the test for 10 times, and each measurement result is less than the given accuracy index of the equipment, so that the detection is qualified; the measurement values of the three test points are analyzed, and the deviation direction of the conveying mechanism of the screen printing machine can be obtained. The method can eliminate the detection errors caused by other process factors, overcome the problem that the magnetic table seat cannot be used for the hollow cavity and the screen printing machine table surface which is not affected by the magnet, facilitate the origin debugging of the test head, fill the blank of the repeated positioning accuracy detection of the automatic screen printing machine, and perfect the detection technology of the CCD automatic positioning screen printing machine in the aspects of manufacturing inspection and use period detection.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of repeated positioning accuracy detection of CCD automatic screen printing machine, and particularly relates to a repeated positioning accuracy measurement of a CCD automatic screen printing machine, and a detection method for measuring and detecting the working accuracy of an automatic positioning transmission mechanism in periodic detection of the CCD automatic screen printing machine. BACKGROUND

[0002] Any screen printing process is composed of multiple printing layers, and the multiple printing layer process requires accurate positioning between layers. The continuous improvement of screen printing process promotes the development and application of automatic screen printing machines. The automatic positioning system of a CCD automatic screen printing machine is a system that captures a target by a CCD image controller, then converts the captured target signal into a stepping numerical control signal to control the transmission mechanism to realize positive transmission. The positive transmission accuracy of the transmission mechanism of the CCD automatic screen printing machine is referred to as "repeated positioning accuracy", and the highest performance index of this item is currently ±0.005 mm.

[0003] "Repeated positioning accuracy" is a core technical index of automatic screen printing machines, which represents the consistency and stability of the combination of the CCD image controller, the running track alignment mechanism and the running track transmission mechanism of the screen printing machine. However, this important core technical index has not yet had a perfect measurement method, and most of them are detected and judged by using two-dimensional detection equipment to detect the printing effect of the printed matter. When the printing layers between two layers are offset and not in position, the screen printing machine will be offset, or the screen printing plate will be offset, and the result of using two-dimensional equipment detection cannot be determined whether it is a screen printing machine positioning offset problem or a screen printing plate offset problem. Only by directly detecting the "repeated positioning accuracy" of the automatic screen printing machine can the final determination be realized, and the "repeated positioning accuracy" project detection of the automatic screen printing machine is still in blank.

[0004] In order to measure the "repeated positioning accuracy" of the automatic screen printing machine, the measurement device must consider: 1) the thickness of the printed matter of the planar screen printing machine is less than 2 mm. 2) the printing table of the planar screen printing machine is a non-ferrous cavity with negative pressure suction function, which cannot be processed with a measurement support, and cannot use magnetic table seat. 3) when using a dial gauge for measurement, the minimum height of the horizontal placement of the dial gauge is 10 mm, and the horizontal height of the dial gauge test head exceeds the thickness of the printed matter. SUMMARY

[0005] To address the aforementioned measurement technology problems, this invention proposes a method for testing the "repeatability" of a CCD automatic screen printing machine. The testing method is implemented as follows: A test board is fabricated using the maximum nominal printing size of the screen printing machine; two φ2 holes are drilled on the test board as CCD targets, according to the target positions in the daily printing process; three test points are selected on the test board: one test point is set on the bottom edge of the test board in the printing conveying direction, and two test points are set perpendicular to the printing conveying direction on the front edge of the test board; test point inserts are installed at the positions of the three test points on the test board to raise the height of the test points, overcoming the minimum height limitation of 10mm required when the dial indicator test head is placed horizontally.

[0006] Based on the above optimizations, the three dial indicator bases are made of marble and rest on the printing table of the screen printing machine. Given that the screen printing machine's "repeatability" deviation can result in the dial indicator not reaching the positioning origin (or exceeding it), the weight and sliding properties of the marble base are utilized to facilitate the vertical calibration of the dial indicator's test head on the test surface and to perform interference presets, thus measuring the negative deviation of the dial indicator from reaching the positioning origin. After determining the interference preset to approximately 0.5mm, the dial indicator reading is set to 0 as the positioning origin.

[0007] Based on the above optimization, the test surfaces formed by the test plate mounting inserts are perpendicular to each other. When the conveying direction of the screen printing machine is from left to right, the corner formed by the test plate mounting inserts is at the lower right; when the conveying direction of the screen printing machine is from right to left, the corner formed by the test plate mounting inserts is at the lower left.

