A fixing device includes a heater, a first rotatable member, a second rotatable member, and a heat equalizing member. In a case that a region including a center of the heat equalizing member with respect to a longitudinal direction is a first region, a region closer to an end of the heat equalizing member than the first region is with respect to the longitudinal direction is a second region, and a region closer to the end of the heat equalizing member than the second region is with respect to the longitudinal direction is a third region. When the heat equalizing member has thermal capacities per unit length in the first region, the second region, and the third region are Cα, Cβ and Cγ, respectively, Cα, Cβ and Cγ satisfy the following relationship:
Cα>Cβ, and Cγ>Cβ.

A device to prevent fire of a fusing belt having a heater positioned inside includes at least one temperature control member adjacent to one side of the fusing belt and, when the at least one temperature control member detects abnormal heat from the fusing belt based on a temperature of the fusing belt, the at least one temperature control member to cut off a supply of electricity to the heater to prevent the fire. The device also includes a heat absorption member adjacent to the other side of the fusing belt and to absorb latent heat from the fusing belt to lower the temperature of the fusing belt to prevent the fire.

An image forming apparatus includes: a fixing portion for fixing an image formed on a recording material; and a guide member for guiding the recording material. The guide member is provided at an entrance to the fixing portion and at an end portion with respect to a direction perpendicular to a feeding direction of the recording material The guide member is moved when the guide member is pushed by the recording material.

The present invention is characterized in that a control portion respectively sets a heating amount with respect to a region in which an image is formed and a heating amount with respect to a region in which an image is not formed in a single sheet of a recording material, and a difference between the heating amount with respect to the region in which an image is formed and the heating amount with respect to the region in which an image is not formed differs depending on a type of the recording material.

A fixing device includes an endless belt and a pressure rotator disposed opposite an outer circumferential surface of the endless belt. The pressure rotator has a first span in an axial direction of the endless belt. A nip formation pad, which is disposed opposite an inner circumferential surface of the endless belt, forms a fixing nip between the endless belt and the pressure rotator. The nip formation pad includes a belt-side thee disposed opposite the endless belt A radiant heater, which is disposed opposite the inner circumferential surface of the endless belt, heats the endless belt. A thermal conduction aid, which contacts the belt-side face of the nip formation pad, conducts heat in the axial direction of the endless belt. The thermal conduction aid has a second span within which the first span of the pressure rotator is provided at the fixing nip.

A heating device includes a heater, a holder, a device frame, a primary positioner, a secondary positioner, and a tertiary positioner. The heater includes a heat generator. The holder holds the heater. The device frame is configured to support the holder. The primary positioner is configured to position the heater and the holder in a longitudinal direction of the heater. The secondary positioner is configured to position the holder and the device frame in the longitudinal direction of the heater. The tertiary positioner is configured to position the device frame and a body of an image forming apparatus in the longitudinal direction of the heater. The primary positioner and one of the secondary positioner and the tertiary positioner are disposed on an identical side defined by a center of the heat generator in the longitudinal direction of the heater.

A photo finisher includes a heating roller, a pressing roller, a belt, a supporting roller and a duct. The heating roller is to generate heat. The pressing roller is pressed against the heating roller to form a heating nip. The belt is supported by the supporting roller and the heating roller to pass through the heating nip, and the belt is extending to a downstream side of the heating nip. The duct is positioned apart from the belt, the duct includes a first end in the width direction being provided with an air inlet port and a second end, opposite to the first end, being blocked, and the duct includes an air discharge port opening towards the belt.

A fixing device includes: a heating unit configured to heat a medium to be conveyed along a conveyance path by radiation; and a shielding unit made of non-metallic material, the shielding unit being configured to form a shielding state in which radiation from the heating unit is shielded and a non-shielding state in which radiation from the heating unit is not shielded, in which the shielding unit being expanded in a direction intersecting the radiation in the shielding state and is stored in the non-shielding state.

A decurling device includes: a rotary body; an endless correction belt configured to correct curl of a recording medium passing between the rotary body and the correction belt; and a pressure contact unit disposed inside the correction belt, an opposite surface of the pressure contact unit to the rotary body being supported by a support unit so as to be in pressure contact with the rotary body, in which a center portion, in an axial direction of the rotary body, of at least one of a contact portion of the pressure contact unit or a contact portion of the support unit further protrudes toward the other of the contact portion of the pressure contact unit and the contact portion of the support unit than both end portions thereof.

An image forming apparatus includes an exposure unit that reflects a laser beam emitted from a light source by a polygon mirror having a plurality of reflection surfaces to form a latent image on a photosensitive member, and a control unit that controls the image forming apparatus in a plurality of operation modes including a normal mode and a low speed mode having a slower process speed than the normal mode. The control unit controls the polygon mirror to use all of the plurality of reflection surfaces to reflect the laser beam when in the normal mode. When in the low speed mode, the control unit makes the process speed faster than 0.5 times that of the normal mode, rotates the polygon mirror faster than in the normal mode, and controls the polygon mirror to use only some of the plurality of reflection surfaces to reflect the laser beam.