Fluid impulse matrix printer

Abstract

A printer is disclosed for use in printing indicia or the like on a sheet of recording medium by selective application of impulses of fluid. The printer comprises a sheet support mechanism, a print head, fluid supply means, a valve assembly, and an input system. The support mechanism supports and selectively advances the sheet of recording medium. The print head includes a one- or two-dimensional array of tubes arranged to form a dot matrix for printing alphanumeric characters on the sheet. It may extend the width of the recording medium or be movable across it. Connected to these tubes are the fluid supply means and a valve assembly that includes a separate valve for each tube for controlling the supply of fluid thereto. In one embodiment of the invention, a heater raises the temperature of the fluid passing through the tubes enough that printing takes place on the recording medium whenever the fluid is ejected from the tubes. In another embodiment, a movable pin is mounted at the distal end of each tube in such a fashion that it is driven into the recording medium when a valve is opened. In still another embodiment the movable pins are also heated enough that they affect the recording medium where they are driven into it. The input system opens and closes the valves in accordance with input signals, such that the impulses of fluid applied to the tubes produce detectable visual changes on the recording medium which represent such input signals.