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US 6,122,479 AGranted
Fixing device for an image forming apparatus and fixing roller for the same
AssigneeRicoh Company, Ltd.
InventorsTakashi Fujita, Hiroshi Wada, Shigeharu Nakamura
Life of this patent
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Abstract
In a fixing device for an image forming apparatus, a heat roller includes a hollow cylindrical base, a heating layer formed of strip-like fibers implementing desired power consumption, and a parting layer provided on the outer periphery of the heating layer with the intermediary of an electrical insulating layer. The strip-like fibers of the heating layer are wound on the base and provided with a preselected resistance.
Claims48
A heat roller using a direct heating system, comprising:
- a hollow cylindrical base;
- a parting layer;
- and
- a heating layer comprising a heating body constituted by strip-like fibers, said heating body extending linearly or helically;
- wherein a resistance R of said heating body and a heating area W.multidot.L of said heating layer for implementing desired power consumption are expressed as:
- R=Rs.multidot.L/W
- [W.multidot.L=2.pi.Rl]W.multidot.L=2.pi.rl
- where Rs, L and W respectively denote a surface resistance, a length and a width of said heating body, .pi. denotes a ratio of a circumference of a circle to a diameter, r denotes a radius of said heating layer, and l denotes a length of said heating layer in an axial direction of said heat roller.
5 more elements
A heat roller using a direct heating system, comprising:
- a hollow cylindrical base;
- a parting layer;
- and
- a heating layer comprising a strip-like heating body consisting at least of fibers and formed with electrodes on both ends thereof, said heating body extending helically or linearly in an axial direction of said heat roller, said fibers intersecting said axial direction at an angle .theta. satisfying a condition:
- .theta.=cos.sup.-1 (lRs/2.pi.rR).sup.1/2
- where l denotes a length of said heating layer in said axial direction, Rs denotes a surface resistance of said heating body, .pi. denotes a ratio of a circumference of a circle to a diameter, r denotes a radius of said heating layer, and R denotes a resistance of said heating body.
3 more elements
A fixing device comprising:
- a hollow cylindrical heat roller;
- and
- a freely rotatable press roller held in pressing contact with said heat roller;
- said heat roller comprising:
- a hollow cylindrical base having a thin wall and a small heat capacity;
- a separating layer formed on an outer periphery of said base;
- and
- at least an electrical insulating layer and a heating layer laminated on an inner periphery of said base, said heating layer extending helically and comprising carbon fibers having an electric resistance,
- wherein said base is formed of aluminum with an Alumite layer formed on an inner periphery thereof.
6 more elements
A fixing device comprising:
- a hollow cylindrical heat roller;
- and
- a freely rotatable press roller held in pressing contact with said heat roller;
- said heat roller comprising:
- a hollow cylindrical base having a thin wall and a small heat capacity;
- a parting layer formed on an outer periphery of said base;
- and
- an electrical insulating layer formed of a fiber reinforced composite material and a heating layer consisting of carbon fibers, said electrical insulating layer and said heating layer laminated on an inner periphery of said base;
- wherein fibers of said fiber reinforced composite material extend in a same direction as an axial direction of said base while carbon fibers constituting said heating layer intersect said fibers of said fiber reinforced composite material.
6 more elements
A heat roller for a fixing device, comprising:
- a hollow cylindrical base having a thin wall and a small heat capacity;
- at least an electrical insulating layer and a heating layer extending helically on an inner periphery of said insulating layer and comprising carbon fibers having an electric resistance;
- and
- a parting layer formed on an outer periphery of said base,
- wherein said base is formed of aluminum with an Alumite layer precipitated on an inner periphery thereof serving as said insulating layer.
2 more elements
A heat roller for a fixing device, comprising:
- a hollow cylindrical base having a thin wall and a small heat capacity;
- an electrical insulating layer formed on an inner periphery of said base and comprising a fiber reinforced composite material;
- a heating layer comprising carbon fibers and extending on said insulating layer helically in an axial direction of said base;
- and
- a parting layer formed on an outer periphery of said base,
- wherein said base is formed of aluminum with an Alumite layer precipitated on an inner periphery thereof serving as said insulating layer.
3 more elements
A heat roller for a fixing device, comprising:
- a hollow cylindrical base having a thin wall and a small heat capacity;
- a parting layer formed on an outer periphery of said base;
- and
- an electrical insulating layer and a heating layer laminated on an inner periphery of said base;
- wherein fibers of a fiber reinforced composite material forming said insulating layer extend in a same direction as an axial direction of said base, while carbon fibers forming said heating layer intersect said fibers of said fiber reinforced composite material.
2 more elements
A fixing apparatus comprising:
- a hollow cylindrical heating means for applying heat to a fixing object;
- and
- a freely rotatable pressing means, held in pressing contact with said heating means, for applying pressure to said fixing object;
- said heating means comprising:
- a hollow cylindrical base having a thin wall and a small heat capacity;
- a separating layer formed on an outer periphery of said base;
- and
- at least an electrical insulating layer and a heating layer laminated on an inner periphery of said base, said heating layer extending helically and comprising carbon fibers having an electric resistance,
- wherein said base is formed of aluminum with an Alumite layer formed on an inner periphery thereof.
6 more elements
A fixing apparatus comprising:
- a hollow cylindrical heating means for applying heat to a fixing object;
- and
- a freely rotatable pressing means, held in pressing contact with said heating means, for applying pressure to said fixing object;
- said heating means comprising:
- a hollow cylindrical base having a thin wall and a small heat capacity;
- a parting layer formed on an outer periphery of said base;
- and
- an electrical insulating layer formed of a fiber reinforced composite material and a heating layer consisting of carbon fibers, said electrical insulating layer and said heating layer laminated on an inner periphery of said base;
- wherein fibers of said fiber reinforced composite material extend in a same direction as an axial direction of said base while carbon fibers constituting said heating layer intersect said fibers of said fiber reinforced composite material.
6 more elements
A heating means for a fixing apparatus, comprising:
- a hollow cylindrical base having a thin wall and a small heat capacity;
- at least an electrical insulating layer and a heating layer extending helically on an inner periphery of said insulating layer and comprising carbon fibers having an electric resistance;
- and
- a parting layer formed on an outer periphery of said base,
- wherein said base is formed of aluminum with an Alumite layer precipitated on an inner periphery thereof serving as said insulating layer.
2 more elements
A heating means for a fixing apparatus, comprising:
- a hollow cylindrical base having a thin wall and a small heat capacity;
- an electrical insulating layer formed on an inner periphery of said base and comprising a fiber reinforced composite material;
- a heating layer comprising carbon fibers and extending on said insulating layer helically in an axial direction of said base;
- and
- a parting layer formed on an outer periphery of said base,
- wherein said base is formed of aluminum with an Alumite layer precipitated on an inner periphery thereof serving as said insulating layer.
3 more elements
A heating means for a fixing apparatus, comprising:
- a hollow cylindrical base having a thin wall and a small heat capacity;
- a parting layer formed on an outer periphery of said base;
- and
- an electrical insulating layer and a heating layer laminated on an inner periphery of said base;
- wherein fibers of a fiber reinforced composite material forming said insulating layer extend in a same direction as an axial direction of said base, while carbon fibers forming said heating layer intersect said fibers of said fiber reinforced composite material.
2 more elements
Dependencies are inferred from the claim text.