Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Solid cake lavoratory cleansing block composition comprising polyethylene glycol distearate having a dissolution time of at least 5.5 hours, and optional ingredients which include a gelling natural gum, fragrances, dyes, solid binders, filler material and mixtures thereof.