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US20070140752A1 Active / In Force US ⏱️ 0.1 years remaining

Fixing apparatus and image forming apparatus using same

Assignee: Ricoh Co Ltd
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Filing: 2006-12-13
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Granted: —
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Expires: 2026-12-13
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Abstract

Abstract The present invention provides a fixing apparatus which effectively prevents a recording medium from coiling around the surface of a fixing member and also prevents damage to the surface of the fixing member, and an image forming apparatus comprising this fixing apparatus. A gap between the tip end of separating means and the fixing member can be managed appropriately, and as a result, the recording medium can be prevented from coiling around the surface of the fixing member. A spacer is mounted near the tip end of a separating claw, and the spacer contacts a protruding portion of a core metal of a fixing roller. Thus, a gap having a predetermined magnitude is formed between the tip end of the separating claw and the peripheral surface of the fixing roller. The gap is maintained by the spacer, and therefore the gap between the fixing roller and the separating claw can be managed appropriately over the long term. Moreover, paper can be prevented from coiling around the surface of the fixing roller by managing the gap appropriately, and since a contact member contacting the surface (fixing surface) of the fixing roller is not provided, the surface of the fixing roller is not damaged.

Inventors

  • 👤 Shin Yamamoto
  • 👤 Masahiro Yagi

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 04:04
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/20; G03G15/2003; G03G15/2014; G03G15/2017; G03G15/2028

