Patent ID: 7527352
Filing Date: 2009-05-05
Classification: B41J

Abstract:
1. An ink discharge method for discharging ink from an ink jet recording head provided with discharge ports for discharging ink, plural ink flow paths communicating with the discharge ports for supplying ink to the discharge ports, heat generating members for generating bubbles in ink filled in the ink flow paths for discharging ink from the discharge ports by pressure exerted by generating the bubbles, each of the ink flow paths having a plurality of the heat generating members, and each of the ink flow paths having one of the discharge ports arranged on an extended line extended in a normal direction from a center of a region including the plurality of the heat generating members and a portion between the plurality of the heat generating members to a surface of a substrate, said method comprising the steps of: using the ink jet recording head having the plurality of the heat generating members in each of the ink flow paths for generating plural bubbles by the plurality of the heat generating members; and discharging ink from a discharge port by pressure of bubbles generated by bringing ink to a boil by the plurality of the heat generating members in an ink flow path, the bubbles communicating with the outside for the first time during a stage in which a volume of each of the bubbles is reduced after the volume of the bubble has grown to a maximum value.