| 摘要 |
PROBLEM TO BE SOLVED: To increase the measurable distance and raise the distance measuring accuracy while suppressing the manufacturing cost increase by constituting such that unwanted portions of a light receiving region for receiving lights have on light receiving sensitivity and the light receiving region is made smaller. SOLUTION: The instrument is provided with a means for projecting a light beam on an object under measurement, a light receiving means which is disposed at a fixed distance from the light projecting means and has a light receiving region shaped like an approximately parallelogram having no right-angle corners, for receiving reflected lights of the light beam projected on the object, and a light shielding means formed so that the light receiving region has no light receiving sensitivity at the corners. |
