Abstract: Density calibration for a printer is achieved using a standard grey scale vignette master and a stored gray scale vignette image that the printer operator can invoke from the operator panel of a printer. The vignette image provides a precalibrated scale that is used in conjunction with the •standard• image to determine the proper optical density. The density is then set by the printer control panel based upon the value obtained by visually matching the two grey scale vignettes.

Abstract: Density calibration for a printer is achieved using a standard grey scale vignette master and a stored gray scale vignette image that the printer operator can invoke from the operator panel of a printer. The vignette image provides a precalibrated scale that is used in conjunction with the “standard ”image to determine the proper optical density. The density is then set by the printer control panel based upon the value obtained by visually matching the two grey scale vignettes.

Abstract: Toner/ink is saved while still being able to print any given color value within the full color gamut of a given printer. Combinations of varying percentages of a printer's toners/inks (cyan, magenta, yellow and black) are determined for maximum black substitution with varying percentages of under color addition (UCA) (e.g., 0%, 50%, 80%, and 100%). Patches of varying combinations of CMYK using maximum black substitution and a given percentage of UCA are printed out, and the color value (L*a*b*) of each patch is measured. Tables are generated having the percentage amounts of C,M,Y, and K and the corresponding measured color value. A first table represents maximum black substitution with 0% UCA. If a desired color value falls within this table, the corresponding CMYK combination represents the most toner/ink that can be saved. If a desired color value does not fall within the first table, subsequent tables representing increasing percentage amounts of UCA are examined.

Abstract: A unique combination of four colorants (C′M′Y′K′) of a given printer that is equivalent to an externally defined four colorant combination (CMYK) by having the same color values (e.g., L*a*b* values). A fourth colorant, e.g., black, (K) of the externally defined four colorant combination is mapped to an equivalent fourth colorant (K′) of the printer by matching optical density, reflectance, L* or similar color value. The L* value is found for various percentages of the fourth colorant of the printer by printing varying percentages of the fourth component and measuring its L*a*b* values and, assuming a* and b* are near zero, using the L* value. These values are inputted into an interpolation program. Then, patches of varying percentages of each one of the three color components of the printer (CMY) are printed out at varying percentages.

Abstract: Density calibration for a printer is achieved using a standard grey scale vignette master and a stored gray scale vignette image that the printer operator can invoke from the operator panel of a printer. The vignette image provides a pre-calibrated scale that is used in conjunction with the □standard□ image to determine the proper optical density. The density is then set by the printer control panel based upon the value obtained by visually matching the two grey scale vignettes.

Abstract: The system, method, program, and print pattern of this invention allows print misregistration to be detected and controlled through density measurements. A special print pattern is used for which a correlation between a density measurement of the print pattern and an amount of misregistration can be made. Initially, for a given printer, and for each printing station within the printer, the special print pattern is printed using two printing stations at varying amounts of misregistration of one of the printing stations. The density of each special print pattern printed at the varied amount of misregistration is measured. A correlation is made between density and amount of misregistration of the one printing station relative to the other printing station. Whenever misregistration is desired to be determined, the special print pattern is printed, the density is measured, and the correlation is applied to the measured density to determine a misregistration amount.

Abstract: A method and apparatus for controlling the density of the printed medium of a printer is provided and comprises the following steps. First a control strip is printed on the print medium having at least two coverage patches having a first and second different standard density. Next, the optical density of each of the patches are measured. Next a first and second tolerance limit is determined for the first and second patch, respectively. The next step is to determine whether the measured optical density of the first patch is within a first tolerance of the first standard density. If the first measured optical density is not within tolerance of the first standard density, then a change of at least one printer parameter is calculated such that the first density is corrected within the first tolerance. Then the effect of the change of the printer parameters on the second optical density is determined.

Abstract: Disclosed is a method, system, and program for converting an externally defined four dimensional colorant, e.g., CMYK, to an equivalent four dimensional colorant, e.g., C'M'Y'K, having components of a printer. A measurement is made of first color values, e.g., L.sup.* a.sup.* b, of a first set of patches having predetermined combinations of varying percentages of three primary colors, e.g., CMY, printed by the printer. Each combination of known CMY values are correlated with corresponding color values, e.g., L.sup.* a.sup.* b, as input to a first inversion program for determining CMY values for any given color value (L.sup.* a.sup.* b). A measurement is also made of second color values, e.g., L.sup.* a.sup.* b, of a second set of patches having predetermined varying percentages of a fourth colorant (K) printed by the printer. The first inversion program is used to determine CMY values corresponding to the color values, L.sup.* a.sup.* b, for the varying percentages of the fourth colorant (D).

