A flashlight includes a light source and a detector for detecting emissions from the surroundings. Depending on the position of a switch, the output of the detector is channeled through either a speaker or a LED array. The speaker outputs a tone having a frequency dependent on the intensity of ...http://www.google.fr/patents/US5839821?utm_source=gb-gplus-shareBrevet US5839821 - Flashlight with forward looking sensing of thermal bodies
Flashlight with forward looking sensing of thermal bodies
