摘要 |
The smoke detecting apparatus of the present invention comprises a detection space (52) into which generated smoke is to be introduced; light-emitting means (2) for emitting a predetermined coded light pulse train into the detection space (52); light-detecting means (3) for detecting scattered light which is generated when the light emitted from the light-emitting means (2) is scattered by the smoke and generating an electric signal corresponding to the detected light; and control means (4) for generating a burst code signal composed of a pulse train coded with a reference pulse to the light-emitting means (2) and judging that the smoke exists in the detection space (52) when the pulse patterns of thus compared signals coincide with each other. According to this configuration, the apparatus can securely operate at the time of smoking and cannot detect when there is no smoke. <IMAGE> |