Ink transfer printing apparatus with drop volume adjustment
AssigneeEastman Kodak Company
InventorsJohn Andrew Lebens, James Michael Chwalek, Pranab Bagchi
Life of this patent
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Abstract
A liquid ink, drop on demand page-width printhead comprises a semiconductor substrate, a plurality of drop-emitter nozzles fabricated on the substrate; an ink supply manifold coupled to the nozzles; pressure means for subjecting ink in the manifold to a pressure above ambient pressure causing a meniscus to form in each nozzle; a means for applying heat to the perimeter of the meniscus in predetermined selectively addressed nozzles; a means for controlling the volume of poised drops in the selectively addressed nozzles; and a means for transferrring the poised drops onto the recording media.
Claims10
An ink transfer printing device comprising:
- a source of liquid ink under pressure and having a surface tension, the ink containing a surface-active agent that is thermally released;
- a nozzle in communication with the ink source, the nozzle having a tip such that a meniscus of ink is poised at the nozzle tip with a predetermined volume of ink in the meniscus;
- and
- a thermal activator in thermal communication with the ink of the meniscus, the thermal activator, when activated by a selectably-variable control signal, heats the ink of the meniscus to thereby release the surface-active agent, reducing the surface tension of the ink and expanding the poised meniscus on the nozzle tip for transfer to a print medium, the ink having a characteristic which causes the meniscus to remain expanded at a stable predetermined volume for a predetermined time period after the electrothermal pulse has terminated.
A process for ink transfer printing from a nozzle, having a critical pressure at which a meniscus of ink cannot be maintained poised at the nozzle tip, said process comprising:
- providing ink containing a surface-active agent at the nozzle;
- pressurizing the ink at above atmospheric pressure but below the critical pressure of the nozzle to form a meniscus, whereby pressure of the ink determines a quiescent meniscus height at the nozzle;
- thermally controlling release of the surface-active agent contained in the ink, thereby causing the surface-active agent in the ink to cause an expansion at the meniscus, increasing its height and volume;
- halting the thermally controlling release of the surface-active agent at a predetermined point, and wherein the ink's material properties are such that the expanded state remains stable for a predetermined time period after termination of the release of the surface-active agent, thus forming ink drops of predetermined size and volume;
- and
- transferring a pre-configured ink volume to printing media.
Dependencies are inferred from the claim text.