Patent ID: 7628480
Filing Date: 2009-12-08
Classification: B41J

Abstract:
1. An ink tank for supplying ink to an ink jet type recording head comprising: a case body having an ink chamber containing the ink, said ink chamber having an ink outlet formed on its bottom portion, for letting the ink out of said ink chamber; and a heat insulating layer provided around said ink chamber in said case body, for insulating said ink chamber from external heat, wherein said ink chamber comprises an absorbent chamber containing at least an ink absorbent that absorbs and holds the ink and generates a negative pressure in said absorbent chamber due to its capillary force, a storage chamber storing the ink to be absorbed by said ink absorbent, a partition wall partitioning said ink chamber into said absorbent chamber and said storage chamber, and an interconnection slot formed through said partition wall near a bottom of said ink chamber, to interconnect said storage chamber with said absorbent chamber, for exchanging the ink in the storage chamber with air that is introduced from outside said case body into said absorbent chamber, at least a vent hole is formed through said partition wall above said interconnection slot, for taking the air from said absorbent chamber into said storage chamber, and said vent hole is initially closed with a stopper, which is released by the time when a liquid surface of the ink goes down to said vent hole.