Patent ID: 6554394
Filing Date: 2003-04-29
Classification: B41J

Abstract:
A liquid ejection head unit for being rotatably and removably carried on a carriage, said head unit comprising:a liquid ejection head for ejecting liquid droplets through a plurality of ejection outlets formed in an ejection side surface thereof to effect printing on a printing medium; a casing for casing said liquid ejection head; a guiding shaft member provided on a bottom surface of said casing at a predetermined position; and a projection having a curved surface provided on a side of said casing extending along an extension of an axis of said guiding shaft member, wherein said guiding shaft member and said projection are engageable with predetermined portions of said carriage and provide a substantial center of rotation for such rotation of said ejection head that said ejection side surface of said ejection head moves in directions along said ejection side surface.