Zoom lens
US5235466A · kind A · utility
15Cited by
5References
5Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 10, 1992 |
| Grant date | Aug 10, 1993 |
| Priority date | — |
| Expiry date | Sep 10, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B15/144113
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A zoom lens comprises sequentially from a side of an object: a fixed first lens group constituted by a convex lens, a double convex lens and a meniscus convex lens; a movable second lens group constituted by a meniscus convex lens, a double concave lens and a convex lens; a fixed third lens group constituted by a single lens having at least one aspherical surface; and a movable fourth lens group constituted by a concave lens and two convex lenses at least one of which has at least one aspherical surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.