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:
Mar. 16, 1999
Filed:
Apr. 14, 1997
Shigeki Kato, Utsunomiya, JP;
Kou Ishizuka, Omiya, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
This invention relates to an apparatus for detecting rotational information, and includes a disk attachable to a spindle, with relative rotational information of the disk to be detected. The apparatus also includes a a rotation detection grating on the disk, a main body unit independent from the disk, an optical detection unit fixed in the main body unit, a light source, a reference grating, and a light-receiving element fixed to the optical detection unit. The rotational information of the disk relative to the optical detection unit is detected by the light-receiving element by detecting a light beam which is emitted by the light source and goes via the rotation detection grating and the reference grating. A positioning block for positioning the spindle attachable to the disk is also included. The positioning block has a V-shaped portion which is arranged so that slope surfaces thereof are substantially symmetrical about a line that connects a rotation center of the spindle to be attached to the disk and the optical detection unit. The spindle is positioned by putting the spindle on the V-shaped portion.