Laser thickness measuring system and method

Abstract

The invention relates to a laser thickness measuring system and method. Laser displacement sensors are mounted in the ends of upper and lower beams of a C-shaped rack respectively, and the inner sideof the lower beam of the C-shaped rack is further provided with a laser displacement sensor; before thickness measurement, a standard sheet measures the distance Y between the upper and lower displacement sensors and the distance X from the laser displacement sensor in the inner side of the lower beam to the upper beam by scanning, the one-to-one correspondence between Y and X is determined aftermeasurement for multiple times, and a function relation is fit; and in the practical film thickness measuring process, in any scanning position, the laser displacement sensor at the ends of the upperand lower beams of the C-shaped rack measure the distance A from the upper laser displacement sensor to the upper surface of a film and the distance B from the lower laser displacement sensor to the lower surface of the film respectively, and the laser displacement sensor in the inner side of the lower beam of the C-shaped rack measures the position X to the upper beam. The distance between the upper and lower laser displacement sensors is measured dynamically in each scanning position, and a measurement result is more accurate.

Description

technical field [0001] The invention belongs to the field of non-contact online thickness measurement of thin films, and more specifically relates to an online laser thickness measurement system and measurement method for thin films. Background technique [0002] In industrial production such as lithium battery pole piece coating and metal foil production line, the uniformity of the thickness of the strip determines the quality of the final product, so the online thickness detection of the strip is very important. For the thickness measurement of non-transparent films such as lithium battery coated pole pieces and metal foils, the more commonly used online thickness measurement method is the upper and lower differential laser triangulation method, that is, the upper and lower laser heads are used to measure the thickness of the upper and lower laser heads respectively. The distance to the upper and lower surfaces of the film is subtracted from the distance between the upper ...

AI Technical Summary

Problems solved by technology

The laser thickness measuring device in the above-mentioned existing equipment is usually based on the thickness measurement form of the C-shaped frame scanning thickness measurement design. Although this C-shaped frame has been widely used, in the actual measurement process, due to the back and forth scanning process of the C-shaped frame There is a large mechanical vibration in the center, which will cause the vibration or even slight deformation of the upper and lower beams of the C-shaped frame, which will make the distance between the upper and lower laser heads unstable, and will cause a large deviation for micron-level thickness measurement

Disclosed in CN106152952A is a differential on-line laser thickness measurement system capable of multi-point correction. Although it solves the measurement deviation caused by the unstable distance between the upper and lower laser heads, its two laser displacement sensors are located on different tracks. It is difficult to achieve precise synchronous movement

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