Real image mode variable magnification finder optical system
AssigneeOlympus Optical Co., Ltd.
InventorYuji Kamo
Life of this patent
Estimating the term…
Abstract
A real image mode variable magnification finder optical system includes an objective system having a positive refracting power and an eyepiece system having a positive refracting power. The objective system includes a first lens unit (a front optical unit) having at least one lens, an intermediate lens unit having at least one lens unit moving along the optical path, and a rear optical unit having a plurality of reflecting surfaces. By replacing the first lens unit with a lens unit of different focal length, the magnification of the finder optical system is changed.
Claims11
A real image mode variable magnification finder optical system forming a finder optical path independent of a photographic optical path formed by a photographic objective lens, comprising:
- an objective system having a positive refracting power as a whole;
- and
- an eyepiece system having a positive refracting power as a whole, for observing an image of an object formed by said objective system,
- wherein said objective system comprises a first lens unit which is a front optical unit having at least one lens, a second lens unit which is an alternative front optical unit having a refracting power different from that of said first lens unit, said first and second lens units being alternatively insertable into the finder optical path, an intermediate lens unit disposed after one of said first and second lens units, whichever is inserted into the finder optical path, said intermediate lens unit having at least one lens unit movable along the finder optical path for performing a zooming operation irrespective of which of said first and second units is disposed in said finder optical path, and a rear optical unit disposed after said intermediate lens unit and having a plurality of reflecting surfaces.
Dependencies are inferred from the claim text.