| 摘要 |
A vacuum printing frame includes a backing plate; a pressurizable bladder assembly positioned on the backing plate, the bladder assembly including a lower wall positioned on the backing plate, a plurality of partitions sealed around lower edges thereof to the lower wall and defining a series of interconnected, nested chambers arranged in alignment from and pressurizable from a head end to a foot end of the vacuum printing frame, and a plurality of holes in each partition at positions close to the securement of the respective partition to the lower wall to provide fluid communication between adjacent bladder chambers; a flexible, fluid impervious membrane positioned above the bladder assembly for supporting a mask and photosensitive sheet; a transparent plate movable between an open position for permitting the mask and photosensitive sheet to be positioned on the membrane, and a closed position for sandwiching the mask and photosensitive sheet between the membrane and the transparent plate in an evacuation region defined between the membrane and the transparent plate; a blower for supplying air under pressure to the bladder assembly when the transparent plate is in the closed position to apply a force pressing the photosensitive sheet and mask against the transparent plate in a predetermined spatial pattern, starting from an innermost chamber at the head end to an outmost chamber; and an evacuation port fluidly connected with the evacuation region for evacuating the same, the evacuation port positioned at the head end of the vacuum frame.
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