Lens array, a line head and an image forming apparatus using the line head

An image forming apparatus, comprising:

• a latent image carrier;
• a lens array which includes a clear substrate and a plurality of plastic lens substrates each of which includes a plurality of lenses and which are arranged on at least one of surfaces of the clear substrate;
• and
• a head substrate on which a plurality of light emitting element groups which are groups of a plurality of light emitting elements are arranged, wherein
• the plurality of plastic lens substrates are arranged in a longitudinal direction and have plane surfaces that are adjoined to a surface of the clear substrate,
• the lenses are arranged opposed to the light emitting element groups in the lens array, and
• light emitted from the light emitting element groups impinges upon the lenses and is imaged by an imaging optical system which include the lenses to form spots on the surface of the latent image carrier.