Printing apparatus, printing method, printing data generation program, and dither mask generation method
First Claim
1. A printing apparatus which forms dots on a printing medium and prints an image, comprising:
- a printing portion that forms the dots on the printing medium and prints the image according to dot data, indicating whether or not the dots are formed, generated through comparison of a grayscale value of each of pixels based on image data of the image to be printed with each of threshold values of a dither mask which is prepared in advance,wherein the printing portion forms the dots through division into a plurality of pixel groups having different printing conditions and performs at least a part of the dot formation by the plurality of pixel groups in a common region,wherein the dither mask has a second threshold value disposition where threshold values corresponding to a part of groups of the plurality of pixel groups are shifted by a predetermined pixel in a predetermined direction, with respect to a first threshold value disposition which is each of dispositions of the respective threshold values set such that distribution of dots formed in the common region has noise characteristics having a peak on a high frequency side in the spatial frequency region, in a case where a relative position of the dots between the pixel groups is formed in a target positional relationship which is a target in at least a part of a printing grayscale region,wherein the predetermined direction is one or two directions,wherein the printing apparatus has singularity in a direction where a relative position of dots between the pixel groups is shifted from a target positional relationship which is a target, andwherein, in relation to a shift amount of the threshold value in the second threshold value disposition, a shift amount in a direction different from a specific direction having the easily shifted singularity is larger than a shift amount in the specific direction.
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Accused Products
Abstract
A printing apparatus which forms dots, according to dot data generated through comparison of a grayscale value of each of pixels with each of threshold values of a dither mask. The printing apparatus forms the dots through division into a plurality of pixel groups having different printing conditions and performs at least a part of the dot formation by the pixel groups in a common region. The dither mask has a second threshold value disposition, with respect to a first threshold value disposition which is each of dispositions of the respective threshold values set such that distribution of dots formed in the common region has noise characteristics having a peak on a high frequency side, in a case where a relative position of the dots between the pixel groups is formed in a target positional relationship which is a target in at least a part of a printing grayscale region.
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Citations
12 Claims
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1. A printing apparatus which forms dots on a printing medium and prints an image, comprising:
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a printing portion that forms the dots on the printing medium and prints the image according to dot data, indicating whether or not the dots are formed, generated through comparison of a grayscale value of each of pixels based on image data of the image to be printed with each of threshold values of a dither mask which is prepared in advance, wherein the printing portion forms the dots through division into a plurality of pixel groups having different printing conditions and performs at least a part of the dot formation by the plurality of pixel groups in a common region, wherein the dither mask has a second threshold value disposition where threshold values corresponding to a part of groups of the plurality of pixel groups are shifted by a predetermined pixel in a predetermined direction, with respect to a first threshold value disposition which is each of dispositions of the respective threshold values set such that distribution of dots formed in the common region has noise characteristics having a peak on a high frequency side in the spatial frequency region, in a case where a relative position of the dots between the pixel groups is formed in a target positional relationship which is a target in at least a part of a printing grayscale region, wherein the predetermined direction is one or two directions, wherein the printing apparatus has singularity in a direction where a relative position of dots between the pixel groups is shifted from a target positional relationship which is a target, and wherein, in relation to a shift amount of the threshold value in the second threshold value disposition, a shift amount in a direction different from a specific direction having the easily shifted singularity is larger than a shift amount in the specific direction. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A printing apparatus which forms dots on a printing medium and prints an image, comprising:
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a printing portion that forms the dots on the printing medium and prints the image according to dot data, indicating whether or not the dots are formed, generated through comparison of a grayscale value of each of pixels based on image data of the image to be printed with each of threshold values of a dither mask which is prepared in advance, wherein the printing portion forms the dots through division into a plurality of pixel groups having different printing conditions and performs at least a part of the dot formation by the plurality of pixel groups in a common region, and wherein the dither mask has a threshold value disposition where threshold values corresponding to a part of groups of the plurality of pixel groups are shifted by a predetermined pixel in a predetermined direction, with respect to the respective dispositions of the threshold values which are set such that a covering ratio which is a ratio of the area where each of the dots covers the printing medium is larger than that when the dots are formed to be shifted from the target positional relationship, in a case where a relative position of the dots between the plurality of pixel groups is formed in a target positional relationship which is a target in at least a part of a printing grayscale region.
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11. A manufacturing method of a dither mask in a printing apparatus which forms dots on a printing medium and prints an image by performing the dot formation on the printing medium through division into a plurality of pixel groups having different printing conditions and performing at least a part of the dot formation by the plurality of pixel groups in a common region, wherein the dither mask, formed by the respective threshold values, is used to generate dot data indicating whether or not the dots are formed, through comparison of a grayscale value of each of pixels based on image data of the image to be printed with each of threshold values of a dither mask which is prepared in advance, the method comprising:
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determining a disposition of the respective threshold values which are set such that distribution of dots formed in the common region has noise characteristics having a peak on a high frequency side in the spatial frequency region, in a case where a relative position of the dots between the pixel groups is formed in a target positional relationship which is a target in at least a part of a printing grayscale region; and generating the dither mask by shifting threshold values corresponding to a part of groups of the plurality of pixel groups by a predetermined pixel in a predetermined direction, with respect to each of the dispositions of the threshold values determined in the determining of the disposition, wherein the predetermined direction is one or two directions, wherein the printing apparatus has singularity in a direction where a relative position of dots between the pixel groups is shifted from a target positional relationship which is a target, and wherein, in relation to a shift amount of the threshold value in the second threshold value disposition, a shift amount in a direction different from a specific direction having the easily shifted singularity is larger than a shift amount in the specific direction.
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12. A manufacturing method of a printing apparatus which forms dots on a printing medium, prints an image, and includes a printing portion that forms the dots on the printing medium and prints the image according to dot data, indicating whether or not the dots are formed, generated through comparison of a grayscale value of each of pixels based on image data of the image to be printed with each of threshold values of a dither mask which is prepared in advance;
- and a storage portion that stores the dither mask, wherein the printing portion forms the dots through division into a plurality of pixel groups having different printing conditions and performs at least a part of the dot formation by the plurality of pixel groups in a common region, the method comprising;
preparing the printing apparatus;
determining a disposition of the respective threshold values of the dither mask which are set such that distribution of dots formed in the common region has noise characteristics having a peak on a high frequency side in the spatial frequency region, in a case where a relative position of the dots between the pixel groups is formed in a target positional relationship which is a target in at least a part of a printing grayscale region;generating the dither mask by shifting threshold values corresponding to a part of groups of the plurality of pixel groups by a predetermined pixel in a predetermined direction, with respect to each of the dispositions of the threshold values determined in the determining of the disposition; and recording the generated dither mask in the storage portion in a computer readable manner, wherein the predetermined direction is one or two directions, wherein the printing apparatus has singularity in a direction where a relative position of dots between the pixel groups is shifted from a target positional relationship which is a target, and wherein, in relation to a shift amount of the threshold value in the second threshold value disposition, a shift amount in a direction different from a specific direction having the easily shifted singularity is larger than a shift amount in the specific direction.
- and a storage portion that stores the dither mask, wherein the printing portion forms the dots through division into a plurality of pixel groups having different printing conditions and performs at least a part of the dot formation by the plurality of pixel groups in a common region, the method comprising;
Specification