A direct imaging system comprises an illumination unit comprising a plurality of light sources, the plurality of light sources (50) configured to emit a plurality of beams (65), an optical system (60) for forming the plurality of beams to be aligned in position or angle, an acoustic optical modulator (70) positioned to receive the plurality of beams (65) aligned in one of position or angle and to consecutively diffract different portions of the plurality of beams (65) as an acoustic wave propagates in an acoustic direction, and a scanning element (80) adapted to scan an exposure plane with the plurality of beams (65) modulated by the acoustic optical modulator (70) at a scanning velocity, wherein the scanning velocity is selected to incoherently unite the different portions of the plurality of beams (65) into a single exposure spot.