Zoom lens system having electrical control of moving elements
US4043642A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 31, 1975 |
| Grant date | Aug 23, 1977 |
| Priority date | — |
| Expiry date | Oct 31, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B17/14
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
From an object side, there are a fixed lens, a first movable lens, a second movable lens, and a fixed lens being positioned in that order, wherein the first movble lens is coupled with a first position detecting means and the second movable lens is coupled with a second position detecting means, and at the same time it is coupled with a lens shifting means which is controlled by the above mentioned two detecting means. For photographing which involves zooming, first the second movable lens is shifted for focusing. Next, as the first movable lens is shifted, the amount of shifting is detected by the first detecting means and then the second movable lens is shifted based on the detected value of the same. The amount of shifting of said second movable lens is determined by a functional equation which has been set as the optical system is designed, while the position adjustment of the second movable lens is controlled by the lens shifting means and the second detecting means. While magnification variation is performed as a result of shifting of the first movable lens and of the second movable lens, there will be no shifting of image in an image.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.