Patent ID: 6286944
Filing Date: 2001-09-11
Classification: B41J

Abstract:
An ink jet unit comprising:an ink cartridge for containing ink having a partition therein forming a first ink chamber for containing the ink and a second ink chamber containing a negative pressure producing material, a receptor port in a side of the second ink chamber opposed to said partition, a communication opening for fluid communication between the first ink chamber and the second ink chamber, wherein said partition extends from the communication opening and includes air introducing means for stably introducing air from the second ink chamber into the first ink chamber, a top end of said air introducing means being above a top of the communication opening; andan ink jet head including an ink supply member in contact with said negative pressure producing material through said receptor port for supplying ink from said ink cartridge to said ink jet head, wherein a gap is formed between said receptor port and said ink supply member when said ink supply member is in contact with said negative pressure producing material, and including a sealing member for effecting sealing at an outside portion of the gap with the gap remaining, wherein said air introducing means is constructed so that an ink level in said negative pressure producing material is no more than 5 mm above a top level of said receptor port as ink is supplied to said ink jet head.