Patent ID: 7796912

Claim:
An image forming apparatus comprising: an image carrying member having a movable surface; a charging means including a rotatable charging member, the charging member supplied with a voltage including a direct voltage superimposed with an alternating voltage, and brought into contact with the image carrying member to charge the surface of the image carrying member; an electrostatic latent image forming device for forming an electrostatic latent image on the surface of the image carrying member; and a development device for developing the electrostatic latent image formed on the surface of the image carrying member, wherein a frequency of the alternating voltage included in the voltage applied to the charging member is lower in a non-image forming area than in an image forming area, and wherein, in the non-image forming area, the image carrying member is charged to a surface potential having a waveform shape that reflects the alternating voltage to form an electrical field for moving toner adhering to a surface of the charging member to the image carrying member from a potential difference between the surface potential and the voltage applied to the charging member to move the toner from the charging member to the image carrying member, wherein a magnitude of the electrical field ranges from approximately 100 volts to approximately 1000 volts, wherein a cycle of the waveform shape of the surface potential of the image carrying member ranges from approximately 3 milliseconds to approximately 100 milliseconds, and wherein a ratio, in the cycle of the waveform shape, of the electric potential for moving the toner to the image carrying member ranges from approximately 30 percent to approximately 70 percent.