Optical printer head and method of lighting it

摘要

An optical printer head is provided in which light exposure of one pixel may be increased. An optical printer head for exposing a photosensitive drum to form pixels thereon comprises a light-emitting element array including two or more lines of light-emitting points, and a rod-lens array for projecting light emitted from the light-emitting array onto the photosensitive drum to form a line of light spots. Each of the lines of light-emitting points has the same pitch in a main-scanning direction in parallel with an axis of rotation of the photosensitive drum, and the light-emitting points of respective lines of light-emitting points are arranged so as to be lined up in a sub-scanning direction perpendicular to the axis of rotation of the photosensitive drum.