Patent ID: 7835661

Claim:
An image forming apparatus comprising: an image carrier on which a latent image is formed; an image writing unit that writes the latent image on a surface of the image carrier with a write light output in a state in which the image writing unit is set in a write position; a supporting unit that supports the image writing unit in such a manner that the image writing unit is retractable from the write position; a developing device that develops the latent image formed on the image carrier to obtain a visible image; a chassis that contains the image carrier, the image writing unit, and the developing device; and either one of an air intake unit that generates intake air by sending air into the chassis from outside and an air exhaust unit that generates exhaust air by sending air from inside of the chassis to the outside, wherein the image writing unit includes an optical system unit containing an optical system element in a unit case, and a holding unit that holds the optical system unit in a movable manner, the holding unit being supported by the supporting unit, the image writing unit causes, upon being set in the write position, the optical system unit to be movable and positions the optical system unit, with a hitting portion of the optical system unit hitting a blocking portion in the chassis, the holding unit includes, in the state in which the image writing unit is set in the write position, a portion defining an opening that faces either one of the air intake unit and the air exhaust unit, and the air intake unit blows the intake air to the optical system unit through the opening, or the air exhaust unit draws the exhaust air around the optical system unit through the opening.