Abstract: The new heater element design has a pit layer which protects the overglaze passivation layer, PSG step region, portions of the Ta layer and dielectric isolation layer and junctions or regions susceptible to the cavitational pressures. Further, the inner walls of the pit layer define the effective heater area and the dopant lines define the actual heater area. In alternative embodiments, the dopant lines define the actual and effective heater areas, and an inner wall and a dopant line define the actual and effective heater areas. Further, when the new heater element designs are incorporated into printheads having full pit channel geometry and open pit channel geometry, the operating lifetime of the printhead is extended because the added protection of the pit layer prevents: 1) passivation damage and cavitational damages of the heater elements; and 2) degradation of heater robustness, hot spot formations and heater failures well into the 109 pulse range.

Abstract: The systems and methods of this invention allows for an electrical contact structure of the drop ejecting transducer in an inkjet printhead to be designed in such a way that the relatively thick electrical contact lines are not in the ink drop ejection path between the drop ejector transducer and the corresponding nozzle. Such a design thereby minimizes any visible defects due to misdirected satellite drops.

Abstract: A printhead and method of fabrication thereof provides that the printhead reservoir has substantially the same cross-sectional ink flow area as the total cross-sectional area of the plurality of individual ink channels which interconnect the reservoir with the printhead nozzles. Since the flow area of the reservoir is substantially matched to the total flow area of the channels, the ink capacity of the reservoir is relatively low and the flow rate therethrough during a printing operation is relatively high. The small capacity of reservoir, together with the high ink flow rate therethrough, assures short ink residency time during printing, so that any exsolved air bubbles in the ink are swept away with subsequent ink droplet ejections during a printing operation and thus prevents any air bubbles present from coalescing into larger bubbles which can cause print quality defects.

Abstract: The nucleation efficiency of a thermal ink jet printhead is improved by forming a heater element with a planar surface. A heater resistor, polysilicon in a preferred embodiment, has an irregular surface which can trap gas or vapors in the cracks or crevices. When the heater resistor is pulsed, the nucleation temperature is reduced by these trapped vapors requiring an increase in electrical input to the resistors, thereby reducing efficiency. The invention recognizes that a heater resistor with a planar surface in contact with an ink layer results in a higher nucleation temperature and increased efficiency. In one embodiment, a phosphosilicate glass (PSG) is flowed directly onto the resistor surface forming a planarization layer. Subsequent deposition of tantalum substantially replicates the underlying topography creating a heater resistor with a smooth surface adjacent the ink.

Abstract: An ink jet ink includes a colorant and a liquid component containing at least one of an epoxy and a vinyl ether. Water may also be dissolved in the liquid component. Preferably, the vinyl ether is ethylene glycol monovinyl ether. An ink jet recording process includes the steps of ejecting an ink jet ink, such as the inks of the present invention, from an orifice to form an image on a recording medium.

Abstract: A method for removing kogation deposits or other materials from the heater element of a thermal ink jet printer includes selecting a pulse voltage, pulse width and number of pulses, and apply the selected number of pulses at the selected pulse voltage and pulse width to the heater element to disrupt the kogation deposits. An apparatus for removing kogation deposits or other materials from the heater elements of a thermal ink jet printer includes a controller and a voltage supply, such that the voltage supply is controlled by the controller to supply a selected number of pulses at a selected pulse voltage and a selected pulse width to the heater elements.

Abstract: An ink jet printhead having off center or offset heaters or thermal transducers to reduce heater damage. The printhead has heaters located beneath channels to eject ink from the channel through a nozzle to a substrate for printing. Edge heaters are spaced away from the dicing edges of the heater plate to avoid damage resulting from dicing for assembly or from thermal expansion due to adjacent printheads if used to form a page width or large array printhead. The spacing distance between the edge heaters to adjacent equally spaced heaters on the same printhead is less than the distance between adjacent equally spaced heaters. Edge heaters are also offset from the centerline of respective channels in the printhead.

Abstract: A thermal transfer printing device, including an ink donor supporting an ink meltable upon the application of a selected temperature, a printing head supporting a resistive heating element for generating the selected temperature at the ink donor, and means for bringing a final image support surface into contacting relationship with the ink donor in timed relationship to the application of the selected temperature to the ink donor including an electrically conductive heat sink layer, a heat resistant organic material having a very low thermal conductivity deposited on the heat sink layer and an array of resistors, supported on the heat resistant organic material, each resistor selectively controllable to apply a melting temperature to the meltable ink. The heat resistant organic material having a very low thermal conductivity is desirably a polyimide.

Abstract: Electrostatographic carrier materials having low bulk densities and high magnetic permeabilities are obtained by providing an alumino-boro-silicate glass particle containing from between about 10 to about 15 molar percent Fe.sub.2 O.sub.3 in which superparamagnetic ferrite crystallites having an average particle size of up to about 500A have been precipitated by heat treatment. The magnetic behavior of the glass carrier particles which is dependent on the number present and size of the ferrite crystallites can be closely controlled by heat treatment at temperatures in the range of between about 600.degree. C and 800.degree. C. When mixed with toner particles, these magnetic glass carrier materials experience significantly reduced toner impaction levels.

Abstract: Electrostatographic carrier materials having low bulk densities and high magnetic permeabilities are obtained by providing an alumino-boro-silicate glass particle containing from between about 10 to about 15 molar percent Fe.sub.2 O.sub.3 in which superparamagnetic ferrite crystallites having an average particle size of up to about 500A have been precipitated by heat treatment. The magnetic behavior of the glass carrier particles which is dependent on the number present and size of the ferrite crystallites can be closely controlled by heat treatment at temperatures in the range of between about 600.degree. C and 800.degree. C. When mixed with toner particles, these magnetic glass carrier materials experience significantly reduced toner impaction levels.

Abstract: Electrostatographic carrier materials having low bulk densities and high magnetic permeabilities are obtained by providing an alumino-boro-silicate glass particle containing from between about 10 to about 15 molar percent Fe.sub.2 O.sub.3 in which superparamagnetic ferrite crystallites having an average particle size of up to about 500A have been precipitated by heat treatment. The magnetic behavior of the glass carrier particles which is dependent on the number present and size of the ferrite crystallites can be closely controlled by heat treatment at temperatures in the range of between about 600.degree. C and 800.degree. C. When mixed with toner particles, these magnetic glass carrier materials experience significantly reduced toner impaction levels.

Abstract: A process for minimizing or avoiding the corrosion of thermal ink jet heater components by the coating thereof with polycrystalline diamond.