| 摘要 |
<p>This invention relates to a bar-code reader for transferring an optical image to an optoelectronic processing unit, for applications such as the reading of bar-codes on goods for sale in supermarkets. The bar-code reader comprises a light inlet (11) and an image detector, light being conveyed from the light inlet (11) to the image detector by means of a light pipe (1), which may comprise any suitably shaped solid body made of a transparent material. The light pipe (1) may be angled at at least one corner and have matt outer surfaces except at the or each corner where the outer surface is polished and at regions where the light is to be transmitted into or out of the light pipe (1). This arrangement allows the bar-code image to be conveyed from the light inlet (11) to the image detector along a bent path without significant loss of intensity of the bar-code image. Preferably the light pipe (1) is formed as a light trap to illuminate multi-paths from the inlet (11) to the image detector. Typically this may be achieved by forming notches, angles or serrations (7) in the side of the light pipe (1).</p> |
