Abstract: One of several corona dischargers used in an electrophotographic apparatus is connected to a power source transformer so as to selectively operate these corona dischargers. The power source transformer is provided with a tertiary winding, to which a switching device is connected. When the switching device is turned on, a secondary output from the transformer becomes lower than a corona discharging limit voltage, whereby the corona discharging stops.

Abstract: An electrophotographic copying apparatus includes original supporting device for supporting thereon an original to be copied, illuminating device for illuminating the original, an electrophotographic photosensitive medium movable through a charging station, a developing station and an image transfer station, the photosensitive medium having an image bearing area and a non-image bearing area set thereon, the non-image bearing area being set on the side edge portion of the photosensitive medium, charging device for charging both of the two areas of the photosensitive medium at the charging station, a projection optical system for projecting the optical image of the original upon the image bearing area of the photosensitive medium between the charging station and the developing station to form an electrostatic latent image, developing device for developing the electrostatic latent image into a visible image, image transfer device for transferring the visible image from the photosensitive medium to a transfer med

Abstract: A developer is composed of colored insulating particles for developing an electrostatic image wherein at least the external surface of each particle comprises two different areas of which one area constitutes a major portion of said external surface and comprises an element which defines the polarity of the triboelectric charge of said particle to a determined polarity while the other area comprises an element capable of being easily separated from said particle, transferred to a surface of a developing device and charged to a polarity opposite to that of said particle.

Abstract: This specification discloses a method of toner transfer development in which one-component magnetic developer is conveyed to a developing position by the action of a magnetic field and a low frequency alternating electrical bias is applied to the space between a latent image bearing member and a developer carrying member at that position to thereby develop a latent image. This development provides visible images excellent in sharpness and tone reproduction.

Abstract: A developing method and apparatus in which a developer supporting member is opposed to a latent image bearing member with a clearance therebetween and developer is caused to be transferred from the developer supporting member to the latent image bearing member to effect development and wherein a first and a second developing portion are provided as the developer supporting member, these effect development in the named order to complete the developing step, a first alternating bias for causing the developer to be transferred so as to mainly develop the image end portion of the latent image is imparted to the first developing portion, and a second alternating bias for causing the developer to be transferred so as to mainly effect the development for reproducing the tone of the latent image is imparted to the second developing portion.

Abstract: A method and apparatus for conveying developing agent for use in an image forming apparatus, in which a magnetic developer is placed under the influence of a forcing magnetic field, then the developer restrained by the forcing magnetic field is caused to pass through a slit-passageway having a narrowing clearance, thereafter the developer is pushed out into a conveying path by reducing the intensity of the forcing magnetic field to the developer which has passed through the minimum clearance in the slit-passageway below the magnetic field in the minimum clearance section of the slit-passageway, and finally the developer which has been pushed out into the conveying path is moved in and through the conveying path by being further pushed by subsequently transported developer.

Abstract: An improved image transfer device for intermittently bringing a continuous image transfer medium into contact with the images on an image bearing member and transferring the images from the image bearing member to the image transfer medium. The image transfer device of the present invention utilizes an air pressure to bring the continuous image transfer medium into contact with and separate it from the image bearing member without the transfer medium and the surface of the image bearing member being contacted by a mechanical member such as an image transfer roller or bar or the like.