Title:
VARIABLE MAGNIFICATION OBJECTIVE LENSE
Document Type and Number:
Japanese Patent JPS5657018
Kind Code:
A
Abstract:
The objective comprises a plurality of movable lens components and at least one stationary lens component group, at least two of said components including an aspherical surface. The movable components are constituted by single lenses of which at least one lens comprises an aspherical surface, while the stationary lens component group(s) may comprise at least one aspherical surface. Steadiness of the image plane is obtained by mechanical compensation for focal-length variations with a ratio greater than five, which may readily reach the value eight. The aspherical lenses are arranged so that for the same focal length variation the total number of lenses of the objective, which may be spherical or non-spherical, is smaller than in any other variable-focus objective with a stationary image plane comprising solely spherical lenses: This results in a reduction of the mass of the objective, namely of the movable parts, and a reduction of the power necessary for moving said parts. Application to color television camera.
Inventors:
EDOGARUDO ARUFUREEDO FUYUKIYUU
YAN HAISUMA
JIYANNMEERU BATSUKASU
YAN HAISUMA
JIYANNMEERU BATSUKASU
Application Number:
JP13451480A
Publication Date:
May 19, 1981
Filing Date:
September 29, 1980
Export Citation:
Assignee:
PHILIPS NV
International Classes:
G02B13/18; G02B15/14; G02B15/20; (IPC1-7): G02B15/16
Domestic Patent References:
| JPS5231743A | 1977-03-10 | |||
| JPS51144653A | 1976-12-11 |