Electro-Optical Micrometer

Author:  Martin O. Patton
Source:  US Patent 5,448,361
Doc ID:  1995041
Year of Publication:  1995
Abstract:  
An electro-optical micrometer for measuring the thickness of a workpiece includes a fixture for holding the workpiece in a fixed position and a plunger that can be moved from a reference position to a second position indicative of the thickness of the workpiece. The plunger carries a spherical convex lens. A laser directs a beam of light against the lens and thereafter onto a sensor that can determine the linear displacement of the beam of light. The movement of the plunger can be correlated to linear displacements of the beam of light which, in turn, can be calculated and displayed by a computer.