Abstract: A method for forming an outline of an image. In this method, at first, an electrostatic latent image bearing member is charged and then irradiated to a positive image to form an electrostatic latent image. Thereafter, the irradiated member is re-charged with a scorotron charger while applying a voltage to a grid, the voltage being lower than the surface potential of the image portion of the latent image, being slightly higher than the background potential of the latent image and being of the same polarity as that of the original charging. By this re-charging, the outline portion of the image is given higher potential than the other portion. Then, the outline portion of the image with higher potential is subjected to a normal development by using a toner charged to a polarity opposite to the polarity of the recharged portions.

Abstract: A method for forming an outline of an image. By this method, at first, an electrostatic latent image bearing member is charged and then irradiated to form an electrostatic latent image. Thereafter, the irradiated member is re-charged with a scorotron charger while applying a voltage to the scorotron grid, the voltage being slightly lower than the surface potential of the image portion of the latent image, and being substantially higher than the background potential of the latent image and being of the same polarity as that of the charging. By this re-charging, the outline portion of the image is given lower potential than the other portion. Then, the outline portion of the image with the lower potential is developed by a reversal development by using a toner charged to a polarity the same as the polarity of charging of the latent image bearing member.

Abstract: An electrophotographic copying apparatus is capable of forming outline images. It comprises a first charging device, an exposing device, a second charging device and a developing device along a moving direction of a photoconductor. A sensor detects an amount of toner adhering to a reference image formed on the surface of the photoconductor. Supply of toner is controlled based on the detected amount. In an outline image forming mode, an amount of toner to be supplied is set to a value smaller than an amount in a standard image forming mode.

Abstract: A developing apparatus which includes a developing sleeve rotatably provided to confront an object to be developed, a magnet roller incorporated within the developing sleeve so as to be driven for rotation in the same direction as the developing sleeve, and a supply device for supplying developing material onto the peripheral surface of the developing sleeve. The developing apparatus is so arranged as to satisfy such conditions asD.multidot..pi..multidot.Wsl>d1.multidot.p.multidot.WmgwhereD: developing sleeve diameter (mm)Wsl: developing sleeve revolutions (rpm)d1: the closest distance between the sleeve surface and the object to be developedp: number of poles of the magnet rollerWmg: revolutions of the magnet roller (rpm).

Abstract: The copier machine of the present invention comprises a second charger having a grid and is capable of executing a mode wherein a toner is deposited onto the latent image exclusive of the outline portion thereof to visualize.When this mode is designated, the grid is applied with the voltage which is lower than the surface potential at the image portion of the latent image and higher than the surface potential at the non-image portion of the latent image.

Abstract: A toner replenishment control method for a developing material including two kinds of toners triboelectrically chargeable to polarities opposite to each other, which includes the steps of causing the respective toners contained in the developing material to separately adhere to each of first and second surface areas of a detecting member having predetermined potentials, obtaining first and second detecting signals substantially proportional to amounts of the respective toners which have adhered to the first and second surface areas, the first and second detected signals being set to become equal to each other when a mixing ratio of the respective toners in the developing material is set at a standard mixing ratio, relatively comparing the first and second detected signals, and in the presence of a difference therebetween, replenishing either one of the respective toners to the developing material for eliminating the difference.