Image forming apparatus and control method of image forming apparatus

Patent metadata

Field	Value
Publication number	US-12416887-B2
Application number	US-202418438273-A
Country	US
Kind code	B2
Filing date	Feb 9, 2024
Priority date	Feb 15, 2023
Publication date	Sep 16, 2025
Grant date	Sep 16, 2025

Abstract

In a case where a type of a feeding standby sheet on a storage unit and a type of a refeeding standby sheet on a reconveyance path are the same, an image forming unit forms an image on one side of a feeding standby sheet on the storage unit, and in a case where a type of a feeding standby sheet on the storage unit and a type of a refeeding standby sheet on the reconveyance path are not the same, the image forming unit forms an image on another side of a refeeding standby sheet on the reconveyance path.

First claim

What is claimed is:

1. An image forming apparatus comprising:
a storage unit configured to store a sheet;
an image forming unit configured to form an image onto the sheet;
a reconveyance path for reconveying a sheet on which an image is formed by the image forming unit on one side, to the image forming unit to form an image on another side of the sheet on which the image is formed on the one side;
a detection unit that is provided on a conveyance path between the storage unit and the image forming unit, and configured to detect a type of a sheet conveyed from the storage unit; and
a control unit configured to cause the image forming unit to form an image on one side of a first sheet on the storage unit, then cause the image forming unit to form an image on one side of a second sheet on the storage unit, and then cause the image forming unit to form an image on another side of the first sheet on the reconveyance path,
wherein, in a case where a type of a third sheet on the storage unit and a type of the second sheet on the reconveyance path are the same, after the control unit causes the image forming unit to form an image on another side of the first sheet, the control unit causes the image forming unit to form an image on one side of the third sheet on the storage unit, and then causes the image forming unit to form an image on another side of the second sheet on the reconveyance path, and
wherein, in a case where a type of the third sheet on the storage unit and a type of the second sheet on the reconveyance path are not the same, after the control unit causes the image forming unit to form an image on another side of the first sheet, the control unit causes the image forming unit to form an image on another side of the second sheet on the reconveyance path, and then causes the image forming unit to form an image on one side of the third sheet on the storage unit.

2. The image forming apparatus according to claim 1 , wherein the control unit causes the detection unit to detect a type of a leading sheet in a bundle of paper stored in the storage unit, and assumes that types of second-page and subsequent sheets in the bundle of paper are the same as the type of the leading sheet.

3. The image forming apparatus according to claim 2 , wherein, in a case where the third sheet is a leading sheet in the bundle of paper, after the control unit causes the image forming unit to form an image on another side of the first sheet, the control unit causes the image forming unit to form an image on another side of the second sheet on the reconveyance path, and then causes the image forming unit to form an image on one side of the third sheet on the storage unit.

4. The image forming apparatus according to claim 2 , wherein, in a case where the third sheet is a leading sheet in the bundle of paper, and a size of the third sheet is equal to or smaller than a threshold value, the control unit conveys the third sheet from the storage unit up to a position of the detection unit, and causes the detection unit to detect a type of the third sheet.

5. The image forming apparatus according to claim 4 , wherein, in a case where the third sheet is a leading sheet in the bundle of paper, and a size of the third sheet is not equal to or smaller than a threshold value, after the control unit causes the image forming unit to form an image on another side of the first sheet, the control unit causes the image forming unit to form an image on another side of the second sheet on the reconveyance path, and then causes the image forming unit to form an image on one side of the third sheet on the storage unit.

6. The image forming apparatus according to claim 1 , wherein the control unit determines a conveyance speed of the sheet in accordance with a type of the sheet.

7. The image forming apparatus according to claim 6 , wherein a conveyance speed of a sheet of which the type of the sheet is thick paper is slower than a conveyance speed of a sheet of which the type of the sheet is plain paper.

8. The image forming apparatus according to claim 1 ,
wherein, in a case where a size and a type of the third sheet on the storage unit and a size and a type of the second sheet on the reconveyance path are the same, the control unit causes the image forming unit to form an image on one side of the third sheet on the storage unit, and then causes the image forming unit to form an image on another side of the second sheet on the reconveyance path, and
wherein, in a case where a size and a type of the third sheet on the storage unit and a size and a type of the second sheet on the reconveyance path are not the same, the control unit causes the image forming unit to form an image on another side of the second sheet on the reconveyance path, and then causes the image forming unit to form an image on one side of the third sheet on the storage unit.

9. The image forming apparatus according to claim 8 , wherein the control unit determines a conveyance speed of the sheet in accordance with a type of the sheet, and determines the number of circulated sheets of the sheet in accordance with a size of the sheet.

10. The image forming apparatus according to claim 9 ,
wherein a conveyance speed of a sheet of which the type of the sheet is thick paper is slower than a conveyance speed of a sheet of which the type of the sheet is plain paper, and
wherein the number of circulated sheets of a sheet of which the size of the sheet is a first size is smaller than the number of circulated sheets of a sheet of which the size of the sheet is a second size smaller than the first size.

11. The image forming apparatus according to claim 10 ,
wherein, in a case where the size of the sheet is the first size, the number of circulated sheets of the sheet is three, and
wherein, in a case where the size of the sheet is the second size, the number of circulated sheets of the sheet is five.

12. The image forming apparatus according to claim 11 ,
wherein the first size is an A3 size, and
wherein the second size is an A4 size.

13. The image forming apparatus according to claim 8 ,
wherein, in a case where the size of a sheet is a first size, the control unit causes the image forming unit to form an image on one side of a first-page sheet on the storage unit, then causes the image forming unit to form an image on one side of a second-page sheet on the storage unit, then causes the image forming unit to form an image on another side of the first-page sheet on the reconveyance path, regards the first sheet as the first-page sheet, regards the second sheet as the second-page sheet, and regards the third sheet as a third-page sheet on the storage unit, and
wherein, in a case where the size of a sheet is a second size smaller than the first size, the control unit causes the image forming unit to form an image on one side of a first-page sheet on the storage unit, then causes the image forming unit to form an image on one side of a second-page sheet on the storage unit, then causes the image forming unit to form an image on one side of a third-page sheet on the storage unit, then causes the image forming unit to form an image on another side of the first-page sheet on the reconveyance path, regards the first sheet as the first-page sheet, regards the second sheet as the second-page sheet, and regards the third sheet as a four-page sheet on the storage unit.

14. The image forming apparatus according to claim 13 ,
wherein the first size is an A3 size, and
wherein the second size is an A4 size.

15. The image forming apparatus according to claim 1 ,
wherein the control unit causes the image for

Assignees

• Canon Kk

Inventors

• Miyajima Jun

Classifications

• G03G2215/00746

  of sheet velocity · CPC title

• G03G2215/00738

  of sheet thickness or rigidity · CPC title

• G03G15/6558

  Feeding path after the copy sheet preparation and up to the transfer point, e.g. registering; Deskewing; Correct timing of sheet feeding to the transfer point · CPC title

• G03G15/5029

  by measuring the copy material characteristics, e.g. weight, thickness · CPC title

• G03G15/5025

  by measuring the original characteristics, e.g. contrast, density · CPC title