摘要 |
<p>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 visible light centered about 6,500 A to the terminus of the wand. The reflected light energy from the symbol when it is scanned by the wand is transmitted to the silicon photodetector via the said second single fiber which is also coupled to a third single fiber which conducts the reflected light energy to the silicon detector.</p> |