A heating device includes a cylindrical film a heater disposed inside the cylindrical film on an inner surface of the cylindrical film. The heater has a plurality of heating elements on a first surface that are spaced from each other at intervals along an axial direction. A heat transfer member contacts a second surface of the heater. The heat transfer member is arranged such that, in a first region of the heater that includes just a single one of the heating elements, contact between the heater and heat transfer member is greater than in a second region of the heater that includes an interval between a pair of adjacent heating elements.

A nip formation member includes a base, a high thermal conduction member, and a securing member. The high thermal conduction member has a thermal conductivity greater than a thermal conductivity of the base. The securing member is independent from the base and the high thermal conduction member. The securing member is configured to restrict movement of the base relative to the high thermal conduction member.

An image forming apparatus, including: an image forming portion that forms an image on a recording material based on image data; a fixing portion that includes a heater having a plurality of heat generating members arranged in a direction perpendicular to a conveying direction of a recording material, and that fixes the image to the recording material using heat of the heater; a storage portion that stores history information on the recording material when image forming operation is performed in which the image forming portion forms the image and the fixing portion fixes the image, a control portion that sets power to be supplied to the heat generating members based on the history information before a type of the recording material on which the image is formed or content of the image data of the image to be formed on the recording material is determined.

A fixing belt and a fixing device suppress charging of the fixing belt and permit securing of a withstand voltage of secondary parts of the fixing belt are provided in addition to a heater. The fixing belt is formed of a tubular endless fixing film including, in order from an inner peripheral side of the film, abase layer, an elastic layer, and a release layer. A surface resistivity of the fixing belt measured from the base layer side is 7 [LOG Ω/sq.] or more and 10 [LOG Ω/sq.] or less.

A slide member over which a sliding member is configured to slide includes a slide portion over which the sliding member slides. The slide portion is weaved with a first fiber having a first color. The slide member further includes a non-slide portion over which the sliding member does not slide. The non-slide portion is weaved with a second fiber having a second color that is different and distinguished from the first color.

An image formation apparatus according to an embodiment may include a fixation device and a controller. The fixation device includes: a fixation member includes a first region and a second region located closer to a center in a longitudinal direction of the fixation member than the first region; a pressurizing member that forms a nip portion between the fixation member and the pressurizing member; first and second heat generating portions that heat the first and second regions, respectively; a first sensor that detects a first temperature of one of the pressurizing member and the fixation member at a position corresponding to the first region; and a second sensor that detects a second temperature of the one at a position corresponding to the second region. The controller controls a drive speed of the pressurizing member or the fixation member based on the first and second temperatures.

A heating apparatus to heat an image borne on a recording material includes a heater having a heater portion with first and second heating elements, where the heating elements have different lengths and resistance values. The heating apparatus also includes a power source, a switching unit, a control unit, and a voltage detection unit. The power source supplies power to the heating elements. The control unit controls the switching unit two switch a connection between the power source and the first heating element and the second heating element. The voltage detection unit detects an input voltage input from the power source to the heating elements. The control unit switches a power ratio, which is a ratio between an electric energy supplied from the power source to the first heating element and an electric energy supplied from the power source to the second heating element, depending on the detected input voltage.

A fixing device includes a heated rotational body, a heating unit, a pressing rotational body, a pressing mechanism, a drive unit, a position recognition part, a rotational state determination part, a drive control part, and a pressing control part. The heated rotational body has a pattern. The position recognition part is configured to recognize a specific point contained in the pattern at a prescribed period. The rotational state determination part is configured to determine a variation in a rotational speed of the heated rotational body and a meandering state of the heated rotational body based on a position of the specific point recognized at the prescribed period. The drive control part is configured to control the drive unit based on the variation in the rotational speed. The pressing control part is configured to control the pressing mechanism based on the meandering state.

An image forming apparatus includes: a pressure roller; a heater that faces the pressure roller and forms a nip part with the pressure roller, the nip part being between the pressure roller and the heater; and a hardware processor that adjusts a pressing force for pressing either the pressure roller or the heater toward the other and determines the pressing force based on a size of a recording medium that passes through the nip part.

A fixing device includes a fixing belt, a pressure applying member, and a heater holding member. The fixing belt fixes toner to a sheet. The pressure applying member forms a nip portion together with an outer peripheral surface of the fixing belt and causes the fixing belt to peripherally rotate while applying pressure to the fixing belt at the nip portion. The heater holding member holds a heater that applies heat to the fixing belt. The heater holding member includes: a side portion that extends from the nip portion along an inner peripheral surface of the fixing belt and guides the fixing belt; and a plurality of inclined ribs that are disposed on the side portion to face the inner peripheral surface and formed such that an interval between them is gradually narrowed as they proceed in a direction in which the fixing belt peripherally rotates.