Objective lens system for endoscopes
US5005957A · kind A · utility
66Cited by
3References
18Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 6, 1989 |
| Grant date | Apr 9, 1991 |
| Priority date | — |
| Expiry date | Sep 6, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B23/243
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An objective lens system for endoscopes comprising, in the order from the object side, a first lens unit having negative refractive power and a second lens unit having positive refractive power, said first lens unit comprising a surface which is concave on the image side and satisfies the following condition (1), and an aspherical surface which is arranged on the object side and satisfies the following condition (2) at 50% or more of the effective area thereof. ##EQU1##
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.