Abstract: A fixing unit includes a rotary member that includes a conductive layer, a magnetic core inserted in an interior space of the rotary member, and an energizing coil that includes a conductor and that is wound helically around a circumference of the magnetic core. In a case where a distance between a first cross section of the conductor in a plane along the longitudinal direction and a second cross section of the conductor in the plane and adjacent to the first cross section in the longitudinal direction is L1 (mm), and a distance between the conductor and the magnetic core in a radial direction orthogonal to the helical axis is L2 (mm), following inequalities are satisfied, L1>0.1 and 0.1<L2<2.0.

Abstract: A fixing apparatus to fix a toner image formed on a recording material to the recording material includes a rotatable member having a heat generation layer, a power supply circuit, and a control unit. The power supply circuit supplies electrical power to the rotatable member. The control unit controls supply of electrical power to the rotatable member and detects a change rate of electrical resistance of the heat generation layer. The heat generation layer generates heat by the electrical power supplied to the rotatable member, and the toner image on the recording material is fixed to the recording material by the heat from the heat generation layer. If the change rate of the electrical resistance to the supplied electrical power is higher than a predetermined threshold, the control unit stops the supply of electrical power to the rotatable member.

Abstract: A fixing member includes a conductive layer that generates heat when a circulation current in a circumferential direction of the fixing member having a tubular shape is induced. The conductive layer includes segments arranged in a row in a longitudinal direction of the tubular shape and electrically separated from each other. Each segment is formed continuously over an entire circumference of the tubular shape in the circumferential direction. The conductive layer is configured such that a heat generation amount in an end portion of the fixing member in the longitudinal direction is less than a heat generation amount in a central portion of the fixing member in the longitudinal direction when an alternating magnetic field is applied to a whole area of the fixing member in the longitudinal direction in a state where a temperature of the central portion is equal to a temperature of the end portion.

Abstract: A fixing apparatus to fix a toner image formed on a recording material to the recording material includes a rotatable member having a heat generation layer, a power supply circuit, and a control unit. The power supply circuit supplies electrical power to the rotatable member. The control unit controls supply of electrical power to the rotatable member and detects a change rate of electrical resistance of the heat generation layer. The heat generation layer generates heat by the electrical power supplied to the rotatable member, and the toner image on the recording material is fixed to the recording material by the heat from the heat generation layer. If the change rate of the electrical resistance to the supplied electrical power is higher than a predetermined threshold, the control unit stops the supply of electrical power to the rotatable member.

Abstract: A fixing apparatus includes a rotary member including a heat-generation layer with a plurality of rings, a temperature detecting portion configured to detect a temperature of the rotary member, a conduction detecting unit configured to detect a conduction failure in an opposing ring that is one of the plurality of rings of the heat-generation layer and that opposes the temperature detecting portion, and a controller configured to control the supply of power to the magnetic field generator. The conduction detecting unit includes a first magnetic core, a second magnetic core, and a current detecting portion that includes a detection coil. A length of one of the first magnetic core and the second magnetic core around which the detection coil is wound is less than a length of another of the first magnetic core and the second magnetic core around which the detection coil is not wound.

Abstract: An image forming apparatus includes an image forming portion, a fixing portion configured to heat the toner image formed on the sheet by the image forming portion and fix the toner image to the sheet, a folding portion configured to fold the sheet having passed through the fixing portion such that a surface of the sheet to which the powder adhesive is applied is inside, and a bonding portion configured to heat the sheet folded by the folding portion and bond the sheet by the powder adhesive. A relationship of Tmax1>Tmax2 is satisfied, where Tmax1 (° C.) is a highest temperature of the powder adhesive when being heated by the fixing portion and Tmax2 (° C.) is a highest temperature of the powder adhesive when being heated by the bonding portion.

Abstract: A fixing apparatus includes a rotary member including a heat-generation layer with a plurality of rings, a temperature detecting portion configured to detect a temperature of the rotary member, a conduction detecting unit configured to detect a conduction failure in an opposing ring that is one of the plurality of rings of the heat-generation layer and that opposes the temperature detecting portion, and a controller configured to control the supply of power to the magnetic field generator. The conduction detecting unit includes a first magnetic core, a second magnetic core, and a current detecting portion that includes a detection coil. A length of one of the first magnetic core and the second magnetic core around which the detection coil is wound is less than a length of another of the first magnetic core and the second magnetic core around which the detection coil is not wound.

Abstract: An image heating apparatus including a sleeve having divided heat generating layers, an exciting coil provided in an inside space of the sleeve, a magnetic core provided inside the exciting coil, a temperature detecting element opposing one of the divided heat generating layers, and a current monitoring sensor. An induced current is generated in the divided heat generating layers by passing an alternating current through the exciting coil, and the divided heat generating layers generate heat. An image on the recording material is heated by the divided heat generating layers. The current monitoring sensor is configured to monitor a current flowing through the above-described one of the divided heating generating layers.

Abstract: An image heating apparatus includes a sleeve including divided heat generating layers, an exciting coil provided in an inside space of the sleeve, a magnetic core provided inside the exciting coil, and a temperature detecting element opposing one of the divided heat generating layers. An induced current is generated in the divided heat generating layers by passing an alternating current through the exciting coil, and the divided heat generating layers generate heat. An image on the recording material is heated by the divided heat generating layers. The image heating apparatus further comprises a current monitoring sensor configured to monitor a current flowing through the above-described one of the divided heating generating layers.

