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:
Dec. 01, 1987
Filed:
Aug. 05, 1986
Applicant:
Inventor:
Richard A Johnson, Pleasanton, CA (US);
Assignee:
C & K Systems, Inc., San Jose, CA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G08B / ; G08B / ;
U.S. Cl.
CPC ...
340522 ; 340523 ;
Abstract
In an improved intrusion detection device system of the dual-sensor type, wherein one sensor is a PIR sensor and the other is a microwave sensor, the improvement comprises counting the detection of intrusion separately by the microwave sensor and by the passive infrared sensor. Thereafter, the counts by the two separate detectors are compared and an indication is given if the number exceeds a certain user selectable threshold, to indicate fault in one of the two sensor subsystems.