Hewlett-packard Development Company, L.p.

Hewlett-packard Company

James A Feinn

Lawrence H White

Ronald Albert Askeland

Thomas R Strand

Clayton L Holstun

Winthrop D Childers

Erik D Torniainen

Matthew David Giere

Albert Nagao

Eric T Martin

James Michael Gardner

Daryl E Anderson

Jason M Quintana

Colin C Davis

Satya Prakash

Jason R Arbeiter

David D Helfrick

Adam L Ghozeil

Donald W Schulte

Jeffery S Beck

Terry E McMahon

David P Markel

David R Thomas

Dennis J Schloeman

Ronald J Ender

Michael J Barbour

Paul A Richards

Kelly Ronk

Scott A Norum

Peter Mardilovich

Ali Emamjomeh

David Alvin Tyvoll

Jeffrey Allen Nielsen

Garrett E Clark

Melissa D Boyd

Douglas A Sexton

Paul Crivelli

Tony S Cruz-Uribe

Hector Jose Lebron

Arun K Agarwal

William R Knight

Jules G Moritz

James Pingel

Stan E Leigh

Jaime H Bohorquez

Ozgur E Yildirim

Julie J Cox

David William Jenkins

Jacob Lum

James Robert Schmedake

Steven Michael Krause

Elizabeth A Fellner

Kevin Kaufmann

Mengqian Lu

Erik D Tomiainen

Thomas A Strand

An example printhead includes a circulation channel having an inlet for receiving a fluid and an outlet for expelling the fluid, a first nozzle fluidically coupled to the circulation channel, the first nozzle being operable at a first absolute pressure, and a second nozzle fluidically coupled to the circulation channel, the second nozzle being operable at a second absolute pressure, the absolute second pressure being lower than the first absolute pressure. The absolute pressure in the circulation channel decreases as the fluid flows from the inlet to the outlet, and the first nozzle is positioned closer to the inlet of the circulation channel than the second nozzle.

Printhead with circulation channel

In one example in accordance with the present disclosure, a fluid analysis system is described. The fluid analysis system includes a fluidic die. The fluidic die includes a fluid chamber to hold a volume of fluid to be analyzed and an impedance sensor disposed within the fluid chamber. The impedance sensor measures an impedance of the fluid in the fluid chamber. The fluid analysis system also includes an evaluator device electrically coupled to the impedance sensor. The evaluator device determines at least one property of the fluid based on the impedance.

Fluidic property determination from fluid impedances

In an example implementation, a method of reducing inkjet aerosol in a fluid drop ejection system includes imaging fluid drops from an ejection event as the drops travel from an ejection nozzle toward a substrate, determining the momentum of each fluid drop from the imaging, comparing the momentum of each fluid drop with a threshold momentum, and determining that a fluid drop will become aerosol when its momentum does not exceed the threshold momentum.

Reducing inkjet aerosol

A method of distinguishing between fluids may include providing a current to an electrode disposed within a fluidic passageway of a fluidic die, the current to be forced into a fluid within the fluidic die, sensing an impedance at the electrode, and determining a particle vehicle separation level of the fluid based on the sensed impedance between a first instance and a second instance.

Fluid distinguishing devices

In one example in accordance with the present disclosure, a fluidic system is described. The fluidic system includes a fluidic die. The fluidic die includes a substrate in which a number of fluid chambers are formed. Each fluid chamber includes a fluid actuator disposed within the fluid chamber. A number of actuator sensors are disposed on the substrate to output at least one value indicative of a sensed characteristic of fluid actuators. A number of substrate temperature sensors are also disposed on the substrate to sense a temperature for the substrate. An actuator evaluation device of the fluidic system determines a state of the fluid actuator based at least in part on the at least one value and at least one correction value associated with the temperature sensed by the number of substrate temperature sensors.

Temperature-based actuator evaluation

An inkjet nozzle includes an aperture with a noncircular opening having a first segment substantially defined by a first polynomial equation and a second segment substantially defined by a second equation.

Noncircular inkjet nozzle

An inkjet nozzle includes an aperture with a noncircular opening substantially defined by a polynomial equation. A droplet generator is also described which includes a firing chamber fluidically coupled to a fluid reservoir a heating resistor and a nozzle. The nozzle includes an aperture forming a passage from the firing chamber to the exterior of the droplet generator through a top hat layer. The nozzle is defined by a closed polynomial and has a mathematically smooth and mathematically continuous shape around aperture's perimeter wall, with two protrusions extending into the center of the aperture.

In some examples, a fluid nozzle includes an aperture comprising a first lobe that is shaped as an ellipse, and a second lobe that has a non-circular shape and has a different size than a size of the first lobe. The fluid nozzle further includes protrusions between the first and second lobes extending inward and forming a throat between the first and second lobes.

According to an example, in a method for enhancing temperature distribution uniformity across a printer die, in which the printer die includes a plurality of drop generators arranged in a plurality of columns, a warming map that identifies the drop generators of the plurality of drop generators that are to be supplied with warming pulses to enhance temperature distribution uniformity across the printer die may be accessed. The warming map may identify a non-uniform distribution of the drop generators across a column of the plurality of columns. In addition, the warming map may be implemented to supply the drop generators identified in the warming map as the drop generators that are to receive the warming pulses.

Enhancing temperature distribution uniformity across a printer die

An inkjet nozzle includes an aperture with a noncircular opening substantially defined by a polynomial equation. A droplet generator is also described which includes a firing chamber fluidically coupled to a fluid reservoir, a heating resistor and a nozzle. The nozzle includes an aperture forming a passage from the firing chamber to the exterior of the droplet generator through a top hat layer. The nozzle is defined by a closed polynomial and has a mathematically smooth and mathematically continuous shape around aperture's perimeter wall, with two protrusions extending into the center of the aperture.

Methods and apparatus are provided related to fluid dispensing heads. A dispense head is formed to define a plurality of fluid jetting nozzles and a surface pattern. The surface pattern is characterized by one or more voids extending inward from an outer surface of the dispense head. Fluid puddle formation during operation of the dispense head is limited in volume by way of the surface pattern. Fluid puddle limiting reduces or eliminates dispensing errors to an entity, undesirable artifacts from resulting on a printed media, or similar problems.

Dispensing heads with fluid puddle limiting surface features

A fluid ejection device includes a firing chamber having an ejection orifice opposite a chamber floor, a heating element and a mesa projecting from the chamber floor, the mesa is spaced from the heating element to define a passive zone between the mesa and heating element.

Fluid ejection device having firing chamber with mesa

Systems, including apparatus and methods, for microfluidic processing and/or analysis of samples. The systems include a microfluidic device having a substrate and a thin-film layer formed on the substrate. The thin-film layer may be included in electronics formed on the substrate. The electronics may provide electronic devices configured to sense or modify a property of the sample. The thin-film layer defines an opening for routing movement of fluid and/or sample within the device.

Microfluidic system utilizing thin-film layers to route fluid

Methods for fabricating a printhead are described. In one embodiment, a method includes forming on a substrate using a single fabrication technique multiple resistors, some of the resistors to be used as heater resistors configured to eject fluid and some of the resistors to be used as storage resistors that store data, annealing the heater resistors, and intentionally not annealing at least one of the storage resistors, wherein the annealed storage resistors have a first state representing a first digital value and the unannealed storage resistors have a second state representing a second digital value, such that the values associated with the storage resistors can be read by an appropriate detection circuit.

Method of fabricating a fluid ejection device having a data storage structure

Growing community of inventors

San Diego, CA, United States of America

James A Feinn