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:
Jan. 30, 1990
Filed:
Sep. 26, 1986
Shigesato Iwasa, Harvard, MA (US);
Neal R Butler, Acton, MA (US);
Jeff L McClelland, Somerville, MA (US);
Honeywell Inc., Minneapolis, MN (US);
Abstract
What is disclosed is a preamplifier used with each pyroelectric detector in an infrared imaging array system. The preamplifier transistor is a MOSFET transistor that can operate with zero volts between its source and gate terminals, and the preamplifier is biased either by a nonconducting diode that provides a high biasing impedance while the bias voltage is low enough to keep the diode below its conduction voltage; or an NPN transistor switch is periodically operated to place charge on the gate of the preamplifier transistor to maintain it at its bias level. When the bias transistor is not operated, the associated detector detects and a detector reading is taken from each detector in the array. NPN transistor switches can be manufactured consistently and their conduction level can be adjusted to balance the gain of all preamplifiers in the detector array.