Hewlett-packard Company

Joseph M Driear

Ronald W Keil

Mark S Barbour

A printhead apparatus and method has a plurality of ink drop generators coupled to a source of ink. Each ink drop generator includes an orifice with a corresponding ink firing chamber and a heating resistor, and a single ink feed channel coupling the firing chamber to the source of ink. The geometry of the ink drop generator relative to the heating resistor is selected to introduce an asymmetry to create a rotational component in the ink fluid velocity following a drop ejection. This swirl, in turn changes the location or intensity of the steam bubble, lessening the damage this collapse causes on the resistor, and thereby increasing the resistor life for the printhead. The asymmetry can be the shifting of a pinch point in the ink flow channel relative to the centerline of the channel, by offsetting of the ink flow channel, or by introducing the asymmetry by the relative location of the orifice or firing chamber relative to the firing resistor.

Growing community of inventors

Corvallis, OR, United States of America

Joseph M Driear