Patent ID: 6639652
Filing Date: 2003-10-28
Classification: G03F

Abstract:
An illumination system, comprising:an optical system for collecting light from a light source, said optical system including a mirror for reflecting the light, said mirror having an ellipsoidal reflection surface of a shape being out of axial symmetry, for defining an aperture of a rectangular or semicircular shape as seen in an optical axis direction; an optical integrator for producing plural light beams by use of light from said optical system, said optical integrator comprising an array of condensing elements each having a light entrance surface of a rectangular shape as seen in the optical axis direction, wherein a lengthwise direction of the rectangular-shaped or semicircular-shaped aperture of the ellipsoidal reflection surface corresponds to a lengthwise direction of the rectangular-shaped light entrance surface of the condensing element; and a condenser for illuminating a surface to be illuminated, by use of the plural light beams.