Macro photographic change-over device for zoom lens barrel
US4324457A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 21, 1980 |
| Grant date | Apr 13, 1982 |
| Priority date | — |
| Expiry date | Mar 21, 2000 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B7/105
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A zoom lens which may include two, three, or four lens groups. One of the lens groups is mounted in a focusing barrel and the others in moving barrels or a mount barrel. A zooming barrel is provided which is rotatable independently from the focusing barrel. A cam sleeve controls the movement of at least predetermined ones of the lens groups for zooming and close-up photographing while a guide ring operatively cooperates with the focusing barrel to provide a mechanical indication as to when a change-over is possible to the close-up photographing mode. A change-over sleeve cooperates with the zooming barrel for controlling the zooming operation. The focusing barrel, the cam sleeve, the guide sleeve and change-over sleeve cooperate with one another after changing to the close-up photographing mode such that the change-over sleeve is prevented from rotating except at one position thereof whereby rotation of the guide ring and focusing barrel are also prevented while simultaneously cooperation between the zooming barrel and change-over sleeve is released to enable the zooming barrel to rotate in the close-up photographing mode.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.