Abstract: The invention is directed to a method of transmitting data from a host computer to a printer. Image data is provided which represents at least a portion of a print image to be printed by the printer. Locations of absolute zero values in the image data and locations of non-absolute zero values in the image data are defined. The locations of the absolute zero values and the locations of the non-absolute zero values are mutually exclusive from each other. Both the host computer and the printer are instructed of the locations of the absolute zero values in the image data. Only the image data having non-absolute zero values is transmitted from the host computer to the printer.

Abstract: A host computer transmits raster information to a multi-color ink jet printer. The printer includes a printhead connected with an electrical processor. The printhead includes a plurality of arrays of ink jetting heaters. Each array of ink jetting heaters corresponds to a different color ink to be jetted onto the print medium, and is offset relative to an adjacent array of ink jetting heaters in an advance direction of the print medium. First raster information for a first raster is transmitted from the host computer to the electrical processor of the printer. The first raster information is associated with a first array of ink jetting heaters. The print medium is printed on by selectively actuating the ink jetting heaters of the first array of ink jetting heaters, using the first raster information. After the first printing step, second raster information for a second raster is transmitted to the electrical processor. The second raster information is associated with the first array of ink jetting heaters.

Abstract: In an ink jet printer, bleed between the boundaries between color and black are avoided by printing process black and black ink in an alternating pattern for the first two dots. Logic (62) determines the boundary from a bit map and issues the control signals for alternating lines (66, 68). Best results are experienced when the process black is printed before the black ink as the vehicle of the colored inks apparently supports penetration of the black ink.

Abstract: A method of printing on a print medium with an ink jet printer uses a first color ink, a second color ink and a black ink. An image area on the print medium has a plurality of pixel locations. Print image data indicate one of a presence and an absence of the first color ink, the second color ink and the black ink at the plurality of pixel locations. A subset of the print image data is defined. A determination is made as to whether the subset of print image data indicates 1) a presence of the first color ink and/or the second color ink within the subset and a presence of the black ink within the subset; 2) a presence of each of the first color ink and the second color ink within the subset at a same corresponding pixel location; and/or 3) a presence of the first color ink and/or the second color ink within the subset at a number of corresponding pixel locations exceeding a threshold value. The print medium is printed on in the image area at an interlace level which is dependent upon the determination.

Abstract: The invention is directed to a method of printing on a print medium using an ink jet printer. The ink jet printer includes a printhead assembly having a plurality of ink emitting nozzles. Ink is jetted onto the print medium from the printhead assembly during a first mode of operation using a first available set of the nozzles. Ink is jetted onto the print medium from the printhead assembly during a second mode of operation using a second available set of the nozzles, dependent upon a physical operating parameter of the ink jet printer. The second available set of nozzles has a smaller number of the nozzles than the first available set of nozzles.

Abstract: Halftoning algorithms such as error diffusion, blue noise mask, and void and cluster mask are known to produce visually pleasing, random, homogeneously distributed patterns of dots on output devices such as color displays or printers, for example. These algorithms are extended to take advantage of the mechanisms of each that cause a homogeneous distribution of dots of one colorant to produce a substantially homogeneous distribution of dots when using multiple colorants. The number of dots of each colorant are combined to form an output dot level number of dots that is caused to be substantially homogeneously distributed.

Abstract: Digital halftoning is used to reduce the number of pixel levels used to represent a multiple dot plane image to a smaller number of pixel levels for display on an output device such as an ink-jet printer. Two algorithms commonly used to halftone the dots of a given dot plane are error diffusion and ordered dither. Error diffusion produces patterns of dots that are pleasing to the human visual system but is computationally complex. Ordered dither operates quickly but produces patterns of dots that are visually objectionable. A method is taught in the present invention that employs error diffusion to halftone dot planes that contain relatively dark dots that are visually apparent, and employs ordered dither to halftone dot planes that contain relatively light dots that are not noticeable. The resulting output is pleasing to the human visual system and computed quickly.

Abstract: The invention is directed to a method of manufacturing a printhead in an ink jet printer for jetting an ink onto a print medium. An advance speed of the print medium in a feed direction in the ink jet printer is determined. An approximate drying time of the ink after being jetted onto the print medium from the printhead is also determined. At least two rows of ink emitting orifices are formed in the printhead, with each row of orifices extending substantially across a width of the print medium. Each row of orifices is spaced apart from an adjacent row of orifices in the feed direction a distance which is dependent upon the advance speed of the print medium and the drying time of the ink.

Abstract: The invention is directed to a method of transmitting data from a host computer to a printer. Image data is provided which represents at least a portion of a print image to be printed by the printer. Locations of aboslute zero values in the image data and locations of non-absolute zero values in the image data are defined. The locations of the absolute zero values and the locations of the non-absolute zero values are mutually exclusive from each other. Both host computer and the printer are instructed of the locations of the absolute zero values in the image data. Only the image data having non-absolute zero values is transmitted from the host to the printer.

Abstract: The invention is directed to a method of printing using an ink jet printer which jets a first color ink and a second color ink onto a print medium at locations defined by an image area having a plurality of pixels. The method inhibits intercolor bleeding between the first color ink and the second color ink. A first array of pixels in the image area is selected, with the first array being an M.times.N array wherein M and N are integers. A portion of the first array is defined as a second array of pixels, with the second array being an X.times.Y array wherein X and Y are integers. The integers X and Y are smaller than the integers M and N, respectively. The pixels within the second array are examined. The pixels within the first array are altered if the examined pixels within the second array substantially all correspond to the first color ink.