Browse Prior Art Database

Diaphragm Ink Drop Generator and Liquid Horn

IP.com Disclosure Number: IPCOM000079635D
Original Publication Date: 1973-Aug-01
Included in the Prior Art Database: 2005-Feb-26
Document File: 3 page(s) / 66K

Publishing Venue

IBM

Related People

Denny, CM: AUTHOR [+3]

Abstract

This ink jet head assembly produces high-velocity ink drops at high frequency without detrimental satellites, over a wide-frequency band. Reliability and reproducibility of drop generator performance are increased. A strong velocity modulation of the ink jet stream is produced at the exit of the liquid horn, with low-input level of driver voltage and electrical power.

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Diaphragm Ink Drop Generator and Liquid Horn

This ink jet head assembly produces high-velocity ink drops at high frequency without detrimental satellites, over a wide-frequency band. Reliability and reproducibility of drop generator performance are increased. A strong velocity modulation of the ink jet stream is produced at the exit of the liquid horn, with low-input level of driver voltage and electrical power.

The device produces a stream of ink drops useful in printing over a wide band of drop generating frequencies (75-150khz). This makes the device relatively insensitive to normal manufacturing tolerances in the order of + 0.001 or + 0.002 inch, and adaptable to assembly procedures using a hand-held screwdriver.

It is known to provide an ink jet drop generator which produces strong jet modulation with minimum voltage and power input; i.e., a highly efficient drop generator. Such apparatus essentially embodies a "piezoelectric sandwich" transducer and,, in addition, employs fluid resonance of a plain-pipe ink-filled cavity.

THE DIAPHRAGM INK DROP GENERATOR This drop generator consists of the following parts: (See the figure) The base 1 Washer 12

Tube connector 2 Seals 13

O-ring 3 Locator 14

Plate 4 Contact rings 15

Long tube 5 Crystal diaphragm 16

Short tube 6 Swivel plate 17

Junction 7 Spring guide 18

Housing 8 Spring 19

Sleeve 9 Plug housing 20

Cover 10 Terminal pin 21

Horn 11.

The drop generator has only one moving part, the diaphragm 16. The diaphragm converts electrical energy directly into mechanical energy, which it transfers directly to the ink. The ink is in intimate contact with the diaphragm's left face. The diaphragm 16 oscillates as a drum head under the influence of applied voltage. If this diaphragm were oscillating in free space, it would oscillate about a nodal ring, a concentric ring in the diaphragm that experiences no motion. Two contact rings 15 clamp the diaphragm between them at the nodal ring. Therefore, the contact rings do not inhibit the diaphragm's activity.

Locator 14 locates the diaphragm 16 diametrically, and also locates rubber seals 13 which prevent ink from leaking around the diaphragm. The diaphragm's edge motion is so small, and the seals are so soft, that these do not inhibit the diaphragm's activity either. Clamping force comes from spring 19 through spring guide 18 and swivel plate 17, which carries contact ring 15. The swivel plate 17 insures that the spring 18 will load the diaphragm 16 uniformally.

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The ink is an electrical conductor, and provides electrical ground contact to the diaphragm's left face. The right contact ring 15 provides electrical voltage to the diaphragm's right face. The spring 19 conducts voltage from terminal pin 21 via plug housing 20 to the contact ring through sp...