Patent ID: 6174049
Filing Date: 2001-01-16
Classification: B41J

Abstract:
A bubble jet head comprising:a common ink supply passage having an ink supply opening in one end portion and introducing an ink supplied from an ink storage portion through said ink supply opening;a plurality of branched ink supply passages, each having an opening end portion communicating with said ink supply opening of said common ink supply passage and supplying the ink to an ink heating portion via said opening end portion; andan ink ejection opening forming surface arranged in opposition to said ink heating portion with a predetermined distance therebetween and having a plurality of ink ejection openings for ejecting ink droplet formed by heating the ink supplied through said branched ink supply passages in said ink heating portion,wherein said branched ink supply passage has a parallel passage portion and a section having a width, the width of the section of said branched ink supply passage being in a direction perpendicular to a direction from the opening end portion to said ink ejection opening in said branched ink supply passage, a uniform passage portion having the width that is uniform along the direction, and the contracted portion that is formed between said ink ejection opening and said uniform passage portion, said contracted portion beiing such that said width is gradually narrowed toward said ejection opening.