Title:
WIDE-ANGLE ZOOM LENS
Document Type and Number:
Japanese Patent JPH05264903
Kind Code:
A
Abstract:
PURPOSE:To provide the zoom lens which has a wide angle and is bright, and can correct satisfactorily its aberration without enlarging the overall length and the outside diameter by constituting a first lens group of two groups of specific front and rear groups. CONSTITUTION:In the lens system which consists of a first lens group of positive refracting power, a second lens group of positive refracting power, and a third lens group of negative refracting power in order from an object side, and can execute variable power by varying an interval between a first lens group and a second lens group, and an interval between a second group and a third group, a first lens group is constituted of two groups of the front group and the rear group, so that the following condition is satisfied. That is, ¦phif/phi1¦<6.0, provided that phif and phi1 denote refracting power of the front group of a first lens group, and a first lens group, respectively. According to this constitution, the overall length of a lens system can be shortened, by forming a first lens group, a second lens group, and a third group zoom lens as a fundamental constitution, a first lens group can be formed to a lens constitution being suitable for converting to a wide-angle, and the wide-angle conversion can be attained moderately.
Inventors:
Takanori Yamanashi
Application Number:
JP4051592A
Publication Date:
October 15, 1993
Filing Date:
January 31, 1992
Export Citation:
Assignee:
Olympus Optical Co., Ltd.
International Classes:
G02B13/18; G02B15/20; (IPC1-7): G02B15/20; G02B13/18
Domestic Patent References:
| JPH04362910A | 1992-12-15 | |||
| JPH0193713A | 1989-04-12 | |||
| JPS58224322A | 1983-12-26 | |||
| JPH0317609A | 1991-01-25 | |||
| JPH0350516A | 1991-03-05 | |||
| JPH0385508A | 1991-04-10 | |||
| JPH0273211A | 1990-03-13 | |||
| JPH0331809A | 1991-02-12 | |||
| JPH02135312A | 1990-05-24 | |||
| JPH02103014A | 1990-04-16 | |||
| JPS58137813A | 1983-08-16 | |||
| JPS6152620A | 1986-03-15 | |||
| JPS63148223A | 1988-06-21 | |||
| JPH03208004A | 1991-09-11 | |||
| JPH04338910A | 1992-11-26 | |||
| JPS4733373A |
Attorney, Agent or Firm:
Koji Mukai
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