Abstract: In an image forming apparatus, when a transferred material exists in a transfer position between a photoreceptor drum and a transfer unit during an image forming operation, a transfer voltage, which has opposite polarity to that of a voltage applied to a brush charger and is used for transferring a developer image on the photoreceptor drum onto the transferred material is applied to the transfer unit. Meanwhile, when a transferred material does not exist in the transfer position during the image forming operation, a non-transfer voltage, which is lower than the transfer voltage, is applied to the transfer unit. As a result, defects on an image due to returning of a developer from the brush charger to the photoreceptor drum can be prevented from being generated.

Abstract: An image forming apparatus which is provided with a developing device having a rotatable developing member opposite to a rotatable photoreceptor at a developing region for transporting a developer to bring the developer into contact with the photoreceptor at the developing region, and a paper particle removing member provided at a downstream side from the developing region with respect to a rotational direction of the developing member for removing paper particles from the developer held on the developing member.

Abstract: An image forming apparatus includes a photosensitive member, a charging device for charging the surface of the photosensitive member at a constant potential, a light beam for exposing the photosensitive member charged by the charging device to form an electrostatic latent image, a developing device for developing the electrostatic latent image by selectively sticking toner to the surface of the photosensitive member so as to correspond to the electrostatic latent image formed by the light beam, and a transfer device for transferring to recording paper the toner image formed by the developing device on the surface of the photosensitive member. The image forming apparatus is applied to a cleanerless system in which the developing device develops the toner image and simultaneously sucks and recovers residual toner remaining on the surface of the photosensitive member after transfer.

Abstract: So as to realize an image forming apparatus capable of withstanding a long period of practical use and which does not waste toners, an image forming apparatus is provided having a cleaning roller and a reverse charge promoting member which applies a bias having a reverse polarity to residual toners which have remained on a photoconductor, a charger unit for establishing the charge polarity of the toners to the same polarity as the surface of the photoconductor, and a developer roller to which is applied a bias voltage to enable the rollers to recover the toners on the photoconductor. In the image forming apparatus, there is a cleaner unit having a simplified construction in which there is a minimum of the waste of toners, and further, since in the image forming process the toners are efficiently discharged from the cleaner unit, the lowering of the cleaning performance hardly occurs.

Abstract: An electrophotographic apparatus including an electrically conductive brush roller for recovering and discharging a residual toner which is located in contact with a photoreceptor drum. A positive voltage is applied to a transfer roller, whereupon the toner is charged positively. As a recording region on the photoreceptor drum with an electrostatic latent image formed thereon passes the brush roller, a voltage of a potential lower than the potential of the recording region is applied to the brush roller, and the brush roller recovers the residual toner. As a non-recording region on the photoreceptor drum without the latent image thereon passes the brush roller, on the other hand, a voltage of a potential higher than the potential of the non-recording region is applied to the brush roller, and the recovered toner is discharged onto the non-recording region. The discharged toner is returned to a developing roller after a charging process.

Abstract: An electrophotographic process cartridge develops an electrostatic latent image with two layers or less of polymeric toner. The electrophotographic process cartridge includes a charging roller for uniformly distributing a layer of electrical charge on an outer surface of a photosensitive drum, a developing roller for transferring particles of polymeric toner each having a substantially spherical shape onto the outer surface of the photosensitive drum, and a control roller for engaging an outer surface of the developing roller to enable formation of two layers or less of polymeric toner particles on the outer surface of the developing roller.