| 摘要 |
In apparatus for scanning a transparent original with a scanning beam relative an optical axis, a tapered optical bar is positioned adjacent the transparent original to collect a diverging beam emerging from the original and, by means of internal reflection, reduce the divergence of the beam relative the optical axis. The emerging beam is especially diverged when the scanning beam sweeps away from the optical axis or is scattered by an artifact, such as a scratch, on the original. Particularly in the case of a polychromatic beam emerging from a color transparency, the tapered bar is interposed between the transparency and color dichroic beam separating mirrors to reduce angle shift and polarization color shading due to light rays diverging from the optical axis upon the dichroic interference layers.
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