Xerox Corporation

Joseph J Wysocki

Gary Alan Kneezel

Joseph F Stephany

Thomas E Watrobski

Richard V LaDonna

Juan J Becerra

Thomas P Courtney

Michael Poleshuk

Thomas A Tellier

Peter J John

James H Becker

James N Eaton

Dale R Ims

Thomas Jay Wyble

Virgil Joseph Hull

Robert V Lorenze, Jr

Sui K Hark

David Allen Mantell

Bing R Hsieh

Ian D Morrison

William G Hawkins

Ram S Narang

Kurt B Gundlach

William M Schwarz

Ivan Rezanka

Min-Hong Fu

Michael P O'Horo

Andras I Lakatos

W Conrad Richards

Robert W Madrid

An improved temperature compensation method is disclosed in which a temperature sensing thermistor is formed on a substrate whose temperature is to be series of fractional thermistors which are selectively shorted out during a manufacturing process to provide a compensation for manufacturing variabilities of the temperature coefficient of resistance of the thermistor.

Sensing the temperature of a printhead in an ink jet printer

Individual printheads are joined together in a manner to provide improved alignment and registration. The multiple printhead assembly is then installed and removed from the printer as a single unit. According to a preferred method of forming the assembly, individual printheads are temporarily mounted on a holddown plate. The location and position of the printheads is monitored and a fast-cure adhesive used to monolithically join the individual printheads together as a unitary assembly. Once the adhesive is cured, the temporary securing of the individual printheads is removed and the entire assembly removed as a single unit from the holddown plate.

Monolithic printheads for ink jet printing apparatus

An ink jet printer has a temperature sensor as a permanent part thereof to measure the temperature of printheads which are an integral part of a replaceable printhead cartridge assembly. The temperature sensor is a part of the maintenance station and senses the temperature of the printheads each time the printhead enters the maintenance station. In the preferred embodiment, the temperature sensor is spring-loaded and is located at a printhead spitting location between fixed wiper blades and the capping location in the maintenance station, so that temperature is sensed each time the printhead enters and leaves the maintenance station to eject nozzle cleaning droplets onto a collection surface at the spitting location to clean the printhead nozzle face by the wiper blades, or to cap the printhead nozzles. To facilitate good thermal contact, a recess is provided in the heat sink upon which the printhead resides for entry by the spring-loaded temperature sensor.

Ink jet printer having temperature sensor for periodic contact with

An ink jet ink includes a colorant and a liquid component containing at least one of an epoxy and a vinyl ether. Water may also be dissolved in the liquid component. Preferably, the vinyl ether is ethylene glycol monovinyl ether. An ink jet recording process includes the steps of ejecting an ink jet ink, such as the inks of the present invention, from an orifice to form an image on a recording medium.

Ink jet ink compositions and recording processes

An ink jet printer has a temperature sensor as a permanent part thereof. The temperature sensor is mounted on the translatable carriage of the printer. A replaceable printhead cartridge having a printhead bonded to a heat sink is installed on the translatable carriage. Once the printhead cartridge is installed on the translatable carriage, the temperature sensor is placed into intimate contact with printhead'heat sink, so that the temperature sensor moves with the printhead and provides continual temperature measurement.

Ink jet printer having temperature sensor for replaceable printheads

A power control system in a thermal ink-jet printer facilitates practically instantaneous voltage changes to a heating element. A first set of selectably-actuable voltage lines is operatively connected in parallel to a first terminal of the heating element, each line having associated therewith a predetermined voltage output. A second set of selectably-actuable voltage lines is operatively connected in parallel to a second terminal of the heating element, each line having associated therewith a predetermined voltage output. One of the first set of selectably-actuable voltage lines and one of the second set of selectably-actuable voltage lines are activated as required.

Power control system for a thermal ink-jet printer

A thermal ink-jet printhead adapted to emit ink onto a print sheet is automatically adjusted. The printhead is caused to emit ink onto a sheet in a manner consistent with an image of a first density, and then substantially immediately caused to emit ink in the form of a first test pattern on the sheet. The density of the first test pattern on the sheet is measured. The printhead is caused to emit ink onto the sheet in a manner consistent with an image of a second density, and then substantially immediately caused to emit ink in the form of a second test pattern on the sheet. The density of the second test pattern on the sheet is measured. The densities of the first test pattern and the second test pattern are correlated with a function relating a characteristic of an image printed with the printhead to a temperature of the printhead.

Calibration system for a thermal ink-jet printer

A control system for a printer having at least one heating element for producing spots applies one of a plurality of voltage levels to at least one heating element disposed on a printhead. A voltage supply supplies a voltage to a first one of a plurality of switches connected in series with a last one of the switches being connected to the at least one heating element. At least one of the switches defines a first path and a second path having different voltage drops. A controller coupled to the plurality of switches selectively actuates the switches to apply one of a plurality of predetermined voltages to the at least one heating element.

