Method and apparatus for providing uniform illumination of a mask in laser projection systems
US7428039B2 · kind B2 · utility
7Cited by
1References
16Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Nov 17, 2005 |
| Grant date | Sep 23, 2008 |
| Priority date | — |
| Expiry date | Sep 2, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B27/54
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An optical system for projecting a laser-beam on a mask to illuminate the mask includes a beam homogenizing arrangement including spaced arrays of microlenses. The beam homogenizing arrangement redistributes light in the laser beam such that the intensity of light in the laser-beam on the mask is nearly uniform along a transverse axis of the laser-beam. A stop extending partially into the laser-beam between the microlens arrays provides a more uniform light-intensity on the mask along the transverse axis than can be achieved by the microlens arrays alone.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.