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ONE-WAY VALVE FOR SHUTDOWN OF CONTINUOUS STREAM INK JET

IP.com Disclosure Number: IPCOM000025255D
Original Publication Date: 1984-Apr-30
Included in the Prior Art Database: 2004-Apr-04
Document File: 2 page(s) / 100K

Publishing Venue

Xerox Disclosure Journal

Abstract

The ink jet stream start-up and shutdown is one of the most difficult tasks required for the successful operation of a continuous stream type ink jet printer. It is crucial to avoid both the air ingestion into the cavity or manifold as well as fouling of the printhead with ink. This task becomes even more difficult in multijet marking modules where the following two additional effects complicate the control of these processes: the pressure wave reflections in the long, full page width printhead and the contribution of the kinetic energy of the ink to the total ink energy. The kinetic energy of the ink is higher in the parts of the printhead close to the ink inlet than in the portions distant from the inlet. It is found that the successful shutdown is generally more difficult to achieve than the successful startup.

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XEROX DISCLOSURE JOURNAL

ONE-WAY VALVE FOR SHUTDOWN OF CONTINUOUS STREAM INK JET
Ivan Rezanka

Proposed Classification
U.S: CI. 346/75 Int. CI. Gold 15/18

FIG. 2

FIG. 20

129 Volume 9 Number 2 March/April 1984

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ONE-WAY VALVE FOR SHUTDOWN OF CONTINUOUS STREAM INK JET (Cont'd)

The ink jet stream start-up and shutdown is one of the most difficult tasks required for the successful operation of a continuous stream type ink jet printer. It is crucial to avoid both the air ingestion into the cavity or manifold as well as fouling of the printhead with ink. This task becomes even more difficult in multijet marking modules where the following two additional effects complicate the control of these processes: the pressure wave reflections in the long, full page width printhead and the contribution of the kinetic energy of the ink to the total ink energy. The kinetic energy of the ink is higher in the parts of the printhead close to the ink inlet than in the portions distant from the inlet. It is found that the successful shutdown is generally more difficult to achieve than the successful startup.

By placing diaphragms 10, 11 shown in Figures 1 and 2, upstream of jet stream orifice 12, 13 shutdown of a continuous stream ink jet printer is improved. The diaphragms act as one-way mechanical valves and produce a sufficient forward to backward rectifying ratio and a small reverse flow. Also, they are biased in the forward direction; that is, a certain finite forward pressure is needed to make the diaphragms pervious.

At start-up, the diaphragms are opened by the pressure of ink and transmits the transient pressure oscillations about the operating pressure. These oscillations do not present a danger and they extinguish long before the actual printing...