Patent ID: 6075657
Filing Date: 2000-06-13
Classification: G02B

Abstract:
A wide-angle lens system which has a long back focal length, comprising, in order from an object side:a first lens unit which has a negative power as a whole;a second lens unit which has a positive power as a whole; anda third lens unit which has a positive power as a whole,wherein said first lens unit comprises, in order from the object side,a 1-1 subunit consisting of a positive lens component or positive lens components and having a positive power,a 1-2 subunit consisting of a negative lens component or negative lens components and having a negative power, andwherein said third lens unit comprises, in order from the object side,a 3-1 subunit of said third lens unit comprising, in order from the object side,a first lens component consisting of a negative lens element or negative lens elements and having a negative power,a second lens component which has a positive power,a 3-2 subunit comprising, in order from the object side, a third lens component which has a negative power and a fourth lens component which has a positive power,wherein an aperture stop is disposed between said second lens unit and said third lens unit or in said third lens unit, and wherein said lens system satisfies the following condition (11):(11) 50.degree.<2.omega.<95.degree.wherein the reference symbol 2.omega. denotes a field angle of the lens system.