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:
Jul. 23, 1996
Filed:
Aug. 11, 1992
Masaaki Takagi, Tokyo, JP;
Takumi Fukuda, Tokyo, JP;
Copal Company Limited, Tokyo, JP;
Abstract
The optical displacement detecting device utilizes an encoder plate 2 mounted displaceably along a given first plane and having thereon a periodic slit pattern 1. A light source 4 is disposed behind the encoder plate 2 to illuminate the slit pattern 1 to form a primary fringe image 3 shifting along the first plane. A lens member 6 is utilized to project the primary fringe image 3 by a given magnification to form a secondary enlarged fringe image 5 shifting along a given second plane. A light receiving unit 8 is fixed in the secondary plane to optically detect the shifting secondary enlarged fringe image 5 through a periodic mask pattern to thereby output an electric signal 7 indicative of a displacement of the encoder plate 2.