Patent ID: 7991311

Claim:
An image forming apparatus, comprising: a charging element to apply a charging voltage to an image-bearing member to charge the image-bearing member; an optical writing device to form a latent image on a charged surface of the image-bearing member charged by the charging element; a developer-bearing member to carry toner having a same polarity as that of the charging voltage to the image-bearing member and which applies the toner to the latent image on the image-bearing member to form a toner image when a developing bias voltage is applied thereto; and a control device to control application of the charging voltage by the charging element and application of the developing bias voltage to the developer-bearing member to increase an absolute value of the charging voltage to the image-bearing member and an absolute value of the developing bias voltage to the developer-bearing member to a predetermined value in a plurality of steps, respectively; wherein the control device controls the developing bias voltage applied to the developer-bearing member, wherein the following relation holds in each of the plurality of steps: 20 V≦(| V D |−|V i |)≦49 V, wherein V D represents a developing bias voltage applied to the developer-bearing member and V I represents a charged potential of the image-bearing member, wherein |V D |>750 V and |V I |>650 V.