A fixing device includes an endless belt, a rotatable pressing member, a pad member inside of the belt, and a sliding member held by the pad member and sliding on an inner circumferential surface of the belt in a nip. The rotatable pressing member nips and feeds a recording material in the nip in cooperation with the belt and fixes a toner image on the recording material by applying heat and pressure. The sliding member includes a base material layer on which a plurality of projections projecting toward the rotatable pressing member are formed on a side sliding with the belt and a sliding layer provided on an outer surface of the plurality of projections. A shape of a surface of the sliding layer is a curved surface and a radius of curvature R of the curved surface satisfies 300 .Math.m ≤ R ≤ 850 .Math.m.

An image forming apparatus includes a fixing unit including a heater including a heating element, a fixing belt having a surface to which a lubricant is applied and contacting the heater through the lubricant, and a pressing roller capable of pressing and rotating the fixing belt, a power supply configured to supply electric power to the heating element, a first thermometer configured to measure temperature of the heating element, and a controller configured to determine a first amount of electric power to be supplied to the heating element based on the temperature of the heating element, and control the power supply to supply the determined first amount of electric power to the heating element, before controlling the pressing roller to start rotation.

A lubricant replacement case for an image forming apparatus includes a housing including a plurality of storage compartments to accommodate at least one lubricant unit. The plurality of storage compartments include at least one storage compartment for unused lubricant to be inserted into the image forming apparatus and at least one storage compartment for used lubricant to be retrieved from the image forming apparatus.

An image forming apparatus includes a fixing unit including a fixing belt having a surface to which a lubricant is applied, a heater contacting the surface and including heating elements arranged along a width direction of the belt and including first end second end heating elements and a central heating element, and a pressing roller capable of pressing and rotating the belt, a power supply configured to supply power to the heating elements, and a controller configured to determine a first amount of power to be supplied to the central heating element and a second amount of power to be supplied to each end heating element such that the first amount is greater than the second amount, and control the power supply to supply the first and second amounts to the central heating element and each end heating element before controlling the pressing roller to rotate.

A heating device including: a rotating member for heating, an opposing member, which is arranged so as to be opposed to the rotating member, and forms a nip portion together with the rotating member, and a biasing member, which is arranged inside the rotating member, has an opposing surface with respect to an inner peripheral surface of the rotating member, and biases the rotating member to the opposing member. The inner peripheral surface and the opposing surface are brought into contact with each other via a grease composition to form a sliding portion. The grease composition contains a base oil. The base oil contains a fluoropolymer having a specific structure and a perfluoropolyether having a specific kinematic viscosity and a specific evaporation loss and having a specific structure.

A heat fixing device including: a first member configured to be rotatable; a heater capable of heating the first member; a second member configured to be rotatable, which forms a nip portion with the first member, and a biasing member, which is arranged inside the first member, has a sliding surface against an inner peripheral surface of the first member, and is configured to bias the first member toward the second member, the heat fixing device having an oil film containing perfluoropolyether between the inner peripheral surface of the first member and the sliding surface of the biasing member, and when adhering a 1-microliter droplet of a perfluoropolyether having a kinematic viscosity of 500 mm2/s at an arbitrary position on the sliding surface at a temperature of 23° C., a contact angle of the droplet being 50° to 65°, and a sliding angle of the droplet being 30° to 40°.

A fixing device includes an endless belt-shaped section; a heating section that supports and rotates the belt-shaped section and generates heat during energization to heat the belt-shaped section; and a terminal portion that is provided at an end part of the heating section and feeds power to the heating section. An outer diameter of the terminal portion is equal to or smaller than an outer diameter of the heating section.

A fixing device includes an endless belt-shaped section; a supply section that supplies a lubricating material to an inner surface of the belt-shaped section; a heating section that supports and rotates the belt-shaped section and generates heat during energization to heat the belt-shaped section; a power feed section that is electrically connected to an end part of the heating section and feeds power to the heating section; and a regulating section that is disposed on an outer surface side of the heating section and inside the power feed section with respect to an axial direction of rotation of the heating section to regulate movement of the lubricating material to a power feed section side.

A fixing device includes a rotator, a heater, a rotator support, a nip formation pad, lubricant, and a pressure rotator. The heater heats an inner circumferential surface of the rotator. The rotator support supports an end of the inner circumferential surface of the rotator in an axial direction of the rotator. The rotator slides on the rotator support. The nip formation pad is in contact with the inner circumferential surface of the rotator. One end of the nip formation pad in a longitudinal direction of the nip formation pad is separated from the rotator support with a clearance of 2 mm or more. The lubricant is between the rotator and the nip formation pad. The pressure rotator presses the nip formation pad via the rotator to form a nip between the rotator and the pressure rotator.

A heating device includes a rotating body, a heating source, a rotating body holder, and a lubricant of liquid or semi-solid. The heating source heats the rotating body. The rotating body holder holds both longitudinal ends of the rotating body rotatably. The lubricant of liquid or semi-solid adheres to the rotating body holder. A temperature of the rotating body holder is lower than a generation temperature of fine particles of the lubricant.