Back to results
US 5,450,181 AGranted
Fixing device
AssigneeCanon Kabushiki Kaisha
InventorsShinichi Tsukida, Koichi Tanigawa, Masahiro Goto, Hiromichi Tsujii, Satoru Izawa
Life of this patent
Estimating the term…
Abstract
In a fixing device, a core material of a fixing rotating member has two largest-diameter portions respectively located between a central portion and each end portion of the fixing rotating member, within a region where a recording material of a largest size passes, and the diameter of each core material is gradually reduced from the largest-diameter portion toward the central portion and toward the nearest end portion. The outer shape of the fixing rotating member conforms to the shape of the core material. According to this configuration, it is possible to prevent corrugation and curl of the recording material, and to provide excellent mountability of the recording material.
Claims49
A fixing device comprising:
- a fixing rotating member comprising a core material and a resin layer provided thereon;
- and
- a pressing rotating member comprising a rubber layer for forming a nip with said fixing rotating member,
- wherein a fixing operation is performed by grasping and conveying a recording material carrying an unfixed image by the nip,
- wherein said core material of said fixing rotating member has two largest-diameter portions respectively located between a central portion and each end portion of said fixing rotating member, within a region where a recording material of a largest size passes, and the diameter of the core material is gradually reduced from each largest-diameter portion toward the central portion and toward the nearest end portion, and
- wherein the outer shape of said fixing rotating member conforms to the shape of said core material.
3 more elements
A fixing device comprising:
- a fixing rotating member for contacting an unfixed image;
- and
- a pressing rotating member, having a hardness less than the hardness of said fixing rotating member, for forming a nip with said fixing rotating member,
- wherein a fixing operation is performed by grasping and conveying a recording material carrying the unfixed image by the nip,
- wherein said fixing rotating member has two largest-diameter portions respectively located between a central portion and each end portion of said fixing rotating member, within a region where a recording material of a largest size passes, and the diameter of said fixing rotating member is gradually reduced from each largest-diameter portion toward the central portion and toward the nearest end portion, and
- wherein said pressing rotating member has one of a substantially straight shape and a substantially inverse-crown shape.
3 more elements
A fixing device comprising:
- a fixing rotating member for contacting an unfixed image;
- and
- a pressing rotating member, having a hardness less than the hardness of said fixing rotating member, for forming a nip with said fixing rotating member,
- wherein a fixing operation is performed by grasping and conveying a recording material carrying the unfixed image by the nip,
- wherein said fixing rotating member has two largest-diameter portions respectively located between a central portion and each end portion of said fixing rotating member, within a region where a recording material of a largest size passes, and the diameter of said fixing rotating member is gradually reduced from each largest-diameter portion toward the central portion and toward the nearest end portion, and
- wherein the hardness of said pressing rotating member is at least 30.degree. and equal to or less than 70.degree..
3 more elements
A fixing device comprising:
- a fixing rotating member for contacting an unfixed image;
- and
- a pressing rotating member, having a hardness less than the hardness of said fixing rotating member, for forming a nip with said fixing rotating member,
- wherein a fixing operation is performed by grasping and conveying a recording material carrying the unfixed image by the nip,
- wherein said fixing rotating member has two largest-diameter portions respectively located between a central portion and each end portion of said fixing rotating member, within a region where a recording material of a largest size passes, and the diameter of said fixing rotating member is gradually reduced from each largest-diameter portion toward the central portion and toward the nearest end portion, and wherein the outer diameter of said fixing rotating member is equal to or less than 30 mm.
2 more elements
A fixing device comprising:
- a fixing rotating member for contacting an unfixed image;
- and
- a pressing rotating member for forming a nip with said fixing rotating member,
- wherein a fixing operation is performed by grasping and conveying a recording material carrying the unfixed image by the nip,
- wherein said fixing rotating member has two largest-diameter portions respectively located between a central portion and each end portion of said fixing rotating member, within a region where a recording material of a largest size passes, and the diameter of said fixing rotating member is gradually reduced from each largest-diameter portion toward the central portion and toward the nearest end portion, and
- wherein the inclination of said fixing rotating member from each largest-diameter portion toward the nearest end portion is at least 0.02 and equal to or less than 0.2.
3 more elements
A fixing device comprising:
- a fixing rotating member for contacting an unfixed image;
- and
- a pressing rotating member for forming a nip with said fixing rotating member,
- wherein a fixing operation is performed by grasping and conveying a recording material carrying the unfixed image by the nip,
- wherein said fixing rotating member has two largest-diameter portions respectively located between a central portion and each end portion of said fixing rotating member, within a region where a recording material of a largest size passes, and the diameter of said fixing rotating member is gradually reduced from each largest-diameter portion toward the central portion and toward the nearest end portion, and
- wherein the inclination of said fixing rotating member from each largest-diameter portion toward the nearest end portion is at least 20 times and equal to or less than 300 times the inclination of said fixing rotating member from each largest-diameter portion toward the central portion.
3 more elements
A fixing device comprising:
- a fixing rotating member for contacting an unfixed image;
- and
- a pressing rotating member for forming a nip with said fixing rotating member,
- wherein a fixing operation is performed by grasping and conveying a recording material carrying the unfixed image by the nip,
- wherein said fixing rotating member has two largest-diameter portions respectively located between a central portion and each end portion of said fixing rotating member, within a region where a recording material of a largest size passes, and the diameter of said fixing rotating member is gradually reduced from each largest-diameter portion toward the central portion and toward the nearest end portion, and
- wherein the inclination of said fixing rotating member from each largest-diameter portion toward the nearest end portion is constant or increases toward the nearest end portion.
3 more elements
A fixing device comprising:
- a fixing rotating member for contacting an unfixed image;
- and
- a pressing rotating member for forming a nip with said fixing rotating member,
- wherein a fixing operation is performed by grasping and conveying a recording material carrying the unfixed image by the nip, and
- wherein the diameter of said fixing rotating member is gradually reduced, in a direction toward a nearest end portion of said fixing rotating member, at each portion corresponding to a region where an end portion of one of a plurality of recording materials having different sizes passes through the nip.
2 more elements
A fixing device comprising:
- a fixing rotating member for contacting an unfixed image;
- and
- a pressing rotating member for forming a nip with said fixing rotating member,
- wherein a fixing operation is performed by grasping and conveying a recording material carrying the unfixed image by the nip,
- wherein said fixing rotating member has two largest-diameter portions respectively located between a central portion and each end portion of said fixing rotating member, within a region where a recording material of a largest size passes, and the diameter of said fixing rotating member is gradually reduced from each largest-diameter portion toward the central portion and toward the nearest end portion, and
- wherein the diameter at predetermined portions of said pressing rotating member decreases toward the nearest end portion of said pressing rotating member.
3 more elements
An image fixing apparatus comprising:
- a heater;
- a movable film in contact with said heater and movable together with a recording material carrying an image to be fixed;
- and
- a pressing member for forming a nip with said heater through said film,
- wherein said heater is gradually separated from said pressing member in a direction toward a nearest end portion of said heater at the positions corresponding to the ends of the recording material.
2 more elements
An image fixing apparatus comprising:
- a heater;
- a movable film in contact with said heater and movable together with a recording material carrying an image to be fixed;
- and
- a pressing member for forming a nip with said heater through said film,
- wherein the width of said heater is gradually reduced toward a nearest end portion of said heater at the positions corresponding to the ends of the recording material.
2 more elements
Dependencies are inferred from the claim text.