[0008] If the measured values ​​at the three test points are less than the given value for "repeatability", the screen printing machine's "repeatability" can be deemed to have passed a single test; if the measured values ​​at the three test points are greater than or less than the given value, the test is deemed to have failed.

[0009] When a test fails, the distribution of the measured values ​​of the angle formed by the three test points is analyzed to determine the direction of the deviation of the screen printing machine's conveyor mechanism.

[0010] [A1] After the dial indicator and socket are installed and the test board assembly is ready, the following testing steps can be performed.

[0011] 1. Place the test board naturally into the CCD target area of ​​the screen printing machine; start the screen printing machine to target the test board and then pick it up and transfer it to the printing area.

[0012] 2. After the test plate reaches the printing area, marble table base is moved respectively, so that the micrometer test head is close to the test point of the test plate, the micrometer table is adjusted to make the test head of the micrometer perpendicular to the test point of the test plate, the position of the marble table base is fine-tuned, the micrometer is preset to the test point, and then the value of the micrometer is set to 0 to set the origin.

[0013] 3. The test plate is taken out from the printing area, the transmission runway of the silk screen printing machine is started to retreat to the CCD target area, the test plate is freely placed into the CCD target area again, the silk screen printing machine is started again to capture the target, and the test plate is sucked and transmitted to the printing area.

[0014] 4. After the test head of the micrometer touches the test point, the measurement values of the three test points are read respectively and recorded. If the measurement value is less than the given value of the "repositioning accuracy", the single detection of the silk screen printing machine is qualified; if the measurement value is greater than or less than the given value, it is unqualified.

[0015] 5. The measurement is repeated 10 times according to steps 3 and 4. If the measurement result is not greater than or less than the given value of the "repositioning accuracy" each time, the detection is qualified.

[0016] 6. When the detection is unqualified, the measurement value distribution of the three test points is analyzed to obtain the deviation direction of the transmission mechanism of the silk screen printing machine.

[0017] The CCD automatic silk screen printing machine repositioning accuracy detection method of the present application directly detects the operation results of the CCD automatic silk screen printing machine itself, completely eliminates the detection errors caused by other process factors. The detection method of the present application fills the gap of the CCD automatic positioning silk screen printing machine in the detection technology of the repositioning accuracy, and perfects the detection technology of the CCD automatic positioning silk screen printing machine in the manufacturing inspection and use period detection. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a schematic diagram of the repositioning accuracy measurement device of the embodiment of the present application.

[0019] Figure 2 It is a schematic diagram of the repositioning accuracy measurement device of the embodiment of the present application. Figure 1 It is a view from the middle K direction.

[0020] Figure 3 It is a schematic diagram of the qualified value deviation less than the accuracy index of the embodiment of the present application.

[0021] Figures 4 to 9 It is a schematic diagram of the unqualified measurement value deviation direction of the embodiment of the present application.

[0022] The reference numerals are explained as follows: 11: micrometer; 12: marble table base; 13: micrometer table stand; 21: test plate; 22: test plate target; 23: test plate insert; 31: screen printing machine; 32: conveying runway; 33: target grabbing camera; 34: printing table surface; Cx1: first test point in x direction, Cx2: second test point in x direction, Cy: test point in y direction; ZCx1: measurement value of test point Cx1 measured by the micrometer; ZCx2: measurement value of test point Cx2 measured by the micrometer; ZCy: measurement value of test point Cy measured by the micrometer. DETAILED DESCRIPTION

[0023] The embodiments are described in detail below with reference to the drawings. Reference Figure 1 and Figure 2 The detection method of the embodiments of the present application includes a micrometer 11, a marble table base 12, a micrometer table stand 13, a test plate 21, a test plate target 22 and a test plate insert 23. The micrometer 11 is a digital micrometer, and is specifically divided into the micrometer 11a, the micrometer 11b and the micrometer 11c in the drawings. The micrometer 11 is clamped and installed on the marble table base 12 by the table stand 13. The marble table base 12 is placed on the side to match the test head of the micrometer 11 clamped by the table stand 13 to be in the horizontal direction and perpendicular to the three test points Cx1, Cx2 and Cy of the measuring insert 23, which are specifically the first test point Cx1 in the x direction, the second test point Cx2 in the x direction and the test point Cy in the y direction. The marble table base 12 is placed on the printing table surface 34 of the screen printing machine by its own weight and can be slid to adjust the working position as needed.

