Patent ID: 7347611

Claim:
An image forming apparatus comprising an eraser which initializes a surface potential of a photoreceptor medium, and an auxiliary transfer device, which facilitates transfer of a toner image by radiating light on a surface of the photoreceptor medium, wherein the eraser and the auxiliary transfer device comprise: light source to emit light; and an optical guide on a side of the apparatus having the light source, which guides the light emitted from the light source and incident therethrough in a lengthwise direction of the optical guide, makes uniform the light in an effective width range of the lengthwise direction and outputs the uniform light, wherein the optical guide comprises: a first surface to receive the incident light, comprising a plurality of reflective slopes to reflect and make uniform the incident light, each having a stripe shape and a length forming a varying angle with respect to the lengthwise direction of the optical guide, and a second surface which is opposite to the first surface and is an output surface from which the light reflected from the reflective slopes is output, wherein the plurality of reflective slopes are formed so that an interval therebetween is varied and the interval between the reflective slopes gradually becomes smaller when moving further from a side onto which the light is incident.