A liquid ink, drop-on-demand printhead includes a substrate having a plurality of drop-emitter orifices, an ink channel coupled to each of the orifices for delivery of a body of ink to the orifices at a pressure above ambient, thereby forming an ink meniscus at the orifices. Drop selection is effected by selectively delivering heat to ink which has been delivered to selectively addressed ones of the orifices, thereby causing a difference in meniscus position between ink in addressed and non-addressed orifices. A heater is suspended in each ink meniscus close to its surface when the meniscus is at its position in a non-addressed orifice, the heater being effective to heat the meniscus and to thereby reduce surface tension of the meniscus at selectively addressed orifices.

Ink printing apparatus with improved heater

An ink jet print device includes a passageway for flowing ink having an outlet for ejecting ink at one end. The passageway has a portion where the cross-sectional dimensions of the passageway change. A generating device which generates energy for ejecting ink from the outlet is disposed on a surface intersecting the passageway and defines a part of the portion where the cross-sectional dimensions of the passageway change.

Ink jet print device and print head or print apparatus using the same

Disclosed is a phase change ink comprising (a) a colorant and (b) a phase change ink carrier, said carrier comprising (i) a branched triamide and (ii) a polyethylene wax having an average peak molecular weight of from about 350 to about 730 and a polydispersity of from about 1.0001 to about 1.500. Also disclosed is a process which comprises (1) incorporating into an ink jet printing apparatus a phase change ink comprising (a) a colorant and (b) a phase change ink carrier, said carrier comprising (i) a branched triamide and (ii) a polyethylene wax having an average peak molecular weight of from about 350 to about 730 and a polydispersity of from about 1.0001 to about 1.500; (2) melting the ink; and (3) causing droplets of the melted ink to be ejected in an imagewise pattern onto a substrate.

Phase change inks

An ink-jet recording head includes a discharge-port portion including a first discharge-port portion continuing from a discharge port, and a second discharge-port portion communicating the first discharge-port portion with a bubble generation chamber. The second discharge-port portion has an end surface that includes a border portion bordering the first discharge-port portion and is parallel to a main surface of an element substrate. The cross-sectional area of the second discharge-port portion, anywhere from an opening surface facing the bubble generation chamber to an end surface facing the first discharge-port portion, that is parallel to the main surface of the element substrate, is larger than the area of the border portion. The cross section of the opening surface of the second discharge-port portion has a length in a direction perpendicular to an arrangement direction of the discharge ports that is greater than its length in a direction parallel to the arrangement direction.

Ink jet recording head

This invention provides an improved ink flow path between an ink reservoir and vaporization chambers in an inkjet printhead. In the preferred embodiment, a barrier layer containing ink channels and vaporization chambers is located between a rectangular substrate and a nozzle member containing an array of orifices. The substrate contains two linear arrays of heater elements, and each orifice in the nozzle member is associated with a vaporization chamber and heater element. The ink channels in the barrier layer have ink entrances generally running along two opposite edges of the substrate so that ink flowing around the edges of the substrate gain access to the ink channels and to the vaporization chambers.

Ink delivery system for an inkjet printhead

A thermal ink jet printer is disclosed in which ink droplets are ejected from an orifice by the explosive formation of a vapor bubble within the ink supply due to the application of a two part electrical pulse to a resistor within the ink supply. The electrical pulse comprises a precurser pulse and a nucleation pulse; the precurser pulse preheats the ink in the vicinity of the resistor to a temperature below the boiling temperature of the ink so as to preheat the ink while avoiding vapor bubble nucleation within the ink supply and the subsequently occuring nucleation pulse very quickly heats the resistor to near the superheat limit of the ink.

Thermal ink jet printer

Disclosed is an ink-jet composition including an organic carrier that is solid at 25° C. and liquid at the operating temperature of an ink-jet nozzle and a driver having a critical pressure greater than 10 atmospheres, the carrier and driver being miscible in liquid phase. The ink-jet composition is characterized by a viscosity of less than 15 centipoise at 90° C. and a surface tension of between about 20 to about 25 dynes per centimeter at 90° C. The ink-jet compositions disclosed herein are particularly useful in thermal ink-jet printing using thermally induced vapor bubbles to eject ink droplets from the printer and onto a substrate.

Solid ink compositions for thermal ink-jet printing having improved printing characteristics

The capability of varying sizes of a dot in a printer is fully exploited to provide a gray scale image of superior quality. Errors in gray level are used to modulate the sizes of the dots in producing the image.

Method for rendering gray scale images with variable dot sizes

A Self Calibrating Color Printer. The present invention enables color printers to accurately reproduce color images despite variations in ink, paper or the printing system. The calibrated printer includes a movable optical sensor assembly which first calibrates itself by measuring an included known color gamut located within the movement range of the sensor assembly. Once calibrated, the sensor assembly measures a color print test pattern newly printed by a movable color print head of the printer. An analog-to-digital converter transforms electrical signals from the sensor assembly to sensor values in digital form, enabling a printer control processor to process the measured data, thereby producing two look-up tables stored in memory: first, a color correction look-up table which adjusts image color values to account for the ink/paper variations, and second, an error diffusion look-up table which spreads color value errors at a given pixel to its neighbors. Once the printer control processor creates these two look-up tables and, the printer is able to process image data, and control the print head via its associated print head electronics to faithfully reproduce the image onto paper. The moveable sensor and associated gamut and print test pattern of the present invention provide an accurate, inexpensive and durable apparatus for calibrating any digital color printer. The Self Calibrating Color Printer disclosed and claimed in this patent applications provides an advanced, accurate and relatively inexpensive instrument for true reproduction of detailed color images.

Method and apparatus for calibrated digital printing using a four by four transformation matrix

A thermal ink jet printer utilizes a printhead resistor which has a central conductive region to excite bubble growth and to cause ejection of ink droplets. The existence of the central conductive region causes bubbles to be created which are toroidal in shape and which fragment during collapse, thereby randomly distributing the resultant acoustic shock across the surface of the printhead resistor and minimizing cavitation damage.

John D. Meyer

Papers

Thermal ink jet printer

Solid ink compositions for thermal ink-jet printing having improved printing characteristics

Method for rendering gray scale images with variable dot sizes

Method and apparatus for calibrated digital printing using a four by four transformation matrix

Thermal ink jet printer utilizing a printhead resistor having a central cold spot