Real image mode variable magnification finder optical system

Details Real image mode variable magnification finder optical system Real image mode variable magnification finder optical system

1995-09-01

1998-08-18

Nguyen, Thong

Optical: systems and elements

Compound lens system

Variable magnification

359421, 359431, G03B 1306

Patent

active

057965188

ABSTRACT:
A real image mode variable magnification finder optical system is provided with an objective system having a positive refracting power, a correctly erect image forming system having a plurality of reflecting members for converting an intermediate image formed by the objective system into a correctly erect image, and an eyepiece system having a positive refracting power. The objective system includes a first lens unit having a negative refracting power, a second lens unit having a positive refracting power, and a third lens unit having a negative refracting power. At least one of the light reflecting members is arranged between the third lens unit and a position of said intermediate image, and the first, second and third lens units are adapted to be moved along the optic axis when magnification of the optical system is to be changed. Thus, the finder optical system enables one to change magnification thereof with high ratios and to form a good image of visual field with decreased flare.

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