| 摘要 |
The conventional rear ground glass and vacuum back of a copy camera is replaced by an optically transparent platen and a flexible vacuum curtain. The vacuum curtain acts both as a copy viewing screen and as a photographic film or paper retainer. A vacuum channel with vacuum passageways is defined around the perimeter of the optically transparent platen to exhaust the air between the vacuum curtain and the transparent platen to thereby retain the light sensitive material to be exposed therebetween. The vacuum curtain is mounted on a roller that engages the transparent platen as the curtain is unrolled and rerolled over the sheet of photographic material.
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