Fuser device and image forming apparatus provided with same
AssigneeKYOCERA Document Solutions Inc.
InventorsSatoshi Ishii, Shogo Usui
Life of this patent
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Abstract
A magnetic core surrounds a coil and has a plurality of first core sections arrayed along the widthwise direction of a recording medium orthogonally to the conveyance direction of the recording medium, and a second core section disposed at both ends in the widthwise direction within a hollow section of the coil. The second core section is formed so that the cross-sectional area thereof in the conveyance direction of the recording medium grows progressively larger from the center of the widthwise direction towards the end thereof.
Claims8
A fuser device comprising:
- a heating member;
- a pressure-applying member configured to clamp, in a space bounded on one side by the heating member, a recording medium that bears an unfused toner image, and to form a nip where the unfused toner image on the recording medium is melted and fused, by causing the pressure-applying member to press against the heating member;
- a coil for generating a magnetic flux for inductively heating the heating member, the coil being looped around the heating member along the lengthwise direction thereof;
- and
- a magnetic core, disposed near the coil, configured to guide the magnetic flux to the inductive heat-generating layer of the heating member, the core having:
- a first core section surrounding the coil and disposed along the widthwise direction of the recording medium orthogonally to the direction of conveyance of the recording medium;
- and
- a second core section disposed only at both ends in the widthwise direction within a hollow area which the loop of the coil forms, the second core section being formed so that the cross-sectional area thereof in the conveyance direction of the recording medium grows progressively larger from the center of the widthwise direction towards the ends,
- wherein the second core section is an only magnetic member provided inside the hollow area.
An image forming apparatus provided with an image forming unit configured to electrolithographically form a toner image on a recording medium, and a fuser device configured to melt and fuse the toner image formed on the recording medium to the recording medium;
- the fuser device comprising:
- a heating member;
- a pressure-applying member for clamping, in a space bounded on one side by the heating member, a recording medium that bears an unfused toner image, and forming a nip where the unfused toner image on the recording medium is melted and fused, by causing the pressure-applying member to press against the heating member;
- a coil for generating a magnetic flux for inductively heating the heating member, the coil being looped around the heating member along the lengthwise direction thereof;
- and
- a magnetic core, disposed near the coil, for guiding the magnetic flux to the inductive heat-generating layer of the heating member, the core comprising:
- a first core section surrounding the coil and disposed in the widthwise direction of the recording medium orthogonally to the direction of conveyance of the recording medium;
- and
- a second core section disposed only at both ends in the widthwise direction within a hollow area which the loop of the coil forms, the second core section being formed so that the cross-sectional area thereof in the conveyance direction of the recording medium grows progressively larger from the center of the widthwise direction towards the ends,
- wherein the second core section is an only magnetic member provided inside the hollow area.
Dependencies are inferred from the claim text.