Illumination optical apparatus
US4939630A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 26, 1988 |
| Grant date | Jul 3, 1990 |
| Priority date | — |
| Expiry date | Aug 26, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70075
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An illumination optical apparatus includes secondary light source forming means for forming a plurality of light source images from collimated light beams emitted from a light source, tertiary light source forming means arranged midway along an optical path from the secondary light source forming means, and a condenser lens arranged midway along an optical path from the tertiary light source forming means. The secondary light source forming means includes an optical integrator having entrance and exit surface. A plurality lens surface having a larger focal length than a distance between the entrance and exit surfaces are formed on the entrance sarfaces. Thus, a plurality of secondary light source images are formed by the secondary light source forming means in a space behind the exit surface of the optical integrator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.