Abstract: Provided is an endless belt-shaped electrophotographic member having a superior durability. The member comprises an endless belt-shaped substrate and a surface layer, the surface layer comprising an ionizing radiation crosslinked product of a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), the surface layer is formed by irradiation of electron beam to a resin layer, the resin layer comprising the PFA, the surface layer has a universal hardness HU at 200° C. of 18 N/mm2?HU?40 N/mm2, and when a degree of orientation of the PFA in the resin layer in a direction orthogonal to the circumferential direction of the substrate is defined as Ri, and a degree of orientation of the crosslinked PFA in the surface layer in the direction orthogonal to the circumferential direction of the substrate is defined as Rf, Ri and Rf satisfy a relationship represented by expression (1): Ri×0.8?Rf?Ri??(1).

Abstract: Provided is an endless belt-shaped electrophotographic member having a superior durability. The member comprises an endless belt-shaped substrate and a surface layer, the surface layer comprising an ionizing radiation crosslinked product of a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), the surface layer is formed by irradiation of electron beam to a resin layer, the resin layer comprising the PFA, the surface layer has a universal hardness HU at 200° C. of 18 N/mm2?HU?40 N/mm2, and when a degree of orientation of the PFA in the resin layer in a direction orthogonal to the circumferential direction of the substrate is defined as Ri, and a degree of orientation of the crosslinked PFA in the surface layer in the direction orthogonal to the circumferential direction of the substrate is defined as Rf, Ri and Rf satisfy a relationship represented by expression (1): Ri×0.8?Rf?Ri??(1).

Abstract: Provided is an image forming apparatus configured to appropriately determine that an abnormality has occurred in a component. The image forming apparatus includes: a charging device configured to charge a photosensitive drum; an exposure device configured to form an electrostatic latent image on the photosensitive drum charged by the charging device; a developing device including a carrying member configured to carry a toner and being configured to develop the electrostatic latent image using the toner to form a toner image; and a transfer portion configured to transfer the toner image onto a sheet. The image forming apparatus is configured to form a measurement image on the sheet, and to determine a unit that needs to be replaced based on a result of measuring the measurement image formed on the sheet. The measurement image includes a first measurement image and a second measurement image.

Abstract: Provided is an image forming apparatus configured to appropriately determine that an abnormality has occurred in a component. The image forming apparatus includes: a charging device configured to charge a photosensitive drum; an exposure device configured to form an electrostatic latent image on the photosensitive drum charged by the charging device; a developing device including a carrying member configured to carry a toner and being configured to develop the electrostatic latent image using the toner to form a toner image; and a transfer portion configured to transfer the toner image onto a sheet. The image forming apparatus is configured to form a measurement image on the sheet, and to determine a unit that needs to be replaced based on a result of measuring the measurement image formed on the sheet. The measurement image includes a first measurement image and a second measurement image.

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 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 control portion executes a measuring mode and generates a value for adjusting a pressurizing mechanism reflecting a difference of pressurizing conditions of a longitudinal center part and a longitudinal end part of a nip portion. The measuring mode is a mode of detecting temperatures of the nip portion by temperature detecting elements in a process of changing temperature of the nip portion heated by a heater and of generating control information based on detected results. The control information is generated in response to a difference of temperature increase amounts of the temperature detecting elements in a predetermined time in the process of increasing the temperature of the nip portion. The control portion adjusts the pressurizing mechanism based on the control value obtained in the measuring mode after executing a process of heating a recording medium in succession of the process of increasing the temperature of the nip portion.

Abstract: An image heating rotatable member for heating an image on a recording material, comprising a base layer; a heat generation layer, provided on the base layer, for generating heat by being supplied with electric power; an electrode layer, provided outside of the heat generation layer with respect to a widthwise direction and having an electric resistance which is smaller than that of the heat generation layer, for supplying the electric power to heat generation layer; an elastic layer provided on the electrode layer and having a length longer than that of the electrode layer measured in the widthwise direction; and a parting layer provided on the elastic layer and having a length which is substantially equal to the length of the electrode layer measured in the widthwise direction.

Abstract: An image heating apparatus includes an endless belt having a heat generation layer; a driving rotatable member forming a nip; a pressing pad for pressing the endless belt toward the driving rotatable member; an electric energy supply device for supplying electric energy to the heat generation layer; and a shut-off element configured to break electric connection between the electric energy supply device and the heat generation layer when a temperature of the endless belt reaches a predetermined upper limit temperature, wherein the shut-off element is disposed contacted with the endless belt in a region, with respect to a widthwise direction of the endless belt, outside a passing region of a maximum width of the sheet usable with the apparatus and inside of a heat generating region of the heat generation layer.

Abstract: A control portion executes a measuring mode and generates a value for adjusting a pressurizing mechanism reflecting a difference of pressurizing conditions of a longitudinal center part and a longitudinal end part of a nip portion. The measuring mode is a mode of detecting temperatures of the nip portion by temperature detecting elements in a process of changing temperature of the nip portion heated by a heater and of generating control information based on detected results. The control information is generated in response to a difference of temperature increase amounts of the temperature detecting elements in a predetermined time in the process of increasing the temperature of the nip portion. The control portion adjusts the pressurizing mechanism based on the control value obtained in the measuring mode after executing a process of heating a recording medium in succession of the process of increasing the temperature of the nip portion.

