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Ultrasonic Cavity Resonance for Ink on Demand Ink Jet Formation

IP.com Disclosure Number: IPCOM000084149D
Original Publication Date: 1975-Sep-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 2 page(s) / 33K

Publishing Venue

IBM

Related People

Fisher, DE: AUTHOR [+2]

Abstract

This is an ink on demand ink jet printer in which jet formation is triggered ultrasonically, and the ink reservoir is an ultrasonic cavity which enhances the ultrasonic effects on the meniscus.

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Ultrasonic Cavity Resonance for Ink on Demand Ink Jet Formation

This is an ink on demand ink jet printer in which jet formation is triggered ultrasonically, and the ink reservoir is an ultrasonic cavity which enhances the ultrasonic effects on the meniscus.

Ink is housed in a reservoir 2, which is an ultrasonic cavity, situated adjacent an ink jet head 4 having an exit aperture 6 formed therein. A high-voltage electrode 8 having an orifice 9 therein has a high voltage on the order of 2-4 KV applied thereto by way of a voltage source 10. An acceleration electrode 12 has high voltage on the order of 7000 volts applied thereto from a source 14. A printing medium 16 is situated intermediate the electrodes 8 and 12. The voltage from the electrode 8 causes a meniscus 17 to be formed about the orifice 6.

When it is desired to provide a drop of ink from the orifice 6, AC power at the resonant frequency is applied from a source 18 to a piezo-electric crystal 19. When the modulator 20 applies a signal not at the resonant frequency, a meniscus 17 is not perturbed sufficiently to pull off a droplet, whereas when the signal is at resonance the meniscus is perturbed sufficiently for a droplet to be pulled off.

The combined electrostatic and hydrostatic forces, when not at resonance, are not sufficient to cause leakage of the ink or formation of a jet. However, if the meniscus is perturbed outward at resonance, the electrostatic field is sufficient to cause an instability in th...