Abstract: A pressure member includes a base, an elastic layer outside the base, and a surface layer on the elastic layer, the surface layer containing a fluorine-containing resin. The surface layer is fixed on the elastic layer in a state of being stretched in the longitudinal direction of the pressure member, the elastic layer has a porosity of 20% by volume or more and 60% by volume or less, and when the elastic modulus of the elastic layer in the thickness direction is defined as E (ND) and the elastic modulus of the elastic layer in the longitudinal direction of the pressure member is defined as E (MD), E (MD)/E (ND) is larger than 1.0.

Abstract: A heater includes a substrate, a first electrical contact, second electrical contacts, first electrode portions and second electrode portions, heat generating portions, a first electroconductive line portion, and a second electroconductive line portion. The heat generating portions are disposed so as to be offset from a center line of the substrate with respect to a widthwise direction of the substrate.

Abstract: A fixing member used for fixing a toner image on a recording material includes: a base layer; and a porous elastic layer provided on the base layer and containing a needle-like filler. The elastic layer has a thermal conductivity with respect to a longitudinal direction thereof in a first region where the elastic layer is contactable to the recording material on the fixing member, and the thermal conductivity is 6 times to 900 times a thermal conductivity with respect to a thickness direction in the first region. The elastic layer has a thermal conductivity with respect to the thickness direction thereof in a second region outside the first region with respect to the longitudinal direction, and the thermal conductivity with respect to the thickness direction in the second region is larger than the thermal conductivity with respect to the thickness direction in the first region.

Abstract: A heater includes a substrate, electrode portions, electrical contact portions, heat generating portions, and electroconductive line portions. The electrode portions include first group electrode portions and second group electrode portions. The electroconductive line portions include a main line portion extending from the electrical contact portions in the longitudinal direction, a first branch line portion branching from the main line portion so as to electrically connect with a first electrode portion of the first group electrode portions, and a second branch line portion branching from the main line portion so as to electrically connect with a second electrode portion of the first group electrode portions. The second electrode portion is spaced farther from the electrical contact portions than the first electrode portion in the longitudinal direction, and the electric resistance of the first branch line portion is larger than the electric resistance of the second branch line portion.

Abstract: A fixing device includes a rotatable heating member and a rotatable pressing member which are configured to fix a toner image on a recording material in a nip therebetween; and a heating mechanism configured to selectively heat regions of the rotatable heating member depending on sizes of the recording material when the sizes are predetermined ones of all sizes usable in the fixing device. The rotatable pressing member includes a base layer and a porous elastic layer provided on the base layer and containing a needle-like filler. The elastic layer having a thermal conductivity, with respect to a longitudinal direction thereof, which is 6 times to 900 times a thermal conductivity with respect to a thickness direction thereof.

Abstract: A fixing member, includes: a base layer; and a porous elastic layer provided on the base layer and configured to contain a needle-like filler. The elastic layer has a thermal conductivity, with respect to a longitudinal direction thereof, which is 6 times to 900 times a thermal conductivity with respect to a thickness direction thereof. The elastic layer has an open cell rate larger at longitudinal end portions than at a longitudinal central portion.

Abstract: A pressing roller includes a cylindrical core metal; a first rubber layer of non-porous material provided on the core metal; and a second rubber layer of porous material provided on the first rubber layer, wherein the second rubber layer includes a thermo-conductive filler dispersed therein such that a thermal conductivity of the second rubber layer in a longitudinal direction is higher than a thermal conductivity thereof in a thickness direction, and wherein the first rubber layer includes a thermo-conductive filler dispersed therein such that a thermal conductivity of the first rubber layer in an thickness direction is higher than a thermal conductivity of the second rubber layer in the thickness direction of the second rubber layer.

Abstract: A heater includes a substrate, electrode portions, electrical contact portions, heat generating portions, and electroconductive line portions. The electrode portions include first group electrode portions and second group electrode portions. The electroconductive line portions include a main line portion extending from the electrical contact portions in the longitudinal direction, a first branch line portion branching from the main line portion so as to electrically connect with a first electrode portion of the first group electrode portions, and a second branch line portion branching from the main line portion so as to electrically connect with a second electrode portion of the first group electrode portions. The second electrode portion is spaced from the electrical contact portions more than the first electrode portion in the longitudinal direction, and an electric resistance of the first branch line portion is larger than an electric resistance of the second branch line portion.

Abstract: A heater includes a substrate, a first electrical contact, a plurality of second electrical contacts, a plurality of electrode portions including first electrode portions electrically connected with the first electrical contact and second electrode portions electrically connected with the second electrical contacts, the first electrode portions and the second electrode portions being arranged alternately with predetermined gaps in a longitudinal direction of the substrate, and a plurality of heat generating portions provided between adjacent ones of the electrode portions so as to electrically connect between adjacent electrode portions, the heat generating portions being capable of generating heat by the electric power supply between adjacent electrode portions. A part of the second electrical contacts is selectably electrically connectable with the second terminal.

Abstract: A heater includes a substrate; a first electrical contact a plurality of second electrical contacts an electroconductive line portion electrically connected with the first electrical contact; a plurality of electrode portions including first electrode portions electrically connected with the first electrical contact through the electroconductive line portion and second electrode portions electrically connected with the second electrical contacts; and a plurality of heat generating portions provided between adjacent ones of the electrode portions. A cross-section of the electroconductive line portion in a side closer to the first electrical contact than the plurality of heat generating portions are with respect to the longitudinal direction is larger than a cross-section of a predetermined electrode portion, between adjacent heat generating portions, of the plurality of electrode portions.

