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:
Mar. 10, 1998
Filed:
Aug. 02, 1995
Hochiki Corporation, Tokyo, JP;
Abstract
A scan type fire detecting apparatus is provided with a scanning unit which stepwise scans a monitoring area in a horizontal direction and vertically scans at each step of the horizontal scan to output a detecting signal obtained during the vertical and horizontal scan while a fire judging section judges an occurrence of a fire based on the detecting signal from the scanning unit. The fire judging section includes a first fire judging section which judges as to whether or not the detecting signal outputted from the scanning unit during the vertical and horizontal scanning is higher than a predetermined threshold value, and stops the horizontal scan of the scanning unit when the detecting signal is higher than the predetermined threshold value. A second fire judging section vertically scans the scanning area at the horizontal stop position, determined by the first fire judging section, and analyzes a frequency of the detecting signal detected through the vertical scan to judge whether or not the detecting signal is on the basis of a fluctuation of a flame, to thereby determine an occurrence of a fire when it is judged that the detecting signal is on the frequency of the fluctuation of a flame.