Sheet stacking apparatus and image forming system

Patent metadata

Field	Value
Publication number	US-10618759-B2
Application number	US-201816165900-A
Country	US
Kind code	B2
Filing date	Oct 19, 2018
Priority date	Nov 9, 2017
Publication date	Apr 14, 2020
Grant date	Apr 14, 2020

Abstract

A sheet stacking apparatus includes: a sheet stacking part on which a sheet is stacked; a tilt detection sensor arranged on an upstream side in a conveying direction of the sheet of the sheet stacking part, and which detects a tail end in the conveying direction in the conveyed sheet; a pair of correction rollers arranged on a downstream side in the conveying direction of the tilt detection sensor and arranged immediately before an upstream side in the conveying direction of the sheet stacking part, and which corrects a tilt of the sheet; and a sheet holder that holds the sheet with the tilt corrected by the pair of correction rollers, and conveys and stacks the sheet on the sheet stacking part.

First claim

What is claimed is:

1. A sheet stacking apparatus comprising:
a sheet stacking part on which a sheet is stacked;
a tilt detection sensor arranged on an upstream side in a conveying direction of the sheet of the sheet stacking part, and which detects a tail end in the conveying direction in the conveyed sheet;
a pair of correction rollers arranged on a downstream side in the conveying direction of the tilt detection sensor and arranged immediately before an upstream side in the conveying direction of the sheet stacking part, and which corrects a tilt of the sheet; and
a sheet holder that holds the sheet with the tilt corrected by the pair of correction rollers, and conveys and stacks the sheet on the sheet stacking part.

2. The sheet stacking apparatus according to claim 1 , wherein
the tilt detection sensor is arranged between a conveyance roller arranged most downstream in the conveying direction of a plurality of conveyance rollers for conveying the sheet, and the pair of correction rollers.

3. The sheet stacking apparatus according to claim 1 , wherein
the sheet holder holds the sheet before the sheet passes through the pair of correction rollers.

4. The sheet stacking apparatus according to claim 3 , wherein
the sheet holder includes
a gripper member that holds an end of the sheet; and
a gripper mover that movably supports the gripper member, wherein
a moving speed in the conveying direction of the gripper member after holding the sheet is same as a conveyance speed of the sheet after correction in the pair of correction rollers.

5. The sheet stacking apparatus according to claim 1 , further comprising:
a contact surface with which the tail end of the sheet stacked on the sheet stacking part comes into contact, wherein
the sheet holder brings the tail end of the sheet into contact with the contact surface and stacks the sheet on the sheet stacking part.

6. The sheet stacking apparatus according to claim 1 , wherein
the pair of correction rollers is conveyance rollers arranged most downstream on a conveyance path on which the sheet is conveyed.

7. An image forming system comprising:
an image forming apparatus that forms an image on a sheet; and
a sheet stacking apparatus to which the sheet is conveyed from the image forming apparatus, wherein
the sheet stacking apparatus according to claim 1 is applied to the sheet stacking apparatus.

8. The sheet stacking apparatus according to claim 1 , additionally comprising conveyance rollers for conveying the sheet, wherein when the pair of correction rollers corrects the tilt of the sheet, the conveyance rollers do not make contact with the sheet.

9. The sheet stacking apparatus according of claim 1 , additionally comprising conveyance rollers positioned immediately upstream of the pair of correction rollers, such that the pair of correction rollers corrects the tilt of the sheet after the sheet has completely passed through the conveyance rollers.

10. The sheet stacking apparatus according to claim 1 , additionally comprising conveyance rollers, wherein no conveyance roller is arranged between the pair of correction rollers and the tilt detection sensor.

11. The sheet stacking apparatus according to claim 1 , wherein the sheet holder comprises a plurality of sheet holders.

12. The sheet stacking apparatus according to claim 1 , wherein the sheet holder comprises a pair of sheet holders, wherein the pair of correction rollers is positioned in between the pair of sheet holders.

13. The sheet stacking apparatus according to claim 1 , wherein the sheet holder comprises:
(a) a first gripper member; and
(b) a second gripper member, spaced apart in a width direction from the first gripper member, wherein the first gripper member and the second gripper member are configured to hold an end of the sheet so as to prevent the sheet from tilting after the pair of correction rollers corrects the tilt of the sheet.

14. The sheet stacking apparatus according to claim 1 , additionally comprising a width direction mover configured to move the sheet holder and the pair of correction rollers in a width direction.

15. The sheet stacking apparatus according to claim 1 , wherein each of the correction rollers is configured to be individually controllable.

16. The sheet stacking apparatus according to claim 1 , additionally comprising:
(a) a first roller diver that rotationally drives one of the correction rollers; and
(b) a second roller driver that rotationally drives the other correction roller of the pair of correction rollers, wherein a CPU independently controls a conveyance speed of the one correction roller by the first roller driver and a conveyance speed of the other correction roller by the second roller driver.

17. The sheet stacking apparatus according to claim 1 , wherein the sheet holder comprises an upper gripper and a lower gripper, wherein in operation, the sheet holder comprises:
(a) a standby mode where the upper gripper does not protrude into a conveyance path of the sheet;
(b) a holding mode where the upper and lower grippers are moved in an upward and downstream direction to an end of the sheet, and engage with one another, for holding the end of the sheet after the pair of correction rollers has corrected the tilt of the sheet;
(c) a conveyance mode where the conveyance speed of the sheet in the pair of correction rollers and the moving speed of the upper and lower grippers in the conveyance direction of the sheet is the same so as to prevent any tilt of the sheet; and
(d) a stacking mode after the sheet passes through the pair of correction rollers, the stacking mode comprises moving the upper and lower grippers to the sheet stacking part and then moving the upper and lower grippers in a upstream direction so that the tail end of the sheet contacts a contact surface of the sheet stacking apparatus, whereby the sheet is stacked.

Assignees

• Konica Minolta Inc

Inventors

• Anezaki Tsutomu

Classifications

• B65H29/003

  by grippers (B65H29/02 takes precedence) · CPC title

• B65H2801/06

  Office-type machines, e.g. photocopiers · CPC title

• B65H2301/4212

  of articles substantially horizontal · CPC title

• B65H2301/44331

  at particular portion of handled material · CPC title

• B65H29/125 Primary

  between two sets of rollers · CPC title