Abstract: An image heating rotatable member for heating an image on a recording material, comprising a base layer; a heat generation layer, provided on the base layer, for generating heat by being supplied with electric power; an electrode layer, provided outside of the heat generation layer with respect to a widthwise direction and having an electric resistance which is smaller than that of the heat generation layer, for supplying the electric power to heat generation layer; an elastic layer provided on the electrode layer and having a length longer than that of the electrode layer measured in the widthwise direction; and a parting layer provided on the elastic layer and having a length which is substantially equal to the length of the electrode layer measured in the widthwise direction.

Abstract: An image heating apparatus includes: (i) an endless belt; (ii) a driving member; (iii) a heater including: (iii-i) a substrate; (iii-ii) a resistor; (iii-iii) a first electroconductive portion electrically connected to the resistor in a widthwise end side; and (iii-iv) a second electroconductive portion electrically connected to the resistor in another widthwise end side; and (iv) a selector for selecting one of first and second electric energy supply paths. The first electric energy supply path is electrically connected to a region of the first electroconductive portion at a longitudinal central portion of the resistor and to a region of the second electroconductive portion in at the longitudinal central portion. The second electric energy supply path is electrically connected to a region of the first electroconductive portion at a longitudinal end portion of the resistor and to a region of the second electroconductive portion at another longitudinal end portion.

Abstract: An image heating rotatable member for heating an image on a recording material, comprising a base layer; a heat generation layer, provided on the base layer, for generating heat by being supplied with electric power; an electrode layer, provided outside of the heat generation layer with respect to a widthwise direction and having an electric resistance which is smaller than that of the heat generation layer, for supplying the electric power to heat generation layer; an elastic layer provided on the electrode layer and having a length longer than that of the electrode layer measured in the widthwise direction; and a parting layer provided on the elastic layer and having a length which is substantially equal to the length of the electrode layer measured in the widthwise direction;

Abstract: A heater includes: a substrate; a resistor, provided obliquely on the substrate with respect to a sheet passing direction, for generating heat by electric energy supply; a pair of first electrodes which are disposed opposed to each other via the resistor and which are electrically connected with respective ends of the resistor with respect to the sheet passing direction; and a pair of second electrodes which are disposed opposed to each other via the resistor and which are electrically connected with respective ends of the resistor with respect to the sheet passing direction. One of the first electrodes and one of the second electrodes overlap with each other as seen from the sheet passing direction.

Abstract: An image heating apparatus includes a belt including a heat generating layer for generating heat by energization and including a power receiving portion which has electroconductivity and is electrically connected to the heat generating layer; a stationary back-up member, provided inside the belt, for sliding on an inner peripheral surface of the belt; a pressing member for pressing the belt against the back-up member to form a nip in which a recording material is to be nip-conveyed between the belt and itself; and an electroconductive portion, provided on the back-up member, for supplying electric power to the power receiving portion by being electrically connected to the power receiving portion.

Abstract: An image heating rotatable member for heating an image on a recording material, includes a base layer, a heat generation layer, provided on the base layer, for generating heat by being supplied with electric power, an electrode layer, provided outside of the heat generation layer with respect to a widthwise direction and having an electric resistance which is smaller than that of the heat generation layer, for supplying the electric power to heat generation layer, an elastic layer provided on the electrode layer and having a length longer than that of the electrode layer measured in the widthwise direction, and a parting layer provided on the elastic layer.

Abstract: An image heating apparatus including: an image heating member for heating an image formed on a sheet at a nip portion; a temperature detector for detecting temperature of a predetermined region of the image heating member; a cooler for cooling the predetermined region; and an activating device for activating the cooler to perform a cooling operation in accordance with an output of the temperature detector, wherein the apparatus has a first mode of stopping a cooling operation in accordance with an output of the temperature detector; and a second mode of stopping the cooling operation in accordance with an end of image heating processing irrespective of the output of the temperature detecting device. The image heating apparatus is capable of suppressing unnecessary energy consumption, and of eliminating uneven glossiness due to a reduced temperature region at a boundary between a sheet passing portion and a non-sheet passing portion.

Abstract: An image heating apparatus includes a belt including a heat generating layer for generating heat by energization and including a power receiving portion which has electroconductivity and is electrically connected to the heat generating layer; a stationary back-up member, provided inside the belt, for sliding on an inner peripheral surface of the belt; a pressing member for pressing the belt against the back-up member to form a nip in which a recording material is to be nip-conveyed between the belt and itself; and an electroconductive portion, provided on the back-up member, for supplying electric power to the power receiving portion by being electrically connected to the power receiving portion.

Abstract: An image heating apparatus includes a heating rotary member, which heats an image on a recording material at a nip portion, an air blowing device for blowing air toward an air blowing port to cool a predetermined area of the heating rotary member, a shutter, which opens and closes the air blowing port, and a determination device. The determination device determines an execution of an operation of the air blowing device with the shutter opened after a first job is completed, in accordance with a size of a recording material in a width direction perpendicular to a recording material transport direction in a second job for supplying a recording material, between an execution termination of the first job for continuously supplying recording materials having a size smaller than a predetermined size in the width direction, while operating the air blowing device, and a start of a recording material supply of the second job, in a case that the second job is executed subsequent to the termination of the first job.

Abstract: An image heating rotatable member for heating an image on a recording material, comprising a base layer; a heat generation layer, provided on the base layer, for generating heat by being supplied with electric power; an electrode layer, provided outside of the heat generation layer with respect to a widthwise direction and having an electric resistance which is smaller than that of the heat generation layer, for supplying the electric power to heat generation layer; an elastic layer provided on the electrode layer and having a length longer than that of the electrode layer measured in the widthwise direction; and a parting layer provided on the elastic layer and having a length which is substantially equal to the length of the electrode layer measured in the widthwise direction;