In an image heating device having a plurality of heating blocks which are controllable independently in a longitudinal direction of a heater, an increase of the size of the heater can be suppressed, and temperatures of a plurality of heating block can be detected. The heater has a first temperature sensor corresponding to a first heating block, a second temperature sensor corresponding to a second heating block, a first electric conductor electrically coupled to the first temperature sensor, a second electric conductor electrically coupled to the second temperature sensor, and a common electric conductor electrically coupled to the first and second temperature sensors.

A heater includes electrodes and heating element pieces. The electrodes energize the heating element pieces with electricity. The heating element pieces are connected to the electrodes and arranged through a gap portion in the heater in a main scanning direction. A ratio of a second surface area of the gap portion to a first surface area of the heating element pieces is 0<(second surface area of the gap portion)/(first surface area of the heating element pieces)≤0.5.

A heating device includes a heating unit that heats a member to be heated, which is transported, as a result of a contact portion of the heating unit being in contact with the member to be heated, a heat pipe that contacts with a portion of the heating unit different from the contact portion in such a manner as to extend in a widthwise direction crossing a transport direction of the member to be heated and that includes a crimped portion formed at a first end of the heat pipe, and a power-supply connection unit that is disposed on a second end side of the heat pipe and that is connected to a wiring line through which power is supplied to the heating unit.

According to one embodiment, a wiring structure includes a substrate, a first conductor, second conductors, a first trace, second traces, heat-generating elements, and a first protruding conductor. The second conductors are spaced apart from the first conductor in a second direction crossing a first direction and are mutually juxtaposed with spacing in the first direction. The heat-generating elements are mutually juxtaposed in the first direction and connected to the respective second conductors and the first conductor. The first protruding conductor protrudes from either of the first conductor and one of the second conductors and is connected to a first one of the heat-generating elements. The first protruding conductor is at least partly located, in the first direction, between a center of the first one of the heat-Generating elements and a center of a second one of the heat-generating elements adjacent to the first one.

A planar heater includes a base, a resister pattern, a conductor pattern, a power supply electrode, and a base pattern. The base includes a surface portion made of an insulative material. The resistor pattern is on the base. The conductor pattern is on the base and electrically coupled to the resistor pattern. The power supply electrode is electrically coupled to the conductor pattern. The base pattern is on the base and made of a material different from a material of the surface portion of the base to print visible identification information.

In an image heating device having a plurality of heating blocks which are controllable independently in a longitudinal direction of a heater, an increase of the size of the heater can be suppressed, and temperatures of a plurality of heating block can be detected.

A heater has a first temperature sensor corresponding to a first heating block, a second temperature sensor corresponding to a second heating block, a first electric conductor electrically coupled to the first temperature sensor, a second electric conductor electrically coupled to the second temperature sensor, and a common electric conductor electrically coupled to the first and second temperature sensors.

A heater includes electrodes and heating element pieces. The electrodes energize the heating element pieces with electricity. The heating element pieces are connected to the electrodes and arranged through a gap portion in the heater in a main scanning direction. A ratio of a second surface area of the gap portion to a first surface area of the heating element pieces is 0<(second surface area of the gap portion)/(first surface area of the heating element pieces)≤0.5.

A heating device includes a heating unit that heats a member to be heated, which is transported, as a result of a contact portion of the heating unit being in contact with the member to be heated, a heat pipe that contacts with a portion of the heating unit different from the contact portion in such a manner as to extend in a widthwise direction crossing a transport direction of the member to be heated and that includes a crimped portion formed at a first end of the heat pipe, and a power-supply connection unit that is disposed on a second end side of the heat pipe and that is connected to a wiring line through which power is supplied to the heating unit.

Whether a first heating region is actually a passing heating region or a non-passing heating region which a recording material does not pass through, is detected by the temperature detected by a temperature detecting portion, based on a difference between a detected temperature by a temperature detecting portion in a reference heating region, which is specified to a heating region including a conveyance reference position of the recording material, and a detected temperature in a first heating region which does not include the conveyance reference position and is specified to a passing heating region which the recording material passing through. In a case where it is determined that the first heating region is the non-passing heating region, a prevention control, to prevent overheat of the first heating region is performed in the heating processing of the recording material that passes the nip portion after the determination.

A fixing device includes a heating rotating member having a conductive layer and an exposed portion in which the conductive layer is partially exposed, and a roller including a metal core and an elastic portion, the roller forming a nip portion with the heating rotating member, the elastic portion being elastically deformed in a region where the nip portion is formed, wherein an annular conductive member provided in a longitudinal end portion of the metal core is in contact with the exposed portion of the heating rotating member while elastically deformed, and wherein in a state where the roller is not mounted to the fixing device, an outer diameter of the conductive member is smaller than an outer diameter of the elastic portion.