Patent ID: 6775073
Filing Date: 2004-08-10
Classification: G02B

Abstract:
A real image type zoom finder comprising, in order from an object side thereof, a positive objective optical system and a positive eyepiece optical system and further including an image inverting means for erecting a real image formed through the objective optical system, wherein:said objective optical system comprises a plurality of moving groups, and said eyepiece optical system comprises positive reflecting surfaces at least one of which is defined by a rotationally asymmetric surface and satisfies the following conditions: 1.25EP/fOC<2.0 â€ƒâ€ƒ(1) 0.5OC/fOC<1.3 â€ƒâ€ƒ(2) where dEp is a distance as measured along an axial chief ray from a final surface to an eye point of the eyepiece optical system, fOC is a focal length of the eyepiece optical system, and lOC is a length as calculated on an air basis and measured along an axial chief ray from an intermediate image-formation plane to the final surface of the eyepiece optical system.