Browse Prior Art Database

Optically Excited Fluid Jet

IP.com Disclosure Number: IPCOM000082484D
Original Publication Date: 1974-Dec-01
Included in the Prior Art Database: 2005-Feb-28
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Heard, RS: AUTHOR

Abstract

Previous ink jet printers include means for applying energy to an ink stream to cause uniform drop formation in the form of "electromechanical transducers", which either cause a mechanical vibration of the nozzle or cause pressure waves in the fluid itself. Undesired mechanical resonances of the nozzle, the driver, or the mounting structure can interfere with drop formation.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 71% of the total text.

Page 1 of 1

Optically Excited Fluid Jet

Previous ink jet printers include means for applying energy to an ink stream to cause uniform drop formation in the form of "electromechanical transducers", which either cause a mechanical vibration of the nozzle or cause pressure waves in the fluid itself. Undesired mechanical resonances of the nozzle, the driver, or the mounting structure can interfere with drop formation.

Since the cyclically varying energy merely provides an initial condition for an exponential increase in disturbance amplitude until the point of breakoff, it need only be large enough to dominate any other disturbances which may be present. This has been observed in many cases where the required driving voltage to a piezoelectric transducer is quite small.

If a sufficiently narrow beam of pulsating light is aimed at a small section of the stream immediately after it leaves the orifice, it is possible to provide the necessary energy optically. The light is absorbed by the stream in the form of heat, which causes periodic thermal expansion of the stream at a wavelength determined by the stream velocity and the pulsation frequency. The electromechanical transducer (and its resonances) may be done away with.

For example, it requires approximately 0.27 x 10/-6/joules to raise the temperature of a 0.002 inch diameter water drop by 1 degree C. At 100,000 drops per second, 27 mw would be required. The 1 degree C rise will cause a
0.03% volume expansion of the water, which...