Sheet conveying device and image forming apparatus incorporating the sheet conveying device

Patent metadata

Field	Value
Publication number	US-2016159598-A1
Application number	US-201514959780-A
Country	US
Kind code	A1
Filing date	Dec 4, 2015
Priority date	Dec 9, 2014
Publication date	Jun 9, 2016
Grant date	—

Abstract

A sheet conveying device, which is incorporated in an image forming apparatus, includes a first detector to detect an angle deviation of a recording medium to a sheet conveying direction, a second detector to detect a lateral shift of the recording medium to a width direction, a third detector to detect at least one of the angle deviation and the lateral shift after correction of the angle deviation detected by the first detector and the lateral shift detected by the second detector, and a rotary body to perform a primary movement by (1) rotating in the sheet conveying direction and returning to a reference position and by (2) moving in the width direction and returning to the reference position, and a secondary movement by performing at least one of (1) and (2) after the primary movement.

First claim

What is claimed is:

1 . A sheet conveying device comprising:
a first detector to detect an angle deviation of a recording medium inclined with respect to a sheet conveying direction of the recording medium during transport of the recording medium via a sheet conveying path through which the recording medium travels; a second detector to detect a lateral shift of the recording medium shifted with respect to a width direction of the recording medium during transport of the recording medium via the sheet conveying path; a third detector to detect at least one of the angle deviation and the lateral shift after correction of the angle deviation detected by the first detector and the lateral shift detected by the second detector; and a rotary body rotated by a driving unit, disposed between the first detector, the second detector, and the third detector, and conveying the recording medium while holding the recording medium along the sheet conveying path, the rotary body performing a primary movement by (1) rotating obliquely in the sheet conveying direction before holding the recording medium and returning to a reference position after holding the recording medium and by (2) moving in the width direction before holding the recording medium and returning to the reference position after holding the recording medium, and a secondary movement by performing at least one of (1) and (2) after the primary movement.

2 . The sheet conveying device according to claim 1 ,
wherein the rotary body corrects the angle deviation based on a result detected by the first detector, the lateral shift based on a result detected by the second detector, and the at least one of the angle deviation and the lateral shift based on a result detected by the third detector.

3 . The sheet conveying device according to claim 1 ,
wherein the first detector includes a first skew detecting sensor having two photosensors disposed spaced apart in the width direction, wherein the second detector includes a contact image sensor (CIS) having multiple photosensors disposed successively along the width direction, wherein the sheet conveying device further includes a downstream sheet conveying roller disposed downstream from the rotary body in the sheet conveying direction and conveying the recording medium to the downstream side, and a second skew detecting sensor having two photosensors disposed spaced apart from each other in the width direction at a position downstream from the rotary body and upstream from the downstream sheet conveying roller in the sheet conveying direction, wherein the third detector includes the second skew detecting sensor and the CIS, wherein, while holding the recording medium, the rotary body rotates obliquely in the sheet conveying direction and moves in the width direction.

4 . The sheet conveying device according to claim 3 ,
wherein the rotary body further corrects the angle deviation based on a result detected by the second skew detecting sensor of the third detector and the lateral shift based on a result detected by the CIS of the third detector.

5 . The sheet conveying device according to claim 3 ,
wherein the rotary body moves in the width direction while holding the recording medium by a feedback control.

6 . The sheet conveying device according to claim 5 ,
wherein the rotary body further corrects the lateral shift based on results serially detected by the CIS of the third detector.

7 . The sheet conveying device according to claim 3 ,
wherein the rotary body further corrects the angle deviation based on results serially detected by the first CIS of the second detector and results serially detected by the second CIS of the third detector.

8 . The sheet conveying device according to claim 1 ,
wherein the first detector includes a first skew detecting sensor having two photosensors disposed spaced apart in the width direction, wherein the second detector includes a first contact image sensor (CIS) having multiple photosensors disposed successively along the width direction, wherein the sheet conveying device further includes a downstream sheet conveying roller disposed downstream from the rotary body in the sheet conveying direction and conveying the recording medium, and a second contact image sensor (CIS) having multiple photosensors disposed successively along the width direction at a position downstream from the rotary body and upstream from the downstream sheet conveying roller in the sheet conveying direction, wherein the third detector includes the first CIS and the second CIS, wherein, while holding the recording medium, the rotary body rotates obliquely in the sheet conveying direction and moves in the width direction.

9 . The sheet conveying device according to claim 8 ,
wherein the rotary body further corrects the angle deviation based on a result detected by the first CIS of the second detector and a result detected by the second CIS of the third detector and the lateral shift based on a result detected by the first CIS of the third detector.

10 . The sheet conveying device according to claim 8 ,
wherein the rotary body moves in the width direction while holding the recording medium by a feedback control.

11 . The sheet conveying device according to claim 10 ,
wherein the rotary body further corrects the lateral shift based on either one of results serially detected by the first CIS of the second detector and results serially detected by the second CIS of the third detector.

12 . The sheet conveying device according to claim 8 ,
wherein the rotary body rotates obliquely in the sheet conveying direction while holding the recording medium by a feedback control.

13 . The sheet conveying device according to claim 3 ,
wherein the rotary body includes a registration roller to convey the recording medium to an image forming part of an image forming apparatus in synchronization with movement of an image to be transferred onto the recording medium, wherein the downstream sheet conveying roller is a transfer roller in contact with an image bearer in the image forming part.

14 . The sheet conveying device according to claim 1 ,
wherein the rotary body includes a registration roller to convey the recording medium toward an image forming part of an image forming apparatus in synchronization with movement of an image to be transferred onto the recording medium, wherein the sheet conveying device further includes a transfer roller disposed in contact with an image bearer provided to the image forming part and transferring an image formed on the image bearer onto the recording medium held together with the image bearer, and a pressure adjuster to change a contact pressure applied by the transfer roller to the image bearer, wherein the third detector detects the angle deviation of the recording medium when the recording medium is conveyed to a downstream side of the sheet conveying path, wherein the pressure adjuster adjust the contact pressure of the transfer roller to the image bearer while the recording medium is held between the transfer roller and the image bearer.

15 . The sheet conveying device according to claim 14 ,
wherein the rotary body further corrects the angle deviation based on a result detected by the third detector.

16 . The sheet conveying device according to claim 14 ,
wherein, in a period after the rotary body performs the primary movement and the secondary movement and before the third detector starts detection, the rotary body rotates obliquely in the sheet conveying direction by the feedback control while holdi

Assignees

• Yamane Jun
• Matsuda Hiromichi
• Miyawaki Katsuaki
• Kudo Koichi
• Watanabe Tetsuo
• Okamoto Toshihiro
• Takayama Hideyuki
• Oyamada Atsuyuki
• Ricoh Co Ltd

Inventors

• Yamane Jun
• Matsuda Hiromichi
• Miyawaki Katsuaki
• Kudo Koichi
• Watanabe Tetsuo
• Okamoto Toshihiro
• Takayama Hideyuki
• Oyamada Atsuyuki

Classifications

• G03G15/6529

  Transporting (G03G15/6555 takes precedence) · CPC title

• B65H7/14

  by photoelectric feelers or detectors · CPC title

• B65H9/20

  Assisting by photoelectric, sonic, or pneumatic indicators · CPC title

• B65H9/002 Primary

  changing orientation of sheet by only controlling movement of the forwarding means, i.e. without the use of stop or register wall · CPC title

• G03G15/6561 Primary

  for sheet registration · CPC title