An image processing apparatus includes an image forming unit configured to form an image on a sheet, a heating device including a belt that contacts the sheet and a plurality of heating elements for heating the belt, a pressure roller configured to press the sheet against the belt, a voltage detection circuit configured to measure a voltage applied to the heating elements, and a controller configured to determine whether at least one of the heating elements is abnormal according to a voltage drop value that is based on voltages measured by the voltage detection unit before and after the plurality of heating elements is energized.

A fixing device includes a fixing belt and an opposed rotator to press against a nip formation pad via the fixing belt to form a fixing nip between the fixing belt and the opposed rotator. A primary heater and a secondary heater heat the fixing belt. The secondary heater includes a lateral end heat generator. The nip formation pad includes a base and at least one thermal conductor being interposed between the base and the fixing nip and having a thermal conductivity greater than a thermal conductivity of the base. The at least one thermal conductor includes an outboard edge disposed between an inboard edge and an outboard edge of the lateral end heat generator and disposed outboard from a conveyance span of the fixing belt in an axial direction of the fixing belt, where a recording medium is conveyed over the fixing belt.

A fixing device includes a fixing rotator being rotatable and a heater to heat the fixing rotator. The heater includes a tube, a heat generator, disposed inside the tube, to generate heat, and a sealing portion, disposed at each lateral end of the tube in a longitudinal direction of the heater, to seal the tube. The sealing portion includes an inboard edge. A reflector reflects heat radiated from the heater toward the fixing rotator. The reflector includes an outboard edge being disposed inboard from the inboard edge of the sealing portion in an axial direction of the fixing rotator.

A heating unit includes a rotating cylinder rotating about an axis parallel to a first direction. A heater having a width in a second direction is on the inner surface of the cylinder. A support member holds the heater fixed relative to the cylinder and includes an upstream member adjacent to the heater in the second direction and a downstream member adjacent to the heater in the second direction. The support member has upstream ribs on the upstream member and downstream ribs on the downstream member, each rib having a curved shape facing the inner surface of the rotating cylinder and being spaced from each other in the first direction. The heating unit may include, in some examples, a stay supporting the support member, a guide member on the stay, and a temperature sensor.

An fixing device comprises a heating member, a first heater, a second heater, and the heating member, a first temperature detector, a second temperature detector, and a controller configured to control energization to the first heater and the second heater based on an energization pattern for each control period. In a case where a length of the control period is T, a length of a period during which a first continuous energization control is T1, and a length of a period during which a second continuous energization control is T2, when a first condition represented by T1+T2<T is satisfied, the controller starts the second continuous energization control just after an end of the first continuous energization control.

An image forming apparatus includes a fixing device and a control unit. The fixing device includes a heating resistor formed of a positive temperature coefficient material. The control unit energizes the heating resistor with a first energization amount if a temperature of the heating resistor is lower than a predetermined temperature, and energizes the heating resistor with a second energization amount that is higher than the first energization amount if the temperature of the heating resistor is higher than the predetermined temperature.

A fuser configured to nip a sheet by a heating member and a pressurizing member and to thermally fix an image formed in a toner on the sheet, is provided. The fuser includes a supporting member, a temperature sensor, and a sensor cover. The supporting member supports the heating member. The temperature sensor is attached to the supporting member and is configured to detect a temperature of the heating member without contacting the heating member. The sensor cover is located on a side of the temperature sensor opposite to the heating member to cover the temperature sensor. The sensor cover includes a base having an opening at an upper position with respect to the temperature sensor and a windshield wall located in adjacent to the base. The windshield wall protrudes upward and extends in a lengthwise direction for the heating member.

A heating device includes a cylindrical body with a hollow interior and a heater inside the hollow interior. A first surface of the heater faces the inner surface of the cylindrical body. A heat transfer member is on a second surface of the heater. A grease is between the heater and the heat transfer member. A support member is provided including a first portion fixed to the second surface of the heater and a second portion contacting a surface of the heat transfer member. The support member includes a third portion between the first and second portions. The third portion does not contact the second surface of the heater between the first and second portions and provides a space for grease from between the heater and the heat transfer member to accumulate.

A fixing apparatus includes a rotary member including a heat-generation layer with a plurality of rings, a temperature detecting portion configured to detect a temperature of the rotary member, a conduction detecting unit configured to detect a conduction failure in an opposing ring that is one of the plurality of rings of the heat-generation layer and that opposes the temperature detecting portion, and a controller configured to control the supply of power to the magnetic field generator. The conduction detecting unit includes a first magnetic core, a second magnetic core, and a current detecting portion that includes a detection coil. A length of one of the first magnetic core and the second magnetic core around which the detection coil is wound is less than a length of another of the first magnetic core and the second magnetic core around which the detection coil is not wound.

An image forming apparatus includes a heating device including a rotator member, a heating member configured to heat the rotator member. The heating member is switchable between a first heat generation state in which an amount of heat generated on a first side is larger than an amount of heat generated on a second side in the intersection direction and a second heat generation state in which the amount of heat generated on the second side is larger than the amount of heat generated on the first side, The image forming apparatus is configured to switch between the first heat generation state and the second heat generation state while executing a job of continuously forming an image on a plurality of recording media having a same length in the intersecting direction.