Abstract: An optical position sensor employs two pairs of light emitting elements and photo sensing elements. Each pair of the light emitting element and the photo sensing element are arranged in a spaced apart relationship with the other pair in a direction of movement of the moving object. The distance between the pairs of the light emitting elements and the photo sensing elements substantially corresponds to the length of the moving object.
Abstract: Optical examination apparatus is described including a basic setup comprising a point source of light, a first optical system forming a converging beam of light reflected from the examined object, and a second optical system located to receive the intercepted beam of reflected light, to collimate it, and to direct the collimated beam to a viewing device. The basic setup is capable of combined operation as a Fizeau interferometer, a schlieren device, and/or a moire deflectometer.