Zoom lens system
US5341244A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 4, 1992 |
| Grant date | Aug 23, 1994 |
| Priority date | — |
| Expiry date | Sep 4, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B15/142
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A zoom lens system consists of five lens elements arranged in two groups, in which the first three elements form a front lens group with positive refracting power and the last two elements form a rear lens group with negative refracting power. In the lens system of the present invention, the front lens group is composed of a positive first lens element, a negative second lens element, and a positive third lens element; the rear lens group consists of a positive fourth lens element and a negative fifth negative lens element. The airspace between the front lens group and the rear lens group is variable for zooming operation. Both the front lens group and rear lens group comprise at least an aspheric lens elements.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.