| 摘要 |
<p>The colour detector consists of a housing with two glass fibre light guides which direct light from primary sources onto the surface of the printed paper under examination. The beams of light emerging from the ends of the guides are non-divergent and have a cross-sectional area equal to that of the guides. A duct provides an air flow through a chamber and aperture onto the paper to hold it down during examination. The light reflected from the paper surface passes through an infra-red filter and into a bundle of glass fibre light guides, which splits into four channels. At the end of each channel is a filter. Each filter allows through a different colour, e.g. red, green, blue and neutral, to the front of an intensity measuring cell.</p> |
