Abstract: This invention relates to a printhead in which a plurality of resistors are selectively activated by an external control circuit to produce the ejection of droplets of ink through nozzles located in correspondence with the resistors. Selection and activation are performed according to a matrix having a plurality of vertical lines corresponding to the number of resistors per group of nozzles and a plurality of horizontal lines corresponding to the number of groups of nozzles in the head. The groups of nozzles in the polychromatic head comprise real nozzles and fictitious nozzles, as a result of which the groups of nozzles have a regular layout, and are uniformly distributed and equivalent to the corresponding layout of a monochromatic head. With this solution, polychromatic heads having the same number and the same disposition of contacts with the external circuit and the same height as a monochromatic head can be manufactured simply.

Abstract: A look up table LUT with specific gray reproduction characteristics is used for converting RGB image data to multi-tone data of ink colors. The gray reproduction characteristics of LUT are set such that the color difference ?E of a gray color area with an arbitrary tone level in the L*a*b* color system is kept at about 4 or less, assuming that the results are observed under two different light sources, such as standard light D50 and standard light A, respectively.

Abstract: A program controls colorant-applying elements (e.g. nozzles) individually, to apply colorants in an order that yields consistent colorant-addressing sequences. In another aspect, the invention inhibits particular elements in particular installments (e.g. printing passes) to produce a fixed color bias between colorants of at least one colorant pair; the other colorant is statistically downweighted to correct the bias. In a third aspect, a printmask-generating program automatically makes a usable mask based on neighborhood and timing constraints; this program is constrained, so as to minimize or eliminate hue shift.

Abstract: A method of predicting colors resulting from using one ink on a printer. The method includes the steps of: producing a test page for the printer, the test page having a plurality of sample ink patches, each patch having a plurality of ink dots according to a predetermined ratio for each patch, the predetermined ratios being based on a number of dots printed for a corresponding patch compared to a maximum number of dots; measuring each of the sample ink patches to produce a plurality of color space coordinates for each patch; and fitting values representing a number of dots for each patch and color space coordinates to a plurality of predetermined functions using a minimization process in order to predict the colors.

Abstract: To perform printing in a predetermined fast printing mode, the same-hue nozzle groups ejecting dark/light inks of each hue are each directed to form ink dots on mutually different main scan lines. This increases the effective number of nozzles, improving printing speed.

Abstract: A method for processing an image in a printer, which can effectively carry out a conversion operation by comparing quantities of light components for R (Red), G (Green) and B (Blue) associated with each pixel to be converted when a two or more-color image is converted into a two-color image, and can decide conversion colors by applying a regular rule to all possible cases when the conversion colors are decided, such that an excellent conversion result can be achieved. In the method, a primary color and a secondary color are set as printable colors in the printer and an original image is inputted. Color difference values associated with the primary color, the secondary color and a white color are produced on an original image pixel-by-pixel basis, and a corresponding pixel color of the original image is converted into the primary, secondary or white color associated with a smallest color difference value.

Abstract: A method and apparatus for calibrating color in an inkjet printing system initiates a calibration procedure by instructing an inkjet printer to print a color calibration sample. From the color calibration sample, an analysis is performed to select a color calibration based on the sample. Based on the characteristics of the selected color calibration, the color of the inkjet printer is calibrated.

Abstract: A method and device for image processing free from full loss of an entire vector in a halftone image relatively low in density. An N*N mask matrix is generated for a given density, based on an N*N dither matrix used in an area gradation method which represents a halftone image with binary (bi-level) image data from multi-level image data. In a case of N*N mask matrix relatively low in density, rearrangements on a column and row basis are performed (N*N?1) times to generate (N*N?1) number of N*N mask matrices which are then combined with the original N*N mask matrix to form an (N*N)*(N*N) mask matrix. Thus, for a halftone image relatively low in density, a binary halftone image is generated via the (N*N)*(N*N) mask matrix from multi-level image data.

