An image heating apparatus includes an endless belt, a rotary member configured to form a nip portion with the endless belt, regulating members for regulating the endless belt from moving in a longitudinal direction by being in contact with longitudinal ends of the endless belt, and a sheet-like heating member. The heating member includes a heat transfer member in contact with the inner surface of the endless belt, and a heating portion located on an opposite side from a side, of the heating member, in contact with the inner surface of the endless belt across the heat transfer member. Both end portions of the heat transfer member are disposed at the same location or outside of both end portions of the heating portion in the longitudinal direction and are disposed inside of both end portions of the rotary member in the longitudinal direction.

An image heating apparatus includes an endless belt, a rotary member configured to form a nip portion with the endless belt, regulating members for regulating the endless belt from moving in a longitudinal direction by being in contact with longitudinal ends of the endless belt, and a sheet-like heating member. The heating member includes a heat transfer member in contact with the inner surface of the endless belt, and a heating portion located on an opposite side from a side, of the heating member, in contact with the inner surface of the endless belt across the heat transfer member. Both end portions of the heat transfer member are disposed at the same location or outside of both end portions of the heating portion in the longitudinal direction and are disposed inside of both end portions of the rotary member in the longitudinal direction.

A heating apparatus includes a heater, a holding member, and a heat equalization member. In a case where a direction of a long side of a first surface of the heater is defined as a longitudinal direction, a direction of the first surface perpendicular to the longitudinal direction is defined as a transverse direction, and a direction perpendicular to the longitudinal direction and the transverse direction is defined as a thickness direction, the heat equalization member is between the heater and the holding member in the thickness direction and includes, in the longitudinal direction, first and second abutment regions that abut against the heater and a first non-abutment region that does not abut against the heater. The first abutment region, the first non-abutment region, and the second abutment region are arranged in this order as viewed from one end toward another end of the heater in the longitudinal direction.

An image heating apparatus includes an image heating portion including first, second, and third heat generating blocks divided in a direction orthogonal to a conveying direction of the recording material. The image heating apparatus also includes a first driving circuit, a second driving circuit, a first temperature detection member, and a second temperature detection member. A control portion controls the first and second driving circuits according to at least one of the temperatures detected by the first and second temperature detection members, and controls energization of the second heat generating block together with a heat generating block that is energized by a driving circuit connected to the second heat generating block. In addition, a connection switching portion selectively connects any one of the first and second driving circuits to the second heat generating block according to a switching instruction from the control portion.

A fixing device includes an endless belt; a pressing unit that is in contact with an outer peripheral surface of the belt and that rotates the belt; a first unit that is provided on an inner peripheral surface of the belt and that retains the belt in contact with the pressing unit; a second unit provided on the inner peripheral surface of the belt and located downstream of the first unit in a rotation direction of the belt, the second unit applying tension to the belt and including a portion that is in contact with a central portion of the belt in a width direction of the belt and that is farther in a direction toward the outer peripheral surface of the belt than both ends of the belt in the width direction of the belt; and a third unit provided on the inner peripheral surface of the belt and located downstream of the second unit in the rotation direction of the belt, the third unit applying tension to the belt and including a portion that is in contact with the central portion of the belt in the width direction of the belt and that is farther in the direction toward the outer peripheral surface of the belt than both ends of the belt in the width direction of the belt.

A fixing device includes an endless belt, a rotatable pressing member, a pad member inside of the belt, and a sliding member held by the pad member and sliding on an inner circumferential surface of the belt in a nip. The rotatable pressing member nips and feeds a recording material in the nip in cooperation with the belt and fixes a toner image on the recording material by applying heat and pressure. The sliding member includes a base material layer on which a plurality of projections projecting toward the rotatable pressing member are formed on a side sliding with the belt and a sliding layer provided on an outer surface of the plurality of projections. A leading end of the plurality of projections is a plane and an average roughness (Ra) of the plane satisfies 0.13 ?m?Ra?1.67 ?m.

A belt deviation correction device for correcting a deviation of an endless belt wound around a plurality of rollers includes a pressing roller that is pressed from outside the endless belt wound around the plurality of rollers. The pressing roller is configured to swing in such a way as to be inclined with respect to the plurality of rollers. A deviation of the endless belt in a direction of an axis of rotation of the plurality of rollers is corrected by swinging the pressing roller.

A heating device includes a base, resistance heating elements, a power control circuit, a first temperature detector, a second temperature detector, a power interrupter, and control circuitry. The resistance heating elements are arranged in a longitudinal direction of the base and electrically connected in parallel. The first detector detects a temperature of a first resistance heating element. The second detector detects a temperature of a second resistance heating element. The power interrupter interrupts power supplied to the resistance heating elements when the temperature of the second resistance heating element becomes a predetermined temperature or more. The control circuitry controls the circuit such that a temperature of each resistance heating element becomes a predetermined temperature, based on a result of detection of the first detector, and interrupts the power supplied to the resistance heating elements when the second detector detects predetermined temperature information regarding the second resistance heating element.

A heating device includes a base, a plurality of resistance heating elements, a power control circuit, a first temperature sensor, a second temperature sensor, and control circuitry. The resistance heating elements is disposed in a longitudinal direction of the base and electrically connected in parallel with each other. The power control circuit is configured to supply electrical power to the resistance heating elements. The control circuitry is configured to control an electrical power amount of the power control circuit so that temperatures of the resistance heating elements become equal to a first predetermined temperature based on a result of sensing with a first temperature sensor of the resistance heating elements and cut off the electrical power supplied from the power control circuit to the resistance heating elements in response to sensing of a second predetermined temperature with a second temperature sensor of the resistance heating elements.

A heating device includes an elongated heater, a first holding member configured to hold the heater, a power shut-off member configured to shut off power supply to the heater, a second holding member configured to hold the power shut-off member, a first urging member configured to press the power shut-off member against the heater, and a regulation member configured to regulate a position of the second holding member, wherein, in a longitudinal direction of the heater, one end side of the second holding member is urged by the first urging member, and another end side of the second holding member is regulated in position by the regulation member.