A power control device includes a heater, a zero-cross detecting unit, a triac, a supplying unit, and a controlling unit. The supplying unit discharges an electric charge when a control signal is outputted in a half-wave of each of a first polarity and a second polarity and charges the electric charge when the control signal is not outputted in the half-wave of the first polarity. The controlling unit outputs: in a first half-wave, a first control signal on the basis of the zero-cross point and a second control signal in a first phase different in timing from the first control signal, and in a second half-wave, a third control signal on the basis of the zero-cross point and a fourth control signal in a second phase different in timing from the second control signal. The first phase and the second phase are different from each other.

In an image-forming apparatus, a fixing device includes first and second fixing members; and a pressure modifying mechanism. The first and second fixing members form a nip. The pressure modifying mechanism modifies a nip pressure at the nip to one of a first nip pressure and a second nip pressure smaller than the first nip pressure. A controller performs: a converting process to convert print data into raster image data; an image-forming process to form a developer image on a sheet using the raster image data; and a fixing process to fix the developer image to the sheet with the fixing device at the first nip pressure. When a second converting process is not completed before a prescribed time following completion of a first fixing process has elapsed, the controller further performs a nip pressure reducing process to modify the nip pressure from the first to the second nip pressure.

A heater includes a heat-resistant insulating substrate, a plurality of heat generating members arrayed in a first direction on a first surface of the substrate, and a plurality of heat radiating bodies disposed on a surface different from the first surface of the substrate at positions corresponding to gap portions between the heat generating members to passively radiate heat generated thereby.

An image forming apparatus includes a transfer unit for transferring a toner image onto a sheet, a fixing device for fixing the image, the fixing device including a belt, a pressure element for pressing against the belt, a heating member on the belt including a heat generating element and electrodes on both sides of the heat element in a sheet conveyance direction and connected to the heat element, and an adjustment mechanism for moving one of the heating member and the pressure element in a manner to move the one closer to or away from the other, and a controller for controlling the adjustment mechanism so that a distance between the heating member and the pressure element becomes a first distance during a fixing process and a second distance larger than the first distance during temperature raising of the heating member, which is conducted before the fixing process.

A fixing apparatus including: a first rotary member; a second rotary member; a nip forming member; and a heater. The nip forming member includes: a first projection portion inside a nip area; and a second projection portion located outside the nip area. The first and second projection portion abut against the inner circumferential surface of the first rotary member. In a direction orthogonal to a nip tangent, a distance between a tip of the second projection portion and the nip tangent is larger than a distance between a tip of the first projection portion and the nip tangent. The second projection portion extends toward the second rotary member without exceeding the nip tangent. A radius of curvature at a tip portion of the second projection portion is smaller than a radius of an inner circumferential circle of the first rotary member.

An image forming apparatus includes a transfer unit for transferring a toner image onto a sheet, a fixing device for fixing the image, the fixing device including a heating member including a heat generating element and electrodes on both sides of the heat generating element in a sheet conveyance direction and connected to the heat generating element, and a pressure element for pressing against the heating member, and a controller for controlling an adjustment mechanism so that a distance between the heating member and the pressure element becomes a first distance during a fixing process and a second distance larger than the first distance during temperature raising of the heating member, which is conducted before the fixing process.

A fixing device includes a fixing belt formed of a tubular film, a heater configured to heat the fixing belt and including an insulating layer, a roller positioned such that the fixing belt extends between the roller the heater, and a heat conductor in contact with the heater. The heater is positioned such that the insulating layer of the heater extends between the fixing belt and the heat conductor to prevent the heat conductor from contacting the tubular film.

An image forming apparatus includes: a heating unit including a heating rotation member configured to heat a recording medium: a pressure rotation member which contacts the heating rotation member to form a nip portion to fix a toner image to the recording medium, a heat source configured to heat the heating rotation member, the heat source including a first heater and a second heater, and a control unit configured to control the first heater and the second heater, wherein the image forming unit is operable to transition to: a fixing state in which an operation to fix the toner image to the recording medium is performed by receiving a job; and a standby state, to wait for the job, in which an operation to fix the toner image to the recording medium is not performed.

The fixing device includes: a fixing belt that is heated by a heater lamp; a pressure roller that makes contact with the fixing belt; a fixing pad that sandwiches the fixing belt from the inner side of the fixing belt and is arranged opposing the pressure roller, and which forms a nip portion between the fixing belt and the pressure roller; a sliding sheet provided between the fixing pad and the fixing belt, which reduces the frictional force with the fixing belt; and a pad heat transfer plate provided between the sliding sheet and the fixing pad, which adjusts the heat transfer in a longitudinal direction of the fixing belt. The fixing pad has protrusions and that make contact with the pad heat transfer plate, and forms a gap between the fixing pad and the pad heat transfer plate in a location where the protrusions and are not making contact.

A fixing device that fixes a toner image by passing a sheet through a fixing nip, including a pressure body and a rotating body pressed together to form the fixing nip and a separator disposed above the rotating body in the vertical direction. The separator separates the sheet from the rotating body downstream of the fixing nip. The separator includes a separation portion that has a first outer surface facing the rotating body and a second outer surface facing a sheet transport path after separation and a support portion that supports the separation portion. The separation portion has a higher releasability than the support portion. The first outer surface and the second outer surface intersect at an acute angle to form a sharp edge portion. The first outer surface has a convex portion at a position between the sharp edge portion and a boundary with the support portion.