An image forming apparatus includes an image forming device that forms images in an image region on a sheet. An image fixing device includes heater elements disposed along a sheet-width direction. A controller is configured to identify a heater element that will overlap with an edge of the image region when a sheet is conveyed to the image fixing device. The controller calculates whether a shift of the image region by a shift amount less than a threshold would cause the heater element to not overlap. If so, the image forming device is controlled to form the image in a shifted image region and only those heater elements in the plurality of heater elements that overlap with the shifted image region are turned on when fixing the sheet if the image has been formed in the shifted image region.

A second heater has such an output that a peak position in a particular direction is located within a largest sheet area. The largest sheet area is an area in which a heating member contacts a sheet having a largest size in the particular direction that is conveyable through a fixing device. A first sensor detects temperature of a center area. A second sensor detects temperature at an outside position in an end area. The outside position is outside the largest sheet area in the particular direction. A controller controls a first heater such that a first detection temperature detected by the first sensor becomes a first target temperature; controls the second heater such that a second detection temperature detected by the second sensor becomes a second target temperature; and determines the second target temperature based on an edge position of a sheet relative to the peak position.

An image forming apparatus includes a plurality of heaters, a switch portion, and first and second supply lines. The heaters heat a toner image. The switch portion is connected to an alternating-current power source, and opens and closes in a manner interlocked with the opening and closing of a cover. The first supply line connects the respective one ends of the heaters to the switch portion. The second supply line connects the respective other ends of the heaters to the switch portion. The second supply line has a branch portion. The respective other ends of the heaters are each connected to one of branch lines which are electric wires that branch off from the branch portion. The switch portion is disposed between the branch portion and the alternating-current power source.

An image forming apparatus includes a controller configured to identify a selected sheet size setting as defined by a dimension in the width direction and a dimension in the conveyance direction, set a cooling threshold at a first threshold if the selected sheet size setting is a first size having a dimension in the width direction larger than a predetermined dimension, and a dimension in the conveyance direction larger than the dimension in the width direction, and set the cooling threshold at a second threshold lower than the first threshold if the selected sheet size setting is a second size having a dimension in the width direction that is the same as the dimension in the width direction of the first size, and a dimension in the conveyance direction smaller than the dimension in the width direction.

In one example in accordance with the present disclosure, a print system is described. The print system includes a drive roller Print System and a heated transfer belt forming a nip with the drive roller. The heated transfer belt transmits thermal energy to print media passing through the nip. The print system also includes multiple independently-controlled heat sources disposed within the heated transfer belt to transfer thermal energy to the heated transfer belt.

An image forming apparatus includes a fixing section, a detection section, and a controller. The detection section detects a passing range of a recording medium in terms of a direction intersecting with a conveyance direction of the recording medium. A heating section of the fixing section includes a first heater and a second heater. The first heater has a longitudinal direction extending in an axis direction. The second heater has a longitudinal direction extending in terms of the axis direction from each of opposite ends of the first heater in terms of the axis direction. When a result of detection by the detection section indicates that the passing range of the recording medium does not overlap with a specific range of the second heater, the controller restricts heat generation by the second heater.

A heater assembly includes a tubular body, a heater, and a support member. The tubular body is formed in a tubular shape and has a length that extends longitudinally. The heater is received within the tubular body. The heater provides thermal energy in response to being electrically energized. The heater includes a first surface side extending laterally and longitudinally along an inner peripheral surface of the tubular body. The heater includes n electrical contact, through which electrical energy is supplied to the heater. The support member is coupled to the heater and extends longitudinally. The support member defines an opening that exposes the electrical contact. The support member is configured to bend to facilitate coupling the heater to the support member.

A heating unit includes a heater, a temperature sensor, an endless belt, a holder, a first heat conductive member, and a second heat conductive member. The first heat conductive member includes a first heater-side surface facing the heater, a first opposite surface, and an opening. The first heat conductive member has a heat conductivity higher than that of the substrate. The second heat conductive member includes a second heater-side surface facing the heater and a second opposite surface. The second heat conductive member is positioned at a position corresponding to the opening when viewed in an orthogonal direction orthogonal to the first opposite surface. The temperature sensor is in contact with the second opposite surface of the second heat conductive member.

In an image heating device having a plurality of heating blocks which are controllable independently in a longitudinal direction of a heater, an increase of the size of the heater can be suppressed, and temperatures of a plurality of heating block can be detected. A heater has a first temperature sensor corresponding to a first heating block, a second temperature sensor corresponding to a second heating block, a first electric conductor electrically coupled to the first temperature sensor, a second electric conductor electrically coupled to the second temperature sensor, and a common electric conductor electrically coupled to the first and second temperature sensors.

A heater holder includes a restriction portion and a recessed portion. The restriction portion determines the position of a cable in the longitudinal direction of the heater. The recessed portion, against which a bare conductive portion of the cable is to be positioned, is provided at a position that is different from the position of the restriction portion as viewed in a direction intersecting with the longitudinal direction. A wire is joined to the bare conductive portion somewhere between the restriction portion and the recessed portion.