Eyepiece lens system and image observation device

1. An eyepiece lens system that forms a magnified virtual image of an object to be observed, the system comprising:

a first group disposed adjacent to the object and having negative refractive power;

a second group disposed adjacent to the first group on a side closer to an eye and having positive refractive power; and

a positive meniscus lens having aspherical surfaces on both sides and having a concave surface facing an image display device, the positive meniscus lens being disposed on the object side of the first group and functioning as a field-curvature correction positive lens, wherein

the first group includes a cemented doublet lens of a biconcave lens and a biconvex lens,

the second group includes three positive lenses,

the object side being telecentric, and

the focal length of the entire system F with F>0, the focal length of the first group F 1 with F 1 <0, and the focal length of the second group F 2 with F 2 >0, satisfying the following conditions:

−5< F 1/ F<− 1; and  (1)

0.5< F 2/ F< 3.  (2)

2. An image observing apparatus for observation of a magnified virtual image of a two-dimensional image, the apparatus comprising:

an optical system that forms the virtual image of the two-dimensional image, the optical system comprising at least one eyepiece lens system according to claim 1 .

3. The image observing apparatus according to claim 2 , further comprising:

an image display device that displays the two-dimensional image; and

the at least one eyepiece lens system,

wherein the image observing apparatus is of a head-mount type.