| 摘要 |
An optical reader is provided for reading a bar code having ultraviolet-wavelength-responsive properties. The optical reader includes an ultraviolet light source, a photodetector, an optical system and a decoder. The ultraviolet light source generates ultraviolet light having a wavelength shorter than visible light and longer than X-rays for illuminating a target region. The photodetector generates output electrical signals indicative of light incident thereon having a wavelength within a predetermined range of wavelengths. The optical system includes a projection portion and a collection portion. The projection portion directs the ultraviolet light along a projection path extending from the ultraviolet light source to the target region. The collection portion collects the light from a bar code when the bar code occupies the target region and directs the collected light along a collection path extending from the target region to the photodetector. The decoder receives the output electrical signals of the photodetector and produces, in response thereto, electrical signals indicative of information encoded in the bar code.
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