Patent ID: 7110188
Filing Date: 2006-09-19
Classification: G02B

Abstract:
1. An imaging lens system comprising: a first lens group consisting of a first-first lens, in which the first-first lens has a concave surface facing an object side; a second lens group having positive refracting power as a whole, said second lens group consisting of a second-first lens having positive refracting power and a second-second lens having negative refracting power, the second-first lens and the second-second lens are sequentially arranged from the object side, and the second-second lens is cemented to or separated from the second-first lens; a third lens group consisting of a third-first lens, in which the third-first lens has a meniscus shape with a concave surface facing the object side; and a fourth lens group consisting of a fourth-first lens, wherein the above lens groups are sequentially arranged from the object side and said imaging lens system has a single fixed focal length.