Patent ID: 6109742
Filing Date: 2000-08-29
Classification: B41J

Abstract:
An ink tank separably connected to an ink jet head of an ink jet printing apparatus, said ink tank comprising:a first chamber having a negative pressure generation member accommodated therein and including a liquid supplying portion for supplying liquid to the ink jet head and an atmospheric air communicating portion communicating with atmospheric air, said negative pressure generation member being accommodated in said first chamber;a second chamber communicating with said first chamber through a communication portion disposed apart from said atmospheric air communicating portion, said second chamber retaining liquid for supply to said first chamber and being substantially sealed except at said communication portion; anda partition wall defining said communication portion and separating said first and said second chambers from each other,wherein said negative pressure generation member is a porous member which has a three-dimensional net-shaped structure and is molded of a condensate composed of a compound having an amino group and a formaldehyde, and wherein, during supply of the liquid to the first chamber, an interface between air and the liquid is located in a region of said negative pressure generation member between said communication portion and said atmospheric air communicating portion, and a region of said negative pressure generation member between said interface and said air communicating portion is used as a buffer region.