| 摘要 |
PURPOSE:To form images of always high quality by adjusting the charging potentials of a recording medium prior to the formation of secondary electrostatic latent images in an image forming method of using a screen form photoreceptor. CONSTITUTION:An insulation drum 32 which comprises covering an insulation layer 34 on a conductive base 33 is subjected to positive corona discharging by the discharge electrode 52a of the first corona discharge chamber 52 of a discharger 51. Next, the drum 32 is subjected to negative corona discharging of polarity opposite from that of modulation ion current by the discharge electrode 54 in the second corona discharge chamber 53. At this time, a positive voltage is applied to grids 57 which have been set nearly equal at the spacing d1 mm from the drum 32 and the inter-grid spacing d2 and at l>=4vd2K/t (t is the thickness mu of the layer 34; K/t is the effective tickness mu; K if relative dielectric constant; v is the moving speed cm/sec. of the drum 32) in the width l mm in the rotating direction of the drum 32, whereby the potentials of the drum 32 are controlled. |
