Zoom lens system
US5745298A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 2, 1995 |
| Grant date | Apr 28, 1998 |
| Priority date | — |
| Expiry date | Oct 2, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B15/145125
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A zoom lens system includes first to fifth lens groups arranged in this order from the object side. The first, third and fifth lens groups are fixed. The second lens group is moved in the direction of the optical axis of the zoom lens system when zooming the zoom lens system and the fourth lens group is moved in the direction of the optical axis to correct change in the image position due to the zooming and to correct change in the image position due to change in the object distance. The first lens group has a positive refracting power, the second lens group has a negative refracting power, the third lens group has a negative refracting power, the fourth lens group has a positive refracting power and the fifth lens group has a positive refracting power.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.