Patent ID: 7027757

Claim:
An image forming apparatus, comprising: a laser scanning unit; a developing device having a photosensitive element rotating in a direction to form a latent electrostatic image on a surface thereof through the laser scanning unit, and having a developing roller developing the latent electrostatic image into a toner image with a developer; a transfer part transferring the toner image onto a transported printing paper disposed on a paper-transporting path to engage the photosensitive element; and a subsidiary transfer part having a light source disposed on a side of the paper-transporting path to expose the photosensitive element to light and thereby to enhance a transfer efficiency, and having an optic fiber guide disposed longitudinally along the photosensitive element to lead the light generated from the light source to the photosensitive element, the optic fiber guide having a reflective part disposed on an outer surface thereof, the reflective part including a plurality of fluorescent material surfaces, each of which is formed to have a different area according to a distance between the light source and corresponding ones of the fluorescent material surfaces.