Abstract: A heater includes: a substrate; an insulating layer that is provided on the substrate; and a heat generating element that is provided on the insulating layer, and in a case where a region including a center of the substrate is defined as a first region, a region on a side closer to one end portion than the first region is defined as a second region, and a region on a side closer to the other end portion than the first region is defined as a third region in a transverse direction that is orthogonal to a longitudinal direction of a surface of the substrate on which the insulating layer is provided, the first region is a plane, and the second region and the third region are bent from the first region in a thickness direction of the substrate that is orthogonal to the longitudinal direction and the transverse direction.

Abstract: A fixing unit includes a film with a tubular shape, a nip forming unit including a heater and configured to be in sliding contact with an inner surface of the film. The heater includes a substrate made of metal. The fixing unit further includes a power supply connector electrically connected to the power supply electrode so that the power supply connector is connected to the heating element at a first end portion of the substrate in a longitudinal direction of the heater, and a pressing member opposed to the nip forming unit. The fixing unit further includes a voltage application circuit configured to apply a voltage of a same polarity as a normal charging polarity of the toner to the substrate, the voltage application circuit being connected to the substrate at a second end portion of the substrate opposite to the first end portion in the longitudinal direction.

Abstract: A heater includes a substrate formed of metal into a plate shape in which a length in a longitudinal direction thereof is greater than a length in a short direction thereof when viewed in a thickness direction thereof, an insulating layer formed of insulating material on a first surface of the substrate on a first side in the thickness direction, a heating element arranged on the insulating layer and configured to generate heat by flowing electric current therethrough, and a cover layer arranged to cover the heating element. The heater is a warped shape when receiving no external force, such that a center portion of the heater in the longitudinal direction protrudes to the first side in the thickness direction compared to both end portions of the heater in the longitudinal direction.

Abstract: A fixing unit includes a film with a tubular shape, a nip forming unit including a heater and configured to be in sliding contact with an inner surface of the film, the heater including a substrate made of metal, an insulating layer formed on the substrate, and a heating element arranged on the insulating layer and configured to generate heat when a first AC voltage is applied from an AC power supply connected thereto, a pressing member opposed to the nip forming unit with the film interposed therebetween and configured to form a nip portion with the film, and a voltage application circuit configured to apply a second AC voltage to the substrate with a waveform that takes a voltage value of an opposite polarity to the first AC voltage when the first AC voltage takes a peak value.

Abstract: A fixing apparatus includes a tubular film, an elongate plate-like heater including a first surface in contact with an inner surface of the film and a second surface opposite to the first surface, the heater being in contact with the inner surface of the film with the second surface, a heat conducting member that is long along the length of the heater and is in contact with the second surface of the heater, and a support member capable of rotating the film while supporting the heater, with the heat conducting member therebetween. The heat conducting member includes an extending portion extending, outside an upstream end of the heater in a rotational direction of the film, in a direction from the second surface of the heater toward the first surface. The extending portion includes a contact portion protruding from the first surface of the heater toward the film into contact therewith.

Abstract: A heater includes a substrate formed of metal into a plate shape in which a length in a longitudinal direction thereof is greater than a length in a short direction thereof when viewed in a thickness direction thereof, an insulating layer formed of insulating material on a first surface of the substrate on a first side in the thickness direction, a heating element arranged on the insulating layer and configured to generate heat by flowing electric current therethrough, and a cover layer arranged to cover the heating element. The heater is a warped shape when receiving no external force, such that a center portion of the heater in the longitudinal direction protrudes to the first side in the thickness direction compared to both end portions of the heater in the longitudinal direction.

Abstract: A fixing unit includes a film with a tubular shape, a nip forming unit including a heater and configured to be in sliding contact with an inner surface of the film, the heater including a substrate made of metal, an insulating layer formed on the substrate, and a heating element arranged on the insulating layer and configured to generate heat when applied first AC voltage from an AC power supply connected thereto, a pressing member opposed to the nip forming unit with the film interposed therebetween and configured to form a nip portion with the film, and a voltage application circuit configured to apply second AC voltage to the substrate with a waveform that takes a voltage value of an opposite polarity as the first AC voltage when the first AC voltage takes a peak value.

Abstract: A fixing unit includes a film with a tubular shape, a nip forming unit including a heater and configured to be in sliding contact with an inner surface of the film. The heater includes a substrate made of metal. The fixing unit further includes a power supply connector electrically connected to the power supply electrode so that the power supply connector is connected to the heating element at a first end portion of the substrate in a longitudinal direction of the heater, and a pressing member opposed to the nip forming unit. The fixing unit further includes a voltage application circuit configured to apply a voltage of a same polarity as a normal charging polarity of the toner to the substrate, the voltage application circuit being connected to the substrate at a second end portion of the substrate opposite to the first end portion in the longitudinal direction.