Abstract: A color ink-jet printer including a first ink ejecting portion operable to eject droplets of a first ink of a first color, a second ink ejecting portion operable to eject droplets of a second ink of a second color other than the first color, which second ink is dried at a higher rate than said first ink, a first control portion operable to control the first ink ejecting portion, on the basis of a gray-scale value at a picture element corresponding to each dot of the first ink to be formed on a recording medium, such that a total volume of at least one droplet of the first ink ejected by the first ink ejecting portion to form each dot of the first ink is equal to any one of a plurality of different total volume values, and a second control portion operable to control the second ink ejecting portion, on the basis of a gray-scale value at a picture element corresponding to each dot of the second ink to be formed on the recording medium, such that a total volume of at least one droplet of the second ink ejected b

Abstract: A printing apparatus of the present invention includes a dither processing unit which converts multi-value data of C (cyan), M (magenta), and Y (yellow) into binary CMY data, and further includes a black generation processing unit which generates a gray plane by a logical product between C, M, and Y of the binary CMY data, and generates K (black) at positions of some of gray pixels of the gray plane according to a probability responsive to a density of the gray pixels in the gray plane while refraining from generating K at positions of remaining gray pixels.

Abstract: The present invention provides a method of printing a digital image on a textile including the steps of selecting 8 to 16 inks to form an ink set, calibrating the ink set to create an ink set profile, using the ink set profile to calculate hue and shade-based look-up tables directly correlating the inks with the color space coordinates of the pixels of the digital image. The present invention also is a system and an apparatus providing a device for performing the calibration of the ink set and direct correlation of the color space coordinates. The printed fabric has a first plurality of dots having 8 to 16 differently colored inks per dot and a second plurality of dots having one color per dot. Significantly, the present invention produces printed textiles having a high detail, deep color, and broad shading, as well as a combination of dyes heretofore considered incompatible.

Abstract: In a color ink jet recording apparatus using ultraviolet cure ink, the time required for printing is shortened and color of the ink can be clearly represented without upsizing the ink jet recording apparatus. The color ink jet printer includes a carriage that can move in a main scanning direction while guided by X-axis guide bars, Y, M, C and K heads aligned in a sub scanning direction on the carriage, and two ultraviolet lamps that are disposed on both sides sandwiching the heads therebetween on the carriage and each have a sufficient length. With this structure, a printed portion of a recording medium formed by each of the Y, M, C and K heads is irradiated with ultraviolet light by the UV lamps at least once after every printing in the main scanning direction.

Abstract: There is provided a method, system, and apparatus of reproducing a digital image on a paper including the steps of the user selecting 8 to 16 inks to form an ink set, calibrating the ink set to create an ink set profile, using the ink set profile to calculate hue-based and/or shade-based look-up tables (LUTs) that directly correlate the inks with the color space coordinates (e.g., RGB values) of the pixels of the digital image. By directly correlating the inks and the color space coordinates using hue and shade, the present method faithfully reproduces the digital image. The method may be practiced using a system and/or apparatus that provides means for performing the calibration of the ink set and direct correlation of the color space coordinates. The printed substrate has a first plurality of dots having 8 to 16 differently colored inks per dot and a second plurality of dots having one color per dot.

Abstract: Ink ejection/non-ejection from a plurality of ink ejection print elements is controlled by looking up a first table that indicates the correspondence between a plurality of inks and gray scale values of print pixels, and a second table indicating combinations of density distribution patterns of print pixels and ink ejection print elements in correspondence with gray scale values, in accordance with a pixel density pattern and its gray scale value.

Abstract: Two print heads combined for each ink color are arranged symmetric to each other with respect to the scan direction and are used for a bidirectional printing. In producing secondary colors, image data is spread-processed by using a “diagonal arrangement” spread pattern to differentiate the ink application order at one of dots arranged in the raster direction from those of the other dots and thereby reduce color variations in the scan direction. Further, when image data has a half-tone, a “horizontal arrangement” spread pattern, different from the previous one, is used to perform image processing on the image data to alleviate an undesired texture. To prevent a driving load from concentrating on only one of the paired print heads, the number of times that each nozzle is driven is counted and an adjustment is made to spread the frequency of use among the two paired print heads.

Abstract: A printing system includes a printer and a print cartridge. The printer includes a carriage configured to move across the medium. The print cartridge is releasably coupled to the carriage and includes a first printhead and at least three achromatic inks. The at least three achromatic inks have distinct L* values and are contained within at least three chambers in communication with the printhead.

Abstract: A print method that uses a printer apparatus based on a multi-pass printing method to reduce the unevenness of colors associated with a scanning direction, even during bidirectional color printing. For this purpose, sets of two print heads that apply cyan (C), magenta (M), and yellow (Y) inks are arranged to be symmetrical in the scanning direction so that a plurality of secondary color pixels arranged in a raster direction can be formed by changing an ink application order (C→M and M→C). Consequently, the pluralities of secondary color pixels arranged in the raster direction undergo the different ink application orders, so that the application order remains the same whether the pixels are formed during forward or backward scanning. Therefore, the unevenness of colors associated with the ink application order can be reduced.

