| 摘要 |
PURPOSE:To eliminate an image forming lens for correcting the difference of optical length and to simplify the structure of a laser beam optical system by setting such that the laser beam image forming error in the central part of a scanned surface is the same as that at its end part. CONSTITUTION:The title recorder is provided with a 1st optical system forming latent images on a photosensitive body with light reflected from an original, and a 2nd optical system scanning laser beams emitted from a laser beam emitting element and forming latent images on the photosensitive body. The image forming point of laser beams is set so that the laser beam image forming error in the central scanned surface of the photosensitive body is identical to that at the end part. Namely, the image forming point of laser beams is not matched to the center of the scanned surface, but it is set so that the image forming error at the end part can be identical to that at the central part of the scanned surface. Thus, an image forming lens for correcting the difference of optical length between the end part and the central part is not needed to simplify the structure of the laser optical system. |
