abstract |
A smoke detection device for use in a portable device such as a mobile terminal. The smoke detection device comprises a light emitter and a light detector disposed on different locations on the portable device so that when smoke or an intruding object is presence in the light path of the light emitter outside the device housing, it causes the light emitted by the light emitter to be scattered or reflected. When the light detector senses the scattered or reflected light, it can cause an alarm signal to be produced by the portable device. The emitted light can be in the infrared region so that the detection is independent of the ambient light. Alternatively, the light emitter is operated in a pulsed mode. Additional light emitter and light detectors can be disposed on the portable device for proximity sensing in addition to smoke detection. |