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: A fixing apparatus includes a holding member including a groove-like holding portion, a heater supported by the holding portion, a film rotatable around the heater, the film being configured to be heated by sliding on the heater and to heat a toner image on a printing material, and a gap filling member including, on an upstream side with respect to the heater in a direction in which the circumferential surface of the film moves, a first portion disposed between the heater and the holding member and a first contact portion connecting to the first portion and being in contact with the film. A second distance between the first portion and the holding member disposed upstream from the first portion and facing the first portion is smaller than a first distance between the heater and the first portion disposed upstream from the heater and facing the holding member.

Abstract: A fixing device including a rotatable tubular film, a heater including a substrate and a heat generating resistor, the heater including a first surface in contact with an inner surface of the film and a second surface opposite to the first surface, the heater extending in a longitudinal direction of the substrate, and a heat conducting member extending in the longitudinal direction and including a heater contact portion in contact with the second surface. The heat conducting member includes a film contact portion at a position adjacent to the first surface, the film contact portion being in contact with the inner circumferential surface, and on one side in the longitudinal direction, the heat generating resistor extends outside of a longitudinal end portion of the film contact portion, and the heater contact portion extends outside of the film contact portion.

Abstract: A fixing apparatus includes a tubular film, an elongate plate-like heater including a first surface in contact with an inner surface of the film and a second surface opposite to the first surface, the heater being in contact with the inner surface of the film with the second surface, a heat conducting member that is long along the length of the heater and is in contact with the second surface of the heater, and a support member capable of rotating the film while supporting the heater, with the heat conducting member therebetween. The heat conducting member includes an extending portion extending, outside an upstream end of the heater in a rotational direction of the film, in a direction from the second surface of the heater toward the first surface. The extending portion includes a contact portion protruding from the first surface of the heater toward the film into contact therewith.

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 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: A fixing apparatus includes a holding member including a groove-like holding portion, a heater supported by the holding portion, a film rotatable around the heater, the film being configured to be heated by sliding on the heater and to heat a toner image on a printing material, and a gap filling member including, on an upstream side with respect to the heater in a direction in which the circumferential surface of the film moves, a first portion disposed between the heater and the holding member and a first contact portion connecting to the first portion and being in contact with the film. A second distance between the first portion and the holding member disposed upstream from the first portion and facing the first portion is smaller than a first distance between the heater and the first portion disposed upstream from the heater and facing the holding member.

Abstract: An image forming apparatus including: a charging member configured to charge a photosensitive member at a charging portion by a charging voltage in which an alternate-current voltage is superimposed on a direct-current voltage; a transfer member configured to transfer a toner image formed on the photosensitive member to a recording material at a transfer portion; and a controller configured to control the charging voltage, a predetermined area of the photosensitive member passing through the transfer portion during a trailing edge of the recording material passing through the transfer portion, wherein the controller controls a value of a peak-to-peak voltage of the alternate-current voltage when the predetermined area passes through the charging portion to be larger than a value of a peak-to-peak voltage when an area that becomes the image area other than the predetermined area passes through the charging portion.

Abstract: A fixing device including a rotatable tubular film, a heater including a substrate and a heat generating resistor, the heater including a first surface in contact with an inner surface of the film and a second surface opposite to the first surface, the heater extending in a longitudinal direction of the substrate, and a heat conducting member extending in the longitudinal direction and including a heater contact portion in contact with the second surface. The heat conducting member includes a film contact portion at a position adjacent to the first surface, the film contact portion being in contact with the inner circumferential surface, and on one side in the longitudinal direction, the heat generating resistor extends outside of a longitudinal end portion of the film contact portion, and the heater contact portion extends outside of the film contact portion.

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: An image forming apparatus including: a charging member configured to charge a photosensitive member at a charging portion by a charging voltage in which an alternate-current voltage is superimposed on a direct-current voltage; a transfer member configured to transfer a toner image formed on the photosensitive member to a recording material at a transfer portion; and a controller configured to control the charging voltage, a predetermined area of the photosensitive member passing through the transfer portion during a trailing edge of the recording material passing through the transfer portion, wherein the controller controls a value of a peak-to-peak voltage of the alternate-current voltage when the predetermined area passes through the charging portion to be larger than a value of a peak-to-peak voltage when an area that becomes the image area other than the predetermined area passes through the charging portion.

Abstract: An image forming apparatus includes a plurality of image bearing members and a control unit. After an image forming mode starts until a toner image is primarily transferred onto an intermediate transfer member from an uppermost-stream image bearing member of the plurality of image bearing members provided at an uppermost stream position, the control unit is configured to provide a toner patch onto at least one of primary transfer portions. The toner patch is formed by developing an electrostatic latent image formed on at least one of the plurality of the image bearing members, and in the image forming mode a timing at which a trailing edge of the toner patch that passes through one of the plurality of the primary transfer portions reaches a secondary transfer portion is earlier than a timing at which the recording material reaches the secondary transfer portion.