Patent ID: 6259564
Filing Date: 2001-07-10
Classification: G02B

Abstract:
A finder optical system comprising, in order from an object side thereof, an objective optical subsystem having a positive refracting power, an image-inversion means for erecting a real image formed by said objective optical subsystem having only one image-formation action to an erect image, and an ocular optical subsystem having a positive refracting power, with at least one of reflecting surfaces being defined by a roof surface, wherein:said objective optical subsystem comprises at least two reflecting surfaces, each defined by a rotationally asymmetric surface having a power, and at least one of said reflecting surfaces is defined by a reflecting surface that is not the same surface as a transmitting surface, with said at least one reflecting surface satisfying the following condition (1):5.degree.<.vertline..theta..vertline.<25.degree. (1)where .theta. is an angle of reflection of an axial chief ray with respect to a normal to said reflecting surface that is not the same surface as the transmitting surface.