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, 1991
Filed:
Jun. 01, 1990
Masaaki Tsukiji, Tokyo, JP;
Tetsuharu Nishimura, Kawasaki, JP;
Koh Ishizuka, Urawa, JP;
Satoshi Ishii, Tokyo, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An encoder for measuring movement of an optical scale by photoelectrically converting light from the optical scale obtained by applying light from a light source to the optical scale, by means of light receiving element, includes detector for detecting a variation in intensity of the light received by the light receiving element and a comparator for comparing a signal from the detector with a predetermined reference signal. Consequently, a predetermined alarm signal is generated on the basis of the result of comparison obtained from the comparator. A measuring system for detecting a moving condition of an object, includes an optical scale connected to the object; a light source for applying light to the optical scale; a first detector for receiving light from the optical scale and for detecting the moving condition of the object; a second detector for detecting a variation in intensity of the light received by the first detector; and a signal forming device for forming a predetermined alarm signal on the basis of an output signal from the second detector.