Title:
【発明の名称】ケプラー式変倍ファインダー
Document Type and Number:
Japanese Patent JP3207848
Kind Code:
B2
Abstract:
A variable magnification viewfinder comprising, in the order from the object side, an objective lens system having a positive refractive power, a field lens component having a positive refractive power and an eyepiece lens system having a positive refractive power; said objective lens system comprising a first lens unit having a negative refractive power, a second lens unit having a positive refractive power and a third lens unit having a negative refractive power, and said variable magnification lens system being designed in such a manner that it performs variation of magnification and correction of diopter by moving said second lens unit and said third lens unit along the optical axis so as to vary the airspace reserved between these lens units with said first lens unit kept fixed on the optical axis. The variable magnification viewfinder has a variable magnification ratio on the order of 2, a compact design and favorably corrected aberrations, and can be manufactured at a low cost in practice.
Inventors:
Koji Ogata
Application Number:
JP2835790A
Publication Date:
September 10, 2001
Filing Date:
February 09, 1990
Export Citation:
Assignee:
Toyo Seikan Co., Ltd.
International Classes:
G03B13/06; G02B13/18; G02B15/177; G02B23/14; G03B13/12; (IPC1-7): G02B13/18; G02B23/14; G03B13/06; G03B13/12
Domestic Patent References:
| JP61156019A | ||||
| JP6325613A |
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