Hewlett-packard Company

Hewlett-packard Development Company, L.p.

Ulrich E Hess

James R Hulings

Duane A Fasen

Kenneth E Trueba

Brian J Keefe

Charles E Moore

Matthew David Giere

Arjang Fartash

Jeffery S Hess

James W Grace

Jaime H Bohorquez

Larry S Metz

Eldurkar V Bhaskar

Samson Berhane

Jerome E Beckmann

John H Stanback

Winthrop D Childers

Paul H McClelland

Ali Emamjomeh

Steven Warren Steinfield

Michael John Regan

Ellen R Tappon

William R Knight

Marzio A Leban

Domingo A Figueredo

Roger J Kolodziej

Niels J Nielsen

Gregory T Hindman

John P Whitlock

Peter M Burke

Nagwa M Elshaik

Zen Kurokawa

Eldukar V Bhaskar

A cavitation structure for a print head has a first dielectric layer overlying at least a first portion of a substrate. A second dielectric layer has a first portion overlying at least a second portion of the substrate and a second portion, different from the first portion of the second dielectric layer, overlying at least a portion of the first dielectric layer. A cavitation layer has a first portion in contact with the first dielectric layer and a second portion in lateral contact with the second portion of the second dielectric layer. A third dielectric layer is disposed on only the first portion of the second dielectric layer.

Fluid-ejection devices and a deposition method for layers thereof

Atomic layer deposition forms a cavitation layer of a print head.

A printhead including a printhead substrate having at least one opening formed in a first surface to provide a fluid path through the substrate. The printhead further includes a thin film membrane formed on a second surface of the substrate. The thin film membrane includes a plurality of fluid ejection elements and has a floating section and a cantilevered section, which are detached and separated from one another by a gap.

Printhead having a thin film membrane with a floating section

A thermal ink jet with a body having an ink firing chamber and an orifice. An electrically activated heating element is connected to the body in thermal communication with the firing chamber, and includes a contoured surface portion coextensive with at least a portion of the heating element. The contoured surface portion of the firing chamber has a plurality of recesses.

Ink jet pen with a heater element having a contoured surface

A high efficiency thermal inkjet printhead. The printhead includes a substrate, a base layer on the substrate, and at least one ink expulsion resistor on the base layer. The base layer is made from a special material that experiences a substantial increase in thermal conductivity at the elevated temperatures associated with resistor operation. As a result, the base layer functions as an effective thermal insulator when the resistors are initially energized, yet allows heat to dissipate from the resistors immediately after the deactivation thereof. Numerous benefits are achieved by this development including (1) rapid resistor cool-down between successive ink ejection cycles (which improves the speed/operational frequency of the system); and (2) the prevention of undesired heat dissipation through the base layer when the resistors are initially energized, with the generated heat instead flowing into the ink.

High efficiency ink delivery printhead having improved thermal characteristics

A thermal ink jet printhead that includes a thin film substrate including a plurality of thin film layers, a plurality of ink firing heater resistors defined in the plurality of thin film layers, a patterned tantalum carbide layer disposed on the plurality of thin film layers, an ink barrier layer disposed over the tantalum carbide layer, and respective ink chambers formed in the ink barrier layer over respective thin film resistors, each chamber formed by a chamber opening in barrier layer. The tantalum carbide layer forms an oxidation and wear resistance layer and/or a barrier adhesion layer.

Transition metal carbide films for applications in ink jet printheads

An inkjet printhead structure comprises novel resistor circuitry that is fabricated on two different substrate layers. The dual layer circuitry reduces the required substrate surface area and printhead shelf length to increase the printer operating frequency and print density. In one embodiment of the invention, heating resistors are spread out over portions of the substrate surface area and conductors are attached to opposite ends of the heater resistors in a novel configuration. To simplify routing, the circuitry is configured so that multiple heater resistors are coupled to the same conductor return path located on a second conductive layer. In a second embodiment of the invention, the heater resistors are dimensioned in the shape of a trapezoid to provide uniform heating. Alternative resistor shapes are then introduced to provide consistent heat dissipation for variances in resistor/conductor sheet resistance.

