Patent ID: 7969658

Claim:
An electronic view finder, comprising: an image display device having a display plane adapted to display an image, and an eyepiece optical system located on a display plane side of said image display device and adapted to enlarge an image displayed on said display plane, wherein said eyepiece optical system comprises, in order from an object side on which said display plane is located toward an exit side, a first lens group having a curved refractive surface and a rear lens group having positive refracting power, wherein: during diopter adjustment, said first lens group remains fixed and said rear lens group moves along an optical axis, and there is no lens group other than said first lens group and said rear leas group, with satisfaction of the following conditions (A) and (B): | F/F 1|≦0.667 (A) 8 ≦|F 1/ D 1 air |≦16 (B) where F is a focal length at −1 diopter of the whole eyepiece optical system, F 1 is a focal length of said first lens group, and D 1 air is a distance, as calculated on an air basis, on the optical axis from said first lens group to said display plane.