Image forming apparatus with cooling configuration

An image forming apparatus comprising:

• a photoreceptor having a rotation axis extending in a first direction connecting a front surface and a rear surface of the image forming apparatus;
• and
• an exposure unit configured to expose the photoreceptor to form a latent image on the photoreceptor,
• wherein the exposure unit includes a substrate that has a longitudinal axis extending in the first direction, has a first surface on which a plurality of light emitting elements configured to emit light toward the photoreceptor are mounted, and has a second surface opposite to the first surface,
• wherein the exposure unit includes a cooling duct configured to guide air along the second surface of the substrate in the first direction, the cooling duct having a first opening through which air is taken into inside of the cooling duct and a second opening through which air is exhausted from inside of the cooling duct,
• wherein the first opening is disposed at a first opening distance in the first direction to the rear surface, the first opening distance being shorter than a first distance in the first direction from a center of the substrate in the rear surface, and
• wherein the second opening is disposed at a second opening distance in the first direction to the front surface, the second opening distance being shorter than a second distance in the first direction from the center of the substate to the front surface.