An image forming apparatus includes an AC input portion to which AC power is to be supplied from a commercial power source, an image forming unit configured to form an image on a recording material, a fixing device including a first fixing heater and a second fixing heater which are configured to generate heat, the fixing device being configured to heat the image on the recording material by using the first fixing heater and the second fixing heater to fix the image to the recording material, a first relay configured to be switched between a first state in which electric connection is established and a second state in which electric connection is not established, and a second relay configured to be switched between a third state in which electric connection is established and a fourth state in which electric connection is not established.

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 is disposed on 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, a rotating body that rotates in such a manner as to press the member to be heated against the contact portion of the heating unit, and a power input unit that is disposed on a second end side of the heat pipe and that inputs a rotational force at least to the rotating body.

Provided is a heater that is excellent in heat equalizing property even when being narrow in a sweep direction. Also provided are a fixing device, an image-forming device, and a heating device each including such a heater. A heater is configured to heat an object to be heated in such a manner that at least one of the object to be heated and the heater is swept with the heater disposed opposite the object to be heated. The heater includes a base having a rectangular shape and a plurality of heating cells each independently receiving power supply, the heating cells being disposed on the base and arranged in a longitudinal direction of the base. Each of the heating cells includes a plurality of lateral wires extending in substantially parallel with the longitudinal direction of the base and a plurality of oblique wires tilted relative to the lateral wires.

Power allocation in printing devices is disclosed. Independent load requests are received from printing device heater systems. Power grants are allocated based on a general power arbitration of a power source in response to the independent load requests. A power grant is adjusted based on a contextual printing condition to provide an adjusted grant from the power source to a printing device heater system of the printing device heater systems. The adjusted grant is based on a power grant limit corresponding with the contextual printing condition.

In some examples, a system includes a first heater and a second heater, and a controller to receive a power request indicating a power level for the second heater, in response to the power request, select a power delivery technique from among different power delivery techniques that employ different ways of delivering power to the first and second heaters, and cause powering of the first and second heaters using the selected power delivery technique.

According to examples, a heated system may include a heat generating device, a temperature sensor to detect temperature in the heated system, and a controller. The controller may store temperatures detected by the temperature sensor over time and based on a determination that the temperature in the heated system has reached a predefined temperature value, stop application of power to the heat generating device. The controller may also calculate a rate of change of the stored temperatures corresponding to a predefined period of time prior to the application of power to the heat generating device being stopped, may determine a seeding value for a control mechanism of the heat generating device based on the calculated rate of change, and based on aa determination that a predefined condition has occurred, control the control mechanism to apply power to the heat generating device beginning with the determined seeding value.

Power allocation in printing devices is disclosed. Independent load requests are received from printing device heater systems. Power grants are allocated based on a general power arbitration of a power source in response to the independent load requests. A power grant is adjusted based on a contextual printing condition to provide an adjusted grant from the power source to a printing device heater system of the printing device heater systems. The adjusted grant is based on a power grant limit corresponding with the contextual printing condition.

The image forming apparatus is characterized in that information about an input voltage detected on the primary side of a transformer is transmitted from a primary-side switching control unit to a secondary-side controller for controlling a heating device, and the controller controls the temperature of a heater of the heating device based on the transmitted information.

According to examples, an apparatus may include a processor that may identify a first period for a heated system, the first period including a first set of power events and a first zero power event for the heated system and may identify a second period for the heated system, the second period including a second set of power events and a second zero power event for the heated system. The processor may also borrow, from the second period, a portion of a second power event of the second set of power events and may apply the borrowed portion of the second power event to a first power event of the first set of power events during the first period to remove the first zero power event from the first period.

An energization control device includes a voltage detection unit, a control portion, and an energization switching unit. The control portion to which the first detection signal and the second detection signal are input from the voltage detection unit is configured to output a first energization signal if the first detection signal is input and output a second energization signal if the second detection signal is input. The control portion is configured to obtain a correction value based on a difference between a first period in which the first detection signal is input to the control portion and a second period in which the second detection signal is input to the control portion and to correct a timing of switching between the first energization signal and the second energization signal with the correction value.