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:
Sep. 29, 1992
Kotaro Hosaka, Ushiku, JP;
Hiroji Narumi, Kawasaka, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
It is an object of the present invention to provide a speckle interference apparatus capable of selecting given phase information at a speed higher than speckle interference fringe patterns with a higher precision. For a speckle interference apparatus in which a light beam from a light source is divided into plural light beams, and one of the light beams is passed through a measuring surface and the other light beam through a reference surface to be superposed respectively for the formation of speckle interference fringe patterns, there are arranged in the optical paths spatial filters having windows for sampling the area of a given phase among the speckle interference fringe patterns. Hence, with such filters, speckle interference fringe patterns of the same phase are produced.