Patent ID: 6710938
Filing Date: 2004-03-23
Classification: G02B

Abstract:
An objective lens comprising:a first lens unit with positive refracting power; and a second lens unit placed on a specimen side of said first lens unit, wherein said first lens unit includes at least one lens and said second lens unit includes at least one optical element, satisfying the following conditions: vdLD>vdHD&it;&NewLine;-0.56&LessFullEqual;Ï†II&it;/Ï†T&LessFullEqual;0.56where &ngr;dLD is an Abbe's number of glass material of said lens, &ngr;dHD is an Abbe's number of glass material of said optical element, &phgr;II{circle around (1)} is a refracting power of a first surface of said second lens unit, and &phgr;T is a refracting power of an entire system of said objective lens.