Abstract: The image forming apparatus includes a fixing apparatus capable of restraining offset of a toner in multifarious types of sheets and in a variety of environments at low costs. The fixing apparatus has a rotary fixing member and a nip forming member which forms a fixing nip portion by coming into contact with the rotary member. A recording material bearing an unfixed toner image is conveyed while being pinched by the nip portion. The fixing apparatus fixes a toner image onto the recording material. The fixing apparatus further has a bias applying means which applies a bias to the nip forming member. The bias applying means, before the recording material reaches the nip portion, applies a first bias to the nip forming member so that a surface of a rotary member is charged with electricity, and applies a second bias to the nip forming member while the recording material is conveyed by the nip portion.

Abstract: The image forming apparatus, includes a conveyor belt for bearing a recording material, capable of suppressing an image blur caused by a separating discharge at the separation of the recording material from the conveyor belt. To fix record materials on a transportation belt, the recording material is charged by a adhering member to electrically adhere the recording material to the conveyor belt. When the recording material is separated from the conveyor belt, a separating discharge occurs between the recording material and the conveyor belt, as the recording material is charged. In order to reduce the faulty of the toner image on the recording material caused by the separating discharge, the voltage applied to the adhering member is controlled for example according to a current which the recording material receives at the transfer position to mutually cancel the charge received at the transfer position by the adhering member.

Abstract: A compact image forming apparatus is provided in which stains on the back of a transfer material can be prevented. In particular, in a marginless print mode in which a toner image can be formed to the edge of a transfer material, a large amount of toner adheres to a transfer-material bearing member. The image forming apparatus includes a collecting member that can temporarily collect the toner adhering to the transfer-material bearing member. The toner that is temporarily collected by the collecting member is transferred to an intermediate transfer member and is cleaned by a cleaning unit.

Abstract: The speed at which transfer-material enters a transfer region is controlled to prevent a phenomenon in which a toner image on an intermediate transfer belt is scraped by the leading edge of the transfer-material when the toner image is transferred onto the transfer-material. While the conveying speed of the transfer-material in a transfer nip coincides with the speed of the intermediate transfer belt, the transfer-material is conveyed at a speed lower than the peripheral speed of the intermediate transfer belt when the leading edge of the transfer-material comes into contact with the intermediate transfer belt, and the conveying speed of the transfer-material is increased by the time when the transfer-material enters the transfer nip.

Abstract: An image forming apparatus for forming image on a recording medium includes a photosensitive member, a motor, a belt, and a drive member to rotate the belt, the drive member including a driven coupling. The apparatus also includes a drive coupling to rotate by a driving force generated by the motor, the drive coupling being movable in an axial direction to take an engagement position at which the driving force is transmittable to the driven coupling, and a release position. The apparatus further includes a transfer member to transfer a toner image onto the recording medium or the belt, a voltage application unit to apply a voltage to the transfer member, and a control unit to cause the voltage application unit to apply the voltage to the transfer member after the drive coupling moves to the engagement position and the driving force is transmitted to the driven coupling.

Abstract: An image forming apparatus operates in a marginless print mode in which the toner image is formed on a first region on a first image bearing member corresponding to a sheet size and a second region on the first image bearing member outside the first region. Reverse-transfer efficiency TR1 and reverse-transfer efficiency TR2 satisfy TR1<TR2. TR1 is a percentage of a mass/area, of toner back-transferred from the sheet onto the second image bearing member by a second transfer member to a mass/area, of toner transferred from the first region onto the sheet by a first transfer member. TR2 is a percentage of a mass/area, of toner back-transferred from a sheet feeder onto the second image bearing member by a second transferring means to a mass/area, of the toner transferred from the second region onto the sheet feeder by the first transfer member.

Abstract: An image forming apparatus includes: an image bearing member for bearing a toner image; a belt for conveying the toner image; and a transfer device for rubbing the belt, and a surface of the transfer device, which is brought into contact with the belt includes linear concave portions or linear convex portions. The image forming apparatus of the present invention prevents a friction force between the belt and the transfer device rubbing the belt from increasing and brings a transfer member into a stable contact with the belt for conveying the toner image, thereby suppressing increase in drive torque of the belt which rubs the transfer device and suppressing occurrence of image failure.

Abstract: Provided is an image forming apparatus in which the image forming apparatus has a marginless mode in which the toner image is formed on said image bearing member in an area that covers the recording material and an area outside the recording material, and the toner image is transferred to extend beyond an edge of the recording material carried by said recording material carrying member, the image forming apparatus further including: a detecting device which detects the toner image that extends beyond the edge of the recording material and is transferred to said recording material carrying member in the marginless mode; and a control device which uses a detection result provided by said detecting device to control where said exposure device forms a latent image on said image bearing member.

Abstract: When a fixing device becomes uncontrollable and a large amount of electric power is continuously supplied to the heater, concentration of mechanical stress on a heater is suppressed, whereby shear fracture of the heater is prevented from occurring. A longitudinal region of the heater in which a heat generation resistive member is provided is supported by a heater support surface of a heater holder, and an opposed surface of the heater holder that is opposed to a longitudinal region of the heater in which the heat generation resistive member is not provided is designed not to be in contact with the heater.

Abstract: A toner image formed on an image bearing member is transferred onto a recording material so as to overflow from an edge portion of the recording material, thereby enabling the toner image to be formed so as to extend to the edge portion of the recording material. To suppress the deposition of the toner in the edge portion of the recording material, a cleaning member for cleaning the edge portion of the recording material obtained after the fixing is provided. In order to make a trailing edge of the recording material come into contact with the cleaning member, the recording material which has passed through a fixing apparatus is temporarily switched back, thereby allowing the trailing edge portion of the recording material to collide with the cleaning member.

