Patent 7395014 was granted and assigned to Samsung on July, 2008 by the United States Patent and Trademark Office.
An improved image forming apparatus comprises a first developing unit comprising a photosensitive body. Also provided is a second developing unit including a developing roller which is moveably installed so that the developing roller selectively contacts the photosensitive body. A pressing member selectively presses the second developing unit. The developing roller contacts the photosensitive body during a developing process and separates from the photosensitive body after the developing process is finished.