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:
Feb. 21, 1995
Filed:
Mar. 12, 1993
Guenter Makosch, Sindelfingen-Maichingen, DE;
International Business Machines Corporation, Armonk, NY (US);
Abstract
A phase measuring method and apparatus are described for determining the phase difference between two polarized light beams which, in contrast to prior phase measuring techniques, permits simultaneous signal evaluation. The orthogonally polarized light beams with the phase difference are initially split by a beam splitter into several partial beam pairs which, by means of a lens are focused as parallel beams into a phase shifter, a polarizer, and an array of light sensors. Phase differences of the light beams create intensity differences between the beams received by the different light sensors. High measuring speed and accuracy are thus provided. When combined with means for directing two spaced orthogonally polarized beams on a surface, the method and apparatus can be used to determine height differences along the surface.