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:
Nov. 13, 1990
Filed:
Dec. 27, 1988
Applicant:
Inventors:
Assignee:
Matsushita Electric Industrial Co., Ltd., Kadoma, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01D / ; H03M / ;
U.S. Cl.
CPC ...
25023114 ; 25023118 ; 341-3 ;
Abstract
A scale (110) having apertures representing a binary code (113A-113E) and other apertures (115, 116, 111) generating two compensation signals and moire fringes in cooperation with a mask (105) having tilted apertures (112A) is scanned by a light beam (101A), and the light beam which has passed through the aperture is detected, and an approximate position of the scale is detected by means of the binary code, then a precise position is detected by a signal of the moire fringes which is compensated on the basis of a predetermined algorithm (Table 1) specified by the compensation signals.