Thickness gauge and thickness measuring method

Abstract

The invention relates to a thickness gauge and a thickness measuring method, and the thickness gauge comprises a first detection unit which detects the shortest distance between the first detection unit and the surface of one side of a detection sample to obtain a first distance; the second detection unit detects the shortest distance between the second detection unit and the surface of the other side of the detection sample to obtain a second distance; the thickness calculation unit is used for subtracting the first distance and the second distance from the known measurement distance between the first detection unit and the second detection unit to obtain the actual thickness; the calibration analysis unit is used for calculating a calibration distance through a set calibration formula according to the actual thickness, a determined standard thickness and a determined standard angle; and the moving unit changes the relative distance between the first detection unit and the second detection unit along the transmission direction of the production line according to the calibration distance. The thickness gauge can automatically calibrate the measurement distance when the detection sample shakes, and ensures the thickness accuracy of the detection sample.

Description

Technical Field

[0001] The present invention relates to the field of thickness detection, in particular to a thickness gauge. Background Art

[0002] For test samples with uniform and consistent thickness parameters, such as electrodes, carbon ribbons or flat plates, their thickness often needs to be measured in the production line to ensure that the thickness parameters of the test samples meet the standards. However, the test samples in motion are not suitable for contact thickness gauges, which will cause significant wear of the test samples and low detection efficiency. For this reason, existing production lines usually use lasers for thickness measurement to achieve non-contact detection.

[0003] See also Figure 1 The existing laser thickness gauge includes a first detection unit 11, a second detection unit 12, and a processor (not shown) respectively arranged on the upper and lower sides of the detection sample P. The first detection unit 11 includes a first transmitting end and a first receiving end. The first transmitting end continuously emits a laser to irradiate the upper surface of the detection sample P. After being reflected by the upper surface of the detection sample P, it is received by the first receiving end, thereby measuring the shortest distance between the first detection unit 11 and the detection sample P, which is the first distance A; the second detection unit 12 includes a second transmitting end and a second receiving end. The second transmitting end continuously emits a laser to irradiate the lower surface of the detection sample P. After being reflected by the lower surface of the detection sample P, it is received by the second receiving end, thereby measuring the shortest distance between the second detection unit 12 and the detection sample P, which is the second distance B; the processor can obtain the thickness D of the detection sample P by subtracting the first distance A and the second distance B from the known measurement spacing C between the first detection unit 11 and the second detection unit 12.

[0004] However, in actual detection using existing laser thickness gauges, since the test sample P will vibrate when moving in the production line, the thickness detected by the laser thickness gauge is not the actual thickness of the test sample P, resulting in inaccurate thickness detection, resulting in a decrease in detection efficiency and an increase in production costs. Summary of the Invention

[0005] Based on this, the object of the present invention is to provide a thickness gauge that can be automatically calibrated to ensure the accuracy of the thickness measurement of the test sample.

[0006] A thickness gauge is used to measure the thickness of test samples on a production line in real time, comprising:

[0007] A first detection unit detects the shortest distance between the first detection unit and a surface of one side of the detection sample to obtain a first distance;

[0008] The second detection unit detects the shortest distance between it and the other surface of the detection sample to obtain a second distance;

[0009] The thickness calculation unit subtracts the first distance and the second distance from the known measurement spacing between the first detection unit and the second detection unit to obtain the actual thickness;

[0010] The calibration analysis unit calculates a calibration distance according to the actual thickness, a determined standard thickness, and a determined standard angle through a set calibration formula;

[0011] The moving unit changes the relative distance between the first detection unit and the second detection unit along the transmission direction of the production line according to the calibration distance.

[0012] Compared with the existing laser thickness gauge, the thickness gauge of the present invention performs calibration and calibration in advance to obtain the required parameter values, and calculates the calibration distance through the set calibration formula, thereby realizing real-time automatic calibration, greatly improving the detection accuracy of the thickness of the detection sample, and also improving the detection efficiency. There is no need to stop the machine for calibration when detection errors occur.

