Patent ID: 7114812
Filing Date: 2006-10-03
Classification: G02B,G03B,H04N

Abstract:
1. An illumination optical system which illuminates an illumination surface with illumination luminous flux from a light source, comprising: a first optical system with an optical power in a first plane including a normal to the illumination surface, which guides the illumination luminous flux from the light source to the illumination surface, wherein the first optical system includes, an optical integrator which has a plurality of lenses with optical powers different between the first plane and a second plane including the normal and being orthogonal to the first plane, and a condenser lens with an optical power in the first plane, which guides the illumination luminous flux emitted from the optical integrator to the illumination surface, wherein light intensity distribution of the illumination luminous flux on the illumination surface represents a relationship between light intensity and incident angle to the illumination surface, and wherein, in the light intensity distribution, an incident angle width at which the light intensity reaches half of a peak value in the first plane is twice or more an incident angle width at which the light intensity reaches half of a peak value in the second plane.