Large-aperture three-lens objective with aspherical-surfaces
US5251063A · kind A · utility
15Cited by
11References
18Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Oct 16, 1992 |
| Grant date | Oct 5, 1993 |
| Priority date | — |
| Expiry date | Oct 16, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B13/18
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A three-lens objective has the following characteristics: A front lens consists of a first material of relatively low dispersion, a median lens consists of a second material of relatively larger dispersion, and a rear lens consists of a material of relatively low dispersion. The front lens has positive power, the median lens has negative power, and the rear lens has positive power. The spacing between front lens and median lens is substantially smaller than the distance between median lens and rear lens. Each of the lenses has at least one aspherical surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.