Abstract: The system, method, and program of this invention is capable of taking as input a three dimensional colorant (e.g., CMY, L*a*b*) and determining an equivalent combination of colors made up of four or more colorants that are used by a given printer. A plurality of patches are printed having predetermined known combinations of varying percentages of three primary colors (e.g., CMY). Another set of patches are printed having predetermined varying percentages of a fourth color (e.g., black). The L*a*b* of these patches are measured. An inversion program is used to determine equivalent CMY component percentage values for the varying percentages of the fourth component based upon similar actually measured L*a*b* values. These determined CMY component percentage values and the known percentages of CMY are used to substitute the fourth colorant (K) for each of the original CMY combinations, known as fourth colorant substitution or black substitution.

Abstract: A system, method, and program of the invention determine a unique combination of four colorants (C'M'Y'K') of a given printer that is equivalent to an externally defined four colorant combination (CMYK) by having the same color values (e.g., L*a*b* values). L*a*b* values associated with each three component combination (CMY) with the fourth component value (K) equal to zero of the externally defined four colorant combination (CMYK) are used in an inversion/interpolation program The printer also prints out a matrix of predetermined varying combinations of the three colorants of the printer (CMY)p with the fourth colorant K equal to zero. L*a*b* values are measured for each patched. These values and the corresponding three colorant combination values are inputted into the inversion/interpolation program.

Abstract: A system, method, and program for generating a color rendering dictionary file or look-up table for an equivalent device dependent four component colorant combination for a given printer from a given device independent three dimensional color space. First input parameters are comprised of varying percentage amounts of an additional fourth colorant and corresponding measured color values for varied percentage amounts of the additional fourth colorant. Second input parameters are comprised of varying percentage amounts of three base colorants and corresponding measured color values for varied percentage amounts of the three base colorants. Percentage amounts of the three base colorants (three colorant values) for each varied percentage amount of the additional fourth colorant are determined from the sets of measured color values.

Abstract: A method and system for printing a high density sequence of characters of M characters per inch from a predetermined character set. A print head having multiple print wires or pins is utilized to print a matrix of "dots" at a selected pel density, preferably 4M pels per inch for higher print throughput. The character set is then examined and a small selected number of characters are identified which require a character matrix having a width of four pels to achieve a desired level of legibility. All remaining characters in a character set are assigned a character matrix having a width of three or three and one-half pels in order to achieve the desired level of legibility. Thereafter, a high density sequence of characters having a high level of legibility can be printed at low pel densities having only a slight degradation in legibility in the event that two characters which each require a four pel width character matrix are adjacent.

Abstract: Disclosed is an improved method, in an impact matrix printer, for extending print ribbon life when used in printing bar codes and for improving the quality of bar codes printed by the ribbon, the printer including a dot matrix print head having a plurality of print pins and print hammers. The printer includes a medium to receive printed indicia thereon, and a print ribbon intermediate the print head and the medium, and means for effecting relative movement between the print head, the medium and the print ribbon so as to position opposite the print head different portions of the medium from time to time when the printer is operational and printing and to position different portions of the print ribbon intermediate the print head and the medium at preselected times when the printer is operational and printing.

Abstract: The present invention provides an ink jet printer which has a mechanism for receiving and incrementing paper or other ink-receiving medium vertically and a print head and a mechanism for moving the print head horizontally across the paper. The print head has a plurality of orifices and associated operating devices to eject ink drops from each orifice. In particular, the orifices are configured such that there is a plurality of black ink orifices to print black ink, which is generated by a single black color from an orifice or orifices, and a plurality of color ink orifices to print color ink, whereby the color is generated by three different color inks, with each color ink being ejected from a separate orifice or orifices. The orifices are arranged in a pattern in which the orifices are spaced vertically and horizontally with respect to each other. In this pattern, there is at least one color ink orifice interposed or interspersed between two black ink orifices in the vertically spaced direction.

Abstract: In an ink jet printer, drops are generated at a test frequency which is a harmonic of the drop generation rate for printing. If an error in velocity is detected at the test frequency, a coarse correction velocity is made to bring the correct number of drops within the range of one-half the wavelength at the nth drop location relative to a drop detector. Drops are then generated at the printing frequency and a fine correction in the velocity is made if a velocity error is detected.