Abstract
In this research, an in-process machine for measuring the cross-sectional profile of parts that have textures on the surface, such as etched parts, is developed. A stripe pattern is projected perpendicularly downward onto the etched surface using an objective lens, and a reflected image signal h(x) is detected by a CCD camera. The cross-sectional profile is measured by moving the objective lens up and down. At this point, the reflected image signal g(x) is obtained by a CCD camera installed in the other detection system that does not project the stripe pattern. The technology for obtaining the stripe pattern signal f(x), calculated as h(x)/g(x), that reduces the effect of the texture on the surface of parts, is developed. Furthermore, a machine that has two optical systems in one unit is developed. h(x) and g(x) are detected at the same position on the surface of parts by separating the detected image into two images using polarized illumination and detection. The cross-sectional profile of parts with roughness Ra of 0.58μm can be measured within an error of ±1.0μm when the height of the surface of parts is measured using the image signal f(x).
