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Bimetallic Differential Wetting Piezoelectric Printing Device

IP.com Disclosure Number: IPCOM000077853D
Original Publication Date: 1972-Oct-01
Included in the Prior Art Database: 2005-Feb-25
Document File: 2 page(s) / 34K

Publishing Venue

IBM

Related People

Kotla, JJ: AUTHOR [+2]

Abstract

A printer head employs an ink-wetting metal for the internal walls of an ink chamber and a nonink-wetting metal for a nozzle through which ink is displaced from the chamber, by pressure pulses to image a document.

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Bimetallic Differential Wetting Piezoelectric Printing Device

A printer head employs an ink-wetting metal for the internal walls of an ink chamber and a nonink-wetting metal for a nozzle through which ink is displaced from the chamber, by pressure pulses to image a document.

As illustrated, piezoelectric printing device 1 comprises a plastic housing 2 in which is embedded a plurality of generally frustro-conical members 3 (only one shown). Each member 3 provides an ink chamber 4 having a nozzle 5 at its small end and a piezoelectric crystal 6 enclosing its large end. Chamber 4 is maintained completely filled with ink fed by gravity via passageway 7 from a suitable source, not shown. When an electric potential is applied across the leads of crystal 6 by closure of switch 8, the crystal will deform and, in so doing, reduce the volume of chamber 4, thereby displacing a discrete droplet of ink out through nozzle 5 onto a document, not shown, to generate one dot of a dot- pattern image thereon.

When using an aqueous base ink, wall 9 of ink chamber 4 should be of aluminum; whereas the nozzle wall 10 (at least adjacent its outer end) should be of copper. Before initial use, the chamber and nozzle are immersed in a phosphoric acid solution. As a result, aqueous inks will fully wet the aluminum inner chamber but be thoroughly repelled by the copper nozzle, thus yielding discrete droplets when a piezoelectric crystal is pulsed to contract the volume of the chamber and ther...