Patent ID: 7151460

Claim:
A portable electronic device having a housing to house a plurality of electronic components, the electronic components including a signal processor and an alerting device operatively connected to the signal processor, said portable device comprising: a first opto-electronic component disposed on the housing; and a second opto-electronic component disposed on the housing in relationship to the first opto-electronic component, wherein the first opto-electronic component comprises a light emitter for emitting light in a light emitting path substantially outside the housing, and the second opto-electronic component comprises a light detector for detecting light coming from a part of the light emitting path, the light detector operatively connected to the signal processor, so that when an object is present in a light emitting path, causing part of the light emitted by the light emitter to be sensed by the light detector, a detection signal is provided to the signal processor for producing an alerting signal on the alerting device.