Patent ID: 7777973

Claim:
A subminiature imaging optical system comprising: an aperture stop; and four lenses, first, second, third and fourth lenses sequentially positioned from an object side to an image plane side, the first lens having positive refractivity, the second lens having a concave image-side surface and having negative refractivity, the third lens having negative refractivity, and the fourth lens having a concave image-side surface and positive refractivity, the second lens satisfies following condition 1, and the third lens satisfies following condition 2, 20<V2<50 condition 1, 20<V3<30 condition 2, where V 2 is an Abbe number of the second lens and V 3 is an Abbe number of the third lens, the four lenses are spatially separated from each other, the aperture stop is disposed in front of an object-side surface of the first lens, and at least one of respective surfaces of the first, third, and fourth lenses is formed of an aspherical surface.