Hewlett-packard Development Company, L.p.

Hewlett-packard Company

James M Brenner

Jason M Quintana

Jeffrey D Langford

David M Wetchler

Harold F Mantooth

Ronald A Juve

Steven H Walker

Robert M Yraceburu

Duane A Koehler

Allan D Donley

Marc A Yousey

Mathew W Pierce

Ronald E Sheely

Examples disclosed herein relate to an imaging device. Examples include a method for increasing the temperature of the imaging device by determining an internal temperature of the imaging device; determining if a start-up routine is to be initiated; pausing the start-up routine if the internal temperature is below a threshold temperature; and energizing at least one of a fan or heating element of the imaging device when the internal temperature is below the threshold temperature.

Pause start-up routine of imaging device

One method of ink formulation may include providing a shipping material in a reservoir of a printing mechanism, placing a concentrated ink in communication with the reservoir, and mixing the shipping material and the concentrated ink together to create a print-ready ink.

Printing mechanism and method of ink formulation

Methods, devices, and programs are provided for refilling a print cartridge reservoir. A method includes tracking an ink volume in the print cartridge reservoir. The method includes tracking an ink volume in a supply tank. The method further includes refilling the print cartridge reservoir from the supply tank when the ink volume in the supply tank substantially equals an ink volume to refill the print cartridge reservoir to a predetermined level.

Refilling a print cartridge reservoir

An embodiment of a printing system is provided with an inkjet printhead having plural portions each having an ink-ejecting nozzle. The printing system includes plural heater elements each associated with one of the plural portions to pre-warm ink dispensed by the nozzle of the associated portion in response to a pre-warming signal. The printing system also includes a controller configured to generate the pre-warming signal for one or more heater elements based on a selection criteria for generating the pre-warming signal only when the nozzle of said associated portion is required to eject ink during an upcoming print swath.

Pre-warming portions of an inkjet printhead

A method of an embodiment of the invention is disclosed that determines the average power utilization for inkjet printing a print swath. In response to determining that the average power utilization exceeds a threshold, an average power reduction action is performed.

Performing power reduction action when average power utilization for inkjet printing a swath exceeds a threshold

The present invention uses various real-time monitoring and resultant data inputs to change the print mode, dynamically during print cycles. Note that as a result of real-time monitoring and print mode adjustment, predetermined primary default print modes can be set a higher performance level. Various feedback subsystems provide real-time information critical to selecting specific print mode operational parameters, or 'Operational Attributes.' The attributes allow the print mode to be fine tuned, dynamically, for each printer and pen combination over the life of the printer. Thresholds that signal a print mode change are defined.

Dynamic ink-jet print mode adjustment

Printhead operating temperature control by sampling of the printhead's temperature in combination with an algorithm for estimating whether the printhead will exceed its maximum operating temperature during a scan across the media. If the estimation shows that the maximum operating temperature will be exceeded, the printing operation is halted (not aborted) at a convenient location in the scan. The unprinted data of that scan is preserved in memory, and the printhead is allowed to cool. The printhead is returned to the beginning of the scan during which the printing was halted, the scan is restarted, and the printhead is controlled to recommence firing ink drops at the location where the firing had been stopped in the previous scan. The technique for estimating whether the printhead maximum operating temperature may be exceeded takes into account factors (such as the distance to the end of the scan) that, in combination with in-scan temperature sensing, enables the operation of the printhead at a temperature very close to its maximum operating temperature, without exceeding that temperature.

Dynamic control of printhead temperature

In an inkjet printing machine, an ink drop error correction apparatus includes a position extrapolator that is responsive to conventional position encoder pulses and uses a second order polynomial equation to compensated for ink drop distortions induced at higher carriage velocities of at least 25 inches per second for generating a series of nozzle firing sub-pulses that account for different carriage velocities. A fire pulse generator responsive to the sub-pulses further adjusts the firing time of the printing machine nozzles to correct for the carriage velocity induced ink drop positional errors for both non constant and constant carriage velocity conditions.

Method and apparatus for improved swath-to-swath alignment in an inkjet print engine device

An ink jet printer wherein unidirectional or bidirectional printing is adaptively selected for predetermined print modes as a function of whether bidirectional alignment has been performed.

Method of improving print quality by selectively changing print direction

In one embodiment of the present invention, for a two-pass print mode, instead of two or more color printheads depositing the same amount of ink for each pass, one of the passes (the primary pass) in a predetermined direction deposits a substantial majority of the ink, and other pass (the secondary pass) deposits the remainder of the ink. The primary pass for a particular composite color must always be in the same direction for minimizing color shift, at least when printing contiguous swaths of the same color. For minimizing color shift, the choice of a direction for the primary pass can be arbitrary, related to performance, or related to the order of the primary colors in the carriage. This majority ink pass will dominate the ink effects and cause color shifts to be less perceptible. The amount of ink per pass may be determined on an empirical basis. This technique of depositing more ink dots during a pass in a predetermined direction applies to any number of passes, but is particularly applicable to two-pass print modes.

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Vancouver, WA, United States of America

James M Brenner