Fixing rotating member, fixing device, electrophotographic image forming apparatus, and method for manufacturing fixing rotating member
AssigneeCanon Kabushiki Kaisha
InventorsMakoto Souma, Matsutaka Maeda, Akira Okano, Naoko Kasai, Takaaki Tsuruya
Life of this patent
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Abstract
A fixing rotating member comprising: a base material and an electro-conductive layer on the base material; the electro-conductive layer extending in a circumferential direction of an outer peripheral surface of the base material, the electro-conductive layer comprising silver, an average crystal grain size of crystals of the silver observed in a cross section along a circumferential direction of the electro-conductive layer being 20 to 200 nm, and the electro-conductive layer having a volume resistivity of 1.0×10−8 to 8.0×10−8 Ω·m.
Claims9
A fixing device comprising:
- a fixing rotating member;
- and
- an induction heating device that causes the fixing rotating member to generate heat by induction heating,
- wherein the fixing rotating member comprises a base material and an electro-conductive layer on the base material,
- wherein the electro-conductive layer comprises heat generating rings, which are electrically connected in a circumferential direction of an outer peripheral surface of the base material and electrically divided in a longitudinal direction, and which are aligned in the longitudinal direction,
- wherein the electro-conductive layer comprises silver,
- wherein an average crystal grain size of crystals of the silver observed in a cross section along a circumferential direction of the electro-conductive layer is 20 to 200 nm,
- wherein the electro-conductive layer has a volume resistivity of 1.0×10−8 to 8.0×10−8 Ω·m, and
- wherein the induction heating device comprises:
- an excitation coil that is arranged inside the fixing rotating member and has a helical portion with a helical axis substantially parallel to a direction along a rotation axis of the fixing rotating member, the excitation coil serving to form an alternating magnetic field for causing the electro-conductive layer to generate heat by electromagnetic induction;
- and
- a magnetic core arranged in the helical portion and extending in the rotation axis direction so as not to form a loop outside the fixing rotating member, the magnetic core serving to guide lines of magnetic force of the alternating magnetic field,
- wherein the magnetic core is made of a ferromagnetic material, and
- wherein heat is mainly generated in the electro-conductive layer by an induced current induced by lines of magnetic force that exit from one longitudinal end of the magnetic core, pass outside the electro-conductive layer, and return to the other longitudinal end of the magnetic core.
An electrophotographic image forming apparatus, the electrophotographic image forming apparatus comprising:
- an image bearing member that bears a toner image;
- a transfer device that transfers the toner image onto a recording material;
- and
- a fixing device that fixes the transferred toner image onto the recording material,
- wherein the fixing device comprises a fixing rotating member and an induction heating device that causes the fixing rotating member to generate heat by induction heating,
- wherein the fixing rotating member comprises a base material and an electro-conductive layer on the base material,
- wherein the electro-conductive layer comprises heat generating rings, which are electrically connected in a circumferential direction of an outer peripheral surface of the base material and electrically divided in a longitudinal direction, and which are aligned in the longitudinal direction,
- wherein the electro-conductive layer comprises silver,
- wherein an average crystal grain size of crystals of the silver observed in a cross section along a circumferential direction of the electro-conductive layer is 20 to 200 nm, and
- wherein the electro-conductive layer has a volume resistivity of 1.0×10−8 to 8.0×10−8 Ω·m.
Dependencies are inferred from the claim text.