| 摘要 |
<p>PURPOSE: To provide a highly practical and reliable and inexpensive hand-carry type scanning device for using a non-laser light source without errors. CONSTITUTION: A light beam is radiated from a light emitting diode so as to read a symbol, a bar code symbol for instance, and reflected light returned from the symbol is received. An optical system inside this scanning device converges the visual field of the light beam 11 and a photosensor 17 to different two planes present at the outside of a housing. A device for image-forming a vision checking window is installed inside the scanning device and the area of the vision checking window is smaller than the one of a scanning spot. The scanning device uses the light emitting diode (LED) 10 as the light source, and since the LED 10 views only the part of the scanning spot viewable through the vision checking window, the scanning spot of the relatively large size (about several millimeters) of the LED 10 is used without sacrificing read performance.</p> |
