Patent ID: 7746239

Claim:
A light scattering type smoke sensor comprising: a sensor body; a light-emitting opening and a light-receiving opening that are disposed on an outer surface of the sensor body; a transparent cover that is attached to the outer surface of the sensor body for covering the light-emitting opening and the light-receiving opening; a light-emitter that is incorporated in the sensor body; a light-receiver that is incorporated in the sensor body; and a fire judging unit that is incorporated in the sensor body, wherein: the light-emitter is configured for emitting light toward a smoke-sensing point that is set in an open smoke-sensing space located outside the transparent cover via the light-emitting opening; the light-receiver is configured for receiving scattered light generated by the light emitted from the light-emitter to the smoke-sensing point via the light-receiving opening, and to output a light-received signal corresponding to an amount of received light scattered; and the fire judging unit is configured for judging presence/absence of fire occurrence based on the amount of received light identified by the light-received signal output from the light-receiver.