Patent ID: 6078040
Filing Date: 2000-06-20
Classification: G01N,G08B

Abstract:
A smoke detecting apparatus which determines a fire by optically detecting smoke particles suspended in air sucked from a monitored zone, comprising:a laser diode which emits laser light having an electric field component in a predetermined direction;an imaging lens which forms a light source image of a light-emitting face of said laser diode in a smoke detecting area through which sucked air passes; anda light receiving device which is disposed on an optical axis, said optical axis passing through an imaging position of the light source image in said smoke detecting area and being set in a plane which is substantially parallel to a direction of the electric field component of the laser light, said light receiving device receiving scattered light due to a smoke particle passing through the imaging position of the light source image and a vicinity of the imaging position in said smoke detecting area.