Abstract: Three nozzle arrays respectively including a plurality of nozzle orifices 23 are provided. Two of the nozzle arrays are divided into a plurality of nozzle blocks NB1 to NB6. One of the nozzle arrays is provided as a unit nozzle block NB7. Different kinds of inks to be ejected are allocated with respect to each nozzle blocks. Dye-family colored inks are ejected from the respective divided nozzle blocks. Pigment-family black ink is ejected from the unit nozzle block.

Abstract: It used to be impossible to convert color component values into dot data for large, medium, and small dots so that a favorable result is obtained with respect to every ink color.

Abstract: A printer that prints an image having a resolution higher than a resolution of nozzles on a print head on a recording medium by scanning the print head across a region of the recording medium a plural-number of times, said print head having nozzles spaced at a nozzle pitch which is a reciprocal number of the resolution of the nozzles and adapted to eject ink from the nozzles on the basis of print data. The printer has a line feeding motor that is actuated in a unit of a pulse, and a line feeding device, driven by the line feeding motor actuated in the unit of the pulse, for feeding the recording medium in a unit of a predetermined feeding length fed by an actuating pulse, the predetermined feeding length being (m/k×nozzle pitch), where k is the resolution of the printed image/the resolution of the nozzles, m and k are integers, and m is greater than k but indivisible by k.

Abstract: A fluid ejection head is disclosed, wherein the fluid ejection head includes an orifice layer disposed on top of a substrate layer. The fluid ejection head includes a first group of fluid ejection orifices and a second group of fluid ejection orifices formed in the fluid ejection head, wherein the first group of fluid ejection orifices and the second group of fluid ejection orifices are configured to eject two different fluids, and an elongate channel formed in the fluid ejection head, wherein the channel is positioned between the first group of fluid ejection orifices and the second group of fluid ejection orifices in such a location as to inhibit cross-contamination of fluids ejected from the first group of fluid ejection orifices and second group of fluid ejection orifices.

Abstract: A method of correcting a difference between dot formation positions in a reciprocally operation of a liquid ejecting head, includes the steps of: reciprocating the liquid ejecting head along a liquid ejecting path in a first direction and a second direction which is an inverse direction of the first direction, the liquid ejecting head having a plurality of nozzles for ejecting a liquid droplet; ejecting the liquid droplet while moving the liquid ejection head in the first direction so as to form first patterns; and ejecting the liquid droplet while moving the liquid ejection head in the second direction so as to form second patterns, each of the second patterns being adjacent to each of the first patterns so that the second patterns respectively pair with the first patterns. Each of the first patterns and the second patterns has a plurality of dots placed in the first direction and a third direction perpendicular to the first direction to form a block.

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 fade resistant dye-based ink and the pen(s) for dispensing color ink(s) contain a pigment-based ink(s). Such a color ink-jet printer provides both superior color gamut with contrast and excellent fade resistance. Since the black ink does not need to be chromatic one can employ fade resistant dyes that do not decrease the lightfastness of the whole ink set. In addition, very soluble fade resistant dyes can be used reliably in high concentrations allowing the black ink to provide more optical density than current pigment-based black inks.

Abstract: An ink jet recording method uses a recording head capable of ejecting a first ink containing a coloring material with a relatively small particle size &phgr;d and a second ink containing a coloring material with a relatively large particle size &phgr;p and also uses a specific recording medium including a porous layer and a base, wherein the porous layer has a gap size &phgr;h that is larger than the particle size &phgr;d and smaller than the particle size &phgr;p. The first ink is ejected to the porous layer side of the recording medium and then the second ink is ejected to the same side. The first ink passes through the porous layer to form an image viewed from the base side, and the second ink fixes on the surface of the porous layer to form an image viewed from the recording side.

Abstract: A multiple ink jet printing system comprising a plurality of rows of dark dye nozzles and light dye nozzles. Each row of dark dye nozzles is coupled to a supply of dark dye ink, and each row of light dye nozzles is coupled to a supply of light dye ink. Each of the rows of dark dye nozzles and light dye nozzles are arranged substantially parallel to each other, and at least one row of dark dye nozzles is separated from the next row of dark dye nozzles by at least one row of light dye nozzles.

