Patent ID: 6848776
Filing Date: 2005-02-01
Classification: B41J

Abstract:
1. An ink tank comprising: a main ink chamber being opened to the air; an ink outlet; a sub ink chamber including: a detected portion, disposed at at least one of said ink passage and said second sub ink chamber, operable to optically detect whether said ink is used up on the basis of an amount of air flowed from said main ink chamber into said sub ink chamber; a main ink chamber side communication port communicatively connecting said main ink chamber with said sub ink chamber; a first filter mounted on said main ink chamber side communication port and having a first permeability for said air bubbles; an ink outlet side communication port communicatively connecting said second sub ink chamber to said ink outlet; and a second filter mounted on said ink outlet side communication port and having a second permeability for said air bubbles which is smaller than said first permeability.