In a longitudinal direction of a heater, a distance from a center portion of the heater to a first temperature detection element is a first distance, and a distance from the center portion of the heater to a second temperature detection element is a second distance greater than the first distance. In a first area which is farther from the center portion of the heater than the second temperature detection element is from the center portion of the heater in the longitudinal direction of the heater, a distance between a first conductor and a second conductor in a transverse direction of the heater is a first inter-conductor distance and a distance between a third conductor and a fourth conductor in the transverse direction is a second inter-conductor distance longer than the first inter-conductor distance.

A fixing device includes a heater, a heating rotator, a nip formation rotator, and an entry guide. The entry guide guides each of a first recording medium having a predetermined length or more and a second recording medium having a length less than the predetermined length to the fixing nip. The entry guide includes a first and second entry guide portion. The first entry guide portion guides the first recording medium toward a harder one of the heating rotator and the nip formation rotator and has an opening. The second entry guide portion guides the second recording passing through the opening to the fixing nip along a reference line connecting an entry and exit of the fixing nip or guides the second recording medium from an area including a softer one of the heating rotator and the nip formation rotator with respect to the reference line to the fixing nip.

A formed article according to one embodiment of the present disclosure includes a cylindrical base layer containing a polyimide as a main component, a sliding layer disposed on an inner circumferential surface side of the base layer and containing a polyether ether ketone as a main component, and an outermost layer disposed on an outer circumferential surface side of the base layer and containing a fluororesin as a main component.

A method of manufacturing a heat generating roller includes forming an insulating portion on a surface of a metal base member by providing poly-ether-ether-ketone resin over the surface of the base member and heating the poly-ether-ether-ketone resin, the poly-ether-ether-ketone resin being electrically insulating and heat-shrinkable; and forming a heat generating portion on a surface of the insulating portion, the heat generating portion generating heat when energized.

A fixing device includes a heater, a heating rotator, a nip formation rotator, and an entry guide. The entry guide guides each of a first recording medium having a predetermined length or more and a second recording medium having a length less than the predetermined length to the fixing nip. The entry guide includes a first and second entry guide portion. The first entry guide portion guides the first recording medium toward a harder one of the heating rotator and the nip formation rotator and has an opening. The second entry guide portion guides the second recording passing through the opening to the fixing nip along a reference line connecting an entry and exit of the fixing nip or guides the second recording medium from an area including a softer one of the heating rotator and the nip formation rotator with respect to the reference line to the fixing nip.

An endless belt includes a metal substrate, and a heat-resistant resin layer that is disposed as an innermost layer on an inner peripheral surface of the metal substrate and that contains a resin and a thermally conductive filler having an aspect ratio of 20 or more. In the heat-resistant resin layer, an orientation ratio of the thermally conductive filler with respect to a circumferential direction of the endless belt is 20% or more.

A nip former that forms a nip between an endless belt and a pressure rotator includes a base that is made of aluminum and has a nip forming face disposed opposite the nip. An anodic oxidation coating is treated with sealing and coats at least the nip forming face. The anodic oxidation coating has a thickness that is not smaller than 22 μm and is not greater than 45 μm and a variation in thickness that is not greater than 20 percent. The base and the anodic oxidation coating define a nip forming portion that is disposed opposite the nip. The nip forming portion has a thickness that is not smaller than 0.40 mm and is not greater than 1.20 mm.

A polymer material molded product includes a polymer material and a porous carbon material having an X-ray diffraction spectral characteristic shown in the following (1) or (2), (1): a peak derived from a (002) plane of carbon is observed, a half width of the peak derived from the (002) plane of carbon is 5° or more, and a half width of a peak derived from a (10) plane of carbon is 3.2° or less, and (2): the peak derived from the (002) plane of carbon is not observed, and the half width of the peak derived from the (10) plane of carbon is 3.2° or less.

A formed article according to one embodiment of the present disclosure includes a cylindrical base layer containing a polyimide as a main component, a sliding layer disposed on an inner circumferential surface side of the base layer and containing a polyether ether ketone as a main component, and an outermost layer disposed on an outer circumferential surface side of the base layer and containing a fluororesin as a main component.

Metal oxide particles having: (1) a volume ratio (a) in 0.7 μm band of 5 to 40 vol %, (2) a volume ratio (b) in 13 μm band of 20 to 45 vol %, (3) a volume ratio (c) in 1.3 μm band of 20 to 50 vol %, and (4) a sum of the volume ratios (a), (b), and (c) of 60 to 100 vol %. The 0.7 μm, 13 μm, and 1.3 μm bands are particle size distributions having peaks at 0.3 to 1.2 μm, 0.3 to 20 μm, and 0.7 to 3 μm, respectively. The volume ratios (a), (b), and (c) of each band have peaks near 0.7 μm, 1.3 μm, and 13 μm in a particle size distribution curve, and being obtained by calculating an abundance ratio of particles in each band from a numerical integration of distribution curves obtained by further dividing the particle size distribution curve into three bands.