Ink jet print device and print head or print apparatus using the same

An ink jet print apparatus for printing images on a printing medium, comprising:

• a plurality of passageway means, each said passageway means defining a passageway for flowing ink having at least one outlet for ejecting ink at one end thereof, said passageway means having a gradually enlarging portion in which a cross-section of the passageway is gradually enlarged partially, said gradually enlarging portion having a terminal, said passageway means being formed in a substrate which has a plate shape, said passageway means having the outlet on a first surface of said substrate and an inlet on a second surface of said substrate, said second surface opposing said first surface, said passageway means extending substantially straight between and connecting said outlet and said inlet, said cross-section of said passageway being gradually enlarged from said inlet side toward said outlet side in said gradually enlarging portion, said outlet being provided on the side of said gradually enlarging portion as a throat a cross-section of which is smaller than a cross-section of said gradually enlarging portion;
• a plurality of generating means, each said generating means generating energy for ejecting the ink from the outlet, said generating means being located at a position by said passageway means between said inlet and said outlet, said generating means being disposed on the terminal of said gradually enlarging portion and on a passageway wall in a vicinity of said throat;
• an ink supply member in communication with said passageway means for supplying ink to the plurality of passageways via the ink inlets;
• and
• a transport mechanism for transporting the printing medium to a printing position at which printing is carried out by the plurality of outlets of said ink discharging means.