Abstract: The image density adjustment method for use in electrophotography in which, when the image density of a copied image is decreased below a standard image density, the development bias-potenial is increased while the exposure to be applied to a photoconductor is kept constant. When the image density of a copied image is increased above the standard image density, the exposure is decreased while the development bias voltage is kept constant. Thus, the image density of a copied image can be adjusted as desired to minimize the effect of light fatigue of the photoconductor.

Abstract: A photoconductive drum is electrostatically charged and radiated with a light image of an original document to produce an electrostatic image. A toner substance is applied to the drum to produce a toner image which is transferred and fixed to a copy sheet. A bias electrode is provided adjacent to the drum during the toner development stage to which is applied a bias voltage selected to prevent application of toner to white or background areas of the electrostatic image. The bias voltage is produced as a function of the sensed electrostatic potential of the electrostatic image and is automatically limited to prevent image degradation and loss of density. To reproduce photographs or low contrast documents such as diazo copies, the bias voltage is limited to a lower value to increase the image density and prevent dark areas from appearing washed out. The light image intensity is increased for reproduction of documents having colored backgrounds so that the backgrounds will reproduce white.

Abstract: A developing system is provided for a copying process such as an electrophotographic copying process in which a developer is supplied to the surface of a member which is formed with an electrostatic latent image to provide developing thereof. An electrode is disposed opposite the surface of the member with the developer interposed therebetween, and the induction potential of the electrode is maintained below a given value by means of a constant voltage element. The potential of the electrode is induced by either the image portion of the member's surface having the electrostatic latent image or by an unexposed, separate charged portion thereof.

Abstract: An improved developing device in electrophotographic copying apparatus in which a plurality of developing electrodes are disposed along a path of movement of a photosensitive drum surface. The electrodes are applied with voltages in a graded manner which conforms to the damping characteristic of the potential on the photosensitive surface at a developing station. The values of voltages applied can be controlled in accordance with the value of potential formed by an imaging area of the drum surface while maintaining the graded potential to thereby achieve an excellent developing effect. Further, the drum surface is provided with an unexposed and hence high potential portion which serves to remove toner which accumulates on the electrodes.

Abstract: An improved developing device in electrophotographic copying apparatus in which a plurality of developing electrodes are disposed along a path of movement of a photosensitive drum surface. The electrodes are applied with voltages in a graded manner which conforms to the damping characteristic of the potential on the photosensitive surface at a developing station. The values of voltages applied can be controlled in accordance with the value of potential formed by an imaging area of the drum surface while maintaining the graded potential to thereby achieve an excellent developing effect. Further, the drum surface is provided with an unexposed and hence high potential portion which serves to remove toner which accumulates on the electrodes.

Abstract: A developing system is provided for a copying process such as an electrophotographic copying process in which a developer is supplied to the surface of a member which is formed with an electrostatic latent image to provide developing thereof. An electrode is disposed opposite the surface of the member with the developer interposed therebetween, and the induction potential of the electrode is maintained below a given value by means of a constant voltage element. The potential of the electrode is induced by either the image portion of the member's surface having the electrostatic latent image or by an unexposed, separate charged portion thereof.