Flame detecting arrangement for detecting a flame through horizontal and vertical scanning of a supervisory region by using a photodetector

Patent 4800285 Issued on January 24, 1989. Estimated Expiration Date:

June 29, 2007. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

Automatic fire extinguisher with infrared ray responsive type fire detector
Patent #: 4671362
Issued on: 06/09/1987
Inventor: Odashima

Fire extinguishing condition monitoring apparatus for automatic fire extinguishing equipment Patent #: 4706760
Issued on: 11/17/1987
Inventor: Arai , et al.

Inventors

Assignee

Hochiki Kabushiki Kaisha

Application

No. 07/068145 filed on 06/29/1987

US Classes:

250/554, Flame light source340/578By radiant energy

Examiners

Primary: Nelms, David C.
Assistant: Allen, Stephone B.

Attorney, Agent or Firm

Fogiel; Max

International Class

G08B 17/12 (20060101)

Foreign Application Priority Data

1986-06-30 JP

Abstract

A flame detecting apparatus and a flame detecting method which utilizes a flame detector having a directivity and provided with a photodetector such as a photodiode or a phototransistor which produces a photo-output in response to the intensity of light incident thereupon. The flame detector is scanned sequentially in the horizontal and the vertical direction within a supervisory region. When a photo-output from said flame detector obtained in the horizontal or vertical scanning by said scanning means exceeds a predetermined threshold value, one of the horizontal and the vertical scanning is suspended, while repeating the other, vertical or horizontal, scanning at the same horizontal or vertical position several times. Flame determination is made when the changes in the photo-outputs, which is obtained through the repeated scanning, exceed a predetermined value and they last over a predetermined scanning angle.