Inkjet printhead having convex wall bubble chamber

An inkjet printhead, comprising:

• an ink via with a longitudinal extent;
• a substantially rectangular heater element having a periphery with a length and width dimension such that an aspect ratio of said length dimension to said width dimension is greater than about 2.0, said width dimension being substantially parallel to said longitudinal extent;
• a substantially straight ink flow channel fluidly connecting said heater element to said ink via, said ink flow channel having a primary direction of ink flow defined by two substantially parallel ink flow walls that are substantially parallel to said length dimension and substantially perpendicular to said longitudinal extent;
• a bubble chamber fluidly connected to said ink flow channel, said bubble chamber having a curved wall portion partially surrounding said heater element, said curved wall portion having a radius of an arc that is greater than about 0.5 said width dimension and less than said length dimension and none of said curved wall portion overlies said periphery of said heater element;
• and
• a nozzle plate having a thickness with an orifice therein, an ink ejection side of said orifice being directly above said heater element.

An inkjet printhead, comprising:

• an ink via with a longitudinal extent;
• a plurality of substantially rectangular heater elements each having a length and width dimension and a heater surface such that an aspect ratio of said length dimension to said width dimension is greater than about 2.5, said width dimension being substantially parallel to said longitudinal extent;
• a plurality of substantially straight ink flow channels each fluidly connecting a single heater element of said plurality of heater elements to said ink via, said each ink flow channel having a primary direction of ink flow defined by two substantially parallel ink flow walls that are substantially parallel to said length dimension and substantially perpendicular to said longitudinal extent;
• a plurality of bubble chambers each fluidly connected to a single ink flow channel of said plurality of ink flow channels, said each bubble chamber having a plurality of walls rising above said heater surface with both a convex wall portion and a rectangular wall portion that substantially surrounds said heater surface, said convex wall portion having a radius of an arc that is greater than about 0.5 said width dimension and less than about 0.5 said length dimension;
• and
• a nozzle plate having a plurality of orifices, each said orifice being above a portion of a single heater element of said plurality of heater elements.