Image forming apparatus having an injection charging system and a two component contact development device

Abstract

An image forming apparatus includes an image bearing member for carrying an electrostatic image, a contact charger for electrically charging the image bearing member while contacting to a surface of the image bearing member, the contact charger forming an oscillating electric field having a frequency of 100-600 Hz; a developer for developing the electrostatic image on the image bearing member with a developer comprising toner and a carrier having a volume resistivity value of 106-1010 Ω.cm, while contacting chains of the carrier to the image bearing member, the developer including a developer carrying member, opposed to the image bearing member, for carrying the developer and electric field forming device for forming an alternating electric filed between the image bearing member and the developer carrying member; wherein the following relationship are satisfied: 5×10−5<T1<1×10−4(sec); and 5×10−5<T2<1×10−4(sec); where T1 is a time duration in which the toner receives force away from the image bearing member toward the developer carrying member; and wherein T2 is a time duration in which the toner receives force away from the developer carrying member toward the image bearing member.

Dependencies are inferred from the claim text.