Image forming apparatus

Patent metadata

Field	Value
Publication number	US-9304474-B2
Application number	US-201514633300-A
Country	US
Kind code	B2
Filing date	Feb 27, 2015
Priority date	Feb 28, 2014
Publication date	Apr 5, 2016
Grant date	Apr 5, 2016

Abstract

An image forming apparatus is disclosed, including a movable image bearer bearing an image thereon which is transferred to a recording medium when the image comes into contact with the recording medium; and a twining prevention member which is arranged in the vicinity of the image bearer on the side downstream of a portion of the contact between the recording medium and the image bearer in a moving direction of the image bearer to prevent the recording medium from twining around the image bearer, wherein the twining prevention member includes, in the portion of the contact with the recording medium, a high friction resistance portion which regulates movement of the recording medium.

First claim

The invention claimed is:

1. An image forming apparatus, comprising:
a movable image bearer bearing an image thereon which is transferred to a recording medium when the image comes in contact with the recording medium; and
a twining prevention member which is arranged in the vicinity of the image bearer on the side downstream of a portion of the contact between the recording medium and the image bearer in a moving direction of the image bearer to prevent the recording medium from twining around the image bearer,
wherein:
the twining prevention member includes, in the portion of the contact with the recording medium, a high friction resistance portion which regulates movement of the recording medium,
the high friction resistance portion includes a projection portion which projects from a base portion of the twining prevention member,
the twining prevention member is made of resin which is formed by a metal mold, and
the projection portion is formed in a parting line of the metal mold.

2. The image forming apparatus as claimed in claim 1 , wherein the parting line is disposed non-linearly to cause the projection portion to be disposed at a predetermined angle.

3. The image forming apparatus as claimed in claim 2 , wherein the predetermined angle is at an angle such that the contact with the recording medium is made at a high friction resistance when the recording medium enters the twining prevention member and the contact with the recording medium is made at a low friction resistance when the recording medium is removed from the twining prevention member.

4. An image forming apparatus, comprising:
an image bearer which bears thereon an image;
a transfer member which forms a transfer nip for transferring, onto a sheet, the image on the image bearer;
a cleaning member which cleans the image bearer; and
a contact member which is disposed on the side downstream of the transfer nip and on the side upstream of the cleaning member in a traveling direction of the image bearer to come in contact with the sheet when the sheet twines around the image bearer,
wherein:
the contact member includes a base portion and a projection portion which projects from the base portion such that a leading edge thereof is oriented toward the upstream side in the traveling direction of the image bearer,
the base portion includes a first plane and a second plane,
the first plane and the second plane intersect with each other at a crossing position,
the projection portion projects from the crossing position in a direction which extends along one of the first plane and the second plane.

5. The image forming apparatus as claimed in claim 4 , wherein the projection portion and the base portion are integrally formed.

6. The image forming apparatus as claimed in claim 4 , further comprising:
a supporting member which supports the cleaning member and the contact member.

7. The image forming apparatus as claimed in claim 6 , wherein the cleaning member is a blade.

8. The image forming apparatus as claimed in claim 4 , wherein the contact member is resin.

9. The image forming apparatus as claimed in claim 4 , further comprising:
a gap between the image bearer and the leading edge of the projection portion.

10. An image forming apparatus, comprising:
an image bearer which bears thereon an image;
a transfer member which forms a transfer nip for transferring, onto a sheet, the image on the image bearer;
a cleaning member which cleans the image bearer; and
a resin which is provided on the side downstream of the transfer nip and on the side upstream of the cleaning member in a traveling direction of the image bearer, wherein the resin includes a burr in a portion opposing the surface of the image bearer.

11. The image forming apparatus as claimed in claim 10 , wherein
the burr is arranged such that a leading edge thereof is oriented toward the side upstream in the traveling direction of the image bearer.

12. The image forming apparatus as claimed in claim 10 , wherein
a gap is provided between the image bearer and a leading edge of the burr.

13. The image forming apparatus as claimed in claim 10 , wherein:
the image bearer comprises a belt that is supported by a plurality of rollers, and
the burr faces one of the plurality of rollers via the belt.

14. The image forming apparatus as claimed in claim 4 , wherein:
the projection portion has a constant thickness from the crossing position to the leading edge.

15. The image forming apparatus as claimed in claim 4 , wherein:
the image bearer comprises a belt that is supported by a plurality of rollers, and
the high friction resistance portion faces one of the plurality of rollers via the belt.

16. The image forming apparatus as claimed in claim 1 , wherein:
the image bearer comprises a belt that is supported by a plurality of rollers, and
the high friction resistance portion faces one of the plurality of rollers via the belt.

17. An image forming apparatus, comprising:
a movable image bearer bearing an image thereon which is transferred to a recording medium when the image comes in contact with the recording medium; and
a twining prevention member which is arranged in the vicinity of the image bearer on the side downstream of a portion of the contact between the recording medium and the image bearer in a moving direction of the image bearer to prevent the recording medium from twining around the image bearer,
wherein:
the twining prevention member includes, in the portion of the contact with the recording medium, a high friction resistance portion which regulates movement of the recording medium,
wherein the high friction resistance portion comprises a comb-tooth shape, and
the high friction resistance portion comes in contact with the recording medium at a high friction resistance when the recording medium enters the twining prevention member and comes in contact with the recording medium at a low friction resistance when the recording medium is removed from the twining prevention member.

18. An image forming apparatus, comprising:
a movable image bearer bearing an image thereon which is transferred to a recording medium when the image comes in contact with the recording medium; and
a twining prevention member which is arranged in the vicinity of the image bearer on the side downstream of a portion of the contact between the recording medium and the image bearer in a moving direction of the image bearer to prevent the recording medium from twining around the image bearer,
wherein:
the twining prevention member includes, in the portion of the contact with the recording medium, a high friction resistance portion which regulates movement of the recording medium,
the high friction resistance portion is plane shaped, and
the friction resistance value of the high friction resistance portion is at least Ra 3.2.

19. The image forming apparatus as claimed in claim 18 , wherein the twining prevention member includes at least two members.

Assignees

• Sakashita Takeshi
• Fujita Masanari
• Meguro Yuuji
• Takai Naoki
• Hasebe Daisuke
• Ricoh Co Ltd

Inventors

• Sakashita Takeshi
• Fujita Masanari
• Meguro Yuuji
• Takai Naoki
• Hasebe Daisuke

Classifications

• G03G15/75 Primary

  Details relating to xerographic drum, band or plate, e.g. replacing, testing (electrographic recording members per se G03G5/00) · CPC title

• G03G15/6532 Primary

  Removing a copy sheet form a xerographic drum, band or plate (removing sheets from printing cylinders B65H29/02) · CPC title

• G03G15/657

  Feeding path after the transfer point and up to the fixing point, e.g. guides and feeding means for handling copy material carrying an unfused toner image · CPC title

• G03G2215/00573

  Recording medium stripping from image forming member · CPC title