Patent ID: 7725049

Claim:
An image forming apparatus configured to form an image on a recording sheet by transferring a developer image onto the recording sheet, the apparatus comprising: a housing having an exhaust outlet; an image forming unit disposed in the housing and configured to form an image on a recording sheet; a duct disposed in the housing, the duct having an inlet at a first side and a wall at a second side opposite to the first side, and the duct communicating with the exhaust outlet; an exhaust fan disposed between the exhaust outlet and the duct, the exhaust fan being configured to cause air entering the duct from the inlet to go toward the exhaust outlet; a first filter which covers the inlet, the first filter being configured to remove dust suspended in the air; and a second filter disposed between the first filter and the wall such that the first filter and the second filter form a first air passage and the second filter and the wall form a second air passage, the first air passage being configured to guide air, which has passed through the first filter, toward the exhaust outlet such that the air is able to reach the exhaust outlet without passing through the second filter, the second air passage being configured to guide air, which has passed through both the first and second filters toward the exhaust outlet, the second filter being configured to remove dust suspended in the air.