Printing system and method of recording images
First Claim
1. A printing system with a head for forming at least two types of dots having different hues on an object, said printing system recording a multi-tone image through a distribution of said dots, said printing system comprising:
- input means for successively inputting multi-color tone signals regarding pixels included in an image to be printed;
first dot formation determination means for carrying out multi-valued coding with respect to one type of dots selected among said at least two types of dots having different hues, based on said input tone signal of a color corresponding to said one type of dots, and determining either one of formation and non-formation of said one type of dots;
second dot formation determination means for enabling the result of multi-valued coding carried out by said first dot formation determination means to affect a recording density to be realized by another type of dots having a different hue, carrying out multi-valued coding with respect to said another type of dots according to said recording density, and determining either one of formation and non-formation of said another type of dots; and
head drive means for driving said head based on the results of determination by said first dot formation determination means and said second dot formation determination means, thereby actually forming said at least two types of dots having different hues.
1 Assignment
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Accused Products
Abstract
The present invention appropriately determines the on/off state of dots having different hues in a printer using at least two inks of different hues, thereby enhancing the quality of printing. The system of the present invention applies the systematic dither method to determine whether or not dots are to be formed by ink of a predetermined hue, for example, magenta. In the case of formation of dots by magenta ink, the system drives a piezoelectric element PE disposed on a head corresponding to the magenta ink to form magenta dots and calculates a resulting value MRST. In the case of non-formation of dots by the magenta ink, on the other hand, the resulting value MRST is set equal to zero. The system then applies the technique of error diffusion to determine whether or not dots are to be formed by cyan ink, based on the tone data of the cyan ink. The structure of the present invention enables a difference between density data M(x,y) of the magenta ink and its resulting value MRST to affect density data of the cyan ink. This makes it difficult to form dots of cyan ink in the vicinity of dots of magenta ink.
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Citations
39 Claims
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1. A printing system with a head for forming at least two types of dots having different hues on an object, said printing system recording a multi-tone image through a distribution of said dots, said printing system comprising:
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input means for successively inputting multi-color tone signals regarding pixels included in an image to be printed; first dot formation determination means for carrying out multi-valued coding with respect to one type of dots selected among said at least two types of dots having different hues, based on said input tone signal of a color corresponding to said one type of dots, and determining either one of formation and non-formation of said one type of dots; second dot formation determination means for enabling the result of multi-valued coding carried out by said first dot formation determination means to affect a recording density to be realized by another type of dots having a different hue, carrying out multi-valued coding with respect to said another type of dots according to said recording density, and determining either one of formation and non-formation of said another type of dots; and head drive means for driving said head based on the results of determination by said first dot formation determination means and said second dot formation determination means, thereby actually forming said at least two types of dots having different hues. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A printing system with a head for forming at least two types of dots having different hues on an object, said printing system recording a multi-tone image through a distribution of said dots, said printing system comprising:
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input means for successively inputting multi-color tone signals regarding pixels included in an image to be printed; first dot formation determination means for carrying out multi-valued coding with respect to one type of dots selected among said at least two types of dots having different hues, based on said input tone signal of a color corresponding to said one type of dots, and determining either one of formation and non-formation of said one type of dots; local error calculation means for calculating a local difference between a first printing density, which corresponds to said input tone signal relating to said one type of dots and regarding a target pixel, and a second printing density, which is realized by said one type of dots in said target pixel, based on the result of multi-valued coding carried out by said first dot formation determination means; second dot formation determination means for enabling the local difference to affect a recording density to be realized by another type of dots having a different hue, carrying out multi-valued coding with respect to said another type of dots according to said recording density, and determining either one of formation and non-formation of said another type of dots; and head drive means for driving said head based on the results of determination by said first dot formation determination means and said second dot formation determination means, thereby actually forming said at least two types of dots having different hues. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
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29. A printing system with a head for forming at least two types of chromatic color dots of different hues by at least two chromatic color inks as well as achromatic color dots by an achromatic color ink on an object, said printing system recording a multi-tone image through a distribution of said dots, said printing system comprising:
