A beam-condensing unit has a first light source, a second light source, and a condenser mirror. The first and second light sources output a plurality of first and second light fluxes arrayed along a first direction, respectively. A condenser mirror has first and second optical plates that intersect with each other. The first optical plate includes a plurality of first reflecting portions that are arrayed along the first direction and reflect the first light fluxes, respectively. The second optical plate includes a plurality of second reflecting portions that are arrayed along the first direction alternately with the first reflecting portions and reflect the second light fluxes, respectively.