In some examples, a heating apparatus includes a light emitting diode (LED) array comprising an LED to heat a target object, and a heat sink thermally coupled to the LED array, to dissipate heat from the LED array, the heat sink comprising a plurality of refrigerant paths to pass a refrigerant through the heat sink in a plurality of different directions.

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 rotator, a heating source, a reflector, a shield, a rotator holder, and a liquid or semi-solid substance. The rotator is rotatably held. The heating source heats the rotator. The reflector reflects radiant heat emitted from the heating source. The shield is disposed closer to a longitudinal end portion of the rotator than to a longitudinal center portion of the rotator to shield, between the heating source and the rotator, the radiant heat emitted from the heating source. The shield has a reflectance lower than a reflectance of the reflector. The rotator holder holds the longitudinal end portion of the rotator. The liquid or semi-solid substance has lubricity and adheres to the rotator holder.

In some examples, a heating apparatus includes a light emitting diode (LED) array comprising an LED to heat a target object, and a heat sink thermally coupled to the LED array, to dissipate heat from the LED array, the heat sink comprising a plurality of refrigerant paths to pass a refrigerant through the heat sink in a plurality of different directions.

According to one embodiment, a fixing device includes a fixing member, a temperature sensor unit, a heater unit, and a controller. The fixing member has a surface that contacts a sheet. The temperature sensor unit is configured to measure a temperature of the surface of the fixing member. The heater unit is configured to heat the member when turned ON. The controller is configured to output a notification indicating an abnormality in the temperature measurement by the temperature sensor unit if an ON time of the heater unit during an operation period for controlling the fixing member to be at a target temperature, as measured by the temperature sensor unit, is longer than a predetermined threshold time.

An example heating apparatus comprises a light emitting diode (LED) array comprising at least one LED to heat a target object. The heating apparatus further comprises a heatsink thermally coupled to the LED array to dissipate heat from the LED array. The heatsink comprises a refrigerant path including an input to and an output from the refrigerant path to pass cooled refrigerant therethrough.

According to one embodiment, a fixing device includes a fixing member, a temperature sensor unit, a heater unit, and a controller. The fixing member has a surface that contacts a sheet. The temperature sensor unit is configured to measure a temperature of the surface of the fixing member. The heater unit is configured to heat the member when turned ON. The controller is configured to output a notification indicating an abnormality in the temperature measurement by the temperature sensor unit if an ON time of the heater unit during an operation period for controlling the fixing member to be at a target temperature, as measured by the temperature sensor unit, is longer than a predetermined threshold time.

An example heating apparatus comprises a light emitting diode (LED) array comprising at least one LED to heat a target object. The heating apparatus further comprises a heatsink thermally coupled to the LED array to dissipate heat from the LED array. The heatsink comprises a refrigerant path including an input to and an output from the refrigerant path to pass cooled refrigerant therethrough.

The present subject matter describes a heating unit. The heating unit comprises a heating element and a controlling unit coupled to the heating element to determine a desired value of a direct current (DC) voltage based on heating element parameters. The desired value is a value of DC voltage desired for operation of the heating element. The controlling unit computes a value of a duty cycle parameter based on device input parameters and the desired value of the DC voltage. The heating unit further comprises a power factor correction (PFC) unit coupled to the controlling unit and the heating element to convert an input alternating current (AC) voltage, received by the PFC unit from an AC supply, to a direct current (DC) voltage of the desired value based on the duty cycle parameter. The PFC unit provides the DC voltage to the heating element.

A power control device includes a heater, a zero-cross detecting unit, a triac, a supplying unit, and a controlling unit. The supplying unit discharges an electric charge when a control signal is outputted in a half-wave of each of a first polarity and a second polarity and charges the electric charge when the control signal is not outputted in the half-wave of the first polarity. The controlling unit outputs: in a first half-wave, a first control signal on the basis of the zero-cross point and a second control signal in a first phase different in timing from the first control signal, and in a second half-wave, a third control signal on the basis of the zero-cross point and a fourth control signal in a second phase different in timing from the second control signal. The first phase and the second phase are different from each other.