Fixing device and image forming apparatus
A fixing device includes a belt member that cyclically moves, a pressing unit that comes into contact with the belt member and presses a recording medium moving between the belt member and the pressing unit, and a heat source that includes a base material, a resistance heating element disposed on a surface of the base material along a longitudinal direction of the base material, and an insulator covering the resistance heating element and that comes into contact with the pressing unit via the belt member to heat an inner surface of the belt member, in which the insulator is formed to cover a corner portion of the base material in a direction of movement of the belt member.
1 . A fixing device comprising:
a belt member that cyclically moves;
a pressing unit, which comprises a pressing roller, that comes into contact with the belt member and presses a recording medium moving between the belt member and the pressing unit;
a heat source that includes a base material, a resistance heating element disposed on a surface of the base material along a longitudinal direction of the base material, and an insulator covering the resistance heating element and that comes into contact with the pressing unit via the belt member to heat an inner surface of the belt member; and
a holding member that holds the heat source,
wherein the insulator is formed to cover a corner portion of the base material in a direction of movement of the belt member,
wherein a nip portion is formed by a pressure contact region between the heat source and the pressing unit,
wherein a surface of the insulator which comes into contact with the inner surface of the belt member is flat,
wherein a portion of the holding member which is closest to the pressing unit is positioned on a side without the pressing unit relative to the nip portion,
wherein a rear end of the nip portion is positioned further downstream side in the direction of movement of the belt member relative to a rear end of the insulator.
2 . The fixing device according to claim 1 ,
wherein the insulator is formed to cover a side portion of the base material in a thickness direction.
3 . The fixing device according to claim 2 ,
wherein the inner surface of the belt member comes into contact with the corner portion of the base material via the insulator on a downstream side in the direction of movement.
4 . An image forming apparatus comprising:
an image forming unit that forms an image on a recording medium and that comprises a photoreceptor drum; and
the fixing device according to claim 3 that fixes the image to the recording medium on which the image has been formed by the image forming unit.
5 . An image forming apparatus comprising:
an image forming unit that forms an image on a recording medium and that comprises a photoreceptor drum; and
the fixing device according to claim 2 that fixes the image to the recording medium on which the image has been formed by the image forming unit.
6 . The fixing device according to claim 1 ,
wherein the inner surface of the belt member comes into contact with the corner portion of the base material via the insulator on a downstream side in the direction of movement.
7 . An image forming apparatus comprising:
an image forming unit that forms an image on a recording medium and that comprises a photoreceptor drum; and
the fixing device according to claim 6 that fixes the image to the recording medium on which the image has been formed by the image forming unit.
8 . An image forming apparatus comprising:
an image forming unit that forms an image on a recording medium and that comprises a photoreceptor drum; and
the fixing device according to claim 1 that fixes the image to the recording medium on which the image has been formed by the image forming unit.