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:
Oct. 05, 1999
Filed:
Jul. 15, 1997
Applicant:
Inventors:
Nobuo Iwata, Sagamihara, JP;
Mitsugu Sugiyama, Yokohama, JP;
Toshiya Sato, Yokohama, JP;
Tadashi Shinohara, Tokyo, JP;
Yutaka Shio, Yokohama, JP;
Tomonori Yabuta, Yokohama, JP;
Assignee:
Ricoh Company, Ltd., Tokyo, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01P / ;
U.S. Cl.
CPC ...
73488 ; 356 25 ;
Abstract
An apparatus for a rotational speed detecting includes a rotating disc having plural slits in a circumferential direction. A radiant element radiates light rays through the slits. A photodetector receives the rays radiated by the radiant element. Peak detectors detects peak points of the detected signal and a calculator calculates a rotational speed. The photodetector include two photodetectors separated by a distance .DELTA.L.