| 摘要 |
PURPOSE:To provide the illumination optical system which resolves problems such as the reduction of resolution caused by speckle or the nonuniformity of illumination, suppresses the generation of the speckle, more uniformly illuminate the surface of a reticule, detects an exposed variable and controls a proper exposed variable. CONSTITUTION:This system is composed of a first light source image generating means 2 to generate plural light source images by using beams emitted from a laser beam source 2, biaxial oscillating mirror 8 to scan the beams from the first light source image generating means 2, second light source image generating means 10 to generate plural light source images by using the beams scanned by the biaxial oscillating mirror 8, condenser lens 15 to irradiate the surface of a reticule 16 in the state of overlapping the beams emitted from the second light source image generating means 10 and laser output control circuit 23 to fixedly control the exposed variable detected by an exposed variable detecting means 13 by arranging the exposed variable detecting means 13 just behind the second light source image generating means 10 so as to integrate and detect the exposed variable caused by the pulsed laser beams. |
