Patent · US Expired

Smoke detecting apparatus with a predetermined direction electric field component

US6078040A · kind A · utility

5Cited by
3References
6Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 30, 1998
Grant dateJun 20, 2000
Priority date
Expiry dateJun 30, 2018

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG08B17/113
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A light source image, i.e., a near field pattern of the light-emitting face of a laser diode which emits laser light having the electric field component in a predetermined direction is formed by an imaging lens at an image forming position of a smoke detecting area through which a flow of sucked air passes. A light receiving device is disposed on an optical axis which passes through the image forming position of a light source image in the smoke detecting area and which is set in a plane that is substantially parallel to the direction of the electric field component of the laser light, and receives scattered light due to a smoke particle passing through the imaging position of the light source image and the vicinity of the imaging position.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.