JPS5792355A - Developing device - Google Patents

Abstract

PURPOSE:To obtain a clear picture which is free from ground fog, by electrically charging a toner for developing an electrostatic latent image on the surface for holding an image, through between a rotating fur brush and a conductive case whose radius of curvature is almost same as said brush. CONSTITUTION:This device is provided with a developing roller 2 slide-rotating in the opposite direction to the surface of a photosensitive body 1 of a dry type electronic copying machine which is rotated in the direction as indicated with an arrow. As for the developing roller 2, a urethane layer 7 is provided around a metallic shaft 6 of negative potential, and a fur body 9 is planted through a conductive adhesion layer 8 of its outside circumferential surface. A toner 3 consisting of a nonmagnetic substance, which has been put into a case 4 of positive or negative potential is stirred by a blade 13, its excess is scraped down when it passes through a net body 14, its proper quantity is supplied to the fur body 9, the fur body 9 contacts with a conductive case 11, slides, and after that, contacts with the photosensitive body 1, and a charged toner is adsorbed by an electrostatic latent image, which is developed. In this way, the supply quantity of a toner is made proper, an uncharged toner is decreased, generation of ground fog is prevented, and a clear image is obtained.