Xerox Corporation

Douglas Dean Darling

David Lyell Knierim

Jonathan Robert Brick

Nasser Alavizadeh

Chad David Freitag

William Bruce Weaver

Brian Edward Williams

Reid Wayne Gunnell

Curtis Douglass Keller

Gautam Dhar

Bradford Stewart

David Allen Mantell

David Jon Metcalfe

Terrance Lee Stephens

James Dudley Padgett

John Milton Brookfield

Walter Sean Harris

Joseph Andrew Broderick

Michael Edward Norkitis

Russell J Watt

Jeffrey Thomas Flynn

John David Means

Jeremiah Dylan Zimmerman

Daniel Mark Platt

Kenneth Eugene Strohmeyer, Jr

Megan Schaffer

Takahiro Peter Terayama

David Lylell Knierim

Monica Louise Maestas

A print head has a jet stack, a jet stack heating and temperature measuring element thermally connected to the jet stack, the jet stack heating and temperature measuring element including: a first, etched copper layer having heat spreading characteristics and including a resistive heat source electrically connected in series to a voltage source and a switch; an electrically insulative on a back side of the first copper layer; and a second, etched copper layer on a side of the electrically insulative layer opposite the first copper layer, the second copper layer having a temperature sensing element to sense a temperature of the print head without a thermistor, the temperature sensing element connected in series with a voltage source and a transistor. A print head may use a thermistor but the heat spreading layer eliminates the need for a heat sink to attach to the print head.

Systems and methods for heating and measuring temperature of print head jet stacks

An inkjet printhead including an inkjet configured to eject drops of ink in response to receiving an electrical signal, a memory configured to store image data, and a processor operatively coupled to the inkjet and the memory. The processor receives the image data and determines a period of latency of the inkjet printhead. When the period of latency is within a predetermined timeframe, the processor increases a voltage of the electrical signal to a second voltage for an initial number of drops to eject the drops of ink in a pattern of printed ink drops with reference to at least a portion of the image data and reduce the voltage of the electrical signal after the initial number of drops to eject drops of ink in a pattern of printed ink drops with reference to a remaining portion of the image data, and generates the electrical signal.

Methods and systems for ejecting drops from inkjets following a period of latency

A method for recovering missing inkjets in a printhead including determining an inkjet in the printhead is not ejecting ink, purging degassed ink into the printhead, adjusting a pressure in the printhead so that ink drools out of an aperture of each nozzle of the printhead, repeatedly applying a non-firing waveform at a frequency for a predetermined amount of time to the printhead while the ink drools out of the aperture of each nozzle of the printhead, and after the predetermined amount of time, adjusting the pressure in the printhead to a normal printhead pressure.

Methods and systems for recovery of failed inkjets

A method for operating an inkjet printhead includes identifying a number of ink drop ejections for an inkjet in the printhead to form a printed image with reference to image data corresponding to the printed image and generating control data that specify a sequence of a plurality of non-firing electrical signals to be applied to the inkjet with reference to a predetermined control sequence stored in a memory and the number of ink drop ejections. The method further includes generating non-firing electrical signals applied to the inkjet with reference to the control data and generating a plurality of firing electrical signals applied to the inkjet to eject ink drops after generating every non-firing electrical signal in the plurality of non-firing electrical signals.

System and method for generation of non-firing electrical signals for operation of ejectors in inkjet printheads

Print head jet stack heating and temperature measurement systems and methods are disclosed that both heat the jet stack and determine a temperature of the jet stack. The heating and temperature determination are performed by a flex circuit that includes multiple layers. One of the layers heats the jet stack and another one of the layers provides data that determines the temperature of the jet stack. The heating layer and the temperature sensing layer are separated by an insulative material in the flex circuit. The temperature of the jet stack can be sent to a print head controller that then determines whether to increase or decrease the temperature of the jet stack.

A method of filling a print head includes drawing a vapor into an empty print head to displace any air in the print head and filling the print head with ink. A method of filling a print head includes connecting a print head to a vacuum pump using a first valve, to a liquid supply using a second valve, and to an ink supply using a third valve, opening the first and second valves, applying vacuum to the print head and liquid supply using the vacuum pump, causing the liquid to generate a vapor that moves into the print head, closing the first valve and the second valve, and opening the third valve to move ink into the print head.

Water-vapor assist for filling aqueous print heads

A method for operating an inkjet printer includes identifying a pattern of ink drops ejected from an inkjet with reference to image data for a printed image, identifying a waveform component for an electrical signal operating the inkjet to eject an ink drop in the pattern of ink drops with reference to at least a portion of the image data, and generating the electrical signal with the identified waveform component to eject the ink drop in the pattern of ink drops at a first velocity onto a first location of an image receiving surface.

System and method for per drop electrical signal waveform modulation for ink drop placement in inkjet printing

The disclosed print head has a two-chamber main reservoir that decouples wasted ink and purge volume in print heads. The two-chamber structure of the print head allows for varying flow of ink through the print head's internal manifolds without varying the wasted ink out of the jet stack. The main reservoir of the print head includes a recirculation chamber and an incoming ink chamber. A vacuum is applied to a vent in the recirculation chamber and a pressure can also be applied to a vent in the incoming ink chamber to cause bubbles in the jet stack to move into the recirculation chamber and be removed through the recirculation chamber vent.

Dual chamber reservoir print head

A drop emitting device that includes a drop generator and a drive signal waveform that includes in sequence a pulse of a first polarity, a first pulse of a second polarity, a delay interval, and a second pulse of the second polarity that includes a high frequency segment.

Ink jet apparatus

A drop generator that includes a pressure chamber and an outlet channel that includes a circular outlet channel section and a non-circular outlet channel section.

Drop generator

A drop emitting device that includes a drop generator and a drive signal waveform that includes in sequence a pulse of a first polarity, a first pulse of a second polarity, a delay interval, and a second pulse of the second polarity.

A drop emitting device that includes a drop generator and a drive signal waveform that includes in sequence a first pulse of a first polarity, a pulse of a second polarity and a second pulse of the first polarity.

A drop emitting device that includes a drop generator and a drive signal waveform that includes in sequence a first negative pulse, a positive pulse and a second negative pulse.

Growing community of inventors

Portland, OR, United States of America

Douglas Dean Darling