Zoom lens system
US5455714A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 27, 1993 |
| Grant date | Oct 3, 1995 |
| Priority date | — |
| Expiry date | Aug 27, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B15/143503
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A zoom lens system comprises from the object side to the image side a negative first lens unit, a positive second lens unit, and a negative third lens unit. The negative first lens unit consists of a negative lens element and a positive lens element. The positive second lens unit consists of a negative lens element and a positive lens element, and has a first air space between the first and second lens units. The negative third lens unit consists of a positive lens element and a negative lens element, and has a second air space between the second and third lens units. All the lens units shift along an optical axis of the zoom lens system during a zooming operation from the shortest focal length condition to the longest focal length condition with decreasing the first and second air spaces.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.