Abstract: A fixing member used for a fixing device includes a tubular base layer; an electrode portion formed on the base layer; a heat generating portion formed on the base layer in such a manner as to be positioned next to the electrode portion in a longitudinal direction of the fixing member, the heat generating portion being electrically connected to the electrode portion; and an overcoat layer formed on the heat generating portion. The heat generating portion is a layer formed by a plurality of thin linear layers extending in the longitudinal direction of the fixing member and spaced from one another along a circumferential direction of the fixing member. The overcoat layer extends over a boundary between the heat generating portion and the electrode portion in the longitudinal direction of the fixing member.

Abstract: A tubular film used for a fixing apparatus includes a heat generating layer, and a first conductive layer and a second conductive layer provided respectively at one end and another end of the film in a longitudinal direction of the film so as to contact the heat generating layer. The first conductive layer and the second conductive layer both have a lower volume resistivity than that of the heat generating layer. A low-resistance layer is formed in an area of the heat generating layer between the first conductive layer and the second conductive layer in the longitudinal direction so as not to contact the first conductive layer and the second conductive layer. The low-resistance layer has a lower volume resistivity than that of the heat generating layer and extends in a circumferential direction of the heat generating layer.

Abstract: A film for use in a fixing device includes a base layer having a cylindrical shape. An electrode portion is formed at an end part of the base layer in a longitudinal direction of the film. A heat generation portion is formed at a central part of the base layer in the longitudinal direction of the film and electrically connected to the electrode portion. The heat generation portion is formed of a conductive layer made of a same material as a material of the electrode portion. A thickness of the conductive layer is larger in the electrode portion than in the heat generation portion. A surface area of the conductive layer per unit length in the longitudinal direction of the film is larger in the electrode portion than in the heat generation portion.

Abstract: Provided is a fixing apparatus provided with a displacement mechanism 21 which displaces a relative position of a fixing film 1 which generates heat when energized, with respect to a pressure roller 3, wherein, when the fixing film is separated from the pressure roller by the displacement mechanism, an interval between a fulcrum at which a contact holding member 10 holds a contact member 9 and a contact at which the contact member 9 comes into contact with the fixing film 1 does not increase.

Abstract: A fixing member for a fixing device includes a cylindrical base layer, and a plurality of heat generating resistors extending in a longitudinal direction of the fixing member on the base layer and arranged with intervals in a circumferential direction of the base layer. Each of the plurality of heat generating resistors has a volume resistivity less than that of the base layer. The plurality of heat generating resistors includes a first heat generating resistor and a second heat generating resistor adjacent to each other in the circumferential direction, and the first heat generating resistor and the second heat generating resistor are at least partly overlapped in the circumferential direction.

Abstract: A cylindrical film used in an image heating device heating a recording material, on which an image has been formed, has a resin layer, this resin layer being made from a resin in which a crystalline resin and an amorphous resin having a higher glass transition temperature than the crystalline resin are blended, wherein a volume ratio of the crystalline resin with respect to the amorphous resin in the resin layer is 70/30 to 99/1.

Abstract: A fixing device includes a cylindrical film including a heat generating layer and an electroconductive layer electrically connected with the heat generating layer. Volume resistivity of the electroconductive layer is lower than volume resistivity of the heat generating layer. The fixing device further includes an energizing member, a roller, a sliding member, and a supporting member. Thermal conductivity of the sliding member is higher than thermal conductivity of the supporting member. A recording material on which a toner image is formed is heated while being fed through a nip. A longitudinal end of the sliding member is positioned between an inner end surface and an outer end surface of the electroconductive layer with respect to the longitudinal direction of the film.

Abstract: A tubular film used for a fixing apparatus, including: a heat generating layer; a first conductive layer and a second conductive layer provided respectively at one end and another end of the film in a longitudinal direction of the film so as to contact the heat generating layer, the first conductive layer and the second conductive layer both having a lower volume resistivity than the heat generating layer; and a low-resistance layer formed in an area of the heat generating layer between the first conductive layer and the second conductive layer in the longitudinal direction so as not to contact the first conductive layer and the second conductive layer, the low-resistance layer having a lower volume resistivity than the heat generating layer and extending in a circumferential direction of the heat generating layer.

Abstract: Provided is a fixing apparatus for fixing a toner image on a recording material while conveying the recording material on which the toner image has been formed at a nip portion that includes a roller, a heating unit configured to heat the roller from outside the roller, the heating unit receiving power supplied from a power supply, a backup unit forming the nip portion with the roller, and a power shutdown member configured to operate in response to an abnormal temperature of the backup unit and shut down power supply to the heating unit.

Abstract: An image forming apparatus includes a fixing unit including a roller, a heating rotary member heating the roller, and a backup member forming a nip portion, a temperature detection unit detecting a temperature of the heating rotary member, and a control unit for controlling power so that the detected temperature is maintained at a target temperature, wherein a print job includes a first step in which the unfixed toner image is formed on the recording material, a second step in which fixing processing is executed, and a third step in which the fixing unit is cleaned, and wherein the third step is executed following the second step, and in the third step, while the target temperature is set higher than the target temperature in the second step, the roller and the heating rotary member are rotated in a state where no recording material is present at the nip portion.

