Illumination system and exposure apparatus with demountable transparent protective member
US5701169A · kind A · utility
4Cited by
9References
60Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | May 21, 1996 |
| Grant date | Dec 23, 1997 |
| Priority date | — |
| Expiry date | May 21, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/30
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An illumination system includes an optical system for receiving light from a light source, a barrel for accommodating the light source and the optical system therein, the barrel having an inside gas containing a material which may cause blur of an optical element of the optical system, and a transparent protecting member demountably mountable on the barrel, for protecting the optical system against the material.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.