Printing apparatus and control method

Patent metadata

Field	Value
Publication number	US-9375955-B2
Application number	US-201314017131-A
Country	US
Kind code	B2
Filing date	Sep 3, 2013
Priority date	Sep 14, 2012
Publication date	Jun 28, 2016
Grant date	Jun 28, 2016

Abstract

A printing apparatus includes a printing unit, a first and second conveying units conveying a printing medium, a driving unit driving the conveying units and a control unit controlling the driving unit. A load mutually acting on the conveying units through the medium in a conveyance state by the conveying units is recursively calculated for each predetermined conveyance unit while setting the initial value to 0. The driving unit is controlled based on the calculation result at the time of the transition to suppress a fluctuation in a conveyance amount at the time of the transition of the conveyance state of the medium from the conveyance state by the conveying units to a conveyance state only by the second conveying unit.

First claim

What is claimed is:

1. A printing apparatus comprising:
a printhead that prints an image on a printing medium;
a first conveyance roller that is provided on an upstream side of said printhead along a conveyance direction of a printing medium and conveys a printing medium;
a second conveyance roller that is provided on a downstream side of said printhead along the conveyance direction and conveys a printing medium;
a conveyance control unit configured to perform a conveyance control for changing a conveyance state from a first conveyance state in which the first conveyance roller conveys a printing medium and the second conveyance roller does not convey the printing medium, to a second conveyance state in which the first conveyance roller and the second conveyance roller convey the printing medium, and then to a third conveyance state in which the first conveyance roller does not convey the printing medium and the second conveyance roller conveys the printing medium;
a calculating unit configured to calculate a load mutually acting on said first conveyance roller and said second conveyance roller through the printing medium in the second conveyance state; and
a correcting unit configured to correct, a conveyance amount when the conveyance state is changed from the second conveyance state to the third conveyance state based on a calculation result of the load.

2. The apparatus according to claim 1 , further comprising a storage unit configured to store conveyance amount information associated with a conveyance amount for a predetermined conveyance unit of each of said first conveyance roller and said second conveyance roller,
wherein said calculating unit calculates the load based on the conveyance amount information.

3. The apparatus according to claim 2 , wherein said storage unit stores
a conveyance characteristic coefficient associated with a conveyance change amount with respect to the load of each of said first conveyance roller and said second conveyance roller, and
a rigidity coefficient associated with a displacement amount with respect to the load of each of said first conveyance roller and said second conveyance roller, and
said control unit calculates the load based on the conveyance amount information, the conveyance characteristic coefficient, and the rigidity coefficient.

4. The apparatus according to claim 1 , wherein said calculating unit calculates the load from a midstream of the second conveyance state up to the time changing from the second conveyance state to the third conveyance state.

5. The apparatus according to claim 2 ,
wherein the conveyance amount information is set
based on a measurement value of an actual conveyance amount of the printing medium in the first conveyance state and the measurement value of the actual conveyance amount of the printing medium in the third conveyance state,
based on the measurement value of the actual conveyance amount of the printing medium in the first conveyance state and the measurement value of the actual conveyance amount of the printing medium in the second conveyance state, or
based on the measurement value of the actual conveyance amount of the printing medium in the third conveyance state and the measurement value of the actual conveyance amount of the printing medium in the second conveyance state.

6. The apparatus according to claim 1 , further comprising a detection unit configured to detect a conveyance position of the printing medium,
wherein said control unit performs the conveyance control based on a detect result of said detection unit.

7. The apparatus according to claim 1 , wherein the printing apparatus comprises a serial printing apparatus configured to form the image by scanning said printhead in a direction perpendicular to the conveyance direction of the printing medium.

8. The apparatus according to claim 1 , wherein the printing apparatus comprises a line-type printing apparatus, and
said printhead comprises a line-type printhead including printing nozzles arranged in a direction perpendicular to the conveyance direction of the printing medium.

9. The apparatus according to claim 2 , further comprising
a first rotation member configured to rotate in accordance with said first conveyance roller, and
a second rotation member configured to rotate in accordance with said conveyance roller, wherein
the printing medium is conveyed while being sandwiched between said first conveyance roller and said first rotation member and/or between said second conveyance roller and said second rotation member, and
the predetermined conveyance unit is a rotation angle of each of said first conveyance roller and said second conveyance roller.

10. A method of controlling a printing apparatus including:
a printhead that prints an image on a printing medium;
a first conveyance roller that is provided on an upstream side of the printhead along a conveyance direction of a printing medium and conveys a printing medium; and
a second conveyance roller that is provided on a downstream side of the printhead along the conveyance direction and conveys a printing medium; the method comprising:
performing a conveyance control for changing a conveyance state from a first conveyance state in which the first conveyance roller conveys a printing medium and the second conveyance roller does not convey the printing medium, to a second conveyance state in which the first conveyance roller and the second conveyance roller convey the printing medium, and then to a third conveyance state in which the first conveyance roller does not convey the printing medium and the second conveyance roller conveys the printing medium;
calculating a load mutually acting on the first conveyance roller and the second conveyance roller through a printing medium in the second conveyance state; and
correcting a conveyance amount when the conveyance state is changed from the second conveyance state to the third conveyance state based on a calculation result of the load.

11. The apparatus according to claim 1 ,
wherein said calculating unit calculates the load during the second conveyance state.

12. The apparatus according to claim 1 , wherein said calculating unit recursively calculates the load for a predetermined conveyance unit while setting an initial value to 0.

Assignees

• Canon Kk

Inventors

• Ishida Takaaki
• Emoto Yuki
• Tokuda Shuichi
• Yoshiike Toshirou
• Shimonishi Tatsunori
• Hirate Junichi
• Masuda Kiyoshi
• Saito Tomoyuki

Classifications

• B41J11/42

  Controlling {printing material conveyance for accurate alignment of the printing material with the printhead; Print registering} · CPC title

• B41J13/03

  driven, e.g. feed rollers separate from platen · CPC title

• B41J13/00

  Devices or arrangements {of selective printing mechanisms, e.g. ink-jet printers or thermal printers,} specially adapted for supporting or handling copy material in short lengths, e.g. sheets · CPC title

• B41J13/0009

  control of the transport of the copy material · CPC title

• B41J13/02

  Rollers (roller platens B41J11/04) · CPC title