[0013] Further, the standard formula is:

[0014]

[0015] Where, H is the actual thickness, L is the calibration distance, h is the standard thickness, and α is the standard angle.

[0016] Further, when H > h / cosα, the calibration distance L is a positive value l, and the first calibration formula is obtained:

[0017]

[0018] Where, l is the absolute value of L.

[0019] Further, when H < h / cosα, the calibration distance L is a negative value -l, and the second calibration formula is obtained:

[0020]

[0021] Where, l is the absolute value of L.

[0022] Further, it further includes an update unit, and the update unit calibrates the measurement spacing according to the calibration distance to obtain an updated spacing:

[0023]

[0024] Where, E is the updated spacing, and C is the measurement spacing;

[0025] And input the updated spacing as the new measured spacing into the thickness calculation unit.

[0026] The present invention also provides a thickness measurement method for real-time detecting the thickness of a detection sample on a production line, including:

[0027] Detect the shortest distance between a first detection point and one side surface of the detection sample to obtain a first distance;

[0028] Detect the shortest distance between a second detection point and the other side surface of the detection sample to obtain a second distance;

[0029] Subtract the first distance and the second distance from the known measurement spacing between the first detection point and the second detection point to obtain the actual thickness;

[0030] According to the actual thickness, a determined standard thickness, and a determined standard angle, calculate a calibration distance through a set calibration formula;

[0031] Change the relative distance between the first detection point and the second detection point along the transmission direction of the production line according to the calibration distance.

[0032] Further, the standard formula is:

[0033]

[0034] Where, H is the actual thickness, L is the calibration distance, h is the standard thickness, and α is the standard angle.

[0035] Further, when H > h / cosα, the calibration distance L is a positive value l, and the first calibration formula is obtained:

[0036]

[0037] Where, l is the absolute value of L.

[0038] Further, when H < h / cosα, the calibration distance L is a negative value -l, and the second calibration formula is obtained:

[0039]

[0040] Where, l is the absolute value of L.

[0041] Further, calibrate the measurement spacing according to the calibration distance to obtain an updated spacing:

[0042]

[0043] Where, E is the updated spacing, and C is the measurement spacing;

[0044] The updated spacing is used as the new measurement spacing to calculate the actual thickness.

[0045] For better understanding and implementation, the present invention is described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a schematic diagram of the structure of a thickness gauge in the prior art.

[0047] Figure 2 This is a schematic diagram of the structure of a thickness gauge in the prior art when detecting sample vibration.

[0048] Figure 3 It is a structural schematic diagram of the thickness gauge of the present invention.

[0049] Figure 4 This is a flow chart of the thickness measurement method of the present invention.

[0050] Figure 5 Schematic diagram of the automatic calibration principle of the present invention. DETAILED DESCRIPTION

[0051] The present invention carefully analyzes the existing laser thickness gauge, please refer to Figure 2 If the first distance A and the second distance B measured by the existing laser thickness gauge are not on the same optical axis, when the test sample P vibrates during movement, resulting in angular deflection, the thickness error of the test sample P measured by the laser thickness gauge will be extremely large, affecting the actual detection effect. To this end, the present invention attempts to first calibrate the actual thickness obtained by real-time detection with the calibration distance using a calibration block, add a calibration analysis unit to analyze and calculate the calibration distance, and then add a moving unit to move the first detection unit 11 or the second detection unit 12 according to the calibration distance, thereby ensuring that the first distance A and the second distance B are collinear, thereby ensuring the accuracy of thickness detection.

[0052] Combine Figures 3 and 4 The thickness gauge of the present invention includes a first detection unit 11, a second detection unit 12, a thickness calculation unit 2, a calibration analysis unit 3, a moving unit 4 and an updating unit 5.

