Abstract: A developing device used in an image forming apparatus has a developing roller at a lower opening of a toner hopper, and the developing roller contacts a photosensitive drum to form a developing portion therebetween. The hopper stores nonmagnetic toner and is provided with a toner stirring member and a toner feed roller being in press-contact with the developing roller in a lower part of the hopper. A doctor blade contacts a circumferential surface of the developing roller on an upstream side of the developing portion in a rotation direction of the drum. A conductive scooping sheet contacts the circumferential surface of the developing roller on a downstream side of the developing portion. A residual toner not used to develop a latent image on the drum and left on the developing roller is passed under the sheet into the hopper with the rotation of the developing roller.

Abstract: A method of forming an image without cleaning on the basis of repeated electrophotographic process cycles. Each process cycle includes charging a surface of a photosensitive drum to a predetermined polarity, and irradiating the charged surface of the photosensitive drum with light which carries image information, thereby forming a latent image corresponding to the image information. The latent image is visualized by using a dry developer material, and the visualized image is transferred from the surface of the photosensitive drum onto a transfer medium. The developer material contains a transfer accelerator (hydrophobic silica or light-transmitting fine powder) for improving efficiency for transfer of the visualized image onto the transfer medium.

Abstract: Two-color image forming apparatus has a bipolar photosensitive body, a first charging means, a first electrostatic latent image forming means, a first developing means, a second charging means, a second electrostatic latent image forming means, and a second developing means. The second charging means is a corona discharger having a corona ion stream control screen forming by laminating a conductive member with an insulating member and disposed at or near an open portion for radiating a corona ion.