Stepped lens with Fresnel surface structure produced by lithography and process for manufacturing of same
US5566023A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 28, 1994 |
| Grant date | Oct 15, 1996 |
| Priority date | — |
| Expiry date | Dec 28, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/2051
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
In a stepped lens with a Fresnel surface structure produced by lithography and a process for fabricating same, the high potential exposure speed of high-speed electron-beam exposure systems which work with variable rectangular beam cross sections is converted in such a way that stepped Fresnel type lenses can be fabricated with high efficiency and, in so doing, the required amounts of data is reduced. According to the invention, radiation dose distributions which correspond to cylindrical lenses are exposed one upon the other, at least one of the radiation dose distributions corresponding to a Fresnel type cylindrical lens. Lens structures with any desired lens curvature, from radially spherical to elliptical, can be efficiently produced by lithography by the disclosed process.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.