Abstract: A nonbuttable full-width array printhead with reduced number of printbars required in a color printer is disclosed. The number of printbars may be reduced by including one single color printbar for each color and an additional printbar with multicolor die modules including each of the colors of the single color printbars. Die modules on each of the single color printbars are spaced closer together but are not butted. The total number of printbars may also be reduced by staggering printbars with multicolor die modules between printbars with the single color die modules. In the latter case, it is possible to preserve the order that inks of the various colors are applied for all regions of the printed paper.

Abstract: An inkjet apparatus and a method of preventing misplacing the inkjet cartridge therein are disclosed. The inkjet apparatus comprises a carriage, a control unit and a sensor. The carriage is equipped with at least an inkjet cartridge that has an identifiable area. The color of the identifiable area is associated with the colors of ink stored in the inkjet cartridge. The sensor detects the color of the identifiable area and sends a signal to the control unit. The control unit receives the signal and determines whether the inkjet cartridge is correctly placed. If the inkjet cartridge is misplaced, a warning signal is generated to alert the user.

Abstract: A method for printing includes estimating ink usage for printing with a first color scheme and a second color scheme, and selecting between the first color scheme and the second color scheme for printing according to the estimating of the ink usage. An apparatus includes a first sensor to measure a level of a first ink, a second sensor to measure a level of a second ink, and a processor coupled to the first sensor and the second sensor and configured to estimate usage of the first ink and the second ink using a first color scheme and a second color scheme and configured to select the first color scheme or the second color scheme for use in printing according to the estimate of the usage of the first ink and the second ink.

Abstract: A printing technique wherein pixel locations that are requested to be marked with only black are identified, black is applied to the identified pixel locations, and non-black color is applied to those identified pixel locations that (A) have an associated black half-tone threshold level that is darker than a predetermined non-white threshold level, and (B) correspond to on-pixels of a reference pattern of non-black color pixels having an on-pixel population of at least 20 percent and a toner transfer efficiency of less than about 20 percent.

Abstract: A color image processing apparatus realizes color reproduction in a color image output apparatus by controlling the total amount of coloring material used while making full use of the color reproduction range of the color image output apparatus. To this end, a signal C′M′Y′K′, obtained after a &ggr; conversion (gamma conversion), is converted into an amount of ink drops V (CMYK) at a conversion unit. Then, at a total ink drop quantity control unit, a total ink quantity of the amount of ink drops converted at the conversion unit and a limit value (maximum total ink drop quantity) stored in a maximum total ink quantity memory unit are compared, and the total ink quantity is controlled to be lower than the limit value. Then, the controlled amount of ink drops is converted into a recording control signal C″M″Y″K″ at a control signal conversion unit.

Abstract: An ink-jet recording apparatus and an ink-jet recording method which provide an image featuring reduced graininess and good gradation. A plurality of inks of different densities are used to obtain a halftone image with controlled graininess. An ink which has low penetrability on a recording medium and which controls the diffusion of dots is used as an ink with a relatively high density. An ink which has high penetrability and which permits easy diffusion of dots is used as an ink with a relatively low density. The present invention also provides a characteristic recorded article to be formed by a plurality of dots having different penetrabilities on a recording medium. Among a plurality of inks with different densities, the inks of the same color category are grouped and held in an ink container and are divided in the container by the ink density. This configuration makes it possible to make the containers smaller and minimize the number of containers.

Abstract: A method of printing a multi-color image on a particular surface, using a digital image file having a discrete number of pixels that collectively represent the multi-color image, comprises: determining a relatively large area of the multi-color image that is represented by less than the total number of pixels, but which pixels each have a common printing color component; forming an outline of the determined relatively large image area on the particular surface the multi-colored image is to be printed; providing a colored receiver layer within the formed outline that is the same color as the common color component, but which color has a selected low color value; applying a non-colored receiver to an area on the particular surface that is outside the formed outline on the particular surface, to provide a non-colored receiver layer on the particular surface in addition to the colored receiver layer on the particular surface; modifying the digital image file by subtracting the selected low color value from the pi

Abstract: The object of the present invention is to provide an ink jet printing apparatus which can realize both a high speed printing and a high quality printing without color deviations when each of the print areas is printed in a plurality of scans by a plurality of print heads ejecting different kinds of ink. For this purse, this invention has a controller for controlling for each print head independently widths and positions of active nozzle groups in the print heads, the active nozzle groups representing those of the plurality of nozzles in the print heads which are used for printing, wherein the controller controls the widths and positions of the active nozzle groups according to a set printing condition.

