Patent ID: 6973266
Filing Date: 2005-12-06
Classification: G02B

Abstract:
1. A real image mode finder optical system comprising, in order from an object side: an objective optical system with a positive refracting power; a field frame located in the proximity of an imaging position of the objective optical system; and an eyepiece optical system with a positive refracting power, wherein the real image mode finder optical system includes an image erecting device, wherein the objective optical system is capable of having a focal length shorter than a focal length of the eyepiece optical system, and wherein the eyepiece optical system includes, in order from the object side, a prism unit with a positive refracting power and a lens unit with a positive refracting power a most field-frame-side surface of the prism unit with a positive refracting power having a positive refracting power and being configured as an aspherical surface with a negative refracting power on a periphery thereof.