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:
Apr. 21, 1992
Filed:
Sep. 22, 1989
Applicant:
Inventor:
Edward Tom, Philadelphia, PA (US);
Assignee:
Pennwalt Corporation, Philadelphia, PA (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01J / ;
U.S. Cl.
CPC ...
250342 ; 2503383 ; 340567 ;
Abstract
A passive infrared detector, including a pyroelectric sensor with three pairs of contiguous, active elements and a Fresnel lens with a plurality of segments each of which has an optical center and an equivalent focal length, each pair of active elements disposed in different plane, with each optical center juxtaposed to the plane of at least one of those active elements, substantially at the focal length.