A heating device includes a first rotator, a second rotator, a heater, and a first, second and third temperature sensors. The second rotator contacts an outer circumferential surface of the first rotator to form a nip through which a recording medium passes. The heater heats the first rotator. The first temperature sensor is disposed outside a space extending from a first region through which a minimum recording medium passes and detects the temperature of the first rotator. The second temperature sensor is disposed outside the space extending from the first region and detects the temperature of the heater. The third temperature sensor is disposed outside the space extending from the first region and detects the temperature of the second rotator. At least one of the second temperature sensor or the third temperature sensor is disposed outside a space extending from a second region through which a maximum sheet passes.

A heating apparatus includes a cylindrical film and a pressing element that rotates with the cylindrical film and forms a nip with the cylindrical film. A medium is conveyed through the nip from an upstream side to a downstream side. The heating apparatus further includes a heater arranged inside the cylindrical film and on which a heating element is disposed. An upstream end of the heater is located downstream of an upstream end of the nip, and a downstream end of the heater is located downstream of a downstream end of the nip.

According to one embodiment, there is provided a temperature abnormality detection circuit provided in a temperature control device includes a target temperature determination circuit, a difference arithmetic circuit, a temperature abnormality determination circuit, and a storage circuit. The temperature abnormality detection circuit is configured to determine the presence or absence of temperature abnormality by a response situation of a detected temperature by a temperature sensor, calculate a current temperature difference from the detected temperature acquired by the temperature sensor if it is determined that there is a temperature abnormality and an estimated WAE temperature value, and determine whether the temperature sensor is abnormal or the control circuit side is abnormal based on the result of comparison between the temperature difference and a preset threshold value.

A heating efficiency 600 includes a substrate 610 and a plurality of heat generating elements 523a to 623f which are provided on both surfaces of the substrate 610 and which generate heat, and heats a fixing belt in contact with an inner peripheral surface of the fixing belt. The plurality of heat generating elements 623a to 623f are different from each other in length with respect to a widthwise direction, and at least three of the heat generating elements are provided on a front surface of the substrate 610 which is a side where the heater 600 contacts the inner peripheral surface of the fixing belt 600, and at least one of the heat generating elements is provided on a back surface. A longest heat generating element 623b, in length with respect to the widthwise direction, of the plurality of heat generating elements 623a-623f is provided on the front surface. Further, as regards the heat generating elements 523a-623c provided on the front surface, with respect to a rotational direction of the fixing belt, the longest heat generating element 623b in length with respect to the widthwise direction is disposed between the heat generating element 623a and the heat generating element 623c.

An image forming apparatus for forming a toner image on a recording material includes a fixing unit and a blower unit to blow air around a roller. The fixing unit includes a tubular shape film, a heating member disposed in a space surrounded by the film, and the roller forming a nip portion with the heating member. The fixing unit heats and fixes the toner image onto the recording material at the nip portion. For printing that forms toner images on continuously conveyed recording materials where a roller surface temperature is lower than a predetermined temperature, fan stop and operation periods are set. During the fan stop period, the blower unit is stopped and an interval between preceding and subsequent recording materials is widened. During the fan operation period, the blower unit is in operation and the interval is narrower than the interval during the fan stop period.

A fixing member is supported so as to be displaceable in a crossing direction that crosses a sheet conveying direction. A pressure member rotationally drives the fixing member by being rotationally driven. A motor rotationally drives the pressure member. A biasing mechanism elastically biases the fixing member toward the pressure member. A sheet detection portion detects a sheet at a first position and a second position. The first position is a position between a mechanism that feeds the sheet to a fixing position and the fixing position in the conveyance path. The second position is a position between the fixing position and a mechanism that takes over conveyance of the sheet from the fixing device. A control device times a time required for detection results from the sheet detection portion to show a predetermined change, and controls a rotational speed of the motor according to the timed time.

A fixing device includes an endless fixing belt, a heater, a pad, a stay and a pressing roller. The endless fixing belt rotates as a sheet is conveyed. The heater heats the fixing belt in a width direction. The pad comes into contact with an inner surface of the fixing belt in the width direction. The stay supports the pad inside the fixing belt. The pressing roller presses the fixing belt against the pad. The pad is made of metal.

A fixing device to fix a toner image formed on a recording medium to the recording medium includes a rotating member, a guide member, a holding member, and a roller. The roller contacts with an outer surface of the rotating member and forms a fixing nip portion together with the guide member between the rotating member and the roller. The fixing device fixes the recording medium toner image to the recording medium while pinching and conveying the recording medium in the fixing nip portion. The guide member is pivotable relative to the holding member about a pivot point that is a shaft substantially perpendicular to a surface of the fixing nip portion. When the rotating member slides on the guide member, the guide member pivots due to a force received from the rotating member so that alignment of the guide member with respect to the holding member is corrected.

A fixing device includes a rotatable endless belt; a planar heat-generating section in which at least a downstream end portion in a movement direction of the belt is in pressure contact with a rotating body via a pressure contact portion and a cross-sectional shape of a downstream edge portion being in contact with an inner surface of the belt is formed in a curved shape having a curvature radius of 0.01 mm or more 0.2 mm or less or in a shape in which the edge portion is cut out over the dimension; and a holding section that is disposed inside the belt and holds the planar heat-generating section to be in pressure contact with the rotating body.

A fixing device includes a movable belt; and a planar heat-generating section that is in contact with the belt and in which, among plural heat-generating portions provided in a movement direction of the belt, a heat-generating portion on an upstream side in the movement direction of the belt has a larger heat generation amount than a heat-generating portion on a downstream side.