Abstract: Image data of an image formed on a recording material includes a plurality of picture elements. A predetermined number of picture elements which is a portion of the image data are converted as one region to thereby convert the image data to conversion data including a plurality of regions. A value related to a print ratio in each of the regions of the conversion data is analyzed to acquire a value related to connection indicating how continuously regions in which the value related to the print ratio exceeds a threshold are adjacent to each other. Energization of the heat generating element is controlled on the basis of the temperature detected by the temperature detection portion and a control target temperature calculated from the value related to the connection.

Abstract: An image forming apparatus includes a photosensitive member; an exposure portion configured to expose the photosensitive member to light depending on image information to form a latent image on the photosensitive member; a developing portion configured to develop the latent image into a toner image with toner; and a transfer portion configured to transfer the toner image from the photosensitive member onto a recording material. The image forming apparatus changes a surface movement speed of the photosensitive member at timing prior to predetermined timing, when a moving speed of a recording material at the transfer portion changes, by a predetermined time.

Abstract: A pressure roller, and the pressure roller to be used in a fixing apparatus of in an image forming apparatus, the fixing apparatus configured to heat a toner image formed on a recording material and fix the toner image on the recording material, the pressure roller including a first elastic layer, and a second elastic layer provided on an outside of the first elastic layer, wherein a thermal conductivity of the first elastic layer is higher than a thermal conductivity of the second elastic layer, and wherein the first elastic layer contains a plurality of void portions, hole pathway portions joining the plurality of void portions to each other, and a needle-shaped high thermal conductive filler.

Abstract: An image forming apparatus includes an image forming portion that forms an image on a recording material, and a fixing portion including a cylindrical heat transfer member, and a heating member contacting an inner surface of the heat transfer member. The fixing portion fixes the image on the recording material by heating the recording material, on which the image has been formed, by heat from the heating member through the heat transfer member. A control unit controls a target temperature of the heating member, and analyzes whether or not a plurality of pixels, of image data corresponding to the image to be formed on the recording material, in each interval corresponding to a circumferential length of the heat transfer member, with respect to a recording material feeding direction, are pixels for forming an image with a predetermined density or more, and sets the target temperature depending on an analyzation result.

Abstract: A fixing device includes a belt, a heater, and a pressing member for forming a nip through the belt in cooperation with the heater. The nip includes a region at which a width of the nip with respect to a feeding direction of a recording material gradually increases from a longitudinal central portion toward a longitudinal end portion, and a pressure of the nip gradually increases from the longitudinal central portion toward the longitudinal end portion. A heat-conductive member includes a regulating portion for regulating movement thereof relative to a supporting member in a longitudinal direction of the heater. The regulating portion is provided in a region of the heat-conductive member corresponding to a position of the nip closer to the longitudinal end portion than to the longitudinal central portion, and a bias member is provided outside of the region of the heat-conductive member corresponding to the position of the nip.

Abstract: A fixing apparatus includes a thermal conductive member that is in contact with a heater and has a thermal conductivity higher than the thermal conductivity of a base material of the heater, and a thermal-resistant member that is disposed between the thermal conductive member and a support member configured to support the heater, a thermal resistance in a thickness direction of the thermal-resistant member being higher than the thermal resistance in the thickness direction of the thermal conductive member.

Abstract: Image data of an image formed on a recording material includes a plurality of picture elements. A predetermined number of picture elements which is a portion of the image data are converted as one region to thereby convert the image data to conversion data including a plurality of regions. A value related to a print ratio in each of the regions of the conversion data is analyzed to acquire a value related to connection indicating how continuously regions in which the value related to the print ratio exceeds a threshold are adjacent to each other. Energization of the heat generating element is controlled on the basis of the temperature detected by the temperature detection portion and a control target temperature calculated from the value related to the connection.

Abstract: An image forming apparatus includes an image forming portion configured to form an image on a recording material; a fixing portion including a cylindrical heat transfer member and a heating member contacting an inner surface of the heat transfer member and configured to fix the image on the recording material by heating the image-formed recording material by heat from the heating member through the heat transfer member; and a control unit configured to control a target temperature of the heating member. The control unit analyzes whether or not a plurality of pixels, of image data corresponding to the image to be formed on the recording material, in each interval corresponding to a circumferential length of the heat transfer member with respect to a recording material feeding direction are pixels for forming an image with a predetermined density or more, and sets the target temperature depending on an analyzation result.

Abstract: In a configuration in which a voltage of polarity opposite to charging polarity of toner is applied to a conveyance guide, controlling deposition of toner on the conveyance guide has been difficult. When performing duplex image formation, a potential difference between a surface potential of a photoconductive drum charged by a charging roller and a potential of the conveyance guide is smaller during printing on the second surface than during printing on the first surface.

Abstract: An image heating device includes a rotator, a heater including a heat generating resistor, a connector electrically connected to the heater, and a power interrupting unit that detects an abnormal temperature rise of the heater and interrupt supply of the power to the heater. The power interrupting unit includes a first terminal and a second terminal, a first conductive sheet metal that electrically connects the connector to the first terminal, a second conductive sheet metal that to electrically connects the connector to the second terminal via the heat generating resistor, a length of the second conductive sheet metal being different from a length of the first conductive sheet metal in the longitudinal direction of the heater, and a supporting member supporting the heater and including a regulation portion that regulates rotation of the power interrupting unit.

