Compact size zoom lens system
US5327290A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 10, 1990 |
| Grant date | Jul 5, 1994 |
| Priority date | — |
| Expiry date | Oct 10, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B15/142
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A new compact-size, light-weight and low-cost zoom lens system having a high optical quality with a very simple structure including, from the object side to the image side, a front lens group having a positive refractive power and a rear lens group having a negative refractive power. The zoom lens system is operated by changing the axial air distance between the front and rear lens groups during a zooming operation. The zoom lens system uses aspherical surfaces whose low-cost manufacturing has been enabled by the recent progresses in plastic molding technology and glass molding technology. Many embodiments of the lens compositions according to the present invention, and further more specific examples of the embodiments are described with figures and data that show compactness and high optical performance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.