INK JET PRINTING APPARATUS AND PRINTING METHOD

• US 20110069100A1
• Filed: 11/23/2010
• Published: 03/24/2011
• Est. Priority Date: 05/26/2006
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Kameda, Hirokazu, Kanazawa, Manabu, Yasutani, Jun, Yazawa, Takeshi, Yano, Fumiko, Ide, Daisaku, Nishikori, Hitoshi
• Granted Patent: US 8,511,779 B2
• Time in Patent Office: Days
• US Class Current: 347/9
• CPC Class Codes: B41J 2/2054 by the variation of dot disposition or characteristics, e.g. dot number density, dot shape

Abstract

By suppressing deviation of dot-formation positions stemming from insufficient accuracy in conveying a printing medium due to eccentricity of a conveying roller, a printed image in which unevenness is less visible is obtained. An accumulated amount of conveyance errors is decreased by narrowing a nozzle-use range and reducing a conveyance amount over an entire printing region according to a mode used for printing an image in which the coverage of a printing medium is low due to a small number of ink colors to be used, for example, a mode used for printing a monochrome image by using a black ink dominantly in all of the density regions.

Claims

1. An ink jet printing apparatus for printing an image on a printing medium by performing a print scan which makes a print while causing a printing head, which includes arrays of printing elements for ejecting inks of different colors, to scan on a printing medium, and by conveying the printing medium in a direction intersecting with a direction of the print scan, the apparatus comprising;

print controller capable of executing the print scan, which makes a print with a using range of the array of printing elements restricted to a part of the array, over an entire printing region on the printing medium, in a case where a printing mode for printing a monochrome image is selected.

2. An ink jet printing apparatus as claimed in claim 1, wherein the monochrome image is an achromatic monochrome image.

3. An ink jet printing apparatus as claimed in claim 2, wherein

the printing head has the array of printing elements for ejecting an achromatic ink, and the array of printing elements for ejecting a chromatic ink, and

the monochrome image is printed by using the achromatic ink and the chromatic ink in the printing mode for the monochrome image, while dominantly using the achromatic ink in all density regions.

4. An ink jet printing apparatus as claimed in claim 1, wherein the print controller can execute the print scan, which makes a print by using the entire array of printing elements, on at least part of the printing regions on the printing medium in a case where the printing mode for the monochrome image is not selected.

5. An ink jet printing apparatus as claimed in claim 1, wherein the print controller (A) executes the print scan, which makes a print with the using range of the array of printing elements restricted to a part of the array, over the entire printing region on the printing medium in a case where the printing mode for the monochrome image is selected, and where a first type of printing medium is designated as a type of the printing medium, and (B) executes the print scan, which makes a print by using the entire array of printing elements, on at least a part of the printing region on the printing medium in a case where the printing mode for the monochrome image is selected, and where a second type of printing medium is designated as the type of the printing medium.

6. An ink jet printing apparatus as claimed in claim 1, wherein, according to the type of printing medium, it is determined whether or not to print with the using range of the printing elements restricted.

7. An ink jet printing apparatus as claimed in claim 1, wherein the print controller includes switching unit which switches, among the printing elements in the array, the printing elements to be used when the using range thereof is restricted.

8. An ink jet printing apparatus as claimed in claim 7, wherein the switching unit performs the switching at a timing when a page of a printing medium is changed to another one.

9. An ink jet printing apparatus as claimed in claim 8, further comprising managing unit which accumulatively manages the number of printed printing media,

wherein, according to an accumulated value obtained by the managing unit, the switching unit performs the switching.

10. An ink jet printing apparatus as claimed in claim 8, further comprising managing unit which manages an accumulated value of the number of ejection operations executed by the printing head,

wherein, after the accumulated value of the number of ejection operations exceeds a predetermined threshold, the switching unit performs the switching at the timing when the page of the printing medium is changed to another one.

11. An ink jet printing apparatus as claimed in claim 7, wherein the switching unit performs the switching within one page.

12. An ink jet printing apparatus as claimed in claim 1, wherein an amount of conveyance of the printing medium between the print scans of printing with the using range of the array of printing elements restricted to a part of the array is smaller than an amount of conveyance of the printing medium between the print scans of printing by using the entire array of printing elements.

13. An ink jet printing method for printing an image on a printing medium by performing a print scan which makes a print while causing a printing head, which includes arrays of printing elements for ejecting inks of different colors, to scan on a printing medium, and by conveying the printing medium in a direction intersecting with a direction of the print scan, the method comprising the steps of:

designating a printing mode for printing a monochrome image; and

executing the print scan, which makes a print with a using range of the array of printing elements restricted to a part of the array, over an entire printing region of the printing medium, according to at least the designation of the printing mode for printing a monochrome image.