Abstract: The present invention relates to an image forming apparatus which comprises an image bearing member for bearing a toner image, a transfer charger for transferring the toner image from the image bearing member to a transfer material, and an electricity removing member for removing electricity from the transfer material to separate the transfer material from the image bearing member, and wherein, when the electricity is removed from the transfer material by the electricity removing member, a potential level applied to the electricity removing member is selected so that the potential level at end portions of the transfer material becomes greater than the potential level at a central portion of the transfer material along a transfer material shifting direction, thereby improving separation of the transfer material from the image bearing member.

Abstract: In a fixing device used in an image forming apparatus, temperature changes in a heating member are reduced by gradually reducing a power supply duty ratio while the heating member is subjected to temperature control aiming at a set temperature.

Abstract: An image forming apparatus includes a movable image bearing member; an image forming device for forming a toner image on the image bearing member; an image transfer device for transferring the toner image onto a transfer material at a transfer position, the transfer device including a rotatable member contactable to such a side of the transfer material as is opposite from a side contactable to the image bearing member and an electric field forming device for forming an electric field between the image bearing member and the rotatable member; wherein the electric field forming device forms a first electric field effective to transfer the toner from the rotatable member to the image bearing member and a second electric field which is opposite in a direction from the first electric field during a period in which the transfer material is absent at the transfer position, wherein each of the first and second electric fields is formed at least for a period required for the entire surface of the rotatable member pass

Abstract: A charging device including a movable member to be charged, and a charging member which is contactable to the member to be charged so as to charge the member to be charged, wherein the coefficient of dynamic friction between the member to be charged and a surface of the charging member contactable to the member to be charged is not lower than 0.4.

Abstract: An image forming apparatus includes a movable image bearing member; a transfer device cooperative with the image bearing member to form a nip, through which a transfer material is passed to electrostatically transfer an image from the image bearing member onto the transfer material; where the resistance R range providing proper image transfer is determined in accordance with the equation:-9.16.times.10.sup.3 .times.v+11.68-0.65.ltoreq.log.sub.10 (R.times.L).ltoreq.-9.16.times.10.sup.3 .times.v+11.68+0.65where V (mm/sec) is movement speed of the image bearing member (v.gtoreq.40), R (ohm) is a resistance of the transfer device when a voltage of 3 KV is applied between the image bearing member and the transfer device, and L (mm) is a length of the nip measured in a direction of a generating line of the image bearing member.

Abstract: An image forming apparatus includes a movable image bearing member; an image forming device for forming a toner image on the image bearing member; image transfer device for transferring the toner image from the image bearing member to a transfer material at an image transfer station, wherein the transfer device includes a charging member press-contacted or faced to the image bearing member and a device for applying a voltage to the charging member, wherein the voltage applying device applies a voltage to the charging member so that the charging member is constant-voltage-controlled when an image region of the image bearing member is in the transfer station, and the charging member is constant-current-controlled during at least a part of a period when it is not in the transfer station, wherein a voltage V2 applied during the constant voltage control is a voltage V1 appearing in the transfer device during the constant current control multiplied by a coefficient R, in which R is larger than 1.

Abstract: An image fixing apparatus for fixing a toner image on a recording material includes a pair of rotatable members for forming a nip through which the recording material is passed; and bias voltage applying source for applying a bias voltage to at least one of the rotatable members, wherein the bias voltage is automatically changed in accordance with change of an ambient condition.

Abstract: An image forming apparatus includes a movable image bearing member, an image forming device for forming the image bearing member, and an image transfer device contactable to the image bearing member at an image transfer position. The transfer device transfers the image formed by the image forming device onto a transfer material while the transfer material is conveyed through the transfer position together with the image bearing member, wherein the transfer device has a hardness of 20-40 degrees (Asker-C), and it is pressed to the image bearing member at a pressure of 50-200 g/cm.sup.2, and wherein a peripheral speed of the transfer device at the transfer position during a transfer operation is higher than a peripheral speed of the image bearing member at the transfer position.

Abstract: An image forming apparatus has a charging device for charging a photosensitive member containing an organic photoconducter, an exposure device, a developing device including a developer, a transfer device and a cleaning device. The photosensitive member employs an organic photoconductor and a polycarbonate resin layer which forms the surface of the photosensitive member. The developer device has a sleeve with a thin layer of an electrical coating material containing dispersed carbon particles. The developer contains insulating magnetic toner particles of relatively small particle size formed from a styrene-acrylic type copolymer or a polyester resin and a magnetic powder.

Abstract: An image forming apparatus includes a movable image bearing member; an image forming device for forming an image on the image bearing member; and a transfer device for transferring the image from the image bearing member onto a transfer material, the transfer device including a movable transfer member contacted to the image bearing member and for conveying the transfer material by the contact portion. The transfer member is disposed in such a direction that a surface friction in the direction of the movement of the transfer member relative to the image bearing member is large.