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:
Aug. 29, 1995
Filed:
Dec. 10, 1993
Pierre Dautriche, Claix, FR;
Thomson-CSF Semiconducteurs Specifiques, Paris, FR;
Abstract
A thermal image detector and, more particularly, linear or matrix pyroelectric detectors. These detectors work differentially in successive phases of illumination and masking via a shutter that is synchronized with signal processing circuits. The detector generates differential measurement signals representing variations of pyroelectric signals recorded during a cycle comprising a masking phase and an illumination phase. To eliminate fixed pattern noise, it is proposed to make the measurements by difference between two successive cycles of masking and illumination, the order of the illumination/masking cycles being reversed between the two cycles but the measurements being made identically in both cycles. A memory records the signals during a cycle. A subtractor subtracts the signal of the current cycle from the signal recorded in the previous cycle.