Abstract: Described is a method for incremental printing with an inkjet swath printer by depositing multiple drops of an ink from a printhead in each column of an image, in each scanning pass of the printhead over a print medium by obtaining the image, analyzing the image to determine which drops of ink will define leading and trailing edges in each row of the image element with respect to a scanning direction, removing at least one drop of ink preceding the drop defining the trailing edges in each of the rows, removing at least one drop of ink after the drop defining the leading edges in each of the rows and depositing the remaining drops of the ink on the medium while passing the printhead over the media in the scanning direction.

Abstract: An inkjet print cartridge includes an ink supply and a substrate having a plurality of individual ink ejection chambers defined by a barrier layer formed on a first surface of the substrate and having an ink ejection element in each of the ink ejection chambers to eject ink drops. A nozzle having a plurality of ink orifices formed therein overlies the barrier layer with the orifices aligned and associated with the ink ejection chambers. An ink channel connects an ink supply. A group of the ink ejection chambers in adjacent relationship forms a primitive in which a maximum of only one ejection chamber in the primitive is energized at a time and the primitive is one of a plurality of primitives on the substrate. A first circuit on the substrate is connected to the ink ejection elements and a second circuit on the print cartridge is connected to the first circuit to transmit ejection signals to the ink ejection elements at high frequency.

Abstract: In a hybrid multi-drop and multi-pass printing system, composite drops are formed from separate drops merging onto media and highlight regions are formed by using single drops to form a dot. Individual drops are nearly invisible and thus can form highlights with low graininess. As the density of the image increases, multi-drop dots are formed by merging two or more drops. Drops merging together on the media cover white space more efficiently, increase optical density without throughput loss and reduce ink ejection frequency. Multiple passes result in error hiding and improved ink/media interaction. An array of ink ejection elements forms a single printhead in a carriage which is passed along a scan axis perpendicular to the media in the advance direction so that the array path defines a swath area on the media surface. The ink ejection elements are energized during the initial passing step.

Abstract: Periodic inking artifacts are reduced by randomness introduced into an image-processing stage. This goes beyond providing a fixed pattern earlier derived through random processing; rather the system literally introduces randomness or at least pseudorandomness into the image-processing stage. Preferably a superpixel is selected, essentially at random, from a plurality of superpixels—at least for points with an intermediate tonal level, which is the part of the tonal range where dot-placement error is most conspicuous. If image scaling or some other reason for using superpixels (and starting with a coarse grid) is not present, the randomness-introduction approach preferably includes preparing the image using a pixel grid that is coarser than the available printer resolution. The selected superpixel is applied at the coarser grid to define a set of individual pixels at printer resolution.

Abstract: A mask generation subroutine forms Z number of stacked n by m blank mask matrix arrays to provide a plurality of columnar mask locations. The subroutine then selects randomly any previously unselected column of mask locations from the stack of blank mask matrix arrays and assigns best print mode parameters to the individual mask locations in the selected column. The process of selecting and assigning is repeated until all columns of mask locations have been selected and all mask locations have been assigned best print mode parameters to provide a complete set of Z number of configured mask matrix arrays. A control program selects desired ones of the Z number of masks and applies the selected mask to control indicia patterns so that the depositing of indicia forming material in adjacent pixel locations is spaced in time to occur in different ones of the Z passes.

Abstract: An ink-jet printing system and ink supply configuration are disclosed that can utilize the advantages of reactive inks while allowing for maximum flexibility in the design and architecture of the ink-jet printing system. The ink-jet printing apparatus comprises a printhead portion having at least three ejector portions; a reservoir portion comprising at least three ink chambers, each ink chamber for providing ink to one of the at least three ejector portions, two of the ink chambers each chamber including one of a first or a second mutually reactive inks and the other ink chamber including an ink non-reactive with the first and second mutually reactive inks.

Abstract: An ink set and method for ink-jet printing using the same are disclosed, the ink set comprising inks comprising an aqueous vehicle and a colorant, the ink set comprising at least two mutually reactive inks, the at least two mutually reactive inks comprising a first and a second ink; and an ink non-reactive with the at least two mutually reactive inks. The present ink set utilizes the advantages of reactive inks while allowing flexibility in the design of the inks and the architecture of the ink-jet printing systems in which they are used.

Abstract: Data input received by a printer is printed. Dot data, which indicates location of dots on a print medium, is generated from the data input. Dot shift data is used in order to make sub-pixel shifts in locations of a subset of the dots on the print medium. Pulses are provided to a printhead which result in ink being emitted through nozzles located on the printhead. When placing the dots on the print medium, sub-pixel shifts in locations of the subset of the dots is achieved by time shifting the occurrence of pulses used to generate the dots.

Abstract: A color ink-jet printer is provided, with one pen for dispensing black ink onto a print medium and at least one pen for dispensing color ink onto a print medium. The pen for dispensing black ink is adapted to jet droplets of black ink of a first volume and the pen(s) for dispensing color ink are adapted to jet droplets of color ink of a second volume, with the first volume being larger than the second volume. Such a color ink-jet printer provides both superior text quality of the black ink and does not require as much ink volume of the color ink(s) as previous ink-jet printers.

