Image forming apparatus capable of preventing a toner-filming phenomenon caused on development roller surface in effective and economical manner

摘要

Image forming apparatus which prevents occurrence of a toner- filming phenomenon on a development roller thereof by performing a toner freshening operation. When the image forming apparatus performs the toner freshening operation, an amount of the toner remaining unused on the development roller can totally be transferred onto a photoconductive drum at a predetermined timing for a predetermined time period at a predetermined rate of frequency so as to effectively prevent occurrence of the toner-filming phenomenon. The amount of toner used for the toner- freshening operation can be kept clean and returned to the development roller in a form without agglomerating by an unused toner returning mechanism mounted in an image forming unit of the image forming apparatus. The image forming apparatus has a dust free configuration, and may further include an air fan including an electrostatic filter and a front loading type paper cassette.