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:
Sep. 24, 1996
Filed:
Mar. 11, 1993
Masaru Nyui, Tokyo, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A rotation measuring apparatus has a grating disposed on a cylindrical surface along the circumferential direction thereof, an illuminating system for applying a light beam to a first location on the grating, light emerging from the first location by the application of the light beam from the illuminating system being incident on a second location on the grating, light beams for detection emerging in a plurality of directions from the second location on which the light is incident, a plurality of light receiving elements for detecting the light beams for detection, respectively, the relative rotation information of the grating and the light receiving elements being measured by the detection by the light receiving elements, and light intercepting means for preventing the light beam for detection which should enter at least one of the light receiving elements from entering a different light receiving element.