A scanning unit includes a scanning member having at least one reflective surface for reflecting light incident thereon, a plurality of light sources controllable to emit light beams onto the at least one reflective surface, and first and second scan lenses for receiving and focusing the light beams reflected from the at least one reflective surface. Each of the first and second scan lenses has a light exit surface having a first curved surface section and a second curved surface section defining therebetween a junction line extending between opposed longitudinal ends of each of the first and second scan lenses. The junction line is nonlinear.