摘要:
The present invention provides an ink jet print head having an improved driver design and capable of extended and continuous periods of operation with substantially reduced rectified diffusion-induced printing quality degradation. In preferred ink jet print heads of the present invention, the ink-contacting portion of the surface of the diaphragm of a piezoelectric ceramic/diaphragm drive mechanism is electropolished. By electropolishing only a portion of one surface, the ink-contacting surface, of one ink jet print head component, rectified diffusion is greatly reduced.
摘要:
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.
摘要:
An aqueous phase change ink contains a selected concentration of hyperthermogelling component that causes the ink to gel when its temperature is increased to its thermo-inversion point or when the concentration of the hyperthermogelling component is increased by evaporation, or substrate absorption, of water from the ink. The ink may be jetted directly onto a heated and/or absorptive substrate or jetted onto a cooler and/or hydrophobic surface before being transferred to the substrate. The thermo-inversion point is preferably about ambient temperature, and the preferred hyperthermogelling component is a nonionic surfactant, such as an ethylene oxide propylene oxide block copolymer surfactant.
摘要:
There is disclosed a piezoelectric ceramic ink-jet print head and made by an inventive ultrasonic bonding process. Specifically, there are disclosed several improved features of ink jet print heads, including a more cost-effective bonding process using an ultrasonic bonding technique, an improved piezoelectric ceramic crystal pattern, and improved print head-piezoelectric electrical contacts. Further, there is disclosed an ultrasonic bonding process joining metallic objects with ultrasonic energy.
摘要:
There is disclosed a piezoelectric ceramic ink-jet print head and made by an inventive ultrasonic bonding process. Specifically, there are disclosed several improved features of inkjet print heads, including a more cost-effective bonding process using an ultrasonic bonding technique, an improved piezoelectric ceramic crystal pattern and improved print head-piezoelectric electrical contacts. Further, there is disclosed an ultrasonic bonding process joining metallic objects with ultrasonic energy.
摘要:
Gray scale ink jet printing method and apparatus produce a high quality image having varying color intensities. This is achieved by mixing a colored phase change ink with varying amounts of a clear phase change ink base, thereby producing multiple gray scale levels of each color. The mixing either can be performed prior to placement of the phase change ink in the printer, or can be performed within the printer to produce different levels of color intensity during the printing process.
摘要:
Ink jet printing on a liquid medium can be performed using a membrane underlayer. A drop of a liquid can spread on the surface of the liquid medium, forming a substrate for the ink jet printing. The liquid ink can include a thermogelling component which can gelled, e.g., forming gel droplets, when contacting the membrane.
摘要:
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.
摘要:
An ink jet head 10 has an ink chamber 14 which receives ink from an ink inlet passageway 38. Pressure pulses applied to the ink chamber cause the ejection of ink drops from an ink drop forming orifice 23 and toward printing medium. A purging outlet 41 communicates with the ink chamber through a purging passageway 40. During purging, ink flows in a vortical path through the ink chamber 14 from the ink inlet passageway 38 to the purging outlet passageway 40. This sweeps air bubbles and contaminants from the ink chamber walls and removes them from the ink chamber. Ink pressure within the ink chamber 14 may be elevated to increase the flow of ink during purging. Also, a negative pressure may be applied to the purging outlet during purging. Variable frequency pressure pulses may also be applied to the ink chamber to assist the purging process.
摘要:
Ink jet printing on a liquid medium can be performed using liquid inks having a thermo inversion gelling property. The liquid ink can include a hyperthermogelling component having a gelling temperature. When the liquid ink is jetted on the liquid medium, the liquid ink can gel to form gel dots. The gel dots can resist against liquid dispersion, allowing the formation of a high resolution image on the liquid medium.