Manufacturing method and structure of slanting diffusive reflector
US6692902B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 16, 2001 |
| Grant date | Feb 17, 2004 |
| Priority date | — |
| Expiry date | Feb 14, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/0007
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A manufacturing method and structure of slanting diffusive reflectors simplifies their manufacturing process and reduces cost. A photo mask comprising a plurality of half-tone exposure units is used. A half-tone photolithography process is performed on the positive photoresist formed on a substrate. Only one exposure process and a suitable drying step are required to form a plurality of slants and rough astigmatisms on the slants. The size of the half-tone exposure units is randomly selected. Each half-tone exposure unit comprises a plurality of parallel transmitting strips or shadow strips. The pitch of the transmitting strips or the shadow strips in one half-tone exposure unit can be arbitrary. The width of the shadow strips is gradually changing from one side of the half-tone exposure unit to the other side.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.