Patent ID: 6540335
Filing Date: 2003-04-01
Classification: B41J

Abstract:
An ink jet print head comprising:plural electrothermal converting elements for generating energy to produce a bubble used to discharge an ink droplet; plural ink discharge ports arranged above the electrothermal converting elements and discharging the ink droplet; plural ink flowing paths respectively communicating with the plural ink discharge ports and internally including said electrothermal converting elements; a substrate on which are arranged said plural electrothermal converting elements in a columnar shape, said substrate having an ink supplying port constructed by a through port which communicates with said ink flowing paths and extends along an arranging direction of said electrothermal converting elements, said through port having a diameter enlarging from an electrothermal converting element formation surface toward a back surface of said substrate; a discharging port plate having said ink discharge ports formed therein; and a wall projecting from said discharge port plate and associated with at least one of said ink flowing paths, said wall being positioned to allow a backflow of ink from each said associated ink flowing path upon production of the bubble by a respective electrothermal converting element and configured to direct the backflow toward surfaces of said ink supplying port to prevent attachment of bubbles within the ink supplying port, wherein said ink jet print head is constructed such that said ink flowing paths are formed between said substrate and said discharging port plate by a junction of said discharging port plate with said substrate.