Optical head having function of detecting positional displacement of photosensitive member and electrophotographic image forming apparatus employing the same

Abstract

The invention provides an optical head which provides between a photosensitive member and a position detector a sufficient distance over which the photosensitive member and the position detector are not brought into contact with each other readily by thermal expansion of the apparatus or a like cause. The optical head includes a latent image forming light emitting element array for irradiating light upon a photosensitive belt to form an electrostatic latent image on the photosensitive belt, a position detecting light emitting element array for irradiating light to be used for detection of the position of an end portion of the photosensitive belt, a position detector for detecting the position of the end portion of the photosensitive member from the light emitted from the position detecting light emitting element array, and an exposure position correction section for varying an electrostatic latent image formation position of the latent image forming light emitting array in response to the position of the end portion of the photosensitive member detected by the position detector. The focal length of a rod lens array for the position detecting light emitting element array is set longer than that of a rod lens array for the latent image forming light emitting element array.

Dependencies are inferred from the claim text.