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input means for successively inputting tone signals regarding pixels included in an image to be printed; density calculation means for calculating densities by said at least two chromatic color inks and a density by said achromatic color ink, based on said input tone signals; achromatic color dot formation determination means for carrying out multi-valued coding with respect to said achromatic color ink based on said density by said achromatic color ink calculated by the density calculation means, and determining either one of formation and non-formation of achromatic color dots by said achromatic color ink; density correction means for obtaining correction data, which are to reflect the densities by said at least two chromatic color inks, based on the result of multi-valued coding with respect to said achromatic color ink, and correcting the densities by said at least two chromatic color inks; chromatic color dot formation determination means for carrying out multi-valued coding with respect to said at least two chromatic color dots of different hues, based on said corrected densities by said at least two chromatic color inks, and determining either one of formation and non-formation of said at least two chromatic color dots of different hues; and head drive means for driving said head based on the results of determination by said achromatic color dot formation determination means and said chromatic color dot formation determination means, thereby actually forming said at least two chromatic color dots of different hues by said at least two chromatic color inks as well as said achromatic color dots by said achromatic color ink. - View Dependent Claims (30, 31, 32)
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33. A method of controlling a head, which is able to form at least two types of dots having different hues on an object, and recording a multi-tone image through a distribution of said dots, said method comprising the steps of:
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(a) successively inputting multi-color tone signals regarding pixels included in an image to be printed; (b) carrying out multi-valued coding with respect to one type of dots selected among said at least two types of dots having different hues, based on said input tone signal of a color corresponding to said one type of dots, and determining either one of formation and non-formation of said one type of dots; (c) enabling the result of multi-valued coding carried out in said step (b) to affect a recording density to be realized by another type of dots having a different hue, carrying out multi-valued coding with respect to said another type of dots according to said recording density, and determining either one of formation and non-formation of said another type of dots; and (d) driving said head based on the results of determination in said step (b) and in said step (c), thereby actually forming said at least two types of dots having different hues.
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34. A method of controlling a head, which is able to form at least two types of dots having different hues on an object, and recording a multi-tone image through a distribution of said dots, said method comprising the steps of:
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(a) successively inputting multi-color tone signals regarding pixels included in an image to be printed; (b) carrying out multi-valued coding with respect to one type of dots selected among said at least two types of dots having different hues, based on said input tone signal of a color corresponding to said one type of dots, and determining either one of formation and non-formation of said one type of dots; (c) calculating a local difference between a first printing density, which corresponds to said input tone signal relating to said one type of dots and regarding a target pixel, and a second printing density, which is realized by said one type of dots in said target pixel, based on the result of multi-valued coding carried out in said step (b); (d) enabling the local difference to affect a recording density to be realized by another type of dots having a different hue, carrying out multi-valued coding with respect to said another type of dots according to the recording density, and determining either one of formation and non-formation of said another type of dots; and (e) driving said head based on the results of determination in said step (b) and said step (d), thereby actually forming said at least two types of dots having different hues.
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35. A method of controlling a head, which is able to form at least two types of chromatic color dots of different hues by at least two chromatic color inks as well as achromatic color dots by an achromatic color ink on an object, and recording a multi-tone image through a distribution of said dots, said method comprising the steps of:
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(a) successively inputting tone signals regarding pixels included in an image to be printed; (b) calculating densities by said at least two chromatic color inks and a density by said achromatic color ink, based on said input tone signals; (c) carrying out multi-valued coding with respect to said achromatic color ink based on the density by said achromatic color ink calculated in said step (b), and determining either one of formation and non-formation of achromatic color dots by said achromatic color ink; (d) obtaining correction data, which are to reflect the densities by said at least two chromatic color inks, based on the result of multi-valued coding with respect to said achromatic color ink, and correcting the densities by said at least two chromatic color inks; (e) carrying out multi-valued coding with respect to said at least two chromatic color dots of different hues, based on said corrected densities by said at least two chromatic color inks, and determining either one of formation and non-formation of said at least two chromatic color dots of different hues; and (f) driving said head based on the results of determination in said step (c) and said step (e), thereby actually forming said at least two chromatic color dots of different hues by said at least two chromatic color inks as well as said achromatic color dots by said achromatic color ink.
