Abstract: Banding at swath boundaries in inkjet printer output is reduced by staggering the pens in the printer so that that the swath produced by each pen overlaps with, but is not coincident with, the swath produced by any other pen in the printer. This may be achieved by physically staggering the pens in the printer, or by selecting a subset of ink nozzles to create a virtual pen that is offset from the subset of ink nozzles selected for each other virtual pen.

Abstract: The present invention includes an embodiment for optimizing the temperature operating range for a thermal inkjet printhead using ink over large print swaths. In general, this embodiment includes receiving the temperature of a digital temperature sensor (DTS) before printing begins, comparing this temperature with the set point for printing, initiating heating elements if the temperature is below the printing threshold, and turning off those heating elements when the threshold temperature of the die has been reached.

Abstract: The present invention is embodied in a system and method for producing print masks to eliminate step advance and swath height error banding. In general, a print mask is probabilistically produced that corrects swath height errors and step advance errors. A printhead controller determines the firing order of the nozzles in a single or multiple swath with particular reference to a probabilistic print mask generator. The generator functions to firstly calculate the ramp height on a formula to include pen height, data resolution, the number of passes and the pen nozzle resolution. Secondly, taking the ramp height into consideration, the controller allocates on a random basis from the print mask, the firing of nozzles, so that the ramp may begin at zero, although other values may be desirable in preserving the life of the printhead, and ends at the ramp height.

Abstract: The present invention is embodied in a system and method for implementing spit strips to reduce service station fluid waste, and to improve throughput. The printing system includes a controller, printhead assembly, and a service station assembly, operating to produce an image on a print media. The operations of the system are produced by controlling the direction of a motor. First, a portion of ink in the nozzles that have become dye enriched are determined and then the dye enriched ink is purged on available margins on a periphery of print media outside an area reserved for images.

Abstract: A photo minilab includes a computer or other device for estimating processing times of jobs accepted by the minilab.

Abstract: Ink-jet ink compositions are described comprising at least one organo-phosphonic acid or its sodium or potassium salt. The ink-jet ink compositions reduce puddling, scale formation, kogation and corrosion, and as such lead to improved print quality.

Abstract: Printing is performed by depositing dots of ink having the same color but different colorant loads. A higher drop weight is used for the lower colorant load ink, and a lower drop weight is used for the higher colorant load ink.

Abstract: A thermal inkjet printer is provided. The printer has a sensor that detects the operating temperature of its printhead. If the temperature of the printhead is below the printhead's normal operating temperature when the printer is going to start to print an image or document, the operating temperature of the printhead is set at a temperature higher than its normal temperature. This is to ensure that the drop-volume of the printer stays at an optimum level when the printer is beginning to start to print the image or document after a period of non-use. Shortly after the printer has started the printing task, the operating temperature of the printhead is reduced to its normal operating temperature.

Abstract: Improved methods and apparatuses are provided for use in printing color swaths in a bi-directional printing device. The bi-directional printing device is configured to use a plurality of color inks including at least one light color ink and at least one dark color ink. One method includes selectively printing at least one dark color ink on a print media based on a non-uniform probabilistic print mask function, and selectively printing at least one light color ink on the print media based on a substantially uniform probabilistic print mask function.

Abstract: A thermal inkjet printer is provided. The printer has a sensor that detects the operating temperature of its printhead. If the temperature of the printhead is below the printhead's normal operating temperature when the printer is going to start to print an image or document, the operating temperature of the printhead is set at a temperature higher than its normal temperature. This is to ensure that the drop-volume of the printer stays at an optimum level when the printer is beginning to start to print the image or document after a period of non-use. Shortly after the printer has started the printing task, the operating temperature of the printhead is reduced to its normal operating temperature.

Abstract: The present invention includes as one embodiment a method of controlling an inkjet printhead assembly, including providing the printhead assembly having ink ejection elements that eject ink from a firing chamber through a nozzle and being energizable by an electrical pulse having a first predetermined energy, monitoring the printhead assembly to determine elapsed time since each ink ejection element on the printhead assembly has been fired, calculating a predetermined maximum amount of time that an ink ejection element is not operating using ink formulation and geometry of the nozzle and the firing chamber, comparing the elapsed time for each ink ejection element on the printhead assembly with the predetermined maximum amount of time and initiating high energy spitting at a second predetermined energy for the printhead assembly if the predetermined maximum amount of time has been exceeded for at least one of the ink ejection elements on the printhead assembly.

Abstract: An embodiment of a temperature compensations system at least partially compensates for temperature induced changes in the mass of drops ejected from printheads in an inkjet printer. A value representing the temperatures of cyan, magenta, yellow, and black printheads is provided to a controller. Using these values, the controller adjusts KCMY color values associated with each pixel to form transformed color values for a swath. A halftone operation is performed upon these transformed color values for the swath. The results of the halftone operation are used by the controller to determine the printheads that must eject drops of ink onto the pixels within the swath and to determine the number of passes of the printheads across the swath to form the portion of the image on the media corresponding to the swath.

