Patent ID: 7347565

Claim:
An optical element switch device for bringing an optical element into an optical path of an image forming lens system and removing it from the optical path, said optical switch device comprising: a holder frame for holding said optical element, said holder frame being supported for pivotal movement on a stationary member of the optical element switch device so as to move said optical element between a rest position in which said optical element is put out of said optical path of said image forming lens system and a working position in which said optical element is put in said optical path of said image forming lens system; manually operable switch means for causing pivotal movement of said holder frame between said rest position and said working position; and a spring in sliding contact with an outer peripheral portion of said holder frame and applying urging force against said holder frame during pivotal movement of said holder frame between said rest position and said working position, said spring being secured to said stationary member of the optical element switch device and inverting said urging force in direction with respect to said holder frame between said rest position and said working position, said outer peripheral portion of said holder frame sliding along said spring during movement of said holder frame between said rest position and said working position, said spring comprising a leaf spring secured at opposite ends to said stationary member and having bent and straight sections so as to be elastically deformable in shape during movement of said holder frame between said rest position and said working position.