[0053] The first detection unit 11 is arranged above the detection sample P and continuously detects the shortest distance to the upper surface of the detection sample P. Specifically, the first detection unit 11 includes a first transmitting end and a first receiving end. The first transmitting end continuously emits a signal to illuminate the upper surface of the detection sample P. After being reflected by the upper surface of the detection sample P, it is received by the first receiving end, thereby measuring the shortest distance between the first detection unit 11 and the detection sample P. This distance is the first distance A, which corresponds to the first optical axis. In particular, the detection point located on the first detection unit 11 is the first detection point, and the shortest distance from the first detection point to the upper surface of the detection sample P is the first distance A. The first detection unit 11 can use laser or infrared rays as the detection signal.

[0054] The second detection unit 12 is positioned below the test sample P and continuously detects the shortest distance to the lower surface of the test sample P. Specifically, the second detection unit 12 includes a second transmitting end and a second receiving end. The second transmitting end continuously emits a signal to illuminate the lower surface of the test sample P. The signal is reflected by the lower surface of the test sample P and received by the second receiving end, thereby measuring the shortest distance between the second detection unit 12 and the test sample P. This distance is the second distance B, which corresponds to the second optical axis. In particular, the detection point on the second detection unit 12 is the second detection point, and the shortest distance from the second detection point to the lower surface of the test sample P is the second distance B. The second detection unit 12 can use laser or infrared light as the detection signal.

[0055] The thickness calculation unit 2 is connected to the first detection unit 11 and the second detection unit 12, receives the first distance A from the first detection unit 11 and the second distance B from the second detection unit 12, and subtracts the first distance A and the second distance B from the initially known measurement distance C between the first detection unit 11 and the second detection unit 12 to obtain the actual thickness H = C-(A+B).

[0056] The calibration analysis unit 3 receives the actual thickness H from the thickness calculation unit 2 and calculates the calibration distance L according to a set calibration formula. Specifically, the calibration analysis unit 3 determines the relationship between the cosine value of the actual thickness H with respect to the standard angle α and the standard thickness h, and calculates the calibration distance L using the corresponding first calibration formula and second calibration formula based on the relationship.

[0057] When the test sample P is shaken, the first optical axis and the second optical axis may be offset. Calibration is required to accurately measure the thickness of the test sample P. Figure 5 , Figure 5 The principle of calibrating the first and second optical axes using a standard gauge block is demonstrated. The standard thickness of the standard gauge block is h, and the angle between the standard gauge block and the transmission direction of the production line is α, which gives the calibration formula:

[0058]

[0059] Specifically, when the upper laser beam is located on the right side of the lower laser beam, and at this time the upper laser beam is at position a, H > h / cosα, and the calibration distance L is a positive value l, the first calibration formula can be obtained:

[0060]

[0061] where l is the absolute value of L.

[0062] When the upper laser beam and the lower laser beam are on the same optical axis, and at this time the upper laser beam is at position b, H = h / cosα, and the calibration distance L is 0, that is, the first optical axis and the second optical axis are collinear, and the thickness D of the detected sample P is equal to the actual thickness H, and no calibration is required;

[0063] When the upper laser beam is located on the left side of the lower laser beam, and at this time the upper laser beam is at position c, H < h / cosα, and the calibration distance L is a negative value -l, the second calibration formula can be obtained:

[0064]

[0065] The moving unit 4 changes the relative distance between the first detection unit 11 and the second detection unit 12 along the transmission direction of the production line according to the calibration distance L. In one embodiment, the moving unit 4 is arranged on the first detection unit 11, and the first detection unit 11 is moved along the straight line in the transmission direction of the production line according to the calibration distance L, so that the first optical axis and the second optical axis are collinear, and then the actual thickness H is calibrated.