[0024] Referring to Figure 1 The detection method of the embodiments of the present application further includes the test plate 21, the test plate target 22 and the test plate insert 23. The test plate 21 is made of a 1.6 mm thick glass fiber cloth plate. Two φ2 holes are directly drilled in the diagonal positions of the test plate 21 as the target 22, or two circular ring stickers can be used to paste the target 22, and the actual position of the target is not limited. The test plate insert 23 is made of hard PVC plate, and the test surface of the insert 23 is required to be perpendicular to the installation surface, with a size of about 30x50 mm and a thickness of 20 mm recommended, which can raise the height of the test points and match the test head of the micrometer 11 to be in the horizontal direction and perpendicular to the test points Cx1, Cx2 and Cy. Three test plate inserts 23 are permanently bonded on the test plate 21 by adhesive according to the positions of the test points.

[0025] Referring to Figure 1 The detection method of the embodiments of the present application further includes the conveying runway 32 of the CCD automatic screen printing machine 31, the CCD target grabbing camera 33 and the printing table surface 34 of the screen printing machine. Figure 1The conveying direction of the conveying track 32 is from left to right, and the corner formed by the test plate inserts 23 is on the lower right. When the conveying direction of the conveying track 32 is from right to left, the corner formed by the test plate inserts 23 is on the lower left.

[0026] The steps of the method for measuring the repeat positioning accuracy of the CCD automatic screen printing machine of the present application are as follows.

[0027] Step 1: calibrate the test points and the origin of the device.

[0028] Place the test plate 21 with the prepared target 22 and inserts 23 in the CCD target grabbing area of the screen printing machine 31. Turn on the suction of the screen printing machine 31 to tightly suck the test plate 21 on the conveying track 32. Then turn on the camera 33 of the screen printing machine 31 to perform normal target grabbing on the target 22 of the test plate, and then turn on the screen printing machine 31 to send the test plate 21 to the printing area of the screen printing machine. Move the three marble bases 12 with the installed dial gauge 11 close to the positions of the test plate inserts 23, and adjust the base 13 of the dial gauge 11 so that the test head of the dial gauge 11 is perpendicular to the test points of the test plate inserts 23. Then, slightly adjust the positions of the marble bases 12, and pre-set an interference of about 0.5 mm on the test head of the dial gauge 11, and then set the value to 0 as the positioning origin.

[0029] Step 2: detect the repeat positioning accuracy.

[0030] Take the test plate out of the printing area of the screen printing machine 31, and start the conveying track 32 of the screen printing machine to return to the CCD target grabbing area. Then, place the test plate 21 in the CCD target grabbing area of the screen printing machine 31 again, and start the suction of the screen printing machine 31 to tightly suck the test plate 21. Then, start the camera 33 of the screen printing machine 31 to perform target grabbing on the target 22 of the test plate 21, and then start the conveying track 32 to suck and convey the test plate 21 to the printing area.

[0031] The test points Cx1, Cx2 and Cy of the test plate inserts 23 touch the test head of the dial gauge 11, and the measured values of the three test points Cx1, Cx2 and Cy are read and recorded as ZCx1, ZCx2 and ZCy respectively. When the measured values of the test points Cx1, Cx2 and Cy are less than the given value of the repeat positioning accuracy (for example, ±0.005 mm), the single detection of the repeat positioning accuracy of the screen printing machine 31 is qualified. If the measured values are greater than the given value, it is unqualified.

[0032] Repeat the measurement 10 times according to the above steps. If the results ZCx1, ZCx2 and ZCy of the corresponding test points Cx1, Cx2 and Cy in each measurement are not greater than the given value of the repeat positioning accuracy, the detection is qualified.

[0033] When the detection is unqualified, the distribution of the measured values ZCx1, ZCx2 and ZCy of the test points Cx1, Cx2 and Cy can be analyzed, so as to obtain the deviation size and deviation direction of the conveying mechanism of the screen printing machine.

[0034] Referring to Figure 3 Fig. 2, the measured values ZCx1, ZCx2 and ZCy of the test points Cx1, Cx2 and Cy are all less than the given value (0.005 mm) of the "repositioning accuracy", which is qualified for single detection.

[0035] Further referring to Figure 4 Fig. 3, the measured values ZCx1(-) > 0.005 mm, ZCx2(-) > 0.005 mm and ZCy < 0.005 mm reflect that the conveying structure does not reach the positioning origin along the conveying direction, and the distance to the positioning origin is greater than the given value (0.005 mm).

[0036] Further referring to Figure 5 Fig. 4, the measured values ZCx1(+) > 0.005 mm, ZCx2(+) > 0.005 mm and ZCy < 0.005 mm reflect that the conveying structure exceeds the positioning origin along the conveying direction, and the distance to the positioning origin is greater than the given value (0.005 mm).

