Title:
OPTICAL SYSTEM AND VARIABLE POWER OPTICAL SYSTEM
Document Type and Number:
Japanese Patent JPH1130701
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To provide the optical system which is suited for mass-production by using optical resin which has good optical characteristics in the visible range and superior characteristics needed as optical resin, specially, environmental resistance. SOLUTION: This system consists of a stop S1, a 1st lens group Gr1 with positive power, and a 2nd lens group Gr2 with negative power in order from the object side. The 1st lens group Gr1 consists of a stop S2 and a 1st lens L1 which is in a positive meniscus shape having its concave surface on both the object side and aspherical on both the object and image sides in order from the object side. Further, the 2nd lens group Gr2 consists of a 2nd lens L2 which is in a negative meniscus shape having its concave surface on the object side and aspherical on both the object and image sides. In this constitution, the 2nd lens L2 is a resin lens comprising amorphous polyester resin wherein the copolymerization ratio of 9,9-bis(4-(2-hydroxyethoxy)phenyl)olefin is 35 to 45 mol.% based on a 100 mol.% dicarboxylic acid component.
Inventors:
MUKAI HIROSHI
YAMAMOTO YASUSHI
KONO TETSUO
YAMAMOTO YASUSHI
KONO TETSUO
Application Number:
JP29839197A
Publication Date:
February 02, 1999
Filing Date:
October 30, 1997
Export Citation:
Assignee:
MINOLTA CO LTD
International Classes:
G02B13/18; C08G63/199; G02B1/04; G02B15/16; (IPC1-7): G02B1/04; G02B13/18; G02B15/16