×

Illumination optical system, exposure apparatus, and exposure method with polarized switching device

  • US 7,423,731 B2
  • Filed: 05/31/2005
  • Issued: 09/09/2008
  • Est. Priority Date: 12/03/2002
  • Status: Expired due to Fees
First Claim
Patent Images

1. An illumination optical system that illuminates an illuminated surface with light from a light source that provides linearly polarized light, comprising:

  • a polarized state switching device positioned in a light path between the light source and the illuminated surface, the polarized state switching device switches a polarized state of the light that illuminates the illuminated surface between a predetermined linearly polarized state and a nonpolarized state while controlling a loss of light amount, and varies a polarization plane of the predetermined linearly polarized light.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×