Heating device, fixing device, and image forming apparatus

Abstract

To prevent an increase in the temperature of a conductive member in an area where the temperature is likely to increase compared with the other area.SOLUTION: A heating device comprises: a pair of rotating bodies 21, 22 that are in contact with each other to form a nip part for passing a sheet; a heat source 23 that heats at least one of the pair of rotating bodies 21, 22; a heat source holding member 24 that holds the heat source 23; a temperature detection member 27 that detects the temperature of the heat source 23; and a conductive member 44 that has flexibility and is connected to the temperature detection member 27. The heat source holding member 24 has a conductive member support part 30 that supports the conductive member 44 on a surface 240 opposite to a surface 241 holding the heat source 23. The conductive member support part 30 supports the conductive member 44 in at least partial area outside a predetermined width W2 of the heat source holding member 24 so as to increase the distance from the conductive member 44 to the heat source 23 compared with an area inside the predetermined width W2.SELECTED DRAWING: Figure 6

Claims

[Claim 1] A pair of rotating bodies that come into contact with each other to form a nip portion through which the sheet passes, A heating source for heating at least one of the pair of rotating bodies, A heat source holding member that holds the aforementioned heat source, A temperature sensing member for detecting the temperature of the heating source, A flexible conductive member connected to the temperature sensing member, A heating device comprising, The heating source holding member has a plurality of conductive member support portions that protrude from the side opposite to the side that holds the heating source and support the conductive member, A heating device characterized in that, of the plurality of conductive member support portions, at least some of the conductive member support portions that are located outside a predetermined width have a greater height in the protruding direction from the heating source holding member than the other conductive member support portions. [Claim 2] A pair of rotating bodies that come into contact with each other to form a nip portion through which the sheet passes, A heating source for heating at least one of the pair of rotating bodies, A heat source holding member that holds the aforementioned heat source, A temperature sensing member for detecting the temperature of the heating source, A flexible conductive member connected to the temperature sensing member, A heating device comprising, The heating source holding member has a plurality of conductive member support portions that protrude from the side opposite to the side that holds the heating source and support the conductive member, A heating device characterized in that, among the plurality of conductive member support portions, the spacing in the sheet width direction between at least some of the conductive member support portions that are arranged outside a predetermined width is smaller than the spacing in the sheet width direction between the other conductive member support portions. [Claim 3] The heating device according to claim 1 or 2, wherein the predetermined width is the minimum sheet passage width. [Claim 4] The heating source has a plurality of heating elements arranged at intervals in the sheet width direction, The heating device according to claim 1 or 2, wherein the conductive member support portion is arranged to overlap the region between the heating elements in the sheet width direction. [Claim 5] The conductive member support portion protrudes from the side of the heating source holding member opposite to the side that holds the heating source, The heating device according to claim 1 or 2, wherein the height of the conductive member support portion in the direction protruding from the heating source holding member is higher than the position where the conductive member is connected to the temperature sensing member. [Claim 6] The conductive member support portion protrudes from the side of the heating source holding member opposite to the side that holds the heating source, The heating source has a heating element in the center of the heating source in the sheet transport direction. The heating device according to claim 1 or 2, wherein the conductive member support portion supports the conductive member at a position offset from the center of the heating source in the sheet conveying direction. [Claim 7] The conductive member support portion protrudes from the side of the heating source holding member opposite to the side that holds the heating source, The heating device according to claim 6, wherein the height of the conductive member support portion in the protruding direction from the heating source holding member is higher at the center of the conductive member support portion in the sheet conveying direction than at both ends in the sheet conveying direction. [Claim 8] comprising a support member that supports the heating source holding member, The heating device according to claim 1 or 2, wherein a low thermal conductivity member having a lower thermal conductivity than the support member is arranged between the support member and the conductive member. [Claim 9] A fixing device characterized by fixing an unfixed image onto a sheet using the heating device described in Claim 1 or 2. [Claim 10] An image forming apparatus characterized by comprising the heating device described in Claim 1 or 2.

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