Title:
【発明の名称】2群構造のズームレンズ装置
Document Type and Number:
Japanese Patent JP3066541
Kind Code:
B2
Abstract:
In a zoom lens device of a two-lens group structure, positive and negative lens groups are sequentially arranged from a photographing field side. The zoom lens device has a controller for controlling a rear focusing operation for moving the negative lens group on a high magnification side. The controller also controls one of an entire drawing-out focusing operation for moving the positive and negative lens groups, and a front focusing operation for moving the positive lens group on a low magnification side. The high and low magnification sides are respectively set to telescopic and wide angle sides. A focal length of the zoom lens device is increased on the high magnification side and is decreased on the low magnification side. Thus, a zoom ratio is increased and a lens drawing-out amount is reduced on the telescopic side so that the zoom lens device can be made compact.
Inventors:
Saburo Sasaki
Ikuya Tsurukawa
Hiroshi Terui
Ikuya Tsurukawa
Hiroshi Terui
Application Number:
JP453991A
Publication Date:
July 17, 2000
Filing Date:
January 18, 1991
Export Citation:
Assignee:
株式会社リコー
International Classes:
G02B7/08; G02B7/10; G02B7/105; G02B15/16; (IPC1-7): G02B7/08; G02B7/10; G02B7/105
Domestic Patent References:
| JP1144006A | ||||
| JP61282811A | ||||
| JP56165106A | ||||
| JP4102812A | ||||
| JP446415U |
Attorney, Agent or Firm:
Mitsutake Murayama