Image printing apparatus and image printing method
AssigneeCanon Kabushiki Kaisha
InventorsYasushi Miura, Yoshiko Miyashita, Shizuko Fukuda
Life of this patent
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Abstract
A density difference correction signal is generated for correcting a density difference upon forward path printing and backward path printing by density difference correction signal generating apparatus to store the generated density difference correction signal in an unevenness correction RAM. A predetermined correction line in a HS table memory is selected depending upon the density difference correction signal. By the selected correction line, the density correction of the image data of forward path printing and backward path printing is performed to output the image data.
Claims22
In an image printing apparatus having scanning means for scanning at least one printing head for ejecting an ink in reciprocal scanning including a forward path and a backward path, and printing control means for ejecting said ink by driving said at least one printing head and printing an image on a printing medium during said reciprocal scanning by said scanning means, the image printing apparatus comprising:
- density difference correction signal generating means for generating a density difference correction signal for correcting a density difference between an image density upon forward path printing by said at least one printing head and an image density upon backward path printing by said printing head;
- storage means for storing the generated density difference correction signal;
- and
- density conversion means for varying image density of image data for forward printing and backward printing depending upon the stored density difference correction signal.
An image printing apparatus reciprocating a plurality of printing heads and performing overlay printing of an image for a printing medium by the combined scans of forward path and backward path of a plurality of said printing heads, comprising:
- density difference correction signal generating means for generating a density difference correction signal for correcting a density difference by the combined scans of forward path and backward path of a plurality of said printing heads;
- storage means for storing the generated density difference correction signal;
- and
- density conversion means for varying image density of image data upon printing by the combined scans of the forward path and the backward path depending upon the stored density difference correction signal.
In an image printing apparatus having scanning means for scanning at least one printing head for ejecting an ink in reciprocal scanning including a forward path and a backward path, and printing control means for ejecting said ink by driving said at least one printing head and printing an image on a printing medium during said reciprocal scanning by said scanning means, the image printing apparatus comprising:
- printing means for printing test images in a forward path scan and backward path scan of said printing head;
- reading means for reading the printed test images;
- density difference correction signal generating means for generating a density difference correction signal for correcting a density difference between the test image density upon forward path printing by said at least one printing head and the test image density upon backward path printing by said at least one printing head;
- storage means for storing the generated density difference correction signal;
- and
- density conversion means for varying image density of image data for forward printing and backward printing depending upon the stored density difference correction signal.
An image printing apparatus reciprocating a plurality of printing heads and performing overlay printing of an image for a printing medium by the combined scans of forward path and backward path of a plurality of said printing heads, comprising:
- printing means for printing test images by the combined scans of forward path and backward path scan of said printing heads;
- reading means for reading the printed test images;
- density difference correction signal generating means for generating a density difference correction signal for correcting a density difference of the test images formed by the combined scans of forward path and backward path of a plurality of said printing heads;
- storage means for storing the generated density difference correction signal;
- and
- density conversion means for varying image density of image data upon printing by the combined scans of the forward path and the backward path depending upon the stored density difference correction signal.
In an image printing method having a scanning step for scanning at least one printing head for ejecting an ink in reciprocal scanning including a forward path and a backward path, and a printing control step for ejecting said ink by driving said at least one printing head and printing an image on a printing medium during said reciprocal scanning by said scanning step, the image printing method comprising the steps of:
- generating a density difference correction signal for correcting a density difference between an image density upon forward path printing by said at least one printing head and an image density upon backward path printing by said at least one printing head;
- and
- varying image density of image data for forward printing and backward printing depending upon generated density difference correction signal.
An image printing method reciprocating a plurality of printing heads and performing overlay printing of an image for a printing medium by the combined scans of forward path and backward path of a plurality of said printing heads, comprising the steps of:
- generating a density difference correction signal for correcting a density difference by the combined scans of forward path and backward path of a plurality of said printing heads;
- and
- varying image density of image data upon printing by the combined scans of the forward path and the backward path depending upon the generated density difference correction signal.
An image printing method having a scanning step for scanning at least one printing head for ejecting an ink in reciprocal scanning including a forward path and a backward path, and a printing control step for ejecting said ink by driving said at least one printing head and printing an image on a printing medium during said reciprocal scanning by said scanning step, the image printing method comprising the steps of:
- printing test images in forward path scan and backward path scan of said at least one printing head;
- reading the printed test images;
- generating a density difference correction signal for correcting a density difference between the test image density upon forward path printing by said at least one printing head and the test image density upon backward path printing by said at least one printing head;
- and
- varying image density of image data for forward printing and backward printing depending upon generated density difference correction signal.
An image printing apparatus reciprocating a plurality of printing heads and performing overlay printing of an image for a printing medium by the combined scans of forward path and backward path of a plurality of said printing heads, comprising the steps of:
- printing test images by the combined scans of forward path and backward path scan of said printing heads;
- reading the printed test images;
- generating a density difference correction signal for correcting a density difference of the test images formed by the combined scans of forward path and backward path of a plurality of said printing heads;
- and
- varying image density of image data upon printing by the combined scans of the forward path and the backward path depending upon the generated density difference correction signal.
Dependencies are inferred from the claim text.