Patent ID: 6247809
Filing Date: 2001-06-19
Classification: B41J

Abstract:
An ink-jet printer comprising:a rotary drum which is rotatable at a constant speed, said rotary drum having a dielectric peripheral surface;a medium loading section, disposed at a position close to the dielectric peripheral surface of the rotary drum, for loading a print medium onto the dielectric peripheral surface of the rotary drum;a medium holding system for causing the print medium loaded from the medium loading section to be held on the dielectric peripheral surface of the rotary drum by electrostatic attraction, such that the print medium is rotatable together with the rotary drum; anda print head section for jetting ink onto the print medium while the print medium is held on the dielectric peripheral surface of the rotary drum and rotated together with the rotary drum through a plurality of rotations for each printing operation;wherein the medium holding system includes a first charger disposed on an upstream side of the medium loading section for charging the dielectric peripheral surface of the rotary drum prior to loading of the print medium in order to generate an electrostatic attraction force for attracting the print medium to the dielectric peripheral surface of the rotary drum, and a second charger disposed on a downstream side of the medium loading section for charging the print medium inversely to a charging polarity of the first charger each time the print medium loaded onto the dielectric peripheral surface of the rotary drum passes the second charger during successive rotations of the rotary drum in order to supplement the electrostatic attraction force at each rotation of the rotary drum as the electrostatic attraction force is attenuated during the successive rotations of the rotary drum.