Printing apparatus and control method therefor

Patent metadata

Field	Value
Publication number	US-10486445-B2
Application number	US-201715477452-A
Country	US
Kind code	B2
Filing date	Apr 3, 2017
Priority date	Jun 4, 2014
Publication date	Nov 26, 2019
Grant date	Nov 26, 2019

Abstract

A printing apparatus comprises a conveyance control unit which controls conveyance of printing sheets so that a trailing edge of a preceding sheet as a printing sheet precedingly fed from the stacking unit and a leading edge of a succeeding sheet as a printing sheet succeedingly fed from the stacking unit overlap each other; and a skew correction unit which performs skew correction of the succeeding sheet while the succeeding sheet overlaps the preceding sheet by the conveyance control unit. The skew correction unit makes the leading edge of the succeeding sheet abut against the conveyance roller during a time from an end of a last line feed operation by the conveyance roller for printing on the preceding sheet by the printing unit to start of a next conveyance operation.

First claim

What is claimed is:

1. A printing apparatus comprising:
a first roller configured to feed a sheet;
a second roller configured to convey the sheet fed by the first roller;
a print head configured to print an image on the sheet conveyed by the second roller based on printing data;
a detection unit configured to detect an edge of the sheet; and
processor and memory configured to function as:
a control unit configured to perform a forming operation for forming an overlap state in which a leading edge of a succeeding sheet is overlapping with a preceding sheet; and
a determination unit configured to determine whether to perform a first conveyance operation for conveying the succeeding sheet to a printing start position at which printing of the succeeding sheet by the print head is started while keeping the overlap state or a second conveyance operation for conveying the succeeding sheet to the printing start position with an interval between a trailing edge of the preceding sheet and the leading edge of the succeeding sheet,

wherein the control unit controls the first roller and the second roller to perform a skew correction operation of the succeeding sheet by abutting the leading edge of the succeeding sheet against the second roller which stops before the trailing edge of the preceding sheet passes the second roller in a case in which the determination unit determines to perform the first conveyance operation.

2. The printing apparatus according to claim 1 , wherein the control unit performs the skew correction operation before completion of printing of the preceding sheet by the print head.

3. The printing apparatus according to claim 2 , wherein the control unit performs the skew correction operation when the second roller stops for printing of the preceding sheet by the print head.

4. The printing apparatus according to claim 3 , further comprising a carriage configured to support the print head and move in a direction intersecting a conveyance direction of the sheet,
wherein the control unit performs the skew correction operation when the second roller stops to perform a scanning of a last print by the carriage for the preceding sheet.

5. The printing apparatus according to claim 1 , wherein the control unit forms the overlap state of the preceding sheet and the succeeding sheet at a location between the first roller and the second roller in the forming operation.

6. The printing apparatus according to claim 5 , wherein the first roller starts to feed the succeeding sheet while having a predetermined interval between the trailing edge of the preceding sheet and the leading edge of the succeeding sheet.

7. The printing apparatus according to claim 6 , further comprising a first motor configured to drive the first roller and a second motor configured to drive the second roller, wherein the control unit controls the first motor and the second motor to cause the first roller, which feeds the succeeding sheet, to rotate continuously when the second roller, which conveys the preceding sheet, rotates intermittently so that the succeeding sheet catches up with the preceding sheet.

8. The printing apparatus according to claim 6 , further comprising a first motor configured to drive the first roller and a second motor configured to drive the second roller, wherein the control unit controls the first motor and the second motor to cause the first roller, which feeds the succeeding sheet, to rotate at a rotation speed higher than that of the second roller, which conveys the preceding sheet, so that the succeeding sheet catches up with the preceding sheet.

9. The printing apparatus according to claim 1 , wherein in a case that an overlap amount of the preceding sheet and the succeeding sheet is less than a threshold value, the determination unit determines to perform the second conveyance operation.

10. The printing apparatus according to claim 1 , wherein in a case that the leading edge of the succeeding sheet will not be conveyed to a predetermined position when the succeeding sheet is conveyed to the printing start position, the determination unit determines to perform the second conveyance operation.

11. The printing apparatus according to claim 1 , further comprising a carriage configured to support the print head and move in a direction intersecting a conveyance direction of the sheet,
wherein in a case that, in the printing data for the preceding sheet, there is no gap between a printing image that is printed by a last movement of the carriage and a printing image that is printed by a movement immediately before the last movement of the carriage, the determination unit determines to perform the second conveyance operation.

12. The printing apparatus according to claim 1 , wherein if the determination unit determines to perform the second conveyance operation, the control unit performs the skew correction operation after the trailing edge of the preceding sheet passes the second roller, and then controls to convey the succeeding sheet to the printing start position.

13. The printing apparatus according to claim 1 , further comprising a carriage configured to support the print head and move in a direction intersecting a conveyance direction of the sheet,
wherein the determination unit determines, before a scanning of a last print by the carriage for the preceding sheet, whether to perform the first conveyance operation or the second conveyance operation.

14. The printing apparatus according to claim 1 , wherein if the determination unit determines to perform the first conveyance operation, the control unit decreases a rotation amount of the second roller for printing of the preceding sheet, as compared with a case in which the determination unit determines to perform the second conveyance operation.

15. The printing apparatus according to claim 1 , further comprising a third roller configured to nip and convey the sheet with the second roller.

16. The printing apparatus according to claim 15 , further comprising a motor configured to drive the third roller,
wherein the second roller is driven by rotation of the third roller.

17. A control method of a printing apparatus having a first roller configured to feed a sheet, a second roller configured to convey the sheet fed by the first roller, a print head configured to print an image on the sheet conveyed by the second roller based on printing data, and a detection unit configured to detect an edge of the sheet, the method comprising:
performing a forming operation for forming an overlap state in which a leading edge of a succeeding sheet is overlapping with a preceding sheet;
determining whether to perform a first conveyance operation for conveying the succeeding sheet to a printing start position at which a printing of the succeeding sheet by the print head is started while keeping the overlap state or a second conveyance operation for conveying the succeeding sheet to the printing start position with an interval between a trailing edge of the preceding sheet and the leading edge of the succeeding sheet; and
controlling the first roller and the second roller to perform a skew correction operation of the succeeding sheet by abutting the leading edge of the succeeding sheet against the second roller which stops before the trailing edge of the preceding sheet passes the second roller in a case of determining to perform the first conveyance operation.

Assignees

• Canon Kk

Inventors

• Asai Yasuyuki
• Kunihiro Syunichi
• Aoyama Naoki
• Ogawa Katsuya
• Sugiyama Noriyuki
• Tanaami Yasufumi
• Yonemoto Ryo

Classifications

• B41J13/0009

  control of the transport of the copy material · CPC title

• B41J11/0095

  Detecting means for copy material, e.g. for detecting or sensing presence of copy material or its leading or trailing end · CPC title

• B65H2301/331

  Skewing, correcting skew, i.e. changing slightly orientation of material · CPC title

• B65H5/068

  between one or more rollers or balls and stationary pressing, supporting or guiding elements · CPC title

• B41J15/046

  for the guidance of continuous copy material, e.g. for preventing skewed conveyance of the continuous copy material · CPC title