Patent ID: 6256144
Filing Date: 2001-07-03
Classification: G02B

Abstract:
A real image mode variable magnification finder comprising:an objective optical system having positive refracting power;an image erecting optical system; andan ocular optical system having positive refracting power,said objective optical system having, in order from an object side, a first lens unit with negative refracting power, a second lens unit having negative refracting power, a third lens unit having positive refracting power, and a fourth lens unit having negative refracting power,wherein an object-side surface of said second lens unit is concave toward an object side and has a smallest absolute value of radius of curvature among lens surfaces of said first lens unit, said second lens unit and said third lens unit, andwherein when a magnification of said finder is changed, a plurality of lens units including said third lens unit are moved, a distance between said second lens unit and said third lens unit is changed, and a distance between said first lens unit and said second lens unit is changed.