Abstract: A fixing device includes a cylindrical film including a heat generating layer and configured to be supplied with electric power so that the heat generating layer generates heat; a first temperature detecting member contacting the film; a second temperature detecting member contacting the film and provided at such a position that temperature change at the position of the second temperature detecting member is slower in responsiveness than at a position of the first temperature detecting member; and a controller configured to control the electric power supplied to the film. A toner image formed on a recording material is heated by heat from the film and is fixed on the recording material. The controller stops supply of the electric power to the film depending on a difference value between detection temperatures of the first and second temperature detecting members.

Abstract: A fixing device includes a heating member including a base layer, first and second electroconductive layers and a plurality of heat generating resistors provided on the base layer and having a volume resistivity smaller than a volume resistivity of the base layer; a temperature detecting member; and an electrode member. The heat generating resistors are provided helically around the base layer so that a helical axis thereof extends along the longitudinal direction of the rotatable member, and are disposed with intervals. One end and the other end of each of the heat generating resistors are electrically connected with the first and the second electroconductive layers, respectively. A temperature detecting region of the rotatable member by the temperature detecting member overlaps with the heat generating resistors.

Abstract: A fixing member for a fixing device, the fixing member includes a cylindrical base layer; and a plurality of heat generating resistors extending in a longitudinal direction of the fixing member on the base layer and arranged with intervals in a circumferential direction of the base layer, wherein heat generating resistors have volume resistivities lower than that of the base layer, the heat generating resistors include a first heat generating resistor and a second heat generating resistor adjacent to each other in the circumferential direction, and the first heat generating resistor and the second heat generating resistor are at least partly overlapped in the circumferential direction.

Abstract: Provided is a fixing apparatus for fixing a toner image on a recording material while conveying the recording material on which the toner image has been formed at a nip portion that includes a roller, a heating unit configured to heat the roller from outside the roller, the heating unit receiving power supplied from a power supply, a backup unit forming the nip portion with the roller, and a power shutdown member configured to operate in response to an abnormal temperature of the backup unit and shut down power supply to the heating unit.

Abstract: An image fixing device includes an elastic roller; a back-up unit forming a fixing nip with the roller therebetween, the back-up unit including a cylindrical film, a film guide, extending inside the film, for guiding the film, and an end portion guiding member including a guiding portion for guiding an inner surface of an end portion of the film. The film guide includes plural ribs contacting the film and arranged in a generatrix direction at positions upstream of the fixing nip with respect to a feeding direction of a sheet. The ribs have free end portions retracted more toward a downstream side with respect to the feeding direction of the recording material than the guiding portion of the end portion guiding member. An inside rib has a free end portion which is retracted more toward the downstream side than free end portions of the opposite end ribs.

Abstract: A film for use in a fixing device includes a base layer having a cylindrical shape. An electrode portion is formed at an end part of the base layer in a longitudinal direction of the film. A heat generation portion is formed at a central part of the base layer in the longitudinal direction of the film and electrically connected to the electrode portion. The heat generation portion is formed of a conductive layer made of a same material as a material of the electrode portion. A thickness of the conductive layer is larger in the electrode portion than in the heat generation portion. A surface area of the conductive layer per unit length in the longitudinal direction of the film is larger in the electrode portion than in the heat generation portion.

Abstract: A fixing apparatus includes a roller, a heating rotation member configured to form a pressure portion by coming into contact with the roller, the heating rotation member being rotated by rotation of the roller, and a pressing rotation member configured to form a nip portion by coming into contact with the roller, the pressing rotation member being rotated by the rotation of the roller, wherein micro-hardness of a surface of the heating rotation member at the pressure portion and micro-hardness of a surface of the pressing rotation member at the nip portion are both higher than micro-hardness of a surface of the roller, and wherein frictional force acting on the roller at the pressure portion is larger than frictional force acting on the roller at the nip portion.

Abstract: An image fixing device includes an elastic roller; a back-up unit forming a fixing nip with the roller therebetween, the back-up unit including a cylindrical film, a film guide, extending inside the film, for guiding the film, and an end portion guiding member including a guiding portion for guiding an inner surface of an end portion of the film. The film guide includes plural ribs contacting the film and arranged in a generatrix direction at positions upstream of the fixing nip with respect to a feeding direction of a sheet. The ribs have free end portions retracted more toward a downstream side with respect to the feeding direction of the recording material than the guiding portion of the end portion guiding member. An inside rib has a free end portion which is retracted more toward the downstream side than free end portions of the opposite end ribs.

Abstract: An image forming apparatus for forming a toner image on a recording material, the apparatus includes a cylindrical film; a plate-like nip forming member contacted with an inner surface of the film, the nip forming member including a base member and a coating layer on the base member, the coating layer having a thermal expansion coefficient smaller than that of the base member; and a roller cooperative with the nip forming member to form a nip, wherein the coating layer is provided on a first surface of the nip forming member which is opposed to the film and on a second surface opposite from the first surface except for an outer edge portion of the nip forming member.

Abstract: A cylindrical film used in an image heating device heating a recording material, on which an image has been formed, has a resin layer, this resin layer being made from a resin in which a crystalline resin and an amorphous resin having a higher glass transition temperature than the crystalline resin are blended, wherein a volume ratio of the crystalline resin with respect to the amorphous resin in the resin layer is 70/30 to 99/1.