Abstract: An inkjet print cartridge uses at least one groove to supply ink from an ink reservoir to the fluid channel, which includes an ink ejection chamber, such that foreign particles within the ink supply are filtered out by the grooves so as not to block the fluid channel. In one embodiment, a barrier layer between a substrate and nozzle member contains the ink ejection chamber which is in communication with a plenum via a flow restrictor, such as pinch points. The nozzle member includes an array of orifices and grooves. The substrate includes two linear arrays of ink ejection elements, such as heater elements, and each orifice in the nozzle member is associated with an ink ejection chamber and ink ejection element. A plurality of grooves is likewise associated with each plenum. The plurality of grooves in the nozzle member supply ink into each plenum, which in turn supplies ink to the ink ejection chamber.

Abstract: A color ink-jet printer having a heating blower system for evaporating ink carriers from the print medium after ink-jet printing. A preheat drive roller engages the medium and draws it to a print zone. The drive roller is heated and preheats the medium before it reaches the print zone. At the print zone, a print heater heats the underside of the medium via radiant and convective heat transfer through an opening pattern formed in a print zone heater screen. The amount of heat energy is variable, depending on the type of the print medium. A crossflow fan at the exit side of the print zone direct an airflow at the print zone in order to cause turbulence at the medium surface being printed and further accelerate evaporation of the ink carriers from the medium. An exhaust fan and duct system exhausts air and ink carrier vapor away from the print zone and out of the printer housing.

Abstract: A thermal ink jet printhead cartridge priming apparatus that includes a plurality of caps respectively associated with a plurality of printhead nozzle arrays for controllably sealing printhead nozzle arrays pursuant to engagement thereof against the printhead cartridge to surround the nozzle arrays, a plurality of vacuum conveying elements respectively associated with the caps for individually conveying priming vacuum to an associated cap, a manually actuated selector assembly for connecting a selected one of the vacuum conveying elements to a source of priming vacuum, and a source of priming vacuum spaced apart from the manually actuated selection means for selectively engaging the selector assembly for application of vacuum thereto, such that a selected printhead cartridge is primed without removal thereof from the carriage and without use of a motorized vacuum pump.

Abstract: Ink jet printhead primer apparatus including a resilient bellows having an upper end cap, a lower end cap, a capper having an opening supported by the upper end cap selective sealing engagement with a nozzle array of a printhead so that negative pressure produced in the opening of the upper end cap is communicated to the nozzles of the nozzle array, or with a conduit structure connected to the nozzles of the nozzle array. Displacement of the lower end cap is controlled by cam surfaces formed on the inner opposing surfaces of parallel plate-like gear sectors of a rotatable cam assembly having gear teeth that drive a flywheel. Cam edges on the gear sectors move a sliding cam member that moves the upper end cap between a retracted position and an extended position.

Abstract: An ink-jet printer having improved print quality and full color printing capability on plain paper media. A radiant print heater heats the medium at the print area to increase the ink carrier evaporation rate. The heater includes a wire heating element placed in a reflectorized cavity beneath the printing area, and radiant heat energy is directed onto the lower surface of the print medium through a grill. The heating element is energized by a low voltage signal. The print heater heats the portion of the medium disposed at the print area during print operations to cause accelerated drying of ink deposited on the medium.

Abstract: A color ink-jet printer having a heating blower system for evaporating ink carriers from the print medium after ink-jet printing. A preheat drive roller engages the medium and draws it to a print zone. The drive roller is heated and preheats the medium before it reaches the print zone. At the print zone, a print heater heats the underside of the medium via radiant and convective heat transfer through an opening pattern formed in a print zone heater screen. The amount of heat energy is variable, depending on the type of the print medium. A crossflow fan at the exit side of the print zone direct an airflow at the print zone in order to cause turbulence at the medium surface being printed and further accelerate evaporation of the ink carriers from the medium. An exhaust fan and duct system exhausts air and ink carrier vapor away from the print zone and out of the printer housing.

Abstract: Ink jet printhead primer apparatus including a resilient bellows having an upper end cap, a lower end cap, a capper having an opening supported by the upper end cap selective sealing engagement with a nozzle array of a printhead so that negative pressure produced in the opening of the upper end cap is communicated to the nozzles of the nozzle array, or with a conduit structure connected to the nozzles of the nozzle array. Displacement of the lower end cap is controlled by cam surfaces formed on the inner opposing surfaces of parallel plate-like gear sectors of a rotatable cam assembly having gear teeth that drive a flywheel. Cam edges on the gear sectors move a sliding cam member that moves the upper end cap between a retracted position and an extended position.

Abstract: Apparatus for protecting optical elements of an optical ink drop detector that detects the presence of an ink drop in a drop detection zone, and for maintaining an aperture plate used in conjunction with the ink drop detector. The apparatus includes a movable plate having an apertured region and a non-apertured region. The plate is movable relative to the optical elements of the drop detector and is configured to have the aperture region adjacent a drop detection zone of the optical ink drop detector when in a first position and to have the non-apertured region adjacent the detection zone when in a second position. Cleaning brushes are provided for cleaning ink from the aperture region of the movable plate when the plate is moved between the first and second positions, and an enclosure is provided for enclosing the aperture region of the plate when said plate is in the second position.