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:
Nov. 12, 1996
Filed:
Dec. 13, 1995
Applicant:
Inventor:
Mikio Mochizuki, Tokyo, JP;
Assignee:
Nohmi Bosai, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G08B / ;
U.S. Cl.
CPC ...
340630 ; 250573 ; 250574 ; 356431 ;
Abstract
A photoelectric type fire detector includes self-testing capabilities. An upper level threshold limit and a lower level threshold define a predetermined range for output levels of an amplifier connected to an output of a light receiving element. In a self-test mode, a gain set in the amplifier is increased automatically. The number of times in which the amplifier output level deviates from the predetermined range is counted. If the deviation count exceeds a predetermined count threshold, it is determined that the photoelectric type fire detector is abnormal.