[0037] Further referring to Figure 6 Fig. 5, the measured values ZCx1 < 0.005 mm, ZCx2 < 0.005 mm and ZCy(-) > 0.005 mm reflect that the conveying structure does not reach the positioning origin by upward offset along the conveying direction, and the upward offset error is greater than the given value (0.005 mm).

[0038] Further referring to Figure 7 Fig. 6, the measured values ZCx1 < 0.005 mm, ZCx2 < 0.005 mm and ZCy(+) > 0.005 mm reflect that the conveying structure exceeds the positioning origin by downward offset along the conveying direction, and the downward offset error is greater than the given value (0.005 mm).

[0039] Further referring to Figure 8 Fig. 7, the measured values ZCx1(-) > 0.005 mm, ZCx2 < 0.005 mm and ZCy < 0.005 mm reflect that the conveying structure does not reach the positioning origin by counterclockwise deflection along the conveying direction, and the counterclockwise deflection error is greater than the given value (0.005 mm).

[0040] Further referring to Figure 9 Fig. 8, the measured values ZCx1 < 0.005 mm, Zx2(-) > 0.005 mm and ZCy < 0.005 mm reflect that the conveying structure does not reach the positioning origin by clockwise deflection along the conveying direction, and the clockwise deflection error is greater than the given value (0.005 mm).

[0041] When the above test is completed, the detector device and the test plate assembly are conveniently stored for next time detection.

[0042] In summary, the CCD automatic screen printing machine repeat positioning accuracy measurement method of the present application completely eliminates the influence of printing process factors, the method is scientific and reasonable, the device is simple and practical, and it meets the measurement technical specification. The measurement method fills the technical gap in the measurement of "repeat positioning accuracy" in the production of CCD automatic screen printing machine equipment industry, and makes a contribution to the equipment period verification technology in the use cycle of CCD automatic screen printing machine in the printing industry.

[0043] The above specific embodiments are only preferred specific embodiments of the present application. Any repeat accuracy measurement device and repeat accuracy measurement method that is the same as or equivalent to the present structure is within the scope of the present application.

Claims

1. A method for detecting the repeatability accuracy of a CCD automatic screen printing machine, comprising a test board (21) and three dial indicators (11a, 11b, 11c), characterized in that: The test board (21) is equipped with a target (22) according to the daily printing process. Test point inserts (23) are installed on the test board (21) at three test points Cx1, Cx2, and Cy in the printing conveying direction. Cx1 is the first test point in the X direction, Cx2 is the second test point in the X direction, and Cy is the test point in the Y direction. The height of the test point inserts (23) is used to overcome the height limitation of at least 10 mm when the test head of the dial indicator (11a, 11b, 11c) is placed horizontally. The measuring instruments are three dial indicators (11a, 11b, 11c) at the same time, and interference preset is performed to measure the test points. The negative deviation values ​​of Cx1, Cx2, and Cy are determined after the interference preset is set. The readings of the three dial indicators (11a, 11b, 11c) are set to 0 as the positioning origin. When the measured values ​​of test points Cx1, Cx2, and Cy are less than the given value of "repeat positioning accuracy", the single test of the "repeat positioning accuracy" of the screen printing machine (31) is deemed to be qualified. If the measured values ​​of test points Cx1, Cx2, and Cy are greater than or negative than the given value, the test is deemed to be unqualified. When the test is deemed unqualified, the distribution of the measured values ​​of the angle formed by the three test points Cx1, Cx2, and Cy is analyzed to obtain the deviation direction of the screen printing machine's conveying mechanism.

2. The method for detecting repeatability accuracy of a CCD automatic screen printing machine according to claim 1, characterized in that: The bases (12) of the three dial indicators (11a, 11b, 11c) are made of marble. The marble bases sit on the printing table (34) of the screen printing machine (31) by their own weight. The marble bases can slide by their own weight, which makes it convenient for the test heads of the dial indicators (11a, 11b, 11c) to perform vertical calibration on the test points Cx1, Cx2, and Cy.

3. The method for detecting repeatability accuracy of a CCD automatic screen printing machine according to claim 1, characterized in that: When the conveyor belt (32) of the screen printing machine (31) is conveyed from left to right, the test points Cx1, Cx2, and Cy formed by the test plate inserts (23) are located at the lower right corner; when the conveyor belt (32) of the screen printing machine (31) is conveyed from right to left, the test points Cx1, Cx2, and Cy formed by the test plate inserts (23) are located at the lower left corner.

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