Large aperture ratio wide-angle photographic lens system
US4770512A · kind A · utility
5Cited by
5References
11Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Dec 13, 1985 |
| Grant date | Sep 13, 1988 |
| Priority date | — |
| Expiry date | Dec 13, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B13/06
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A large aperture ratio wide-angle photographic lens system comprising a first, second and third lens groups in which an aspherical surface is provided to a lens located near a stop and having a comparative low refractive index, the large aperture ratio wide-angle photographic lens system being thereby arranged that aberrations, especially coma flare, are corrected favorably up to the marginal portion and arranged to be compact in size.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.