Abstract: A method of printing with a printing system comprising an array of print heads, the array of print heads including a redundant print head, and a service station, includes, with the redundant print head located at the service station, printing using a remainder of the array of print heads; and positionally and functionally replacing a second print head in the array with the redundant print head while printing continues.

Abstract: An ink jet printer system includes a partially redundant page-wide array of moveable ink jet print heads in a print zone, means outside of the print zone for servicing the print heads, and a transfer system, configured to selectively move a redundant portion of the array of print heads out of the print zone for servicing while printing with a remainder of the array.

Abstract: A media print system includes a first print unit, a second print unit, at least one actuator configured to move the first unit and the second unit relative to one another and a controller configured to generate control signals. The at least one actuator positions the first unit and the second unit at the first and second positions, respectively, during a first longitudinal pass of a medium and positions the first unit at a third position during a second longitudinal pass of the medium in response to the control signals.

Abstract: A media print system includes two or more printhead carriages adapted to print on a medium in a print area, the print area including two or more print regions. Each of the printhead carriages is adapted to print in one or more of the print regions. The system also includes a controller adapted to reconfigure a positioning of the two or more printhead carriages in a configuration selected from a predetermined set of configurations. The controller is adapted to reconfigure the positioning each time a predetermined criterion is satisfied.

Abstract: One aspect of the invention checks mechanical misalignment of plural pens and shifts data to allow for at least part of misalignment—and automatically prints images with the shifted data. If pens are aligned within a dot row then preferably the image prints without data shift. In one other preference, the pens print respective ink types; in this regard a particular preference is that the inks include plural colors, or alternatively plural dilutions. The invention is particularly beneficial in printing on a particular printing medium that is insensitive to relative timing of deposition of ink types; in this case an ideal print medium is plain paper. In some such situations the data shift best compensates for only part of misalignment, and pen-nozzle selections for the rest. In other situations the shifting step best compensates for all the misalignment. In another aspect, the invention extends marking element life and thereby printhead life by distributing usage over a maximum number of elements.

Abstract: The present invention provides a dynamic adjustment for black ink volume to print a black object whose height is greater than one swath of the inkjet printer. The black ink volume is increased by using a greater number of nozzles compared to the number of nozzles used to print color or a second fluid for underprinting the black ink.

Abstract: A method of operating a printing system having a media advance direction and a transverse direction that is perpendicular to the media advance direction and a first plurality of ink drop generators and a second plurality of ink drop generators by moving the first plurality of ink drop generators along the transverse direction while ejecting first ink droplets onto the media in a dot grid pattern having a first resolution in the transverse direction and moving the second plurality of ink drop generators along the transverse direction while ejecting second ink droplets onto the media in a second dot grid pattern having a second resolution in the transverse direction. The first and second resolutions being non-integer multiples of each other.

Abstract: A method of printing includes receiving print data for a swath to be printed. The swath has a matrix of pixels arranged in rows and columns. For a succession of adjacent row segments of the swath, a cumulative total of pixels to be printed is calculated. If the cumulative total exceeds a preselected threshold upon inclusion of row segment, printing is limited to a limited subset of row segments of the swath.

Abstract: One aspect of the invention checks mechanical misalignment of plural pens and shifts data to allow for at least part of misalignment—and automatically prints images with the shifted data. If pens are aligned within a dot row then preferably the image prints without data shift. In one other preference, the pens print respective ink types; in this regard a particular preference is that the inks include plural colors, or alternatively plural dilutions. The invention is particularly beneficial in printing on a particular printing medium that is insensitive to relative timing of deposition of ink types; in this case an ideal print medium is plain paper. In some such situations the data shift best compensates for only part of misalignment, and pen-nozzle selections for the rest. In other situations the shifting step best compensates for all the misalignment. In another aspect, the invention extends marking element life and thereby printhead life by distributing usage over a maximum number of elements.

Abstract: A thermal monitoring system determines whether a fluid ejecting nozzle is healthy and operating in a thermal fluid ejection system to eject precise amounts of fluid in response to a firing signal. If not, a nozzle recovery routine is preformed to remove any nozzle blockages, with different routines being preformed to address the type of blockage encountered. If recovery is not possible, or if the nozzle failure is detected “on-the-fly” during a normal fluid application routine, a substitute healthy nozzle is engaged without interrupting the job. Nozzle health is determined by monitoring the temperature change of the nozzle following application of the firing signal. In one embodiment, an inkjet printing mechanism uses a thermal inkjet printhead to eject an inkjet ink as the fluid. A method of monitoring the health of a fluid ejection nozzle is also provided.

Abstract: Throughput of imperfectly aligned plural multinozzle pens is optimized by determining pen-to-pen mechanical misalignment, ascertaining the maximum number of nozzles that can be used while printing with the used nozzles of all pens substantially aligned (and without shift of data), and then automatically printing with that maximum number of nozzles. Preferably if the determining step finds that the pens are aligned within a dot row, all the nozzles can be used and the print step prints with all nozzles. Also preferably the print step includes automatically using a printmode that specifically accommodates the ascertained maximum number of nozzles. It is preferred that each pen have a few hundred nozzles, all the pens be in mechanical alignment within a few nozzle spacings, and the ascertaining step include eliminating from printing use only at most a few nozzles that are outside the mechanical alignment.