Abstract: The center-to-center spacing of pens containing a "problematic" combination of inks is increased to introduce a relatively small additional time-delay in which those particular constituents are applied to the same or adjacent areas during a single pass, thereby providing a substantial improvement in print qualities (such as Halo or Bleed) on plain (untreated) and special purpose (matt, glossy, transparent) print media, without substantially increasing the throughput rate. The center-to-center spacing of a critical combination of pens is substantially greater than the width of a single pen, thereby providing an increased delay that is equal to the increased spacing divided by the traverse speed.

Abstract: A color ink-jet printer is provided, with one pen for dispensing black ink onto a print medium and at least one pen for dispensing color ink onto a print medium. The pen for dispensing black ink contains a pigment-based ink and the pen(s) for dispensing color ink contain a water-miscible dye-based ink. Such a color ink-jet printer provides both superior text quality (black ink) and relative ease of service (color inks), since the black ink is used more than the color inks and thus tends to require less spitting due to its frequency of use. On the other hand, since the color inks are used less, the utilization of water-miscible inks, which require less spitting than pigmented inks to keep the nozzle clear, also require less spitting even with relatively lower frequency of use.

Abstract: An inkjet printer system fires smaller ink droplets in a single-pass print mode to achieve addressible print resolution of 600 dpi in the carriage scan axis along with 300 dpi resolution in the media advance axis, without having to employ any dot-depletion algorithms. In one embodiment, the system provides a fast print mode which prints the smaller drops of ink on a 300 dpi grid in the carriage scan axis. In another embodiment, the system provides a single-pass color print mode wherein primary colors are printed with two color droplets of the same primary color in two adjacent sub-pixels on the 300.times.600 grid, and secondary colors are printed with two color droplets of different primary colors in two adjacent sub-pixels on the 300.times.600 grid.

Abstract: An inkjet printer system fires smaller ink droplets in a single-pass print mode to achieve addressible print resolution of 600 dpi in the carriage scan axis along with 300 dpi resolution in the media advance axis, without having to employ any dot-depletion algorithms. In one embodiment, the system provides a fast print mode which prints the smaller drops of ink on a 300 dpi grid in the carriage scan axis. In another embodiment, the system provides a single-pass color print mode wherein primary colors are printed with two color droplets of the same primary color in two adjacent sub-pixels on the 300.times.600 grid, and secondary colors are printed with two color droplets of different primary colors in two adjacent sub-pixels on the 300.times.600 grid.

Abstract: An inkjet printer has a pen holder for removably holding an ink pen, a detector circuit for detecting whether ink with a degraded quality is likely to be ejected by said ink pen, and a servicing circuit responsive to said detector circuit for causing an initial quantity of ink to be discharged from said ink pen to ensure that ink with a degraded quality will not be used during normal printing.

Abstract: At least one certain primary or secondary color is established that receives special treatment for at least one printing medium. Such treatment may include (1) using more than two drops of primaries per pixel for binary printing of a particular secondary; or (2) binary-printing the chromatic primary or secondary--but not other hues--after rendition, by use of a "superpixel"; or (3) application of, in effect, a nonintegral number, greater than one, of ink drops per pixel; or (4) combinations of these treatments. As an example of the first of these treatments--using inks optimized for plain paper at one drop of ink for primaries and two (one of each of two primaries) for secondaries--red is printed on transparency film as one drop of yellow ink and two of magenta in each pixel. As to the second treatment, the superpixel is preferably a group of pixels (e.g., a two-by-two array) including the target pixel, in which group each pixel is inked and at least one pixel receives at least two drops of ink.

Abstract: Ink jet ink compositions consisting essentially of an aqueous carrier medium; an anionic dye; and an anionic polymer have excellent decap and puddling behavior and may be used with a variety of ink jet printers such as continuous, piezoelectric, drop-on-demand and thermal or bubble jet drop-on-demand, and are particularly adapted for use in thermal ink jet printers.

Abstract: Aqueous ink compositions containing anti-curl agents substantially reduce or eliminate paper curl in plain-paper printed elements without adversely effecting storage stability, decap properties or print quality, and thus eliminate the need for expensive and bulky mechanical curl-arresting devices or special curl-resistant substrates. Printing the inks on plain-paper substrates is the sole step in a process for reducing paper curl in plain-paper printed elements.

Abstract: Inks used in ink-jet printing comprise a vehicle and a dye. The vehicle consists essentially of about 5 to 10 wt % of a glycol and/or glycol ether and the balance water. The dye is typically an anionic dye, associated with undesirable cations such as sodium or potassium cations. Several properties of such inks are improved by replacing substantially all of said cations on the anionic dye with lithium cations and removing such cations, preferably to leave a maximum concentration of such cations of less than about 500 ppm, and most preferably less than about 350 ppm.

Abstract: Inks used in ink-jet printing comprise a vehicle and a dye. The dye is typically an anionic dye, associated with undesirable cations such as sodium or potassium cations. Several properties of such inks are improved by replacing at least about one-fourth of such cations on the anionic dye with tetramethylammonium cations.