Claims Analysis

Total Claims: 18
Claim 1
Independent Claim 116 words
1 . A fixing apparatus having a fixing member that is heated by a heat source and a pressure member that is pressed against the fixing member, in which a recording material carrying an unfixed image is passed between the fixing member and the pressure member to fix the unfixed image on the recording material, the fixing apparatus further comprising separating means for separating the recording material from the fixing member following fixing, wherein the separating means comprise a separating member and a spacer attached to the separating member, and a gap between the separating member and the fixing member is maintained by bringing the spacer into contact with a structural body of the fixing member.
Claim 2
Dependent Claim 116 words
1 . A fixing apparatus having a fixing member that is heated by a heat source and a pressure member that is pressed against the fixing member, in which a recording material carrying an unfixed image is passed between the fixing member and the pressure member to fix the unfixed image on the recording material, the fixing apparatus further comprising separating means for separating the recording material from the fixing member following fixing, wherein the separating means comprise a separating member and a spacer attached to the separating member, and a gap between the separating member and the fixing member is maintained by bringing the spacer into contact with a structural body of the fixing member.
Claim 3
Dependent Claim 28 words
2 . The fixing apparatus as claimed in claim 1 , wherein the fixing member is a fixing roller, and the structural body is a roller core metal.
Claim 4
Dependent Claim 37 words
3 . The fixing apparatus as claimed in claim 1 , wherein the fixing member is an endless fixing belt, and the structural body is a core metal of a support roller for supporting the fixing belt.
Claim 5
Dependent Claim 45 words
4 . The fixing apparatus as claimed in claim 3 , wherein the fixing belt is wrapped around a plurality of guide rollers including the support roller, and the pressure member is pressed against at least one of the guide rollers via the fixing belt.
Claim 6
Dependent Claim 53 words
5 . The fixing apparatus as claimed in claim 1 , wherein the spacer is disposed at both end portions of the separating member in an orthogonal direction to a paper conveyance direction of the fixing apparatus such that the spacer contacts the structural body at both end portions of the separating member.
Claim 7
Dependent Claim 49 words
6 . The fixing apparatus as claimed in claim 3 , wherein the fixing member or the support roller comprises an elastic layer, and the structural body comprises a protruding portion which protrudes outward from end portions of the elastic layer such that the spacer contacts the protruding portion.
Claim 8
Dependent Claim 35 words
7 . The fixing apparatus as claimed in claim 1 , wherein the separating means are biased in a direction for causing a tip end side of the separating member to approach the fixing member.
Claim 9
Dependent Claim 32 words
8 . The fixing apparatus as claimed in claim 1 , wherein a tip end portion of the separating member is formed in a thin plate form or a sharp edged form.
Claim 10
Dependent Claim 53 words
9 . The fixing apparatus as claimed in claim 1 , wherein the pressure member is constituted by a plurality of guide rollers and an endless pressure belt wrapped around the plurality of guide rollers, and the fixing member is pressed against at least one of the guide rollers via the pressure belt.
Claim 11
Dependent Claim 83 words
10 . The fixing apparatus as claimed in claim 1 , wherein the separating means comprise a contact member which contacts the surface of the fixing member to separate the separating member from the fixing member, the spacer is provided so as not to contact the structural body, and when a gap between the separating member and the fixing member is G 1 and a gap between the spacer and the structural body is G 2 , G 1 >G 2 is satisfied.
Claim 12
Dependent Claim 49 words
11 . The fixing apparatus as claimed in claim 1 , wherein, when a hardness of an outer layer portion of the fixing member is B 1 and a hardness of an outer layer portion of the pressure member is B 2 , B 1 <B 2 is satisfied.
Claim 13
Dependent Claim 31 words
12 . The fixing apparatus as claimed in claim 1 , wherein the unfixed image is formed by a toner containing at least a resin, a coloring agent, and a wax.
Claim 14
Dependent Claim 121 words
13 . An image forming apparatus comprising a fixing apparatus having a fixing member that is heated by a heat source and a pressure member that is pressed against the fixing member, in which a recording material carrying an unfixed image is passed between the fixing member and the pressure member to fix the unfixed image on the recording material, the fixing apparatus further comprising separating means for separating the recording material from the fixing member following fixing, wherein the separating means comprise a separating member and a spacer attached to the separating member, and a gap between the separating member and the fixing member is maintained by bringing the spacer into contact with a structural body of the fixing member.
Claim 15
Dependent Claim 121 words
13 . An image forming apparatus comprising a fixing apparatus having a fixing member that is heated by a heat source and a pressure member that is pressed against the fixing member, in which a recording material carrying an unfixed image is passed between the fixing member and the pressure member to fix the unfixed image on the recording material, the fixing apparatus further comprising separating means for separating the recording material from the fixing member following fixing, wherein the separating means comprise a separating member and a spacer attached to the separating member, and a gap between the separating member and the fixing member is maintained by bringing the spacer into contact with a structural body of the fixing member.
Claim 16
Dependent Claim 34 words
14 . The image forming apparatus as claimed in claim 13 , wherein the image forming apparatus is a color image forming apparatus for forming an image using toner of a plurality of colors.
Claim 17
Dependent Claim 160 words
15 . An image forming method for causing a recording material to carry an image formed by a toner containing at least a resin, a coloring agent, and a wax, and fixing the toner image carried on the recording material onto the recording material using a fixing apparatus, wherein the fixing apparatus comprises a fixing member that is heated by a heat source and a pressure member that is pressed against the fixing member, and fixes an unfixed image on the recording material carrying the unfixed image by passing the recording material between the fixing member and the pressure member, the fixing apparatus further comprising separating means for separating the recording material from the fixing member following fixing, the separating means comprise a separating member and a spacer attached to the separating member, and a gap between the separating member and the fixing member is maintained by bringing the spacer into contact with a structural body of the fixing member.
Claim 18
Dependent Claim 160 words
15 . An image forming method for causing a recording material to carry an image formed by a toner containing at least a resin, a coloring agent, and a wax, and fixing the toner image carried on the recording material onto the recording material using a fixing apparatus, wherein the fixing apparatus comprises a fixing member that is heated by a heat source and a pressure member that is pressed against the fixing member, and fixes an unfixed image on the recording material carrying the unfixed image by passing the recording material between the fixing member and the pressure member, the fixing apparatus further comprising separating means for separating the recording material from the fixing member following fixing, the separating means comprise a separating member and a spacer attached to the separating member, and a gap between the separating member and the fixing member is maintained by bringing the spacer into contact with a structural body of the fixing member.

References Cited (Backward Citations)

US5465146A Cited
US6674978B1 Cited
US20030185590A1 Cited
US20070212131A1 Cited

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