Abstract: A fixing device includes a heating rotating member having a conductive layer and an exposed portion in which the conductive layer is partially exposed, and a roller including a metal core and an elastic portion, the roller forming a nip portion with the heating rotating member, the elastic portion being elastically deformed in a region where the nip portion is formed, wherein an annular conductive member provided in a longitudinal end portion of the metal core is in contact with the exposed portion of the heating rotating member while elastically deformed, and wherein in a state where the roller is not mounted to the fixing device, an outer diameter of the conductive member is smaller than an outer diameter of the elastic portion.

Abstract: An image heating device includes a rotator, a heater including a heat generating resistor, a connector electrically connected to the heater, and a power interrupting unit that detects an abnormal temperature rise of the heater and interrupt supply of the power to the heater. The power interrupting unit includes a first terminal and a second terminal, a first conductive sheet metal that electrically connects the connector to the first terminal, a second conductive sheet metal that to electrically connects the connector to the second terminal via the heat generating resistor, a length of the second conductive sheet metal being different from a length of the first conductive sheet metal in the longitudinal direction of the heater, and a supporting member supporting the heater and including a regulation portion that regulates rotation of the power interrupting unit.

Abstract: In a configuration in which a voltage of polarity opposite to charging polarity of toner is applied to a conveyance guide, controlling deposition of toner on the conveyance guide has been difficult. When performing duplex image formation, a potential difference between a surface potential of a photoconductive drum charged by a charging roller and a potential of the conveyance guide is smaller during printing on the second surface than during printing on the first surface.

Abstract: An image forming apparatus includes a photosensitive member; an exposure portion configured to expose the photosensitive member to light depending on image information to form a latent image on the photosensitive member; a developing portion configured to develop the latent image into a toner image with toner; and a transfer portion configured to transfer the toner image from the photosensitive member onto a recording material. The image forming apparatus changes a surface movement speed of the photosensitive member at timing prior to predetermined timing, when a moving speed of a recording material at the transfer portion changes, by a predetermined time.

Abstract: A fixing device includes a cylindrical belt; a heater including an elongated substrate and a heat generating resistor provided on the substrate; a heat-conductive member contacting a surface of the heater opposite from a belt contacting surface of the heater, and having thermal conductivity higher than that of the substrate; a supporting member; and a pressing member. The nip includes a region where a width of the nip with respect to a feeding direction of the recording material gradually increases from a longitudinal central portion toward a longitudinal end portion. The heat-conductive member includes a preventing portion for preventing movement thereof relative to the supporting member in a longitudinal direction of the heater. The preventing portion is provided in a region of the heat-conductive member corresponding to a position of the nip closer to the longitudinal end portion than to the longitudinal central portion.

Abstract: A fixing apparatus includes a film, a heater contacting an inner surface of the film, a heat conducting member contacting a back surface of the heater, and a supporter supporting the heater, the supporter including a groove accommodating the heater and the heat conducting member. A surface of the groove facing an end surface of the heater on a downstream side includes a first protrusion, a second protrusion, and a third protrusion with gaps between each other in a direction orthogonal to the conveyance direction, the third protrusion being disposed between the first protrusion and the second protrusion and having a smaller protruding amount than the first protrusion and the second protrusion. a portion of the heat conducting member facing the third protrusion is recessed more than portions of the heat conducting member facing the first protrusion and the second protrusion.

Abstract: A fixing apparatus for fixing an image on a recording material includes a cylindrical film, a heater configured to heat the film, the heater contacting an inner surface of the film, a heat transfer member configured to contact a surface opposite to a surface of the heater that contacts the inner surface of the film, and a support member configured to support the heater. A heat capacity per unit length of a first portion that is a portion of the heat transfer member corresponding to a region near an end of the recording material in a width direction among non-sheet passing region is larger than that of a second portion that is a portion of the heat transfer member corresponding to a center of the recording material in the width direction.

Abstract: A fixing apparatus includes a film, a heater contacting an inner surface of the film, a heat conducting member contacting a back surface of the heater, and a supporter supporting the heater, the supporter including a groove accommodating the heater and the heat conducting member. A surface of the groove facing an end surface of the heater on a downstream side includes a first protrusion, a second protrusion, and a third protrusion with gaps between each other in a direction orthogonal to the conveyance direction, the third protrusion being disposed between the first protrusion and the second protrusion and having a smaller protruding amount than the first protrusion and the second protrusion. a portion of the heat conducting member facing the third protrusion is recessed more than portions of the heat conducting member facing the first protrusion and the second protrusion.

Abstract: A fixing apparatus configured to heat a recording material having a toner image formed thereon and fix the toner image fixing on the recording material comprising: a film; a heater configured to contact the film, the heater including a substrate and a heat generation resistor formed on the substrate; a thermal conduction member configured to contact a surface of the heater opposite to a surface of the heater that contacts the film, the thermal conduction member having a thermal conductivity higher than that of the substrate; and a pressurizing roller configured to form a pressing portion with the heater via the film, wherein the thermal conduction member contacts the heater so as not to overlap with an end region of the heat generation resistor in a longitudinal direction of the heat generation member.

Abstract: A fixing device includes a tubular film; a heater including a substrate and a heat generating resistor, the heater having a first region on which the heat generating resistor is formed and a second region, located outside of the first region in a longitudinal direction of the substrate, on which the heat generating resistor is not formed; and a heat conductive member configured to contact a surface of the heater opposite to a surface of the heater that contacts the film, the heat conductive member having a higher heat conductivity than the substrate. The heat conductive member contacts the heater in a region extending across the first region and the second region, and an amount of heat generated by the heat generating resistor at its end portion is greater than that at its middle portion in the longitudinal direction.