The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 12, 1989
Filed:
May. 31, 1988
Gerd Ulbers, VS-Schwenningen, DE;
Hommelwerke GmbH, VS-Schwenningen, DE;
Abstract
A device for measuring the distance between the device and a measuring surface, with an optical interferometer, which has a measuring wave guide, one end of which is connected with a laser and the other of which is directed to optical measuring reflector which is positioned on the measuring surface or is connected with the same in an effective manner, which reflects the light back into the measuring wave guide. The interferometer furthermore has a reference wave guide which is coupled with the measuring wave guide at a coupling point, has a mirror on its one end, and on its other end, a photoelectrical converter, which is connected with an indicator device for indicating the electrical output signal of the photoelectrical converter. The reference wave guide is coupled, preferably by means of a polarizing beam splitter, with a branch wave guide, the end of which is connected with an additional photoelectrical converter. The reference wave guide has a phase adjustment device. The outputs of the photoelectrical converter are connected with a differential amplifier, the output signal of which is free from direct current and, is fed into the indicator device. Because the output signal of the differential is free from direct current, the further processing of the interference output signal is facilitated and the measuring precision is increased.