MEDIUM PRESSING DEVICE FOR HARD COPY DEVICE

摘要

PROBLEM TO BE SOLVED: To maintain a negative pressure applied on the rear surface of the medium at a predetermined value for supporting a medium 12 on a platen 11 flatly regardless of the width of the medium in a medium pressing device for a hard copy device. SOLUTION: A predetermined negative pressure is maintained by limiting the air inflow amount from a platen hole 15 not covered with a medium regardless of the width of the medium to be used by installing a negative pressure chamber divided in a plurality in the lower part of a platen. Moreover, by disposing the negative pressure chamber separated in the front row and the rear row with respect to the medium proceeding direction, the flatness in the vicinity of the medium upper rim end and the lower rim end is improved for improving the printing quality.