A heater control device includes a triac connected in series between an alternating-current power supply and a heater, the triac including a first main electrode, a second main electrode, and a gate electrode; a phototriac coupler configured to transmit a heater trigger signal to the gate electrode of the triac; a first resistor and a second resistor each of which is connected in series to the phototriac coupler and configured to limit current in accordance with a phase control enable signal indicative of a period of phase control; and a resistor selection circuit configured to select one of the first resistor and the second resistor and connect the selected resistor to the second main electrode of the triac. The first resistor and the second resistor have different rated powers and different breakabilities from each other.

A resistance heating component is to come into contact with and heat a fixing belt made of a heat resistant material, and is to be provided at a position away from a fixing area between which the resistance heating component and the fixing belt a recording material is held and conveyed, the resistance heating component including: a metal base material having a low heat capacity; and a resistance heating layer laminated on a front surface or a rear surface of the base material with an insulating layer interposed between the base material and the resistance heating layer.

Power to an electrical device is controlled using a phase control that changes a cutoff phase of an alternating current (AC) electrical signal delivered to the electrical device. The power delivered to the electrical device is increased to an operational level using the phase control. A level of the power delivered to the electrical device is maintained at the operational level using an integral half cycle control that selectively removes a plurality of half cycles from the AC electrical signal delivered to the electrical device such that a plurality of remaining half cycles in the AC electrical signal delivered to the electrical device have a frequency outside a range of sub-harmonic frequencies.

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.

A resistance heating component is to come into contact with and heat a fixing belt made of a heat resistant material, and is to be provided at a position away from a fixing area between which the resistance heating component and the fixing belt a recording material is held and conveyed, the resistance heating component including: a metal base material having a low heat capacity; and a resistance heating layer laminated on a front surface or a rear surface of the base material with an insulating layer interposed between the base material and the resistance heating layer.

Disclosed is a heat source for radiating heat onto an intermediate printing material transfer element of a printing apparatus. The heat source can include a plurality of heat generating segments disposed along an axis, the plurality of heat generating segments including a first heat generating segment, a second heat generating segment and a third heat generating segment. The second heat generating segment is disposed between the first heat generating segment and the third heat generating segment. The second heat generating segment has a length shorter than a length of the first heat generating segment and shorter than a length of the third heat generating segment. Also disclosed is a printing system that includes the disclosed heat source. Also disclosed is a method of selecting a heat radiating pattern of a heat source.

A fixing device includes a heater, a switching element, a zero-cross detecting portion, a controller, a power source, a driving portion. In a case that an amount of electric charge charged in the power source is predetermined value or more, the controller outputs a first signal to the driving portion so that a time in which a current is passed from the power source to the switching element is a first time. In a case that the amount of the electric charge is less than the predetermined value, the controller outputs a second signal to the driving portion so that the time in which the current is passed from the power source to the switching element is a second time shorter than the first time.

A conveyance device to convey a recording medium includes a heater, a first temperature detector, a second temperature detector, and a recording medium detector. The heater heats the recording medium. The first temperature detector and the second temperature detector detect a temperature of the heater. The recording medium detector detects the recording medium. The first temperature detector is disposed at a position farther from a center position of a heating region of the heater than the second temperature detector in a conveyance orthogonal direction. The conveyance orthogonal direction is along a surface of the recording medium and orthogonal to a direction in which the recording medium is conveyed. The recording medium detector is disposed on a side opposite to the first temperature detector with respect to the second temperature detector in the conveyance orthogonal direction.

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.

A heating device is provided. The heating device includes a heating unit, heating a member to be heated, which is transported, and a contact portion of the heating unit contacting with the member to be heated; a heat pipe, having a first end and a second end opposite to the first end in a widthwise direction, and contacting with a portion of the heating unit different from the contact portion so as to extend in the widthwise direction crossing a transport direction of the member to be heated; a rotating body, rotating so as to press the member to be heated; and a power input unit, having a gear disposed on a second end side of the heat pipe and inputting a rotational force at least to the rotating body. The first end of the heat pipe has a thickness smaller than that of the second end.