[0066] The updating unit 5 calibrates the measurement distance between the first detection unit 11 and the second detection unit 12 according to the calibration distance L to obtain an updated distance E, and the updated distance satisfies Let the updated distance E be input into the thickness calculation unit 2 again as a new measurement distance. Specifically, when multiple calibrations are performed, and the calibration distances are L1, L2, L3 respectively, at this time the updated distance satisfies And so on. It can be understood that since the calibration distance L is very small, in a right triangle with the calibration distance L and the measurement distance C as the right sides and the updated distance E as the hypotenuse, the very small calibration distance L corresponds to a very small angle, and at this time the right side of the measurement distance C is approximately equal to the hypotenuse of the updated distance E; therefore, even if the initial measurement distance C is always used for calculation, it will not have a great impact on the actual measurement accuracy. The updating unit 5 of the present invention updates the measurement distance only to obtain higher accuracy, rather than a necessary limitation of the present invention.

[0067] The present invention calibrates the actual thickness and calibration distance obtained by real-time detection in advance, and calculates the corresponding calibration distance in real time according to the actual thickness in actual production, thereby automatically calibrating the thickness detection of the test sample in real time to ensure the accuracy of thickness detection.

[0068] The above-described embodiments merely represent the best modes of carrying out the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that variations and modifications are possible, as would be apparent to those skilled in the art, without departing from the spirit of the present invention, and the present invention is intended to encompass such variations and modifications.

Claims

1. A thickness gauge that measures the thickness of test samples on a production line in real time, characterized by: Comprising: A first detection unit that detects the shortest distance between it and one side surface of the detection sample to obtain a first distance; A second detection unit that detects the shortest distance between it and the other side surface of the detection sample to obtain a second distance; A thickness calculation unit that subtracts the first distance and the second distance from the known measurement spacing between the first detection unit and the second detection unit to obtain the actual thickness; A calibration analysis unit that calculates a calibration distance through a set calibration formula according to the actual thickness, a determined standard thickness, and a determined standard angle; A moving unit that changes the relative distance between the first detection unit and the second detection unit along the transmission direction of the production line according to the calibration distance.

2. The thickness gauge according to claim 1, characterized in that: The standard formula is: Where H is the actual thickness, L is the calibration distance, h is the standard thickness, and α is the standard angle.

3. The thickness gauge according to claim 2, characterized in that: When H > h / cosα, the calibration distance L is a positive value l, and the first calibration formula is obtained: Where l is the absolute value of L.

4. The thickness gauge according to claim 2, wherein: When H < h / cosα, the calibration distance L is a negative value -l, and the second calibration formula is obtained: Where l is the absolute value of L.

5. The thickness gauge according to claim 1, wherein: It further includes an update unit that calibrates the measurement spacing according to the calibration distance to obtain an updated spacing: Where E is the updated spacing and C is the measurement spacing; And inputs the updated spacing as a new measurement spacing into the thickness calculation unit.

6. A thickness measurement method for measuring the thickness of a test sample on a production line in real time, characterized by: Comprising: Detecting the shortest distance between the first detection point and one side surface of the detection sample to obtain a first distance; Detecting the shortest distance between the second detection point and the other side surface of the detection sample to obtain a second distance; Subtracting the first distance and the second distance from the known measurement spacing between the first detection point and the second detection point to obtain the actual thickness; Calculating a calibration distance through a set calibration formula according to the actual thickness, a determined standard thickness, and a determined standard angle; Changing the relative distance between the first detection point and the second detection point along the transmission direction of the production line according to the calibration distance.

7. The thickness measurement method according to claim 6, characterized in that: The standard formula is: Where H is the actual thickness, L is the calibration distance, h is the standard thickness, and α is the standard angle.

8. The thickness measurement method according to claim 7, characterized in that: When H > h / cosα, the calibration distance L is a positive value l, and the first calibration formula is obtained: Where l is the absolute value of L.

9. The thickness measurement method according to claim 7, characterized in that: When H < h / cosα, the calibration distance L is a negative value -l, and the second calibration formula is obtained: Where l is the absolute value of L.

10. The thickness measurement method according to claim 6, characterized in that: Calibrating the measurement spacing according to the calibration distance to obtain an updated spacing: Where E is the updated spacing and C is the measurement spacing; And calculating the actual thickness using the updated spacing as the new measurement spacing.

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