Abstract: A heater includes: a substrate; a first electrical contact; second electrical contacts; first electrode portions and second electrode portions; heat generating portions; a first electroconductive line portion electrically connecting the first electrical contact and the first electrode portions; and a second electroconductive line portion electrically connecting one of the second electrical contacts and a part of the second electrode portions. A cross-sectional area of a portion, of the first electroconductive line portion, into which all of currents flowing through the first electrode portions merge when the currents flow from the first electrode portions toward the first electrical contact is larger than a cross-sectional area of a portion, of the second electroconductive line portion, into which all of currents flowing through the part of the second electrode portions merge when the currents flow from the part of the second electrode portions toward the one of second electrical contacts.

Abstract: A pressure member includes a base, an elastic layer outside the base, and a surface layer on the elastic layer, the surface layer containing a fluorine-containing resin. The surface layer is fixed on the elastic layer in a state of being stretched in the longitudinal direction of the pressure member, the elastic layer has a porosity of 20% by volume or more and 60% by volume or less, and when the elastic modulus of the elastic layer in the thickness direction is defined as E (ND) and the elastic modulus of the elastic layer in the longitudinal direction of the pressure member is defined as E (MD), E (MD)/E (ND) is larger than 1.0.

Abstract: An elastic layer includes a needle-shaped filler and a void and has a porosity of 20 vol % or more and 60 vol % or less. The elastic layer contains a first area and a second area. The first area extends from a surface of the elastic layer opposite to a surface facing the mandrel toward the mandrel and has a thickness of 30% of the thickness of the elastic layer. The second area is a central area in a thickness direction of the elastic layer and has a thickness of 40% of the thickness of the elastic layer. The needle-shaped filler in the second area has an orientation degree of 50% or lower. The needle-shaped filler in the first area has an orientation degree higher than that of the needle-shaped filler in the second area.

Abstract: A fixing member, includes: a base layer; and a porous elastic layer provided on the base layer and configured to contain a needle-like filler. The elastic layer has a thermal conductivity, with respect to a longitudinal direction thereof, which is 6 times to 900 times a thermal conductivity with respect to a thickness direction thereof. The elastic layer has an open cell rate larger at longitudinal end portions than at a longitudinal central portion.

Abstract: A fixing device includes a rotatable heating member and a rotatable pressing member which are configured to fix a toner image on a recording material in a nip therebetween; and a heating mechanism configured to selectively heat regions of the rotatable heating member depending on sizes of the recording material when the sizes are predetermined ones of all sizes usable in the fixing device. The rotatable pressing member includes a base layer and a porous elastic layer provided on the base layer and containing a needle-like filler. The elastic layer having a thermal conductivity, with respect to a longitudinal direction thereof, which is 6 times to 900 times a thermal conductivity with respect to a thickness direction thereof.

Abstract: A fixing member used for fixing a toner image on a recording material includes: a base layer; and a porous elastic layer provided on the base layer and containing a needle-like filler. The elastic layer has a thermal conductivity with respect to a longitudinal direction thereof in a first region where the elastic layer is contactable to the recording material on the fixing member, and the thermal conductivity is 6 times to 900 times a thermal conductivity with respect to a thickness direction in the first region. The elastic layer has a thermal conductivity with respect to the thickness direction thereof in a second region outside the first region with respect to the longitudinal direction, and the thermal conductivity with respect to the thickness direction in the second region is larger than the thermal conductivity with respect to the thickness direction in the first region.

Abstract: A manufacturing apparatus for manufacturing a fixing member includes: a metal mold capable of holding a base material of the fixing member in an inside thereof; and an injecting member including a group of openings configured to inject a liquid rubber containing a needle-like filler into the metal mold in which the base material is held. The injecting member is configured so that a ratio of a total perimeter of the group of openings to a sum of a perimeter of an inner surface of the metal mold and an outer surface of the base material is 1.3 or more and 3.3 or less.

Abstract: Provided are an electrophotographic member having excellent durability and an electrophotographic image forming apparatus. The electrophotographic member includes: an elastic layer including a silicone rubber; an intermediate layer including at least one of an aromatic polyimide and an aromatic polyamideimide, and a fluororesin; and a surface layer including a fluororesin, in which the aromatic polyimide or the aromatic polyamideimide is bonded to the silicone rubber through an amide bond-containing group, and in which a carbon atom constituting the amide bond is directly bonded to a carbon atom constituting an aromatic ring in a molecule of the aromatic polyimide or aromatic polyamideimide.

Abstract: Provided are an electrophotographic member having excellent durability and an electrophotographic image forming apparatus. The electrophotographic member includes: an elastic layer including a silicone rubber; an intermediate layer including at least one of an aromatic polyimide and an aromatic polyamideimide, and a fluororesin; and a surface layer including a fluororesin, in which the aromatic polyimide or the aromatic polyamideimide is bonded to the silicone rubber through an amide bond-containing group, and in which a carbon atom constituting the amide bond is directly bonded to a carbon atom constituting an aromatic ring in a molecule of the aromatic polyimide or aromatic polyamideimide.

Abstract: A pressing roller includes a cylindrical core metal; a first rubber layer of non-porous material provided on the core metal; and a second rubber layer of porous material provided on the first rubber layer, wherein the second rubber layer includes a thermo-conductive filler dispersed therein such that a thermal conductivity of the second rubber layer in a longitudinal direction is higher than a thermal conductivity thereof in a thickness direction, and wherein the first rubber layer includes a thermo-conductive filler dispersed therein such that a thermal conductivity of the first rubber layer in an thickness direction is higher than a thermal conductivity of the second rubber layer in the thickness direction of the second rubber layer.