Patent ID: 8274741

Claim:
An image forming apparatus, comprising: an exposure head that includes a light emitting element substrate that is provided with light emitting elements that emit lights and are arranged in a first direction and a second direction orthogonal or substantially orthogonal to the first direction, a lens array that has lenses that are arranged in the first direction and the second direction and image a light emitted from the light emitting elements, and a diaphragm that is arranged between the light emitting elements and the lenses; and a latent image carrier that is exposed by the exposure head to form a latent image and moves in the second direction, wherein a relationship defined by a following formula: 1 <L 1 /L 2 is satisfied, where the symbol L 1 denotes a length of the lens in the first direction and the symbol L 2 denotes a length of the lens in the second direction.