A wand suitable for scanning the universal product code (UPC) symbol uses a light emitting diode for illuminating the symbol and a silicon photodetector for receiving the reflected energy. A single optical fiber is coupled to the diode and to a portion of a second single fiber for conducting narrow bandwidth...http://www.google.se/patents/US3983389?utm_source=gb-gplus-sharePatent US3983389 - Wand for reading optically encoded graphic symbols