Abstract: A thermal monitoring system determines whether a fluid ejecting nozzle is healthy and operating in a thermal fluid ejection system to eject precise amounts of fluid in response to a firing signal. If not, a nozzle recovery routine is preformed to remove any nozzle blockages, with different routines being preformed to address the type of blockage encountered. If recovery is not possible, or if the nozzle failure is detected “on-the-fly” during a normal fluid application routine, a substitute healthy nozzle is engaged without interrupting the job. Nozzle health is determined by monitoring the temperature change of the nozzle following application of the firing signal. In one embodiment, an inkjet printing mechanism uses a thermal inkjet printhead to eject an inkjet ink as the fluid. A method of monitoring the health of a fluid ejection nozzle is also provided.

Abstract: The present invention provides a dynamic adjustment for black ink volume to print a black object whose height is greater than one swath of the inkjet printer. The black ink volume is increased by using a greater number of nozzles compared to the number of nozzles used to print color or a second fluid for underprinting the black ink.

Abstract: A method of reducing a time required for an inkjet printer to print a page minimizes unused pen nozzles during printmode transitions. An image to be printed is typically partitioned into different image regions based on a content of each region, such as text, graphics, or photographic images, each characterized by a different printmode. The image is represented in terms of rows of dots, each dot printed by a pen nozzle as a print carriage sweeps across an output medium. The data representing the dots that are printed in a single sweep is termed a swath. According to the method, a swath contains data from more than one image region, thus reducing the number of swaths required to print an image.

Abstract: An printing apparatus and method for reducing hue shift due to differing deposition orders of different color ink drops. A differing deposition order occurs in bidirectional inkjet printers with printheads that deposit overlapping drops in a single scan in either a forward or rearward direction. Different print masks for each color ink are used to govern ink drop deposition in the different scan directions in order to vary the deposition order and/or number of drops deposited in a given location. A different mask pattern is applied to a top and bottom set of nozzles corresponding to the print advance height. This technique reduces the perceived difference in color shade between an area of a composite color printed in the forward direction followed by the rearward direction, and an area of the same composite color printed in the rearward direction followed by the forward direction.

Abstract: A rotary capping system services inkjet printheads in an inkjet printing mechanism. A rotary service station has a tumbler with a dual pivoting link that supports a cap platform. The cap platform is gimbal mounted to the link and spring-biased away from the tumbler. The platform has an extending arm that contacts the printhead carriage to align the cap and printhead. When the printhead is positioned for capping, rotation of the tumbler around an axis parallel to the printhead scanning direction brings the platform arm into contact with the carriage. Continued rotation of the tumbler pivots the link and the platform to sweep the cap through a non-linear, generally arcuate path into a capping position at the printhead. The illustrated cap has a multi-ridge lip for sealing over surface irregularities on the printhead nozzle face. A method of sealing inkjet printhead nozzles is also provided.

Abstract: An inkjet printer with multiple printheads in a carriage divides service station functions between a first service station and a second service station. In a preferred embodiment, a black ink printhead is carried by the carriage to a stop position in the first service station where a wiper dedicated to the black ink printhead moves across a stationary nozzle array in a first wiping procedure, and color ink printheads are carried by the carriage to a second service station to move a nozzle array across stationary wipers respectively dedicated to each color ink printhead. The first service station provides spittoon services to all printheads, and the second service station provides capping as well as priming services to all printheads.

Abstract: An inkjet printer has a printhead mounted in a carriage which periodically moves along a printhead path in a carriage scan direction to a stop position in a service station where an actuation device imparts translational motion to a wiper blade. The wiper blade moves along a linear wiping path orthogonal to the printhead path and across ink orifices on a nozzle surface of the printhead during a wiping operation. The wiper blade is removably mounted on a base and is split to form a first blade for wiping one column of ink orifices and a second blade for simultaneously wiping another column of ink orifices on a nozzle surface of the printhead. In a preferred form of the invention, the service station provides different sequential wiping steps with successive wiper blades by first drawing ink onto the nozzle surface from the ink orifices with a rounded blade edge of a leading wiper blade, and then wiping the ink from the nozzle surface with a sharp blade edge of a following wiper blade.

Abstract: A rotary self-cleaning servicing system services inkjet printheads in an inkjet printing mechanism. A rotary service station has a wiper supporting tumbler that rotates about an axis parallel to the printhead scanning direction to wipe the printhead orthogonally along the length of a linear nozzle array. A dual blade wiper has a forked wiping tip with wiping surfaces separated by recessed land portions. The wiper wicks ink from one nozzle and drags it along the linear array to other nozzles to lubricate the pen face and to dissolve any accumulated ink residue. Any ink rolls escape through the wiping tip recessed lands and move away from the nozzles. An optional wiper scraping system pivots through cammed engagement with the tumbler to selectively engage and scrape the wipers. A method is also provided of cleaning an inkjet printhead to maintain pen health, particularly for pens using fast drying pigment based inks.

Abstract: A method for operating an ink jet printer that includes the steps of performing a printer turn-on printhead service on a printhead cartridge of the printer; resetting a page counter, an uncapped condition time counter, and an ink drop counter, wherein the page counter counts the number of pages printed, the uncapped condition time counter counts the amount of time that the printhead cartridge is in the uncapped condition, and the ink drop counter counts the number of ink drops emitted by the printhead cartridge; printing a plurality of pages of print media; after a page is printed performing a post-prime printhead service if the printhead cartridge was primed during the printing of the page; and after a page is printed performing a print time printhead service if the printhead cartridge was not primed during the printing of the page and if (a) the ink jet printer has printed at least a predetermined number of pages since the page count counter was reset, (b) the printhead cartridge has been uncapped for at le