Lens controller includes a zooming optical system and a zooming speed control device
US5028773A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 23, 1989 |
| Grant date | Jul 2, 1991 |
| Priority date | — |
| Expiry date | Aug 23, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B7/102
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A lens controller comprises a varifocal lens changed by a focusing position with respect to a shifting amount of an image forming position; a focusing drive unit for driving a focusing lens group constituting a zooming optical system; a zooming drive unit for driving a zooming lens group constituting the zooming optical system; a detector for detecting the position of the focusing lens group between proximate and infinite positions; a detector for detecting the position of the zooming lens group on the optical axis thereof corresponding to the focal distance of the entire zooming optical system; a focusing correction control device for calculating a correcting amount of the shift of the image forming position with respect to the focal distance when the zooming operation is performed to change the focal distance of the entire zooming optical system by the zooming drive unit, the focusing correction control device controlling the focusing drive unit so as to move the focusing lens group to the focusing position in accordance with the correcting amount; and a zooming speed control device for receiving an output of the focusing lens group position detector and changing the zooming spee…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.