摘要 |
Apparatus for supporting a sheet of photosensitive material in the image plane of an optical imaging system for exposure thereat. The apparatus includes a first cover plate assembly having a transparent cover plate and a second backing plate assembly including a relatively flexible backing sheet. The cover plate assembly is driven into contact with the backing plate assembly with the photosensitive sheet to be exposed supported therebetween such that an air-tight chamber is defined between the cover plate assembly and the relatively flexible backing sheet. The air-tight chamber is then evacuated through the cover plate assembly, and as it is evacuated, the flexible backing plate will be sucked towards the cover plate assembly and drive the photosensitive sheet into firm contact with the transparent cover plate.
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