Power control system for a printer

Data relating to the performance of an individual ink-jet printhead is stored in an electrically-readable form on a silicon substrate forming an essential part of the printhead. A template of electrically-detectable structure is created on the substrate at manufacture, and then portions of the structure are removed in accordance with the data desired to be stored. In one embodiment, the digital performance data may be encoded and also read out in serial form using a shift register on the chip.

Electronically readable performance data on a thermal ink jet printhead

An apparatus and method compensates for a voltage drop of electrical pulse signals selectively applied to a plurality of heater elements on a printhead of an ink jet printing device. A number of heater elements to be pulsed at a given time is determined and a time duration of each of the pulse signals is selected based on information including the determined number of heater elements to be pulsed. In another aspect, the position on the printhead of the heater elements to be pulsed is determined and the time duration of the pulse signals is selected further based on the determined position. By varying the time duration of the pulse signals applied to the heater elements, a voltage drop across the heater elements due to the number of heater elements simultaneously pulsed and/or the position of the heater elements on the printhead is compensated for, maintaining reliable jetting performance while minimizing the voltage by which operating printing voltage needs to exceed the threshold printing voltage.

Voltage drop correction for ink jet printer

A thermal ink jet printhead is controlled to minimize missing droplets at elevated operating temperatures by varying the voltage and pulse width applied to the heater element that causes droplets to be formed and ejected. Increasing the applied voltage reduces the size of the formed droplets. At increased operating temperatures, smaller droplets minimize the introduction of air into the nozzles of the printhead upon ejection. Minimizing the introduction of air eliminates printhead misfirings and causes more consistent jetting of the ink droplets.

Minimization of missing droplets in a thermal ink jet printer by drop

A thermal ink-jet printhead comprises a substrate having a plurality of heating elements defined thereon. A thermistor, disposed on the substrate, includes a conductor loop which does not encompass the heating elements on the substrate. The configuration of the thermistor significantly reduces both electromagnetic and capacitance interference caused by the heating elements.

Low-interference thermistor for a thermal ink jet printhead chip

A system controls an ink jet printing apparatus for propelling ink jet droplets on demand from a printhead having a plurality of drop ejectors. In the printhead, each ejector includes a heating element actuable in response to electrical input signals, each input signal having an amplitude and a time duration, selectably applied to the heating element to produce a temporary vapor bubble and cause a quantity of ink to be emitted for the creation of a mark on a copy sheet. The temperature of ink in the printhead is sensed, and a combination of power level and time duration of the electrical input signal for the heating element to result in a desired size of the mark of the copy sheet is selected, by entering the sensed temperature of the ink into a predetermined function relating the energy of the electrical input signal to the corresponding resulting size of the mark on the copy sheet.

Electronic spot size control in a thermal ink jet printer

Liquid crystal devices are provided with a DC current blocking layer which improves the lifetime of the liquid crystal device and also permits the use of two-level drivers, thus reducing the complexity of the driving scheme necessary to address the liquid crystal devices. Preferably, the blocking layer is the alignment layer which is made from poly-para-xylylene having a thickness sufficient to act as a DC blocking layer. Additionally, specific driving schemes for driving liquid crystal devices are provided. When the liquid crystal device includes a material which relaxes when no voltage is applied thereto (e.g., a nematic material), the information signal is entirely removed from alternating time frames during which the liquid crystal device is addressed. When the liquid crystal device includes a ferroelectric material, an arbitrarily large voltage potential is applied to the electrodes located on one side of the ferroelectric material for a first portion of a dwell time so that the pixels of the liquid crystal device are easily cleared of any previous information.

Control of liquid crystal devices

A light shutter is provided wherein a first plate which includes a pixel electrode for use in applying a includes a background electrode located adjacent the pixel voltage potential across a ferroelectric material also electrode and substantially surrounding the pixel electrode, whereby an electronic mask can be created adjacent the pixel electrode in the ferroelectric material. A second plate which, along with the first plate sandwiches the ferroelectric material, includes a backplane electrode which is used in conjunction with the pixel and background electrodes on the first plate for applying voltage potentials across the ferroelectric material. By maintaining a minimal amount of spacing between the background electrode and the pixel electrode, a voltage potential can be applied between the background and backplane electrodes so that the ferroelectric material located adjacent the pixel electrode can be maintained in, for example, a non-light transmissive state whereby the contrast between the pixel and inter-pixel regions is greatly improved. Image bars or displays can be formed by arranging a plurality of light shutters (and consequently, pixel electrodes) on the first plate with one or more background electrodes surrounding the plurality of pixel electrodes. Additionally, the background electrode and/or other electrodes can be used for applying electric fields to the ferroelectric material which are non-parallel to the polarization direction of the molecules of the ferroelectic material to reduce the time required to change the ferroelectric material between light transmissive and light blocking states.

Growing community of inventors

Webster, NY, United States of America

Joseph J Wysocki