Patent ID: 6532343
Filing Date: 2003-03-11
Classification: G02B

Abstract:
A finder device of a camera having a variable focusing device for changing the focal length of a photographic optical system comprising:a finder optical system including a movable optical member, wherein said finder optical system is independent from said photographic optical system; a focus detector system for providing a detection control signal, said focus detector system having a focus detection plane situated on the optical path of said focus detector system at a position equivalent to the focal plane of an objective lens system of said finder optical system; means for branching the optical path of the finder optical system onto the focus detector system; and driving means coupled to said focus detector system and to said finder optical system for moving said movable optical member of said finder optical system forward and backward along an optical axis on the basis of said detection control signal from said focus detector system so that said finder system focuses on said focal plane.