Title:
内視鏡用対物レンズ
Document Type and Number:
Japanese Patent JP4245985
Kind Code:
B2
Abstract:
An objective lens for endoscopes comprises a front lens unit component and a rear lens unit component, between which a stop is located, wherein a front lens unit component comprises, in order from the object side, a first lens having a negative refractive power and a second lens having a positive refractive power which directs a surface of the small radius of curvature toward the object side; wherein a rear lens unit component comprises a third lens having a positive refractive power which directs a surface of the small radius of curvature toward the image side, a fourth lens having a positive refractive power and a fifth lens having a negative refractive power; and wherein the fourth lens and the fifth lens are cemented, and satisfying the following condition: 2.0<|f3/f|<3.0 where f is the composite focal length of the total system and f3 is the focal length of the third lens.
Inventors:
Shinichi Saito
Application Number:
JP2003154925A
Publication Date:
April 02, 2009
Filing Date:
May 30, 2003
Export Citation:
Assignee:
Olympus Endo Technology America Inc.
International Classes:
G02B13/04; G02B23/26; A61B1/00; G02B23/24
Domestic Patent References:
| JP9080305A | ||||
| JP8122632A | ||||
| JP2000330015A | ||||
| JP2000162514A | ||||
| JP2002028126A | ||||
| JP11142730A |
Attorney, Agent or Firm:
Yasushi Shinohara
Masayuki Fujinaka
Masayuki Fujinaka