Patent ID: 6917376

Claim:
An exposing device comprising: a light source which emits a plurality of light beams; a first lens provided on a light beam emitting side of the light source; a second lens provided on a light beam emitting side of the first lens for focusing the light beams on a surface to be irradiated; and a supporting means which supports the light source and the first lens movably from reference positions to positions corresponding to displacement amounts of a first distance and a second distance corresponding to a predetermined imaging magnification, the positions being determined based on an imaging characteristic representing the imaging magnification and corresponding to a displacement amount of the first distance between the light source and the first lens in the case that at least one of the light source and a first lens is moved from a reference position and a displacement amount of the second distance between the first lens and the second lens in the case that at least one of the first lens and the second lens is moved from a reference position, positions of the light source, the first lens and the second lens with respect to a predetermined imaging magnification being determined as the reference positions.