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:
Jul. 28, 1992
Filed:
Aug. 12, 1991
Nippon Mining Co., Ltd., Tokyo, JP;
Abstract
Infrared rays radiated from a moving object is converged into a plurality of infrared ray detectors by optical system. Detecting area is instituted by the optical system so as to put the infrared rays into a plurality of the infrared ray detectors with time difference therebetween. Signal processing unit produces a detecting signal when there is a predetermined time difference between signals produced by a plurality of the infrared ray detectors. It is possible to avoid wrong operation which is caused by popcorn noise and a differential noise having a bit of time difference caused by temperature gradient in space. Forming a curved imaginary boundary line, a plurality of detecting zones are disposed at out side and inside of the curved imaginary boundary line to detect the object invading from any direction.