Abstract: The image forming apparatus includes a fixing apparatus capable of restraining offset of a toner in multifarious types of sheets and in a variety of environments at low costs. The fixing apparatus has a rotary fixing member and a nip forming member which forms a fixing nip portion by coming into contact with the rotary member. A recording material bearing an unfixed toner image is conveyed while being pinched by the nip portion. The fixing apparatus fixes a toner image onto the recording material. The fixing apparatus further has a bias applying means which applies a bias to the nip forming member. The bias applying means, before the recording material reaches the nip portion, applies a first bias to the nip forming member so that a surface of a rotary member is charged with electricity, and applies a second bias to the nip forming member while the recording material is conveyed by the nip portion.

Abstract: The image forming apparatus, includes a conveyor belt for bearing a recording material, capable of suppressing an image blur caused by a separating discharge at the separation of the recording material from the conveyor belt. To fix record materials on a transportation belt, the recording material is charged by a adhering member to electrically adhere the recording material to the conveyor belt. When the recording material is separated from the conveyor belt, a separating discharge occurs between the recording material and the conveyor belt, as the recording material is charged. In order to reduce the faulty of the toner image on the recording material caused by the separating discharge, the voltage applied to the adhering member is controlled for example according to a current which the recording material receives at the transfer position to mutually cancel the charge received at the transfer position by the adhering member.

Abstract: An image heating apparatus includes a flexible sleeve, a sliding member for sliding on the inner periphery of the sleeve, and a back-up member for forming a nip portion together with the sliding member through the sleeve. A recording material for bearing an image is heated while being held and conveyed by the nip portion, and a regulation member is set by facing the edge surface of the sleeve in the generatrix direction to regulate the movement of the sleeve in the generatrix direction, the regulation member having a regulation surface with which the edge surface of the sleeve contacts when the sleeve moves in the generatrix direction. The regulation surface of the regulation member has a curved-surface area in which a line when the regulation surface is cut at a virtual plane almost parallel with the nip portion is a curved line expanded toward the edge surface of the sleeve. Thereby, an image heating apparatus is provided which is able to restrain deterioration of the durability of the flexible sleeve.

Abstract: When a fixing device becomes uncontrollable and a large amount of electric power is continuously supplied to the heater, concentration of mechanical stress on a heater is suppressed, whereby shear fracture of the heater is prevented from occurring. A longitudinal region of the heater in which a heat generation resistive member is provided is supported by a heater support surface of a heater holder, and an opposed surface of the heater holder that is opposed to a longitudinal region of the heater in which the heat generation resistive member is not provided is designed not to be in contact with the heater.

Abstract: An image heating apparatus has a flexible rotatable member, a slidable member contacting an internal surface of the flexible rotatable member, a holder for holding the slidable member, and a pressure roller for applying a pressure to the flexible rotatable member thereby forming a nip portion with the slidable member. A holding surface of the holder includes a first holding area of a crowned shape, and a second holding area of a crowned shape, which is provided at a downstream side of the first holding area in a moving direction of the flexible rotatable member, and the second holding area has a crown amount larger than a crown amount of the first holding area.

Abstract: The image heating apparatus includes a flexible sleeve, a sliding member for sliding on the inner periphery of the sleeve, a back-up member for forming a nip portion together with the sliding member through the sleeve, wherein a recording material for bearing an image is heated while being held and conveyed by the nip portion and a regulation member set by facing the edge surface of the sleeve in the generatrix direction to regulate the movement of the sleeve in the generatrix direction, the regulation surface having a regulation surface with which the edge surface of the sleeve contacts when the sleeve moves in the generatrix direction, wherein the regulation surface of the regulation member has a curved-surface area in which a line when the regulation surface is cut at a virtual plane almost parallel with the nip portion is a curved line expanede toward the edge surface of the sleeve.

Abstract: An image forming apparatus having a sharp neutralizing member which can perform uniform neutralizing effects for a long period of time. The sharp neutralizing member includes sharp projections in which tip portions having the following relationship between a distance P between the tip portions of neighboring projections and the distance D between the tip portion of the projection and an object of neutralization: D?4.0 mm, and 0.8*D?P?1.5*D. Particularly for neutralization of a carrier of toner images, it is possible to achieve uniform neutralization of the medium and to provide a high-quality image.

Abstract: An image heating apparatus for heating an image formed on a recording material, including a heater, a holder for holding the heater, a rotating member rotating around the holder and being flexible and having a metal layer, and a pressure roller forming a nip with the heater across the rotating member, wherein the rotating member moves detaching from the pressure roller just after passing through a downstream end portion of a surface of the heater opposed to the pressure roller. Thus, an uneven heating of a toner image can be prevented even in a case where the recording material becomes undulated after passing the nip portion.

Abstract: A charging apparatus has a discharging member with a plurality of protrusions and an auxiliary member for assisting discharges by the discharging member, and an insulating member formed among the plurality of protrusions of the discharging member, so that discharge is made between the discharging member and the auxiliary member upon application of a voltage between the discharging member and the auxiliary member. Where an interval among distal ends of the plurality of protrusions of the discharging member is denoted as P and an interval between the discharging member and the auxiliary member is denoted as D, P is at least equal to or greater than D.

Abstract: There is provided an image forming apparatus that can suppress the formation of creases when forming images on both surfaces of a sheet and can greatly reduce the incidence of unprinted areas. The image forming apparatus has a sheet stacking section in which sheets are stacked, a sheet conveying section that conveys a sheet, an image forming section that forms an image on the sheet while the sheet is conveyed, a re-conveying section that again conveys the sheet with the image formed on a first surface thereof to the image forming section, and a sheet feeding section that feeds a sheet from the sheet stacking section or the re-conveying section to the image forming section.