Patent ID: 6231158
Filing Date: 2001-05-15
Classification: B41J

Abstract:
An ink jet printer comprising:a printer main body;a recording medium conveyance means for conveying a recording medium in a subsidiary scanning direction;a plurality of ink jet heads, each having a plurality of nozzles jetting drops of ink to a surface of the recording medium, the ink jet heads being capable of moving in a primary scanning direction which is substantially perpendicular to the subsidiary scanning direction, the ink jet heads being arranged in the printer main body and being aligned in the subsidiary scanning direction, and each of the plurality of ink jet heads is driven in opposite directions from one another; anda head reciprocation drive means for driving the ink jet heads in the primary scanning direction at phases different to each other,wherein the plurality of ink jet heads includes at least one pair of ink jet heads provided and driven by the head reciprocation drive means at precisely opposite phase,the head reciprocation drive means includinga permanent magnet directly attached to each of the at least one pair of ink jet heads, andan electromagnetic coil generating a drive force for driving, arranged in a stationary portion of the printer main body in such a manner that the electromagnetic coil is opposed to both permanent magnets,wherein the permanent magnets are disposed so that a magnetic field of one of the permanent magnets and a magnetic field of the other of the permanent magnets can act on the electromagnetic coil in opposite directions.