Printing apparatus and processing method thereof

• US 8,974,021 B2
• Filed: 07/24/2014
• Issued: 03/10/2015
• Est. Priority Date: 10/11/2011
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Yazawa, Takeshi, Konno, Yuji, Ojiro, Hinako, Hayashi, Masashi, Chikuma, Toshiyuki, Tanaka, Hirokazu
• Primary Examiner(s): JACKSON, JUANITA DIONNE
• Application Number:
  US14/339,813
• Publication Number:
  US 20150015640A1
• Time in Patent Office: 229 Days
• Field of Search: 347/9, 347 12- 14, 347/40, 347/42, 347 56- 57
• US Class Current: 347/9
• CPC Class Codes: B41J 19/96 Variable-spacing arrangements
• CPC Class Codes: B41J 2/01 Ink jet
• CPC Class Codes: B41J 2/2135 Alignment of dots
• CPC Class Codes: B41J 25/001 Mechanisms for bodily moving print heads or carriages parallel to the paper surface

Abstract

A printing apparatus comprising, a printhead including an element array in which a plurality of printing elements are arrayed, scanning unit configured to reciprocally scan the printhead, driving unit configured to time-divisionally drive the printing elements, conveyance unit configured to convey a printing medium, and setting unit configured to set a driving order, wherein the conveyance unit performs a first conveyance operation of conveying the printing medium by a conveyance amount which is an integer multiple of a width of the group of the time-divisional driving, and a second conveyance operation of conveying the printing medium by a conveyance amount which is not an integer multiple of the width of the group, and the setting unit sets the driving order in the time-divisional driving for each scan based on the conveyance amount by the conveyance unit.

Claims

1. A printing apparatus comprising:

a printhead including an element array in which a plurality of printing elements, for applying ink to a printing medium so as to print an image on the printing medium, are arrayed;

a scanning unit configured to scan said printhead in a direction perpendicular to an array direction of the plurality of printing elements;

a conveyance unit configured to convey the printing medium in the array direction of the plurality of printing elements, wherein a scan of the printhead by the scanning unit and a conveyance of the printing medium by the conveyance unit are alternately performed such that an image is printed in a predetermined printing region by a plurality of scans;

a driving unit configured to drive the plurality of printing elements such that printing elements in each of a plurality of groups are driven in a set driving order, wherein the plurality of printing elements are divided into the plurality of groups each including consecutive printing elements;

an obtaining unit configured to obtain, after a first scan is performed for the predetermined printing region, information, wherein the information indicates whether or not a position of printing elements which is used in a second scan for the predetermined printing region in the group to which the printing elements used in the second scan belong, coincides with a position of printing elements which is used in the first scan in the group to which the printing elements used in the first scan belong; and

a setting unit configured to set the driving order for the printing elements in each of the plurality of groups,

wherein said conveyance unit performs a first conveyance operation of conveying the printing medium for printing on a first area of the printing medium by a conveyance amount, which is an integer multiple of an amount corresponding to a width of the group, and a second conveyance operation of conveying the printing medium for printing on a second area of the printing medium by a conveyance amount, which is not an integer multiple of the width of the group, and

wherein said setting unit sets, for the second scan, the driving order for the printing elements in each of the plurality of groups, based on the information obtained by the obtaining unit.

2. The apparatus according to claim 1, wherein said setting unit sets the driving order for the printing elements in each of the plurality of groups, so as to make driving orders in respective scans of a same printing region coincide with each other, based on the information obtained by the obtaining unit.

3. The apparatus according to claim 1, wherein said setting unit sets the driving order in each scan by changing driving order patterns for determining the driving order, to shift in the array direction of the printing elements.

4. The apparatus according to claim 1, further comprising a calculation unit configured to calculate a cumulative conveyance amount of one printing medium conveyed by said conveyance unit,

wherein said setting unit sets the driving order based on the cumulative conveyance amount calculated by the calculation unit.

5. The apparatus according to claim 4, wherein said obtaining unit obtains a result obtained by dividing the cumulative conveyance amount calculated by the calculation unit by an amount corresponding to the width of the group.

