Patent Number: 6,295,132

Title: Interferometric measuring device having parallelly-displacing arrangement and compensating grating in the reference path

Abstract: An interferometric measuring device for measuring shapes of rough surfaces of an object to be measured. The measuring device has a radiation generator that emits a short-coherent radiation; a beam splitter for forming a reference beam that is directed toward a device having a reflecting element for periodically changing the light path, and a measuring beam which is directed toward the object to be measured; a superposition element at which the measuring beam coming from the object to be measured and the reference beam coming from the device are made to interfere; and a photodetector that receives the interfered radiation. In a simple design, a high measuring accuracy is achieved in that the device for changing the light path has a parallelly-displacing arrangement arranged in the beam path, and, fixedly arranged behind it, the reflecting element, and that a compensating grating is arranged in the beam path of the reference beam upstream of the parallelly-displacing arrangement. The reference beam is diffracted at the grating both prior and subsequent to passing through the parallelly-displacing arrangement.

Inventors: Drabarek; Pawel (Tiefenbronn, DE)

Assignee: Robert Bosch GmbH

International Classification: G01B 9/02 (20060101); G01J 9/02 (20060101); G01J 9/00 (20060101); G01B 009/02 ()

Expiration Date: 09/25/2018