Title:
ZOOM LENS HAVING HIGH VARIABLE POWER
Document Type and Number:
Japanese Patent JPH04186213
Kind Code:
A
Abstract:
PURPOSE:To obtain a zoom lens having high variable power ratio by satisfying a prescribed condition in an optical system equipped with six lens groups having positive, negative, positive, negative, positive and negative refractive powers in order from an object side. CONSTITUTION:The first lens group I having positive refractive power, the second lens group II having negative refractive power, the third lens group III having positive refractive power, the fourth lens group IV having negative refractive power, the fifth lens group V having positive refractive power and sixth lens group VI having negative refractive power are provided in order from an object side. When air space of both the (i)th group and the (i + 1)th group at the wide angle edge and the tele edge are set respectively as diw and diT, zooming from the wide angle edge to the tele edge is carried out so as to satisfy conditions in equations I - IV. When focal distances of the first, the second and the fifth lens groups 1, 2 and 5 are set respectively as f1, f2 and f3, and when focal distance at the tele edge of whole points is set as fT, zooming is carried out so as to satisfy conditions in equations V-VII. Thereby, in spite of a compact type, a zoom lens having high performance and high variable power ratio can be obtained.
Inventors:
ENDO HIROSHI
Application Number:
JP31626190A
Publication Date:
July 03, 1992
Filing Date:
November 20, 1990
Export Citation:
Assignee:
CANON KK
International Classes:
G02B15/20; (IPC1-7): G02B15/20
Attorney, Agent or Firm:
Giichi Marushima (1 person outside)