| 摘要 |
An illumination apparatus for using a beam emitted from a light source to illuminate an object area includes a condensing optical system for condensing the beam emitted from the light source, and a reflection type optical integrator located between the condensing optical system and the object area, the optical integrator having an m-gonal (where m is an even number) sectional shape, forming multiple pairs of opposing reflection surfaces, and reflecting the beam between the multiple pairs of opposing reflection surfaces, wherein a length L in an axial direction of the reflection type optical integrator meets the following equations: R=PHI/[tan {sin-1(sin theta/n)}]; and Cx(A-0.1)xR<=L<=Cx(A+0.1) X R, where n is a refractive index of a medium between the reflection surfaces, PHI is a distance between the reflection surfaces, theta is an angle of divergence when the beam emitted from the condensing optical system enters the reflection type optical integrator, C is a constant determined in relation to the sectional shape of the reflection type optical integrator, and A is a natural number.
|
