Patent ID: 8092000

Claim:
A heater for use in a phase change ink printhead reservoir, the heater comprising: a first insulating layer including at least one ink supply path opening, the first insulating layer having a uniform thickness at least around the at least one ink supply path opening; a second insulating layer including at least one ink supply path opening that aligns with the at least one ink supply path opening in the first insulating layer, the second insulating layer having a uniform thickness at least around the at least one ink supply path opening, the first and second insulating layers being formed of a material including polyimide; a resistance heating element interposed between the first and the second insulating layers, the resistance heating element being configured to receive electric current and to generate heat, the resistance heating element including uniform material thickness encircling and aligned with each ink supply path opening in the first and second insulating layers, the heating element being a configuration from the group comprised of uniform width traces, non uniform width traces, wires, discontinuous film and continuous film, and the resistance heating element being formed of a material from the group comprising inconel, aluminum alloy, PTC compound and NTC compound; and a foil layer consisting of a material from the group comprising aluminum, copper, aluminum alloy and copper alloy, adhered to one of the first and second insulating layers, the foil layer including at least one ink supply path opening that aligns with the at least one ink supply path opening in the first and second insulating layers, the first insulating layer, the resistance heating element, second insulating layer, and the foil layer being for bonding between a first and a second heat distribution plate of a phase change ink reservoir assembly.