Zoom lens system having a focusing lens consisting of only one lens component
US3994571A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 4, 1974 |
| Grant date | Nov 30, 1976 |
| Priority date | — |
| Expiry date | Dec 4, 1994 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B15/1441
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The zoom objective is of the type in which the provision for focusing is made at the front component consisting of only one element comprising a simple planoconvex component of forward convexity movable for focusing, and comprises further a variator of negative power consisting of a doublet component having a positive meniscus element in front of a double-concave element, a compensator of positive power consisting of a doublet component having a negative element in front of a double-convex element followed by a positive simple meniscus component of forward convexity, and a relay system. Because of the incapability of concentrating aberration correction especially with respect to chromatic aberrations in the front component for focusing, the present invention gives rise to the possibility of achieving a high standard of correction of various aberrations by use of the variator and particularly the compensator throughout the zooming range.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.