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:
May. 29, 1990
Filed:
Mar. 17, 1989
Applicant:
Inventor:
Edgar M Smith, Millersville, PA (US);
Assignee:
Burle Technologies, Inc., Wilmington, DE (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01J / ;
U.S. Cl.
CPC ...
2503381 ; 250342 ; 250221 ; 315159 ; 340567 ;
Abstract
A digital infrared detector circuit which converts changes in detector current to time varying pulses and uses feedback to adjust the coincidence of a reference signal with the trigger signal to accommodate to circuit variations caused by changes in infrared detector sensitivity or ambient temperature. To supply a highly accurate feedback reference signal an internal high frequency oscillator is used for feedback control and counted down to furnish the reference signal. The conversion from detector current to time is accomplished by using the detector to discharge an accurately charged capacitor and measuring the time to recharge the capacitor.