US 12,455,524 B2
Fixing rotating member, fixing apparatus, and electrophotographic image forming apparatus
Matsutaka Maeda, Kanagawa (JP); Takaaki Tsuruya, Shizuoka (JP); Akira Okano, Kanagawa (JP); Makoto Souma, Kanagawa (JP); and Naoko Kasai, Kanagawa (JP)
Assigned to Canon Kabushiki Kaisha, Tokyo (JP)
Filed by CANON KABUSHIKI KAISHA, Tokyo (JP)
Filed on Oct. 20, 2023, as Appl. No. 18/490,933.
Claims priority of application No. 2022-171564 (JP), filed on Oct. 26, 2022; and application No. 2023-175062 (JP), filed on Oct. 10, 2023.
Prior Publication US 2024/0160135 A1, May 16, 2024
Int. Cl. G03G 15/20 (2006.01)
CPC G03G 15/2057 (2013.01) 7 Claims
OG exemplary drawing
 
7. An electrophotographic image forming apparatus comprising:
an image bearing member bearing a toner image;
a transfer device transferring the toner image to a recording material; and
a fixing apparatus fixing the transferred toner image to the recording material,
wherein the fixing apparatus comprises a fixing rotating member, and an induction heating device causing the fixing rotating member to generate heat by induction heating,
wherein the fixing rotating member comprises a substrate comprising a resin, an electro-conductive layer on the substrate, and a resinous layer on a surface of the electro-conductive layer, the surface being opposed to a side of the electro-conductive layer facing the substrate,
wherein the electro-conductive layer extends in a circumferential direction of an outer peripheral surface of the substrate,
wherein the electro-conductive layer comprises silver,
wherein the electro-conductive layer has, in a thickness direction thereof, a through-hole,
wherein at least a part of the through-hole is penetrated by a resin that constitutes at least a part of the resinous layer,
wherein the induction heating device has:
an excitation coil for forming an alternating magnetic field causing the electro-conductive layer to generate heat by electromagnetic induction, the excitation coil being disposed in an interior of the fixing rotating member, and having a spiral shape portion, a spiral axis of which is substantially parallel to a direction of a rotation axis of the fixing rotating member; and
a magnetic core, which is disposed within the spiral shape portion and which does not form a loop outward of the fixing rotating member to extend in the rotation axis direction, for guiding magnetic force lines of the alternating magnetic field,
wherein a material of the magnetic core is a ferromagnetic body,
wherein the electro-conductive layer generates heat mainly by an induced current induced by magnetic force lines exiting from one longitudinal end of the magnetic core, passing by an outer side of the electro-conductive layer, and returning to another longitudinal end of the magnetic core, and
wherein the electro-conductive layer has a ring shape in a circumferential direction of the fixing rotating member and is formed in plurality while electrically divided from each other in a rotation axis direction.