US 12,332,588 B2
Image heating device having heating element groups and safety elements for shutting off power to the heating element groups
Takashi Honke, Shizuoka (JP)
Assigned to Canon Kabushiki Kaisha, Tokyo (JP)
Filed by Canon Kabushiki Kaisha, Tokyo (JP)
Filed on Feb. 16, 2023, as Appl. No. 18/170,132.
Claims priority of application No. 2022-025647 (JP), filed on Feb. 22, 2022.
Prior Publication US 2023/0266700 A1, Aug. 24, 2023
Int. Cl. G03G 15/20 (2006.01); G03G 15/00 (2006.01)
CPC G03G 15/2039 (2013.01) [G03G 15/2042 (2013.01); G03G 15/2053 (2013.01); G03G 15/80 (2013.01); G03G 2215/2035 (2013.01)] 16 Claims
OG exemplary drawing
 
1. An image heating device comprising:
a heater having a plurality of heating elements arranged in a width direction of a recording material that is perpendicular to a conveyance direction of the recording material;
a nip forming portion that forms a nip where the recording material is nipped; and
a control portion that controls power supplied to the plurality of heating elements,
wherein the image heating device heats an image formed on the recording material, which is nipped in the nip, by heat from the heater;
wherein the plurality of heating elements include a first heating element group, a second heating element group, and a central heating element, the first heating element group being arranged symmetrically with respect to a conveyance reference position of the recording material in the width direction, the second heating element group being arranged symmetrically with respect to the conveyance reference position so as to be adjacent to the first heating element group in the width direction, and the central heating element being arranged in an area of the conveyance reference position,
wherein the control portion supplies power to the first heating element group through a first common circuit, supplies power to the second heating element group through a second common circuit, and supplies power to the central heating element through a circuit for the central heating element,
wherein the image heating device includes a first safety element for shutting off the power supply to the first heating element group, the second heating element group, and the central heating element, and a second safety element for shutting off the power supply to the first heating element group, the second heating element group, and the central heating element,
wherein the first safety element is arranged at a position corresponding to the first heating element group, and is arranged on one side with respect to the conveyance reference position in the width direction,
wherein the second safety element is arranged at a position corresponding to the second heating element group and is arranged on the other side with respect to the conveyance reference position in the width direction,
wherein only one first safety element is disposed at a position that satisfies both the position corresponding to the first heating element group and the position on the one side in the width direction,
wherein the first safety element is the only one first safety element,
wherein only one second safety element is disposed at a position that satisfies both the position corresponding to the second heating element group and the position on the other side in the width direction,
wherein the second safety element is the only one second safety element, and
wherein with respect to the width direction, a distance between the conveyance reference and the first safety element is smaller than a distance between the conveyance reference and the second safety element.