Precursor electrical pulses to improve inkjet decel
AssigneeHewlett-Packard Development Company, L.P.
InventorsThomas W. Linder, Linda C. Uhlir-Tsang
Life of this patent
Estimating the term…
Abstract
A print command is received and a short, single, electrical precursor pulse is generated to preheat the ink components near the surface of the heating element. The precursor pulse returns precipitated ink components near the resistor to solution. For best results, the precursor pulse occurs approximately 1.50 microseconds prior to the main drive pulse even though other times, such as 1.00 microsecond, can produce adequate results. The main drive pulse then occurs to print the required information.
Claims20
A method for reducing a decel characteristic of ink that is part of an inkjet pen device, the inkjet pen device comprising a print head having heating elements that are coupled to the ink, the method comprising the steps of:
- receiving a print command from a computer apparatus;
- generating a main drive pulse in response to the print command;
- and
- generating a single, electrical pulse to the heating element in response to the print command, the single, electrical pulse occurring prior to the main drive pulse and having a duration that is less than one microsecond.
An inkjet printing apparatus for reducing a decel characteristic of ink, the apparatus comprising:
- an
- inkjet pen that contains the ink, the inkjet pen comprising an ink reservoir for containing the ink and a heating element, coupled to the ink, for heating the ink at predetermined times in order to expel ink from the inkjet pen;
- a power supply, coupled to the controller, for generating a predetermined voltage level;
- and
- controller logic, coupled to the power supply, for causing a single electrical pulse to be applied to the heating element prior to start of printing thereby heating the ink coupled to the heating element.
An inkjet pen for improving a decel characteristic of ink contained within the inkjet pen, the inkjet pen comprising:
- an ink reservoir for holding the ink;
- a print head, coupled to the ink reservoir, the print head comprising:
- a silicon substrate into which are etched a plurality of heating elements, the plurality of heating element coupled to and receiving a precursor pulse and a main drive pulse, the first precursor pulse having a duration in the range of 0.20-0.60 microseconds and occurs more than 1.00 microsecond prior to the main drive pulse;
- a barrier layer, coupled to the silicon substrate, having an opening over each heating element and a firing chamber adjacent to the heating element;
- and
- an orifice plate, coupled to the barrier layer, in which an orifice is present over each heating element;
- wherein the ink is preheated by the precursor pulse heating a first heating element to force the ink into a liquid state before the main drive pulse heats the first heating element and boils the ink to force it out the orifice over the first heating element.
Dependencies are inferred from the claim text.