Viewfinder optical system
US5978145A · kind A · utility
5Cited by
4References
31Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 16, 1997 |
| Grant date | Nov 2, 1999 |
| Priority date | — |
| Expiry date | Apr 16, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B13/06
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A viewfinder optical system has a relay lens system and an eyepiece optical system. The relay lens system refocuses a primary image as a secondary image. The relay lens system consists of a single lens element which has a surface having optical power of diffraction. The eyepiece optical system magnifies the secondary image and has a surface having optical power of diffraction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.