Title:
レンズ系
Document Type and Number:
Japanese Patent JP4416411
Kind Code:
B2
Abstract:
A lens system disclosed in the present application comprises: in order from the front to the rear, a first lens element having a meniscus shape whose concave surface is directed rearward and having a negative optical power; an aperture stop; a second lens element whose both lens surfaces have a convex shape; a third lens element whose both lens surfaces have a concave, and a fourth lens element whose rear surface has a convex shape and having a positive optical power. Thus, a lens system which maintains telecentricity and high optical performance despite a simple and small-sized structure is disclosed.
Inventors:
Daisuke Ito
Application Number:
JP2003028597A
Publication Date:
February 17, 2010
Filing Date:
February 05, 2003
Export Citation:
Assignee:
Canon Inc
International Classes:
G02B13/04; G02B9/34; G02B13/00; G02B13/16; G02B13/18; G02B13/22
Domestic Patent References:
| JP1183617A | ||||
| JP1048514A | ||||
| JP1130745A | ||||
| JP9113803A | ||||
| JP6365416A | ||||
| JP9113964A | ||||
| JP200453813A | ||||
| JP2003307671A |
Attorney, Agent or Firm:
Yukio Takanashi