Hewlett-packard Development Company, L.P.

Hewlett-packard Company

Trudy L Benjamin

James P Axtell

Joseph M Torgerson

Kevin Bruce

Blair M Kent

Ning Ge

David J Lowe

Preston D Seu

Michael D Miller

David Miller Lowe

Steven B Elgee

Timothy L Weber

Iue-Shuenn Chen

George H Corrigan

Wen-Li Su

Thomas F Uhling

Michael Thomas Dangelo

Bruce A Axten

Neel Banerjee

James Walter Pearson

Preston Seu

Teck-Khim Neo

Kerry J Lundsten

Xiuting C Man

Tamara L Hahn

Bryan D Woll

Matthew Allen Shepherd

Adam L Ghozeil

Stan E Leigh

William S Eaton

Winthrop D Childers

Alexander N Govyadinov

Steven H Walker

Simon Dodd

Mark H MacKenzie

Jeffrey Allen Nielsen

Jason M Quintana

Manish Giri

Michael L Bullock

Erik D Ness

Ronald R Anderson

Brett E Dahlgren

Sam Michael Sarmast

Huston W Rice

Chaw Sing Ho

Teck Khim Neo

Gregory N Burton

Bee Ling Peh

Daniel Burger

Kenneth Hickey

Ernesto A Garay

Anton Nicholas Clarkson

Walter D Clark

Jianhui Gu

Tuan Wong

Joe Torgerson

Kerry Trent Christensen

Ken Kiat Ng

Mark H Mackenzie

In some examples, a method of sensing an ink level includes applying a pre-charge voltage to a sense capacitor to charge the sense capacitor with a charge, sharing the charge between the sense capacitor and a reference capacitor, causing a reference voltage at a gate of an evaluation transistor, and determining a resistance from a drain to a source of the evaluation transistor that results from the reference voltage.

Ink level sensing

In some examples, a transistor includes a drain, a channel, and a gate. The channel surrounds the drain and has a channel length to width ratio. The gate is over the channel to provide an active channel region that has an active channel region length to width ratio that is greater than the channel length to width ratio.

Device having an active channel region

In some examples, an ink level sensor includes a sense capacitor between a first node and ground, a first switch to couple a first voltage to the first node and charge the sense capacitor, a second switch to couple the first node with a second node and share the charge between the sense capacitor and a reference capacitor, causing a second voltage at the second node, and a transistor having a drain, a gate coupled to the second node, and a source coupled to ground, the transistor to provide a drain to source resistance in proportion to the second voltage.

An inkjet print head includes data signal lines configured to supply inkjet control voltages and non-volatile memory cell random access addresses. The inkjet print head includes an inkjet nozzle array wherein each nozzle in the array is configured to communicate with a data signal line. Also a non-volatile attribute memory cell array is included in the inkjet print head wherein each memory cell in the array is accessed through a data signal line shared with the nozzle array.

Inkjet print head with shared data lines

An EPROM cell includes a semiconductor substrate, having source and drain regions, a floating gate, including a semiconductive polysilicon layer electrically interconnected with a first metal layer, and a control gate, including a second metal layer. The floating gate is disposed adjacent to the source and drain regions and separated from the semiconductor substrate by a first dielectric layer, and the second metal layer of the control gate is capacitively coupled to the first metal layer with a second dielectric layer therebetween.

Modified-layer EPROM cell

Transistor having an active channel region

In an embodiment, a method of sensing an ink level includes applying a pre-charge voltage Vp to a sense capacitor to charge the sense capacitor with a charge Q, sharing Qbetween the sense capacitor and a reference capacitor, causing a reference voltage Vg at the gate of an evaluation transistor, and determining a resistance from drain to source of the evaluation transistor that results from Vg.

Ink level sensor and related methods

A fluid ejection device includes a plurality of address lines and a fire line for communicating a fire signal. The device also includes a plurality of nozzle circuits coupled to the fire line and the plurality of address lines. Each nozzle circuit is configured, when enabled, to eject fluid via a different one of a plurality of nozzles in response to the fire signal. A subset of the plurality of address lines is coupled to each pair of the plurality of nozzle circuits. Each subset that is coupled to one of the pairs of nozzle circuits is selected so that simultaneous activation of every address line of that subset simultaneously enables each nozzle circuit in the pair or pairs of nozzle circuits coupled to that triad and none of the other nozzle circuits of the plurality of nozzle circuits.

Fluid ejection device

A system for drop detection of fluid drops ejected by a printing device includes a drop detector comprising a radiation source and radiation sensor for illuminating a region in which drops are ejected by a print bar and detecting radiation from the radiation source that is reflected by backscattering from the drops to the radiation sensor; and a controller for controlling the drop detector and the print bar, wherein the controller uses a signal output by the drop detector to determine whether nozzles of the print bar are operating properly.

Drop detection

In one example, a drop detector includes a light source for illuminating drops passing through a drop zone, multiple light detectors near the light source for detecting light scattered off drops passing through the drop zone, and multiple lenses each configured to focus light from the drop zone on one of the light detectors. In one example, each light detector is arranged in the same plane with all of the other light detectors. In one example, the lenses are configured to focus light from two different spaces in the drop zone on different detectors or groups of detectors. In one example, the lenses are configured to focus light from a single space in the drop zone on multiple detectors.

Drop detector

A device including a drain, a channel, a floating gate, and a control gate. The channel surrounds the drain and has a channel area. The floating gate includes an active floating gate region that has an active floating gate region area. The control gate is coupled to the active floating gate region via a control capacitance, wherein the active floating gate region area is smaller than the channel area.

Device including active floating gate region area that is smaller than channel area

The present disclosure describes a compound slot, and systems and methods of forming the compound slot. An example of a compound slot includes a wafer, where the compound slot includes a trench along a long axis of the compound slot and on a top surface of the wafer, where the trench passes through an initial portion of a total depth of the wafer. A number of openings pass through a remaining portion of the total depth of the wafer, where at least a retained portion of a bottom of the trench is present around a perimeter of each of the number of openings.

Compound slot

An assembly includes an election chamber, an ejection member, and a capacitance detection unit. The ejection chamber holds a fluid. The ejection member is disposed in the ejection chamber to selectively receive a predetermined amount of power from a power supply line. The capacitance detection unit detects art amount of capacitance.

Method and assembly to detect fluid

Growing community of inventors

Portland, OR, United States of America

Trudy L Benjamin