Developing method for image production of high quality.

摘要

PURPOSE:To form a most suitable image whose image density and resolution are both preferable by developing the image by using a developer wherein toner and carrier are blended with a specific surface area ratio and setting the circumferential speed ratio of a magnet sleeve to a photosensitive drum to be in a fixed range. CONSTITUTION:As for a magnetic brush developing method using a two- component developer, a mechanical developing condition significantly depends on the circumferential speed ratio of the photosensitive drum 1 to the magnet sleeve 21 for carrying the magnetic brush. When the average grain diameter of the magnetic carrier of the developer 7 is dmum where the saturation magnetization of the carrier measured by a 50KOe is xemu/g and an electric resistor R is OMEGAcm, the image is developed on condition that the circumferential speed ratio K of the magnet sleeve 21 to the photosensitive drum 1 meets a formula. The toner and the magnetic carrier of the developer in use are ranged in the specific surface area ratio of 0.9:1 - 1.1:1. The magnetic carrier is ranged 20-200mum in the average grain diameter and 30-70emu/g in the saturation magnetization.