An image forming apparatus includes an electrostatic latent image forming medium, a charge unit charging the surface of the electrostatic latent image forming medium with a predetermined potential, a toner supply unit (TSU) supplying toner to an electrostatic latent image formed on the surface of the electrostatic latent image forming medium to develop the electrostatic latent image into a toner image, and a transfer unit transferring the toner image to a print medium, the electrostatic latent image forming medium including a transparent frame member, a light source inside the frame member, an optical shutter array including a plurality of optical shutters, and a photoconductive layer on which the electrostatic latent image is formed using light transmitted through the optical shutter array. A diffuser may surround the light source to diffuse light to maintain the intensity of light reaching the optical shutters at a uniform level.