Abstract: An image forming apparatus for forming a toner image on a recording material has an image forming unit configured to form the toner image on the recording material; a fixing unit configured to fix the toner image on the recording material while heating and conveying the recording material bearing the toner image at a nip portion, the fixing unit including a heating rotation member and a roller forming the nip portion with the heating rotation member; and a voltage applying unit configured to apply a potential difference between a surface of the heating rotation member and a surface of the roller, wherein a plurality of print modes different in conveyance speed of the recording material at the nip portion are carried out, and wherein the voltage applying unit applies the potential difference smaller in a first print mode than the potential difference in a second print mode.

Abstract: A fixing device includes: a cylindrical film; a nip forming member; and a back-up member for forming a nip. The nip forming member includes a projected portion. The projection amount of the projected portion is smaller in an end portion region positioned at an end portion of the projected portion with respect to a generatrix direction of the film than in a central region positioned at a central portion of the projected portion with respect to the generatrix direction, at least a part of the end portion region being inside a feeding region of a maximum-sized recording material usable in the fixing device. With respect to the recording material feeding direction, the width of the part of the projected portion inside the nip is broader in the end portion region than in the central region.

Abstract: A roller used for a fixing apparatus has: a core; a first elastic layer that is formed outside the core and includes a first tapered portion on an edge of the roller in an axis direction; and a second elastic layer that is formed outside the first elastic layer and includes a second tapered portion on the edge in the axis direction on the same side as the first elastic layer. The second elastic layer has a hardness that is higher than the hardness of the first elastic layer. A second start point, which is a start point of the second tapered portion, is set in a position closer to the center of the roller in the axis direction than a first start point, which is a start point of the first tapered portion.

Abstract: A fixing apparatus fixes a toner image on a recording material by conveying and heating the recording material at a nip portion, and includes a first rotating member, a second rotating member configured to form the nip portion with the first rotating member, the first and second rotating members being arranged such that rotation of the second rotating member causes rotation of the first rotating member, a frame configured to support the second rotating member, so as to be rotatable and an opening and closing part arranged to open and close relative to the frame on the downstream side of the nip portion in the conveyance direction of the recoding material, the opening and closing part having a duct through which air flows.

Abstract: A fixing device includes first and second members, a frame supporting the second member, and two pressure mechanisms provided on either end of the first member. The mechanism includes a lever having one end supported by the frame in a rotatable manner in a pressure direction, and a helical compression spring disposed between a first spring support provided on the other end of the lever and a second spring support on the frame. At least one of the first and second spring supports includes a first area and a second area closer to the spring in the axial direction than the first area, the first area is in contact with an area of the spring close to a winding end of the spring, and the second area is in contact with an area of the spring farther away from the winding end in a winding direction than the first area.

Abstract: An image forming apparatus for forming a toner image on a recording material has an image forming unit configured to form the toner image on the recording material; a fixing unit configured to fix the toner image on the recording material while heating and conveying the recording material bearing the toner image at a nip portion, the fixing unit including a heating rotation member and a roller forming the nip portion with the heating rotation member; and a voltage applying unit configured to apply a potential difference between a surface of the heating rotation member and a surface of the roller, wherein a plurality of print modes different in conveyance speed of the recording material at the nip portion are carried out, and wherein the voltage applying unit applies the potential difference smaller in a first print mode than the potential difference in a second print mode.

Abstract: A fixing device includes: a cylindrical film; a nip forming member; and a back-up member for forming a nip. The nip forming member includes a projected portion. A projection amount of the projected portion is smaller in an end portion region positioned at an end portion of the projected portion with respect to a generatrix direction of the film than in a central region positioned at a central portion of the projected portion with respect to the generatrix direction, at least a part of the end portion region being inside a feeding region of a maximum-sized recording material usable in the fixing device. With respect to the recording material feeding direction, a width of the part, of the projected portion, inside the nip is broader in the end portion region than in the central region.

Abstract: A roller used for a fixing apparatus has: a core; a first elastic layer that is formed outside the core and includes a first tapered portion on an edge of the roller in an axis direction; and a second elastic layer that is formed outside the first elastic layer and includes a second tapered portion on the edge in the axis direction on the same side as the first elastic layer, the second elastic layer having hardness that is higher than hardness of the first elastic layer. A second start point, which is a start point of the second tapered portion, is set in a position closer to the center of the roller in the axis direction than a first start point, which is a start point of the first tapered portion.

Abstract: A fixing device includes: a cylindrical film; a nip forming member; and a back-up member for forming a nip. The nip forming member includes a projected portion. The projection amount of the projected portion is smaller in an end portion region positioned at an end portion of the projected portion with respect to a generatrix direction of the film than in a central region positioned at a central portion of the projected portion with respect to the generatrix direction, at least a part of the end portion region being inside a feeding region of a maximum-sized recording material usable in the fixing device. With respect to the recording material feeding direction, the width of the part of the projected portion inside the nip is broader in the end portion region than in the central region.

Abstract: A fixing device includes: a cylindrical film; a nip forming member; and a back-up member for forming a nip. The nip forming member includes a projected portion. A projection amount of the projected portion is smaller in an end portion region positioned at an end portion of the projected portion with respect to a generatrix direction of the film than in a central region positioned at a central portion of the projected portion with respect to the generatrix direction, at least a part of the end portion region being inside a feeding region of a maximum-sized recording material usable in the fixing device. With respect to the recording material feeding direction, a width of the part, of the projected portion, inside the nip is broader in the end portion region than in the central region.

