Patent ID: 8941505
Filing Date: 2015-01-27
Classification: G01N,G08B

Abstract:
1. A smoke detector comprising: a plurality of light emitting devices which emit light beams of mutually different wavelengths; and a plurality of scattered light receiving sections which receive, at a different scattering angle for each light beam of the respective wavelength, scattered light generated due to the plurality of light beams emitted simultaneously from these light emitting devices impinging on smoke, wherein a light emission driving under a first driving condition which makes the plurality of the light emitting devices simultaneously emit light with a light emission current of the same current value, and a light emission driving under a second driving condition which changes a light emission current of at least one of the plurality of the light emitting devices so that the light emission current is different from that of the other light emitting device, are performed at a different timing.