Special geometry ink jet resistor for high dpi/high frequency structures

A bipolar ink jet driver circuit includes a plurality of individual driver cells having a common collector and a resistive heater element. A common collector obviates the need for any isolation between adjacent driver cells. The driver cells each include two bipolar transistors configured as a Darlington pair, which drive an associated resistive heater element. The cells are grouped together to form individual driver circuits each having a control line for enabling each driver circuit. The cells within each driver circuit are individually addressable via address lines which are coupled to each of the driver elements. The resistive heater elements are actuated by enabling a driver circuit and addressing a driver cell within the enabled driver circuit.

Method for forming a bipolar integrated ink jet printhead driver

This invention provides an apparatus and method of fabrication thereof for an inkjet printhead with 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. The apparatus is fabricated without using ion implant technology.

Edge feed ink delivery thermal inkjet printhead structure and method of

A printhead includes a substrate with an ink feed aperture extending from a first surface to a second surface and a plurality of heater resistors disposed on it. Primitive groupings of the resistors are coupled to associated group power sources. An ink barrier layer is deposited on the substrate to create ink firing chambers for each resistor. One wall of the ink barrier has a constricted opening through which ink is supplied from the ink feed aperture. A plurality of transistors are disposed in the substrate with each transistor output coupled to an associated one of the resistors and each input coupled to one of a plurality of addressing signal lines. The number of addressing signal lines is equal to the number of resistors in a primitive grouping.

Thermal inkjet printer printhead with offset heater resistors

Bipolar integrated ink jet printhead driver

An improved thermal inkjet printhead having MOSFET drive transistors incorporated therein. The gate of each MOSFET transistor is formed by applying a layer of silicon dioxide onto a silicon substrate, applying a layer of silicon nitride onto the silicon dioxide, and applying a layer of polycrystalline silicon onto the silicon nitride. Portions of the substrate surrounding the gate are oxidized, forming field oxide regions. Drain and source regions are then conventionally formed, followed by the application of a protective dielectric layer onto the field oxide, drain, source, and gate. A resistive layer is deposited on the dielectric layer and directly connected to the source, drain, and gate. A conductive layer is deposited on a portion of the resistive layer, ultimately forming both covered and uncovered regions thereof. The uncovered region functions as a heating resistor, and the covered regions function as electrical contacts to the transistor and resistor.

Thermal inkjet printhead structure and method for making the same

An improved thermal inkjet printhead and manufacturing method in which driver circuitry (e.g. MOSFET transistors), heating resistors, and a specialized arrangement of conductive elements are used. A substrate is provided having a plurality of drive transistors thereon. A layer of resistive material (e.g. a tantalum-aluminum mixture) is deposited on the substrate and directly connected to the source, gate, and drain of at least one transistor. A layer of conductive metal (e.g. aluminum) is deposited on a portion of the resistive layer, forming both covered and uncovered regions thereof. The uncovered region functions as a heating resistor, and the covered regions function as direct electrical contacts to the transistor, thereby minimizing the number of conductive elements in the printhead. The resistor is positioned beneath an ink-retaining cavity, and is designed to heat ink therein for expulsion through an orifice plate.

Thermal inkjet printhead having driver circuitry thereon and method for

This application discloses a novel thermal ink jet printhead and related integrated pulse driver circuit useful in thermal ink jet printers. This combined printhead and pulse drive integrated circuit includes a first level of metalization comprising a refractory metal which is patterned to define the lateral dimension of the printhead resistor. A passivation layer or layers are deposited atop this first level of metalization and patterned to have an opening or openings therein for receiving a second level of metalization. This second level of metalization such as aluminum may then be used for electrically interconnecting the printhead resistors to MOSFET drivers and the like which have been fabricated in the same silicon substrate which provides support for the printhead resistors. Thus, this 'on-chip' driver construction enables these pulse driver transistors to be moved from external electronic circuitry to the printhead substrate.

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Corvallis, OR, United States of America

Ulrich E Hess