6. The apparatus according to claim 5, wherein said setting unit sets the driving order in each scan by changing driving order patterns for determining the driving order, to shift in the array direction of the printing elements, and the shift amounts of the driving order patterns are based on the result obtained by the obtaining unit.

7. The apparatus according to claim 1, wherein said conveyance unit includes:

a first conveyance unit, arranged upstream of said printhead in a conveyance direction, for conveying a printing medium, and

a second conveyance unit, arranged downstream of said printhead in the conveyance direction, for conveying a printing medium.

8. The apparatus according to claim 7, wherein said conveyance unit makes different a printing medium conveyance amount when both said first conveyance unit and said second conveyance unit are used, from a printing medium conveyance amount when one of said first conveyance unit and said second conveyance unit is used.

9. The apparatus according to claim 1, wherein the printing element includes an electrothermal transducer for generating thermal energy for discharging ink.

10. The apparatus according to claim 1, wherein when the position of the printing elements used in the second scan in the group to which the printing elements used in the second scan belong, coincides with the position of the printing elements used in the first scan in the group to which the printing elements used in the first scan belong, the setting unit sets the driving order based on an original driving order pattern, and

when the position of the printing elements used in the second scan in the group to which the printing elements used in the second scan belong, does not coincide with the position of the printing elements used in the first scan in the group to which the printing elements used in the first scan belong, the setting unit sets the driving order based on a pattern which is obtained by shifting the original driving order pattern in the array direction of the plurality of printing elements.

11. A printing apparatus comprising:

a printhead including an element array in which a plurality of printing elements, for applying ink to a printing medium so as to print an image on the printing medium, are arrayed;

a scanning unit configured to scan said printhead in a direction perpendicular to an array direction of the plurality of printing elements;

a conveyance unit configured to convey the printing medium in the array direction of the plurality of printing elements, wherein a scan of the printhead by the scanning unit and a conveyance of the printing medium by the conveyance unit are alternately performed such that an image is printed in a predetermined printing region by a plurality of scans;

a driving unit configured to drive the plurality of printing elements such that printing elements in each of a plurality of groups are driven in a set driving order, wherein the plurality of printing elements are divided into the plurality of groups each including consecutive printing elements; and

a setting unit configured to set the driving order for the printing elements in each of the plurality of groups,

wherein a conveyance amount of the printing medium by said conveyance unit is smaller than an amount corresponding to a width of the group, and

wherein said setting unit sets the driving order for the printing elements of each of the plurality of groups for each scan, based on the conveyance amount by said conveyance unit.

12. The apparatus according to claim 11, wherein said setting unit sets the driving order for the printing elements in each of the plurality of groups, so as to make driving orders in respective scans of a same printing region coincide with each other, based on the conveyance amount.

13. The apparatus according to claim 11, wherein said setting unit sets the driving order in each scan by changing driving order patterns for determining the driving order, to shift in the array direction of the printing elements.

14. The apparatus according to claim 11, further comprising a calculation unit configured to calculate a cumulative conveyance amount of one printing medium conveyed by said conveyance unit,

wherein said setting unit sets the driving order based on the cumulative conveyance amount calculated by the calculation unit.

15. The apparatus according to claim 14, wherein said setting unit sets the driving order, based on a result obtained by dividing the cumulative conveyance amount calculated by the calculation unit by an amount corresponding to the width of the group.

16. The apparatus according to claim 11, wherein said conveyance unit includes:

a first conveyance unit, arranged upstream of said printhead in a conveyance direction, for conveying a printing medium, and

a second conveyance unit, arranged downstream of said printhead in the conveyance direction, for conveying a printing medium.

17. The apparatus according to claim 16, wherein said conveyance unit makes different a printing medium conveyance amount when both said first conveyance unit and said second conveyance unit are used, from a printing medium conveyance amount when one of said first conveyance unit and said second conveyance unit is used.

18. The apparatus according to claim 11, wherein the printing element includes an electrothermal transducer for generating thermal energy for discharging ink.