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. 28, 1990
Filed:
Jun. 06, 1989
Andrew A Turnbull, Reigate, GB;
Andrew I Cox, Reigate, GB;
U.S. Philips Corp., New York, NY (US);
Abstract
A thermal radiation detection apparatus has an array of pyroelectric detector devices (10) for receiving radiation from a scene whose outputs, e.g. from associated source followers (12) are supplied via a multiplexer (14) in turn to a processing circuit (20) which is responsive to each detector device signal to produce an output which substantially faithfully reproduces the received radiation signal without requiring that a chopper be used. The processing circuit operates with a correction factor to produce an output signal with first and second components proportional respectively to the device signal and its rate of change, the relative proportions of the components being in a ratio according to the device's thermal time constant. Initial device voltage level and the device's electrical time constant effects can be corrected by additional processing in the circuit (20), producing a third component of the output proportional to the integral of the device's output and in a ratio to the first component according to the electrical time constant.