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36. An image display apparatus for forming at least two types of dots having different hues on an object and expressing a multi-tone image through a distribution of said dots, said image display apparatus comprising:
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input means for successively inputting multi-color tone signals regarding pixels included in an image to be displayed; first dot formation determination means for carrying out multi-valued coding with respect to one type of dots selected among said at least two types of dots having different hues, based on said input tone signal of a color corresponding to said one type of dots, and determining either one of formation and non-formation of said one type of dots; second dot formation determination means for enabling the result of multi-valued coding carried out by said first dot formation determination means to affect a display density to be realized by another type of dots having a different hue, carrying out multi-valued coding with respect to said another type of dots according to the recording density, and determining either one of formation and non-formation of said another type of dots; and dot formation means for actually forming said at least two types of dots having different hues, based on the results of determination by said first dot formation determination means and said second dot formation determination means.
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37. A computer program product configured to store program instructions for execution on a computer system, which is connected to a printing system with a head for forming at least two types of dots having different hues on a printing object and recording a multi-tone image through a distribution of said dots, enabling the computer system to perform the steps of:
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successively inputting multi-color tone signals regarding pixels included in an image to be printed; carrying out multi-valued coding with respect to one type of dots selected among said at least two types of dots having different hues, based on said input tone signal of a color corresponding to said one type of dots, and determining either one of formation and non-formation of said one type of dots; enabling the result of multi-valued coding with respect to said one type of dots to affect a recording density to be realized by another type of dots having a different hue, carrying out multi-valued coding with respect to said another type of dots according to said recording density, and determining either one of formation and non-formation of said another type of dots; and driving said head based on the results of determination with respect to both said one type of dots and said another type of dots, thereby actually forming said at least two types of dots having different hues.
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38. A computer program product configured to store program instructions for execution on a computer system, which is connected to a printing system with a head for forming at least two types of dots having different hues on a printing object and recording a multi-tone image through a distribution of said dots, enabling the computer system to perform the steps of:
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successively inputting multi-color tone signals regarding pixels included in an image to be printed; carrying out multi-valued coding with respect to one type of dots selected among said at least two types of dots having different hues, based on said input tone signal of a color corresponding to said one type of dots, and determining either one of formation and non-formation of said one type of dots; calculating a local difference between a first printing density, which corresponds to said input tone signal relating to said one type of dots and regarding a target pixel, and a second printing density, which is realized by said one type of dots in said target pixel, based on the result of multi-valued coding with respect to said one type of dots; enabling the local difference to affect a recording density to be realized by another type of dots having a different hue, carrying out multi-valued coding with respect to said another type of dots according to said recording density, and determining either one of formation and non-formation of said another type of dots; and driving said head based on the results of determination with respect to both said one type of dots and said another type of dots, thereby actually forming said at least two types of dots having different hues.
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39. A computer program product configured to store program instructions for execution on a computer system, which is connected to a printing system with a head for forming at least two types of chromatic color dots of different hues by at least two chromatic color inks as well as achromatic color dots by an achromatic color ink on a printing object and recording a multi-tone image through a distribution of said dots, enabling the computer system to perform the steps of:
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successively inputting tone signals regarding pixels included in an image to be printed; calculating densities by said at least two chromatic color inks and a density by said achromatic color ink, based on said input tone signals; carrying out multi-valued coding with respect to said achromatic color ink based on the calculated density by said achromatic color ink, and determining either one of formation and non-formation of achromatic color dots by said achromatic color ink; obtaining correction data, which are to reflect the densities by said at least two chromatic color inks, based on the result of multi-valued coding with respect to said achromatic color ink, and correcting the densities by said at least two chromatic color inks; carrying out multi-valued coding with is respect to said at least two chromatic color dots of different hues, based on the corrected densities by said at least two chromatic color inks, and determining either one of formation and non-formation of said at least two chromatic color dots of different hues; and driving said head based on the results of determination with respect to both said achromatic color dots and said at least two chromatic color dots, thereby actually forming said at least two chromatic color dots of different hues by said at least two chromatic color inks as well as said achromatic color dots by said achromatic color ink.
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Specification