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. 14, 1992
Filed:
Sep. 11, 1990
Aisaku Nagai, Iwaki, JP;
Tetuaki Kon, Iwaki, JP;
Kureha Kagaku Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
A pyroelectric infrared sensor includes a package having a light-receiving window, and at least two dual pyroelectric elements arranged in the package, each of the dual pyroelectric elements having first and second unit pyroelectric elements, the first and second unit pyroelectric elements being connected in series or parallel with each other so as to have opposite polarities, wherein the first and second light-receiving electrodes and the first and second back electrodes are formed such that an effective light-receiving electrode area of the first unit pyroelectric element opposing a central portion of the light-receiving window is smaller than an effective light-receiving electrode area of the second unit pyroelectric element opposing a peripheral portion of the light-receiving window. A difference between secondary infrared rays incident on the first and second unit pyroelectric elements which is caused by a difference between angles of visibility of these elements with respect to the light-receiving window can be compensated. This invention also relates to a method of manufacturing the dual pyroelectric element.