Hewlett-packard Company

Peter M Burke

Timothy L Weber

William R Knight

Ulrich E Hess

Eldurkar V Bhaskar

Earl L Barton

Zen Kurokawa

An inkjet printhead structure comprises novel resistor circuitry that is fabricated on two different substrate layers. The dual layer circuitry reduces the required substrate surface area and printhead shelf length to increase the printer operating frequency and print density. In one embodiment of the invention, heating resistors are spread out over portions of the substrate surface area and conductors are attached to opposite ends of the heater resistors in a novel configuration. To simplify routing, the circuitry is configured so that multiple heater resistors are coupled to the same conductor return path located on a second conductive layer. In a second embodiment of the invention, the heater resistors are dimensioned in the shape of a trapezoid to provide uniform heating. Alternative resistor shapes are then introduced to provide consistent heat dissipation for variances in resistor/conductor sheet resistance.

Special geometry ink jet resistor for high dpi/high frequency structures

In order to reduce particle clogging of ink firing chambers in an inkjet printer printhead, the barrier layer is configured to have a plurality of inner barrier islands, each associated with a respective one of the heater resistors, disposed between an ink firing chamber and the ink plenum, to form two ink feed channels. The two ink feed channels are designed to have a right angle turn to prevent particles from entering the ink firing chamber. A plurality of outer barrier islands, having a number equal to twice the number of inner barrier islands, are disposed between the inner barrier islands and the ink plenum, and are configured in lines parallel to the lines of heater resistors to prevent particles from reaching the ink feed channels.

Particle tolerant inkjet printhead architecture

An inkjet printer printhead is coupled to an ink source and has a plurality of ink firing chambers dimensionally defined by a barrier layer disposed between a substrate and an orifice plate. Two ink feed channels are coupled to one ink firing chamber and are dimensionally defined, in part, by the barrier layer. One of these ink feed channels has a smoothly converging wide dimension inlet at the ink source and a narrow dimension outlet at the ink firing chamber. The other ink feed channel also has a converging wide dimension inlet at the ink source and a narrow dimension outlet at the ink firing chamber but has an 'S' shaped wall contour to make it asymmetrical to the first ink feed channel. An island of the barrier layer separates one ink feed channel from the other ink feed channel serving the ink firing chamber. This island has an essentially flat wall surface disposed toward the ink firing chamber.

Inkjet printhead with tuned firing chambers and multiple inlets

An automatic system for cleaning a thermal inkjet printhead. A thermal inkjet cartridge and service station are provided within a printer unit. The service station is directly beneath the cartridge when it is not printing. Attached to the service station is a printhead wiper unit consisting of a single member or, in the alternative, dual members positioned against each other to form a capillary pathway therebetween. The cartridge includes a compartment having an opening therethrough and an absorbent member impregnated with cleaning solution When the cartridge is not printing, the wiper unit is aligned with the compartment containing the absorbent member and is in contact therewith. This supplies the wiper unit with cleaning solution The service station may include a secondary absorbent member contacting with the wiper unit to absorb cleaning solution from the capillary pathway in a dual wiper system or supply the pathway with additional solution

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Corvallis, OR, United States of America

Peter M Burke