Abstract: An apparatus and method distributing data for high-speed digital printing on a printable material, includes a printer processor for receiving preflighted image data in a vector-oriented page description language, separating the color image data into a plurality of monochrome image data sets, and distributing the monochrome image data sets to respective print heads. Each print head raster image processes the monochrome images into bitmap images for printing on the printable material. A computational complexity of ripping the monochrome image data sets is reduced by preflighting, and distributed over the plurality of print heads to enable high speed printing.

Abstract: A printing apparatus and a method for correcting a difference in a color between a forward printing and a backward printing, by performing gamma correction parameter switching between a gamma correction parameter for the forward printing and a gamma correction parameter for the backward printing. A first chromaticity reproduced by the forward printing, and a second chromaticity reproduced by the backward printing are plotted in a chromaticity space. A correction coefficient is calculated based on a difference in an angle made by a first line and a second line in the chromaticity space. The first line is drawn on a point of the first chromaticity and an origin of axes of the chromaticity space, and the second line is drawn on a point of the second chromaticity and the origin of the axes of the chromaticity space.

Abstract: Disclosed is an ink set comprising at least a normal yellow ink composition and a dark yellow ink composition, the lightness of the dark yellow ink composition being lower than that of the normal yellow ink composition. This ink set can realize recorded images having excellent color reproduction and image reproduction.

Abstract: One general aspect of the invention provides for creating half-tone ink-jet proofs on print-enhanced sheets based on an effective image cell pitch that substantially matches a cell pitch used to create press plates. Print process variables can be adjusted for the ink-jet proofing printer based on received color matching information. These adjustments can define preprint ink mixing ratios that allow at least some image cells to be printed with ink mixtures. Or they can define sub-area printing values that allow at least some dots to be printed with areas of different inks.

Abstract: A gradation control system includes means for deriving 2n decoded data from lower n bits expressing a gradation per dot, means for grouping the 2n decoded data with respect to a plurality of dots, to produce 2n first bit planes, means for giving to an element a signal of pattern corresponding to each of the first bit planes for a time obtained by adding a time that depends on a decoded value of each of the first bit planes, to an initializing time, means for grouping, per bit weight, respective bits excluding the lower n bits that express the gradation per dot, to produce a second bit plane, and means for giving to the element a signal of pattern corresponding to the second bit plane for a time that depends on a weight of the second bit plane.

Abstract: An ink jet image producing device for reproducing digital image data of photographic images is disclosed with at least one printing head (32) which has more than three base colors or ink jet colors available which stretch a color space. A processing device determines the location or color coordinates of color values of the image data in the image space which is stretched by the colors of the printing head. A determining device determines with which base or ink jet printing colors or mixtures or with which densities thereof the color values of the image data can be reproduced. A threshold device (20) is provided which has at least one threshold for a degree of coverage or the like of at least one printing medium.

Abstract: A printer is disclosed that includes one or more first print bars each having a first printhead carriage, one or more first printhead service stations for servicing each of the first printhead carriages, one or more second print bars each having a second printhead carriage, and one or more second printhead service stations for servicing each of said second printhead carriages. The printer also includes first circuitry for controlling the one or more first print bars and the one or more second print bars such that while the one or more first printhead carriages are being serviced the one or more second print bars are in operation. The printer further includes a second circuitry for recognizing the number of first and second print bars present in the printer and for formatting print jobs to utilize the recognized number of first and second print bars. A second printer having multiple print bars, where each print bar has an array of printheads arranged in a pagewide configuration is also disclosed.

Abstract: The present invention provides a method of printing a high quality color image with no color variations at high speed. For this purpose, this invention arranges in a main scan direction a plurality of print heads that eject different color inks, and reciprocally moves each of the print heads to perform a multipass printing in which a print operation is executed in both the forward and backward passes. During the multipass printing, the print duties of the print heads are set by mask patterns. Each of the mask patterns divides the print duty setting area for each nozzle group of each head into subdivided areas, sets the print duties of the subdivided areas to values different from each other and sets the print duties of the print heads to different values.

