Ink jet printer and ink jet recording unit

An ink jet recording unit for supplying ink supplied from an ink reservoir into a print head, comprising:

• a first member having a groove including a curved surface;
• and
• a second member having a flat portion for forming said flow passage with the groove defined in said first member when said second member is joined to said first member,
• wherein the ink is supplied via the flow passage along a flow path from the ink reservoir to the print head.

An ink jet printer, comprising:

• an ink reservoir for storing ink;
• an ink supply passage being coupled to said ink reservoir for allowing the ink to pass through, the ink supply passage having a transverse cross section with a substantially semicircular curved portion and a substantially straight portion opposed to said curved portion;
• and
• a print head being coupled to said ink supply passage for jetting the ink supplied from said ink supply passage,
• wherein the ink supply passage has at least two segments, and the segments have different cross-sectional shapes.