PURPOSE: To measure the curvature of a body to be checked automatically by projecting indexes on the body to be checked by parallel luminous fluxes in the directions which are symmetrical with respect to an optical axis of an objective lens, focusing the index images on an image sensor by the specified objective lens, detecting the interval, and performing computation and processing.
CONSTITUTION: Point light sources 10a and 10b are arranged at the symmetrical positions with respect to the optical axis of the objective lens system comprising a front lens 1, a rear lens 2 whose front focal point is the rear focal point of the lens 1, and a stop 3 which is arranged at the focal point. The bright points 10a and 10b are projected on the body to be checked 100 by the parallel luminous fluxes in the directions which form an equal angle θ with the optical axis of the objective lens from projecting lenses 11a and 11b. The reflected image are focused on an image sensor 14 and a reticle 13 through the objective lens and a beam splitter 12. Focusing is performed by an eyepiece lense 13', and the output from the sensor 14 is inputted into a computor 17, through a waveform shaping circuit 16. Then the curvature of the body to be checked 100 is computed and displayed 18. Thus the curvature can be automatically measured.
NOUDA MASAO
NAKABARAI SHIYUUICHI
