Patent ID: 6070969
Filing Date: 2000-06-06
Classification: B41J,Y10T

Abstract:
A thermal inkjet printhead arranged such that a consistently located gas phase ink bubble is formed comprising:an ink firing chamber for containing ink;an electrically activated essentially planar heating element disposed in thermal communication with said ink firing chamber;a thermally insulating layer disposed continuously between said heating element and said ink firing chamber, said thermally insulating layer further comprising at least one preferred heterogeneous nucleation site as a discontinuity in said thermally insulating layer which reduces the critical free energy of formation for the gas phase ink bubble and selectively disposed on a surface of said thermally insulating layer which is in contact with ink when ink is in said ink firing chamber, whereby a consistently located gas phase ink bubble may be formed; andan orifice plate forming at least one boundary of said ink firing chamber and including at least one orifice from which ink from said ink firing chamber is expelled normal to the plane of said heating element when said heating element is electrically activated.