Abstract: A fixing device includes an endless belt member, a secured member disposed to contact the belt member, a heating unit that heats the belt member, and a rotary pressurizing roller including an elastic layer that is elastically deformed when the belt member is pressed against a pressing surface of the secured member to form a fixing part. The pressurizing roller is curved such that a center portion is smaller in outside diameter than end portions along the axial direction. The pressing surface is curved such that a center portion projects toward the pressurizing roller more than end portions along the longitudinal direction. On the pressing surface, an amount of projection of the center portion with respect to the end portions along the longitudinal direction is set to be larger on an output side than on an input side of the fixing part along a moving direction of the belt member.

Abstract: A fixing device includes: a fixing unit that transports a recording medium as nipped between a pressure rotary member and a heating rotary member, to thereby fix a developer image on the recording medium; temperature detectors that detect temperatures of regions of the pressure rotary member; cooling units that cool the detected regions; and a controller that controls the cooling units to, if a temperature difference between the regions is more than a set temperature difference, execute first cooling for reducing the temperature difference to the set temperature difference or less, and to, if a width of the recording medium perpendicular to a transport direction thereof used in an immediately preceding image formation is equal to or less than a preset width, execute, subsequently to the first cooling, second cooling for cooling the pressure rotary member for a preset time.

Abstract: A fixing device includes an endless belt, a heating unit that heats the belt, a rotating body that rotates while applying pressure to a recording medium interposed between the rotating body and the belt, a pressing member that forms a first area in which the recording medium is to be nipped between the belt and the rotating body by pressing the belt against the rotating body from an inside of the belt, and a driving member that drives the rotating body so that the rotating body rotates at a speed determined such that a time obtained by dividing a length of the first area in a direction in which the rotating body is rotating by the speed is approximately 20 milliseconds or less.

Abstract: A fixing device includes a fixing rotary body that heats and pressurizes, together with a recording medium, toner having particle diameter of 4.5 [?m] or less and a softening point of 100 [° C.] or higher and 125 [° C.] or lower to fix the toner on the recording medium, a heating unit that heats the fixing rotary body, and a pressurizing unit that sandwiches and pressurizes the toner and the recording medium in a contact part formed by the fixing rotary body, wherein the maximum pressure in the contact part is equal to or more than 2.9×105 [Pa], the width of the contact part in a movement direction of the recording medium is equal to or more than 10 [mm], and the heating time of the toner in the contact part is equal to or more than 20 [msec].

Abstract: A fixing device includes a fixing rotary body that heats toner while rotating and fixes the toner on a recording medium, a pressurizing rotary body that sandwiches and pressurizes the toner and the recording medium by the fixing rotary body, and a supporting part that supports the fixing rotary body from the inside so that a peak pressure on an outlet side of the recording medium becomes equal to or lower than a peak pressure on an inlet side, in a contact part where the fixing rotary body and the pressurizing rotary body come into contact with each other.

Abstract: A fixing device includes a heating member heating a recording medium to fix a developer image thereto; an endless heating belt rotatably wrapped around the heating member and heating the medium; a rotating member around which the belt is wrapped and having a fixed first axial end; a position detecting unit detecting a position of the belt when moved in first and second opposite directions parallel to an axial direction of the rotating member; and a controller controlling a rotational movement angle by which a second axial end of the rotating member is rotationally moved about the first end in an axis-intersecting direction based on information from the position detecting unit when the belt is moved in the first and second directions so that first and second speeds for respectively moving the belt in the first and second directions are made equal to or close to each other.

Abstract: A fixing device includes: a fixing unit that transports a recording medium as nipped between a pressure rotary member and a heating rotary member, to thereby fix a developer image on the recording medium; temperature detectors that detect temperatures of regions of the pressure rotary member located along an axial direction of the pressure rotary member; cooling units that cool the detected regions; and a controller that controls the cooling units to, if a temperature difference between the regions is more than a set temperature difference, execute first cooling for reducing the temperature difference to the set temperature difference or less, and to, if a width of the recording medium perpendicular to a transport direction thereof used in an immediately preceding image formation is equal to or less than a preset width, execute, subsequently to the first cooling, second cooling for cooling the pressure rotary member for a preset time.

Abstract: An image forming apparatus includes image forming units forming toner images with first toners having different colors and a second toner having a different softening point from the first toners, an image transfer unit superposing the toner images one on top of another and transferring the superposed toner images onto a recording medium at least such that the toner image formed of the second toner is at the top of the superposed toner images, an image fixing unit fixing the transferred toner images, and an image controller that causes the image forming unit that uses the second toner to form the toner image over at least part of an image area and also causes the image transfer unit to perform the transfer such that the toner image formed of the second toner is at the top of the superposed toner images in the at least part of the image area.

Abstract: A heating device includes: a heating member heating a recording medium; a pressure member forming a heating pressure portion with the heating member, through which the recording medium passes; a tensioning member facing the pressure member across the heating member, and providing a tension to the heating member; a peeling member placed downstream of the heating pressure portion and adjacent to the tensioning member, and peeling off the recording medium from the heating member; and an inside heating unit heating the heating member and controlling meandering of the heating member, the inside heating unit including: a secured center shaft; an outer circumferential portion rotating about the center shaft; a heater placed inside the outer circumferential portion to heat thereof from inside; and a heat reflecting member secured to the center shaft and placed at each end portion of the outer circumferential portion, and that reflects heat from the heater.

Abstract: An image forming device includes: an image forming section forming an image on a surface of a recording medium; a conveyance section conveying the recording medium on which the image is formed on a first conveyance course; a return section that returns the recording medium on which the image is formed to the image forming section, by conveying the recording medium on a second conveyance course diverging from the first conveyance course and running to the image forming section; and a medium correction section disposed at a point on the first conveyance course before a diverging location of the second conveyance course, corrects a curl of a recording medium conveyed by the conveyance section after passing through the point, and gives a curl bulging in a predetermined direct ion to a recording medium conveyed by the return section after passing through the point, among recording media passing through the point.

Abstract: A heating device includes: a heating member heating a recording medium; a pressure member forming a heating pressure portion with the heating member, through which the recording medium passes; a tensioning member facing the pressure member across the heating member, and providing a tension to the heating member; a peeling member placed downstream of the heating pressure portion and adjacent to the tensioning member, and peeling off the recording medium from the heating member; and an inside heating unit heating the heating member and controlling meandering of the heating member, the inside heating unit including: a secured center shaft; an outer circumferential portion rotating about the center shaft; a heater placed inside the outer circumferential portion to heat thereof from inside; and a heat reflecting member secured to the center shaft and placed at each end portion of the outer circumferential portion, and that reflects heat from the heater.

Abstract: A fixing unit prevents surface temperature of a fixing roller from becoming too high or too low and of always attains good fixing performance by employing an external heating method that makes an external heating member abut the surface of the fixing roller to heat the surface of the fixing roller. The fixing unit has the fixing roller having a heating source therein, a pressurizing member which press-contacts the fixing roller, the external heating member which heats the surface of the fixing roller from the outside, an abutting-separating device that makes the external heating member abut or separate from the surface of the fixing roller; and a control unit which controls timing for making the external heating member abut the surface of the fixing roller according to at least one of the surface temperature of the external heating member and/or fixing roller, the type of the transfer medium which undergoes the fixing process and an image forming mode for the transfer medium.