Tektronix, Inc.

Other

Ronald L Adams

Hue Phuoc Le

Joy Roy

James D Buehler

Jon C Mutton

Douglas M Stanley

Thomas R Shrout

James D Rise

Ronald F Burr

Edward F Burke

James E Blomquist

Qiming Zhang

Arthur C Van Horne

L Eric Cross

James C Oswald

Eldon P Hoffman

David A Tence

Charles Bradford

Qiyue Chia Jiang

Jeffery J Anderson

Rodney B Gilbert

A ferroelectric relaxor ceramic actuator material, such as lead magnesium niobate ('PMN'), has high electromechanical conversion efficiency, exhibits wide operating and manufacturing temperature ranges, does not require permanent polarization, and provides useful mechanical activity with reduced electrical drive voltages. A PMN actuator (66) may be bonded to an actuator diaphragm (64) with a high temperature soldering or brazing process. PMN material also has a diffuse Curie point range in which the dielectric constant (40), 'd' coefficient (32), and dielectric loss (42) characteristics all rise to a peak and then fall as the temperature increases. A phase-change ink-jet print head (50) employs a PMN actuator that is compounded with lead titanate ('PT') to increase the temperature (T.sub.M) at which the peak dielectric constant occurs. The print head is operated at a temperature beyond the peak where the PMN:PT actuator 'd' coefficient decreases as the temperature increases such that an increase in ink-jet drop ejection velocity caused by reduced ink viscosity is compensated for by a corresponding reduction in mechanical activity. The PMN:PT actuator thereby relaxes the temperature regulation and heat spreading requirements of the phase-change ink-jet print head.

Ferroelectric relaxor actuator for an ink-jet print head

An ink jet (10) apparatus and method provides high-resolution gray scale printing by providing multiple PZT drive waveforms (100, 110, 120), each having a spectral energy distribution that excites a different modal resonance of ink in an ink jet print head orifice (14). By selecting the particular drive waveform that concentrates spectral energy at frequencies associated with a desired oscillation mode and that suppresses energy at the other oscillation modes, an ink drop (170, 180, 190) is ejected that has a diameter proportional to a center excursion size of the selected meniscus surface oscillation mode. The center excursion size of high order oscillation modes is substantially smaller than the orifice diameter, thereby causing ejection of ink drops smaller than the orifice diameter. Conventional orifice manufacturing techniques may be used because a specific orifice diameter is not required. Jetting reliability and contaminant susceptibility are, thereby, improved by eliminating the need for an unconventionally small orifice. Changing a selected PZT drive waveform amplitude changes drop ejection velocity without changing drop volume. This invention, therefore, provides for selection of ejected ink drop volumes having substantially the same ejection velocity over a wide range of ejection repetition rates.

Method and apparatus for producing dot size modulated ink jet printing

A printer accurately controls the passage of print media therethrough and maintains the print media taut as the print media passes through a printing zone while the media is printed by an ink jet printer. The print media sheet is preferably carried by a rotating drum in a first direction through the printing zone, with the drum being reversed to cause the exiting of the print media sheet from the printer. A pressure fixing or fusing apparatus may be positioned to flatten ink spots on the print media as the print media exits from the printer. The pressure fixing or fusing mechanism is preferably used in the case of a hot-melt or phase-change ink jet printer.

Ink jet printer architecture and method

A drop-on-demand ink jet print head (9) has an ink pressure chamber (22) coupled to a source of ink (11) and an ink drop ejecting orifice (103) with an ink drop ejection orifice outlet (14). An acoustic driver (36), in response to a drive signal (100), produces a pressure wave in the ink and causes the ink to pass outwardly through the ink drop ejecting orifice (103) and the ink jet ejection orifice outlet (14) of the ink jet print head (9). In accordance with the present invention, controlling the operation of the ink jet print head (9) with a particular drive signal reduces print quality degradation resulting from rectified diffusion, which is the growth of .air bubbles dissolved in the ink from the repeated application of pressure pulses to the ink residing within the ink pressure chamber (22) of the ink jet print head (9), such pressure pulses causing the application of pressures below ambient pressure. This method of controlling the operation of the ink jet print head (9) applies pressure below ambient pressure to the ink residing within the ink pressure chamber (22) of the ink jet print head (9) at magnitudes less than the threshold pressure magnitude that leads to the air bubble growth.

Method of operating an ink jet to reduce print quality degradation

An improved striking device is provided as including a main post having two main longitudinal slots. An insert post having an outside diameter that is less than the inside diameter of the main post is provided. A striking surface is provided that is attached to an arm which in turn is attached to an arm housing. The arm housing has a first housing end and a second housing end. The arm housing is placed around the main post and the second housing end rests upon a support axle passing through the insert post. The first housing end includes a cam surface having two peaks located on opposite sides thereof and two valleys located on opposite sides thereof with each of the two valleys disposed between each of the two peaks. A cam follower is included which is retained in contact against the cam surface by a pair of springs. During rotation of the arm housing the cam follower cooperates with the cam surface of the arm housing to provide a first striking position and a second striking position that are each located one hundred and eighty degrees of rotation apart with respect to each other. As the arm housing rotates the cam surface extends the cam follower which is turn extends the pair of springs in proportion to the contour of the cam surface. If sufficient force is imparted to the striking surface, the arm housing is urged away from the first striking position, and indexes into the second striking position.

Striking device

A drop-on-demand ink jet print head (9) has an ink pressure chamber (22) coupled to a source of ink (11) and an ink drop ejecting orifice (103) with an ink drop ejection orifice outlet (14). An acoustic driver (36), in response to a driver signal (100), produces a pressure wave in the ink and causes the ink to pass outwardly through the ink drop ejecting orifice (103) and the ink jet ejection orifice outlet (14) of the ink jet print head (9). In accordance with the present invention, controlling the operation of the ink jet print head (9) with a particular drive signal reduces print quality degradation resulting from rectified diffusion, which is the growth of air bubbles dissolved in the ink from the repeated application of pressure pulses to the ink residing within the ink pressure chamber (22) of the ink jet print head (9), such pressure pulses causing the application of pressures below ambient pressure. This method of controlling the operation of the ink jet print head (9) applies pressure below ambient pressure to the ink residing within the ink pressure chamber (22) of the ink jet print head (9) at magnitudes less than the threshold pressure magnitude that leads to the air bubble growth.

An air-assisted drop-on-demand ink jet head 10 has a single compartment ink chamber 14 and is designed for operation over a wide range of ink drop repetition rates, including extremely high repetition rates, such as twenty kilohertz. The components included in the ink jet head have natural resonance frequencies which are greater than the desired maximum drop generation frequency of the ink jet head. In addition, the natural frequency of each of the components of the ink jet head are sufficiently different from one another to prevent intercoupling. Ink is supplied to the ink chamber 14 via a supply inlet passageway 38 which has a cross-sectional area which is sized large enough to allow the supply of ink to the ink chamber. Yet, this area is small enough so that the natural frequencies of ink in the ink inlet do not significantly alter drop generating pressure pulses in the ink chamber 14.

Air assisted ink jet head with single compartment ink chamber

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Portland, OR, United States of America

Ronald L Adams