Abstract
To measure the 3-dimensional profiles of objects with free-form surfaces such as in pattern making and die sinking, a new optical noncontact measuring sensor is proposed in this paper. The optical sensor is based on the triangulation method in order to obtain the signal which is proportional to the displacement of the object surface to be measured. In the optical sensor, a linearly polarized laser beam illuminates the surface. The depolarized component of the light scattered from the surface is detected, excepting the specularly reflected light, by using optical components. Therefore, the profiles of diffuse reflection surfaces and metal surfaces can be measured by using the optical sensor. Using the optical sensor, a spherical surface of 4 mm diameter, coated with white paint, can be measured over ±73° in inclination angle and with 3.3 μm in standard deviation from values measured by means of a contact coordinate measuring machine.
