Patent ID: 9244265
Filing Date: 2016-01-26
CPC Classification: G02B

Claim Text:
1. A view finder for guiding an image displayed on an image display device into the eye of a viewer, comprising: said image display device; and a viewing optical system positioned between said image display device and an eye point wherein said image display device is adapted to display said image, wherein said viewing optical system comprises, in order from said image display device toward said eye point, a front group including a first lens, and a filter, wherein said filter is located on a side of said front group opposite to a side thereof having said image display device located, wherein said viewing optical system comprises at least three lens elements, said filter includes an incident plane and an exit plane lined up and located substantially vertically with respect to the optical axis of said viewing optical system, wherein a lens system between said image display device and said filter in said viewing optical system is defined by said front group, said front group includes at most a total of two lens components, a lens system between said filter and said eye point in said viewing optical system is defined by a rear group, said rear group consists of a lens group having positive refracting power, and said lens group having positive refracting power includes at most a total of two lens components, wherein said image display device has a viewing plane, with satisfaction of the following condition (2): where d is a distance between said viewing plane and said first lens, and Y is a position on said viewing plane where a farthest off-axis ray passes.