Ink jet recording apparatus

A method of introducing ink into an unused head unit including:

• a buffer tank for storing ink, the buffer tank having an ink outlet and an ink supply path, the ink supply path being for connecting to an ink supply source;
• and an ink jet head having a plurality of ejection nozzles through which ink supplied from the ink outlet is ejected onto a recording medium, the ink introducing method comprising:
• maintaining the buffer tank filled with a preservation fluid before the head unit is used;
• introducing the preservation fluid from the buffer tank into the ink jet head before introducing ink into the head unit;
• expelling the preservation fluid from the ink jet head;
• and
• introducing ink from the ink supply source into the ink jet head through the buffer tank.

A method of manufacturing a buffer tank for an ink jet recording apparatus, the buffer tank being for holding ink that is supplied from an ink supply source through a supply path and for supplying the ink to an ink jet head, the manufacturing method comprising:

• preparing a bottom lid with an ink outlet for supplying ink to the ink jet head, the bottom lid having one side designated to face inward when joined into the buffer tank;
• attaching a filter to the bottom lid so as to cover the ink outlet from the side designated to face inward;
• preparing a top lid with an ink inflow port for receiving ink from the supply path;
• subjecting at least the filter on the bottom lid to a process for enhancing hydrophilic properties;
• and
• joining the bottom lid and top lid to form the buffer tank, wherein the filter is located inside the buffer tank.

An ink jet recording apparatus, comprising:

• an ink jet head for ejecting ink droplets;
• a buffer tank for storing ink and supplying ink to the ink jet head, the buffer tank including a bottom wall, a top wall, and a side wall, the bottom wall having an outer edge, the top wall being in confrontation with the bottom wall through a space for holding ink, the top wall having an outer edge, and the side wall being connected to the outer edges of the bottom wall and the top wall;
• an outflow port formed in the top wall, the outflow port being for removing bubbles from the space;
• and
• an ink inflow port formed in the top wall of the buffer tank, the ink inflow port having A cylindrical shape and projecting down towards the bottom wall, the ink inflow port having a bottom end nearest the bottom wall, the bottom end being formed with a notch that faces towards the outflow port.

An ink jet recording apparatus comprising:

• a head unit including:
• a buffer tank for storing ink including an ink outlet and an ink supply path, the ink supply path being for connecting to an ink supply source, the buffer tank being filled with a preservation fluid before the head unit is used;
• and
• an ink jet head including a plurality of ejection nozzles for ejecting ink that is supplied from the ink outlet onto a recording medium;
• and
• a fluid introducing unit that introduces the preservation fluid from the buffer tank into the ink jet head and expels the preservation fluid from the ejection nozzles to make the head unit ready for use.

An ink jet recording apparatus for recording onto a recording medium, the ink jet recording apparatus comprising:

• an ink supply source that supplies ink;
• a supply path connected to the ink supply source;
• a buffer tank that stores ink supplied from the ink supply source through the supply path;
• an ink jet head having a plurality of ejection nozzles from which ink supplied from the buffer tank is ejected onto the recording medium;
• a top lid member forming at least a top wall of the buffer tank, the top lid member being formed with an ink inflow port that is connected to the supply path;
• a bottom lid member forming a bottom wall of the buffer tank, the bottom lid member being formed with an ink outlet for supplying ink to the ink jet head;
• and
• a filter attached to the bottom lid to cover the ink outlet from inside the buffer tank, at least the filter having been subjected to a process for enhancing hydrophilic properties.