Abstract: An ink jet printing method and apparatus using a color ink and a print performance improving ink which minimizes an image quality degradation due to blank lines formed by failed or faulty nozzles. This system enables the use of a print head even with failed or faulty nozzles by minimizing the image quality degradation and extends the life of the print head before replacement. The print performance improving ink is deliberately ejected onto a blank line or its vicinity to produce the so-called primer effect, thereby inducing the color ink dots on the lines adjoining the non-ejecting nozzle line to spread into the blank line to make the blank line undistinguishable.

Abstract: An apparatus and method distributing data for high-speed digital printing on a printable material, includes a printer processor for receiving preflighted image data in a vector-oriented page description language, separating the color image data into a plurality of monochrome image data sets, and distributing the monochrome image data sets to respective print heads. Each print head raster image processes the monochrome images into bitmap images for printing on the printable material. A computational complexity of ripping the monochrome image data sets is reduced by preflighting, and distributed over the plurality of print heads to enable high speed printing.

Abstract: A multicolor ink jet printing method which includes the steps of moving a carriage is moved relative to a recording medium in a main scanning direction and a subscanning direction orthogonal to the main scanning direction, printing each color with a different group of nozzle heads mounted on the carriage, wherein at least one color is printed with a larger number of nozzle heads than the other colors, and printing the at least one color with a larger printing resolution in the main scanning direction than the other colors.

Abstract: A method for printing color images with an ink jet printer. The ink jet printer includes a printhead having printing nozzles arranged in first, second, and third columns. The first, second, and third columns each have a length approximately equal to 3*H, where H represents a length of first, second, and third sections of the second column. The method includes ejecting ink from the nozzles of the first, second, or third sections of the second column during each pass of the printhead over a printing medium as necessitated by characteristics of the color image, advancing the printing medium in the first direction by the length H, and ejecting ink from the nozzles of the first and third columns during every third pass that the printhead makes over the printing medium as necessitated by the characteristics of the color image.

Abstract: A method for mixing ink for use in an imaging apparatus including an ink jet printer capable of printing a plurality of primary color inks includes the steps of identifying available printing levels for each of the primary color inks, determining a target color profile for each of the primary color inks, and determining a graininess factor for each printing level. A mixing order is set up for at least some of the available printing levels, based in part on corresponding graininess factors and at least one mixing rule. At least a portion of the plurality of available printing levels is mixed, based on the mixing order and the target color profile, generating a plurality of mixing tables. Each mixing table corresponds to one of each of the primary color inks.

Abstract: A first array state has a first nozzle group 50 provided with first nozzles 25a arranged at an array pitch d0, and second nozzle groups 51 each provided with first nozzles 25a arranged at an array pitch d1. The second nozzle groups 51 are disposed on both sides of a nozzle array, and the first nozzle group 50 is disposed therebetween. A second array state has a first nozzle group 50 provided with second nozzles 25b arranged at the array pitch d0, and second nozzle groups 52 each provided with second nozzles 25b arranged at an array pitch d2. The second nozzle groups 52 are disposed on both sides of a nozzle array, and the first nozzle group 50 is disposed therebetween. A diameter of each first nozzle 25a is set greater than that of each second nozzle 25b, and a volume of an ink droplet discharged is also greater. The array pitch d1 is set greater than the array pitch d2, and the array pitch d0 is set smaller than the array pitch d1 and the array pitch d2.

Abstract: An inkjet printer is provided. The printer includes a body, a printhead assembly disposed at least partially within the body, and a media advance system disposed at least partially within the body for advancing a media sheet within the printer. The printhead assembly includes a first printhead and a second printhead, the first and second printheads being configured to simultaneously deposit ink on the media sheet when the media sheet is positioned adjacent the printhead assembly, and to move across the media sheet in an opposed manner relative to one another during printing.

Abstract: A program controls colorant-applying elements (e.g. nozzles) individually, to apply colorants in an order that yields consistent colorant-addressing sequences. In another aspect, the invention inhibits particular elements in particular installments (e.g. printing passes) to produce a fixed color bias between colorants of at least one colorant pair; the other colorant is statistically downweighted to correct the bias. In a third aspect, a printmask-generating program automatically makes a usable mask based on neighborhood and timing constraints; this program is constrained, so as to minimize or eliminate hue shift.

Abstract: A method for printing images using light black ink. The method sets a first and second threshold determined by an intensity value of the light black ink relative to standard black ink. The method then determines a gray component density value for a pixel, calculates a black generation value based upon the first and second thresholds and then generates values for other colors dependent upon the black generation value.