Abstract: A cylindrical fixing member for use with a fixing device includes a heat generating layer and an electrode layer contacting the heat generating layer. The electrode layer is smaller in volume resistance value than the heat generating layer. The electrode layer is formed in a helical shape so that a helical axis thereof extends in a direction along a generatrix direction of the fixing member. One end and the other end of the electrode layer are electrically open.

Abstract: A fixing device fixes an image onto a recording material. The recording material is fed through and heated in a nip to fix the image. A nip plate is provided with a projection in a region downstream of the nip with respect to a feeding direction of the recording material, the projection projecting toward a roller and extending in a longitudinal direction of a cylindrical belt. The nip plate has a recess on a side opposite from an outside provided with the projection at a position corresponding to that of the projection with respect to the feeding direction, the recess extending in the longitudinal direction of the cylindrical belt. At least a part of one of the two end portions of a supporting member overlaps the recess of the nip plate with respect to the feeding direction of the recording material and a longitudinal direction of the cylindrical belt.

Abstract: A cylindrical fixing member for use with a fixing device includes a heat generating layer and an electrode layer contacting the heat generating layer. The electrode layer is smaller in volume resistance value than the heat generating layer. The electrode layer is formed in a helical shape so that a helical axis thereof extends in a direction along a generatrix direction of the fixing member. One end and the other end of the electrode layer are electrically open.

Abstract: A fixing device fixes an image onto a recording material. The recording material is fed through and heated in a nip to fix the image. A nip plate is provided with a projection in a region downstream of the nip with respect to a feeding direction of the recording material, the projection projecting toward a roller and extending in a longitudinal direction of a cylindrical belt. The nip plate has a recess on a side opposite from an outside provided with the projection at a position corresponding to that of the projection with respect to the feeding direction, the recess extending in the longitudinal direction of the cylindrical belt. At least a part of one of the two end portions of a supporting member overlaps the recess of the nip plate with respect to the feeding direction of the recording material and a longitudinal direction of the cylindrical belt.

Abstract: A fixing device for fixing an image on a recording material. A heater radiates radiant light to heat a nip plate. A roller cooperative with the nip plate forms a nip between a cylindrical belt and an outer peripheral surface of the roller. A recording material carrying the image is fed through and heated in the nip to fix the image on the recording material. The nip plate has a projection in a region downstream of the nip with respect to a feeding direction of the recording material. At least a part of one of the two end portions of a supporting member overlaps the projection of the nip plate with respect to the feeding direction of the recording material and the longitudinal direction of the cylindrical belt to support the projection. A spacer is provided between the projection and at least part of one of the two end portions.

Abstract: An image fixing device includes a cylindrical belt; a nip plate contacting an inner surface of the belt; a U-shaped supporting member provided in a hollow portion a cylindrical belt and having two end portions defining an opening of a U-shape thereof and supporting the nip plate; a heater provided in a region enclosed by the supporting member and the nip plate; a roller forming a nip between the belt and an outer peripheral surface of the roller. The nip plate is provided with a projection in a region downstream of the nip with respect to a feeding direction of a sheet. The projection projects toward the roller and extending in a longitudinal direction of the cylindrical belt. At least a part of one of the two end portions of the supporting member overlaps the projection of the nip plate to support the projection.

Abstract: In an image forming apparatus that forms an electrostatic latent image for detection on a photosensitive member by light irradiation and performs color-misregistration correction control on the basis of detection of a change in detection current due to the detecting electrostatic latent image passing through a processing unit disposed close to the periphery of the photosensitive member, the intensity of at least one of the apply voltage of the processing unit and the output of the light irradiation unit is set higher than that during normal image formation.

Abstract: An image forming apparatus includes: an image bearing member for bearing a toner image; a movable intermediary transfer member onto which the toner image is to be transferred from the image bearing member; and a cleaning member, contacting a surface of the intermediary transfer member, for scraping off a toner from the surface of the intermediary transfer member which moves. At the surface of the intermediary transfer member, a plurality of grooves are formed along a surface movement direction of the intermediary transfer member. The surface of the intermediary transfer member has an average in-plane roughness of 10 nm or more and 30 nm or less in an area of a square of an average particle size of the toner.

Abstract: An image forming apparatus includes a removal unit configured to remove developer that was not transferred to a recording material; and a control unit configured to control an image forming unit for supplying developer to the removal unit. The image forming unit is configured to form first developer image, and second developer image whose length in the sub-scanning direction is longer than that of the first developer image, and whose amount of developer per unit area is less than or equal to that of the first developer image, and the control unit is further configured to, based on a predetermined relationship between the recording material type and the supplying image, select a supplying image formed by the image forming unit before or after the developer image transferred to the recording material.

Abstract: An image forming apparatus includes: an image bearing member for bearing a toner image; a movable intermediary transfer member onto which the toner image is to be transferred from the image bearing member; and a cleaning member, contacting a surface of the intermediary transfer member, for scraping off a toner from the surface of the intermediary transfer member which moves. At the surface of the intermediary transfer member, a plurality of grooves are formed along a surface movement direction of the intermediary transfer member. The surface of the intermediary transfer member has an average in-plane roughness of 10 nm or more and 30 nm or less in an area of a square of an average particle size of the toner.

Abstract: An image forming apparatus includes an image bearing member, an intermediate transfer member, and a secondary transfer member having a plurality of protrusions which come into contact with the intermediate transfer member. A superficial layer of the intermediate transfer member includes a superficial layer and a plurality of insulating particles buried in the superficial layer so as to be partially exposed from she superficial layer. In the case where the insulating particles are present in a contact region in which the protrusions are brought into contact with the intermediate transfer member, a portion in which the protrusions are brought into direct contact with the superficial layer is present in the contact region.