PURPOSE: To prevent the generation of hygroscopic wrinkle in a high temperature/high humidity condition in the case of using a photosensitive sheet obtained by thinning an original sheet by providing a printing mask on the photosensitive sheet whose water contents is adjusted to 6.0 to 10.0%.
CONSTITUTION: A heater 105 is provided under a photosensitive sheet holding drum, and when a device power supply is OFF, the heater 105 is always held at the ON state to remove humidity from the sheet wound around the drum. The device is provided with a means for selectively locking the rotation of a delivering roll 75 when the device is not used, a torque control means for a winding roll 76 and a reverse rotation preventing means 88. Interlocking with the ON of device power supply, a control means locks the roll 75 and a driving means applies prescribed tensile force to the sheet to prevent the surface of the drum 26 from being wrinkled. Or the diameter of a guide roll 27 is maximized at the center part of the axial direction to prevent the generation of hygroscopic wrinkles. Or the humidity of the sheet is adjusted to 6.8 to 7.6%. In the constitution, the original sheet can be thinned without generating hygroscopic wrinkles and the cost of the device can be reduced.
KAGEYAMA TOSHIICHI
SAGAMI SHIZUO
IWASHITA RYOSUKE
YAMAMOTO MASAHIKO
YANAGISAWA MASAMI
TOMOEGAWA PAPER CO LTD