Abstract: An image forming apparatus includes a toner carrying member for carrying a toner; an image carrying member on which a toner image is formed with the toner; and a plurality of divided electrode portions provided at a position in which the electrode portions oppose the toner carrying member via the image carrying member interposed therebetween. The electrode portions are supplied with a voltage on the basis of image information to move the toner between the toner carrying member and the image carrying member thereby to form the toner image. The electrode portions includes a first electrode portion for forming an image portion and a second electrode portion, adjacent to the first electrode portion, for forming a non-image portion.

Abstract: The image heating apparatus includes an endless belt, a roller which contacts an outer face of the belt, and a nip portion forming unit which contacts an inner face of the belt, and forms a nip portion with the roller, for nipping and conveying a recording material. The nip portion forming unit includes a component which is longer than the belt in a generatrix direction of the belt. The apparatus also includes a regulation portion provided to oppose an end face of the belt, for regulating a shift movement of the belt to the generatrix direction of the belt. The regulation portion is integrally-molded with the component. As a result, damage of the end of the endless belt can be reduced.

Abstract: An image heating device includes an endless belt including a base layer and an elastic layer formed around the base layer, a contact member contacting an inner surface of the endless belt, a pressure rotating member forming a nip portion configured to convey a recording material while nipping the recording material along with the contact member via the endless belt, wherein an image formed on the recording material is heated at the nip portion using heat from the endless belt, and wherein one end of the endless belt is coated with the elastic layer and the other end of the endless belt is not coated with the elastic layer, and a belt lateral shifting direction regulating mechanism configured to regulate a direction in which the endless belt shifts when the endless belt is rotated, toward the end coated with the elastic layer.

Abstract: An image heating device includes a rotatable image heating member including an elastic layer and a surface layer in which a filler is dispersed; and a fixed pressing member which is contacted to a surface of the rotatable image heating member and forms a nip, between itself and the rotatable image heating member, in which a recording material for carrying an image is to be nip-conveyed. The surface of the rotatable image heating member has a shape such that projections are distributed by the filler so that a coefficient of dynamic friction ?(hot) relative to said fixed pressing member when a surface temperature of the rotatable image heating member is a temperature during image heating and a coefficient of dynamic friction ?(cold) relative to the fixed pressing member when the surface temperature is a normal temperature satisfy, ?(hot)<1.2×?(cold).

Abstract: An image forming apparatus includes a toner carrying member for carrying a toner; an image carrying member on which a toner image is formed with the toner; and a plurality of divided electrode portions provided at a position in which the electrode portions oppose the toner carrying member via the image carrying member interposed therebetween. The electrode portions are supplied with a voltage on the basis of image information to move the toner between the toner carrying member and the image carrying member thereby to form the toner image. The electrode portions includes a first electrode portion for forming an image portion and a second electrode portion, adjacent to the first electrode portion, for forming a non-image portion.

Abstract: The image heating apparatus includes an endless belt, a roller which contacts an outer face of the belt, a nip portion forming unit which contacts an inner face of the belt, and forms a nip portion with the roller, for nipping and conveying a recording material, the nip portion forming unit including a component which is longer than the belt in a generatrix direction of the belt; and a regulation portion provided to oppose an end face of the belt, for regulating a shift movement of the belt to the generatrix direction of the belt, wherein the regulation portion is integrally-molded with the component. Thereby, a damage of the end of the endless belt can be reduced.

Abstract: An image forming apparatus includes a transfer roller. The transfer roller includes an elastic layer disposed on a metal core bar. The elastic layer is made of a non-foamed solid rubber. The surface of the elastic layer includes a plurality of convex portions extending in a line in the axis direction of the transfer roller.

Abstract: Energy consumption in a fixing process of an electrophotographic image-forming apparatus is reduced. An unfixed toner image T1 is fixed on a recording medium by applying a photopolymerizable composition D1 to the unfixed toner image T1 formed on the recording medium and then performing irradiation with light having a maximum emission wavelength in a wavelength range of from 420 to 470 nm using a light emitting diode or an organic EL device for curing the photopolymerizable composition D1 by photopolymerization.

Abstract: An image heating device includes a rotatable image heating member including an elastic layer and a surface layer in which a filler is dispersed; and a fixed pressing member which is contacted to a surface of the rotatable image heating member and forms a nip, between itself and the rotatable image heating member, in which a recording material for carrying an image is to be nip-conveyed. The surface of the rotatable image heating member has a shape such that projections are distributed by the filler so that a coefficient of dynamic friction ?(hot) relative to said fixed pressing member when a surface temperature of the rotatable image heating member is a temperature during image heating and a coefficient of dynamic friction ?(cold) relative to the fixed pressing member when the surface temperature is a normal temperature satisfy, ?(hot)<1.2×??(cold).

Abstract: A toner image fixing method reduces energy consumed in a fixing step in an electrophotographic image forming apparatus. A photopolymerization composition is coated on an unfixed toner image formed on a recording medium. Then, the photopolymerization composition is irradiated with light, which does not have an emission wavelength band in a far infrared range and which has a maximum emission wavelength of 360 nm or longer to 420 nm or shorter, by using an LED, whereby the photopolymerization composition is cured and the unfixed toner image is fixed to the recording medium.