Fixing device including an endless belt for fixing a toner image on a recording material

Patent metadata

Field	Value
Publication number	US-11269272-B2
Application number	US-202017094077-A
Country	US
Kind code	B2
Filing date	Nov 10, 2020
Priority date	Nov 12, 2019
Publication date	Mar 8, 2022
Grant date	Mar 8, 2022

Abstract

A fixing device includes a rotatable fixing belt, a pad, a rotatable pressing member, a pressing member driving source, an auxiliary driving roller, and a transmission mechanism for transmitting a driving force from the pressing member driving source to the auxiliary driving roller, wherein a peripheral speed of the auxiliary driving roller is faster than a peripheral speed of the pressing member, and a steering roller provided so as to stretch the fixing belt at the inner surface of the fixing belt in a position downstream of the auxiliary driving roller and upstream the pad with respect to a rotational direction of the fixing belt. The steering roller adjusts a position of the fixing belt with respect to a widthwise direction of the fixing belt by inclining the fixing belt so as to be positioned within a predetermined range.

First claim

What is claimed is:

1. A fixing device for fixing a toner image on a recording material, comprising:
a rotatable fixing belt configured to fix an unfixed toner image on the recording material in contact with the unfixed toner image formed on the recording material;
a pad provided inside said fixing belt;
a rotatable pressing member configured to press said fixing belt toward said pad so as to form a nip in which the recording material is nipped and fed;
a driving source configured to impart a driving force, for rotating said fixing belt, to said pressing member;
an auxiliary driving roller which is provided on a side downstream of the nip with respect to a rotational direction of said fixing belt and which stretches said fixing belt at an inner surface of said fixing belt without forming a nip in which the recording material is nipped and fed, wherein said auxiliary driving roller is configured to impart a driving force to said fixing belt;
a transmission mechanism configured to transmit the driving force from said driving source to said auxiliary driving roller, wherein a peripheral speed of said auxiliary driving roller is faster than a peripheral speed of said pressing member and a peripheral speed of said fixing belt; and
a steering roller provided so as to stretch said fixing belt at the inner surface of said fixing belt in a position downstream of said auxiliary driving roller and upstream said pad with respect to a rotational direction of said fixing belt, wherein said steering roller is configured to adjust a position of said fixing belt with respect to a widthwise direction of said fixing belt by inclining said fixing belt so as to be positioned within a predetermined range.

2. A fixing device according to claim 1 , wherein said transmission mechanism transmits, to said auxiliary driving roller, a driving force for making the peripheral speed of said fixing belt substantially equal to the peripheral speed of said pressing member.

3. A fixing device according to claim 1 , wherein the following relationship is satisfied:
1.03≤(peripheral speed of auxiliary driving roller)/(peripheral speed of pressing member)≤1.20.

4. A fixing device according to claim 1 , further comprising a separating member provided with an interval from an outer peripheral surface of said fixing belt and configured to separate, from said fixing belt, the recording material passed through the nip.

5. A fixing device according to claim 1 , further comprising a heating source provided inside said auxiliary driving roller and configured to heat said fixing belt.

6. A fixing device according to claim 1 , wherein said auxiliary driving roller is made of aluminum, and a surface layer thereof is subjected to anodized treatment.

7. A fixing device according to claim 1 , wherein a winding amount of said fixing belt about said auxiliary driving roller is larger than a winding amount of said fixing belt about said steering roller.

8. A fixing device according to claim 1 , further comprising an application member contacting the inner surface of said fixing belt and configured to apply a lubricant onto said fixing belt.

9. A fixing device according to claim 8 , wherein said application member is provided on a side downstream of said pad and upstream of said auxiliary driving roller with respect to the rotational direction of said fixing belt.

10. A fixing device according to claim 1 , further comprising a sliding member contacting an outer surface of said fixing belt and configured to slide on said fixing belt.

11. A fixing device according to claim 10 , wherein said sliding member presses said fixing belt toward said auxiliary driving roller.

12. A fixing device for fixing a toner image on a recording material, comprising:
a rotatable fixing belt configured to fix an unfixed toner image on the recording material in contact with the unfixed toner image formed on the recording material;
a pad provided inside said fixing belt;
a rotatable pressing member configured to press said fixing belt toward said pad so as to form a nip in which the recording material is nipped and fed;
a first driving source configured to impart a driving force, for rotating said fixing belt, to said pressing member;
an auxiliary driving roller which is provided on a side downstream of the nip with respect to a rotational direction of said fixing belt and which stretches said fixing belt at an inner surface of said fixing belt without forming a nip in which the recording material is nipped and fed, wherein said auxiliary driving roller is configured to impart a driving force to said fixing belt;
a second driving source configured to transmit a driving force to said auxiliary driving roller, wherein a peripheral speed of said auxiliary driving roller is faster than a peripheral speed of said pressing member and a peripheral speed of said fixing belt; and
a steering roller provided so as to stretch said fixing belt at the inner surface of said fixing belt in a position downstream of said auxiliary driving roller and upstream said pad with respect to a rotational direction of said fixing belt, wherein said steering roller is configured to adjust a position of said fixing belt with respect to a widthwise direction of said fixing belt by inclining said fixing belt so as to be positioned within a predetermined range.

13. A fixing device according to claim 12 , wherein said second driving source transmits, to said auxiliary driving roller, a driving force for making the peripheral speed of said fixing belt substantially equal to the peripheral speed of said pressing member.

14. A fixing device according to claim 12 , wherein the following relationship is satisfied:
1.03≤(peripheral speed of auxiliary driving roller)/(peripheral speed of pressing member)≤1.20.

15. A fixing device according to claim 12 , further comprising a separating member provided with an interval from an outer peripheral surface of said fixing belt and configured to separate, from said fixing belt, the recording material passed through the nip.

16. A fixing device according to claim 12 , further comprising a heating source provided inside said auxiliary driving roller and configured to heat said fixing belt.

17. A fixing device according to claim 12 , wherein said auxiliary driving roller is made of aluminum, and a surface layer thereof is subjected to anodized treatment.

18. A fixing device according to claim 12 , wherein a winding amount of said fixing belt about said auxiliary driving roller is larger than a winding amount of said fixing belt about said steering roller.

19. A fixing device according to claim 12 , further comprising an application member contacting the inner surface of said fixing belt and configured to apply a lubricant onto said fixing belt.

20. A fixing device according to claim 18 , wherein said application member is provided on a side downstream of said pad and upstream of said auxiliary driving roller with respect to the rotational direction of said fixing belt.

21. A fixing device according to claim 19 , further comprising a sliding member contacting an outer surface of said fixing belt and configured to slide on said fixing belt.

22. A fixing device according to claim 21 , wherein said sliding member presses said fixing belt toward said auxiliary driving roller.

23. A fixing device according to claim 1 , wherein said pad is a substantially plate-like member long along the widthwise direction.

24.

Assignees

• Canon Kk

Inventors

• Tatezawa Hidekazu
• Chikugo Youichi
• Takemasa Rikiya
• Tanaka Kenichi
• Tsuno Yutaro
• Hasegawa Mitsuru
• Takeuchi Suguru
• Kawai Hiroki
• Toratani Yasuharu
• Ogata Ayano

Classifications

• G03G15/2057

  relating to the chemical composition of the heat element and layers thereof · CPC title

• G03G2215/2022

  the fixing nip having both a stationary and a rotating belt support member opposing a pressure member · CPC title

• G03G2215/2048

  Surface layer material · CPC title

• G03G2215/2045

  Variable fixing speed · CPC title

• G03G15/2064

  combined with pressure · CPC title