A fixing belt includes: a base having an endless shape; and a resin layer covering a surface on an inner peripheral side of the base, the resin layer comprising a resin and a filler, and having a second surface opposite to a first surface facing the base, the second surface having cell structures, and being roughened with the filler. When arithmetic mean roughnesses of the second surface in the central region X and the end regions Y and Z are defined as RaX, RaY and RaZ respectively, a difference between RaX and RaY, a difference between RaY and RaZ, and a difference between RaX and RaZ are all 0.1 μm or smaller, and a coefficient of variation of areas of the cell structures contained in each of the central region X, and end regions Y and Z is 25% or smaller.

A fixing member having a base layer and a surface layer, wherein the surface layer includes a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, and having at least one pore communicating with an opening on an outer surface thereof. A composition containing perfluoropolyether and a fluoropolymer is contained in at least a part of the at least one pore. The fluoropolymer has a particular repeating unit composed of perfluoropolyether, and at least one structure selected from the group consisting of a T unit of siloxane and a Q unit of siloxane.

A fixing member having an endless belt shape or a roller shape includes a base layer and a surface layer. The surface layer contains a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, and has a pore communicating with an opening of an outer surface thereof. Perfluoropolyether is contained in at least a part of the pores. A ratio (E″(1)/E″(2)) is 0.60 to 1.00, where E″(1) is an average value of loss elastic moduli E″ of the surface layer in a direction orthogonal to a circumferential direction of the fixing member measured at a frequency of 10 Hz at 100 to 150° C., and E″(2) is an average value of loss elastic moduli E″ of the surface layer in a direction orthogonal to the circumferential direction of the fixing member measured at a frequency of 10 Hz at 100 to 150° C. after removal of the perfluoropolyether contained in the pore.

A temperature detection section is disposed opposite to a heater so as to be out of contact with the heater, and detects a temperature of the heating element. A spacer is disposed so that the heater and the temperature detection section are out of contact with each other. The spacer includes a separator that separates the temperature detection section from the heater and that has a gap through which the heat is transferred from the heater to the temperature detection section and that melts upon the temperature of the heating element increasing to a specific temperature or higher. The separator after melting fills the gap.

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 duration measuring section measures a plurality of times. A temperature measuring section measures a temperature of a heater at each of the times. A temperature information outputting section outputs heater temperature information. A temperature tendency computing section outputs temperature tendency information of the heater. A drive controller outputs linear velocity information for controlling the linear velocity of a pressure roller. A pressure roller drive section drives the pressure roller.

A fixing device includes a fixing rotating member, a heater, a fixing pad, a pressurizing member, a lubricant, and a surface layer. The fixing rotating member is configured to fix a toner image on a recording medium and is heated by the heater. The fixing pad is positioned on an inner circumferential side of the fixing rotating member, and presses the fixing rotating member from the inner circumferential side. The pressurizing member faces an outer circumferential surface of the fixing rotating member, and forms a nip for fixing between the pressurizing member and the fixing rotating member. The lubricant is applied to the fixing rotating member. The surface layer is disposed in a vicinity of an end portion of a pressurizing surface of the fixing pad and returns the lubricant to a longitudinal central side of the pressurizing surface.