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. 29, 1994
Filed:
Feb. 25, 1994
Applicant:
Inventor:
Masaru Nyui, Tokyo, JP;
Assignee:
Canon Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01D / ;
U.S. Cl.
CPC ...
25023116 ; 2502 / ;
Abstract
In a rotation detector, a light beam from a light irradiating device is projected onto a first scale of an optical scale comprising gratings having a constant period provided around a cylindrical member of a rotating member, the light beam modulated by the first scale is projected onto a second scale of the optical scale via a region away from the center of the rotation shaft of the rotating member, the light beams as a result of modulation by the second scale are sensed by a light sensing device, and information regarding the rotation of the rotating member is detected using signals from the light sensing device.