Hewlett-packard Company

Hewlett-packard Development Company, L.p.

Patrick J Coven

Anthony Donald Studer

Dustin W Blair

Satya Prakash

Jules G Moritz

Richard W Riper

Mark S Barbour

Jessica M Jemmott

A finisher is to receive output. The finisher includes a plurality of destinations in which to store the output. A controller is to identify an operational history of the plurality of destinations, and direct the output to the plurality of destinations based on the operational history.

Finisher output destinations

A method of ejecting fluid from an ejection device is described. This method includes adding fluid to a firing chamber, and passing a first amount of charge through a heating element of the firing chamber. The first amount of charge causes the heating element to emit a first quantity of thermal energy, thereby forming a vapor bubble in fluid adjacent the heating element to eject fluid from the firing chamber. A second amount of charge is passed through the heating element to cause the heating element to emit a second amount of thermal energy that is insufficient to eject fluid from the firing chamber.

Method of ejecting fluid from an ejection device

A method and apparatus for reducing power droop for an inkjet printing system comprising a computer, an inkjet printer and a print cartridge. The print cartridge contains a printhead wherein the print head comprises a power supply circuit and a plurality of heater resistors that are arranged in primitive groups. The primitive groups of heater resistors are further arranged into a first and second column. The power supply circuit generates pulses that sequentially energizes one half of the heater resistor group (odd column then even column) within the same time period previously required to fire all of the heater resistors simultaneously. Thus, by employing this configuration and firing technique of the heater resistors, power droop is minimized because a reduced number of primitives are fired at any one time.

Power droop compensation for an inkjet printhead

An inkjet printhead includes multiple printing elements grouped in sets about an ink refill channel. Each printing element includes a nozzle chamber and firing resistor. Respective nozzle chambers are located at a staggered distance away from the ink refill channel. A printing element's feed channel couples its nozzle chamber to the ink refill channel. A pinch point defined by barrier walls occurs along the feed channel. Converging and diverging half angles for each barrier wall of a given printing element are the same. Such angles differ among a plurality of printing elements. The specific angle for a given printing element defines where along the feed channel the pinch point occurs. The specific angle is prescribed according to the distance from a given printing element's firing resistor to the ink refill channel. A certain angle is used for a certain resistor stagger position to provide ink refill balancing among printing elements.

Pinch point angle variation among multiple nozzle feed channels

An inkjet printhead includes multiple printing elements grouped in sets about an ink refill channel. Each printing element includes a firing chamber and resistive element in communication with the refill channel via an ink feed channel. The feed channels are of differing length resulting in resistive elements being at staggered distances from the refill channel. To balance fluidic dynamics among printing elements a first constriction and second constriction occur along the length of the feed channels. The first constriction is adjacent the firing chamber and acts as a diffuser during firing. The second constriction is adjacent the refill channel and slows the refill process for feed channels of shorter length. For longer feed channels the second constriction is wider. For shorter feed channels the second constriction is narrower. Differing widths of the second constriction slow down refill by differing amounts to balance fluid dynamics among the printing elements.

Growing community of inventors

Albany, OR, United States of America

Patrick J Coven