Image forming apparatus with partition wall between scanning optical device and photosensitive drum

摘要

An image forming apparatus includes a scanning optical device which performs scanning on a photosensitive drum with laser light. The scanning optical device includes a polygon motor unit, an emergence unit and a projecting unit. The polygon motor unit includes a polygon mirror which performs the scanning on the photosensitive drum with the laser light emitted from a light source. The laser light emerges from the emergence unit so that the photosensitive drum is irradiated with the laser light. The projecting unit projects to a first side where the photosensitive drum is disposed from a partition wall. The polygon motor unit is disposed in the projecting unit. The emergence unit is disposed on a second side separated from the first side by the partition wall. A gap is provided between the partition wall and the scanning optical device.