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.