Title:
広角レンズ系
Document Type and Number:
Japanese Patent JP3595476
Kind Code:
B2
Abstract:
A wide-angle lens system includes a negative first lens group and a positive second lens group with a diaphragm, in this order from an object. Upon focusing, the positive second lens group is arranged to be moved along the optical axis. The wide-angle lens system satisfies the following conditions:whereinTL2 designates the distance, in the second lens group, between the most object-side surface of the most object-side lens element and the most image-side surface of the most image-side lens element;f designates the focal length of the entire lens system when an object at an infinite distance is in an in-focus state;f1 designates the focal length of the first lens group; andf2 designates the focal length of the second lens group.
Inventors:
Takayuki Izumi
Application Number:
JP35477299A
Publication Date:
December 02, 2004
Filing Date:
December 14, 1999
Export Citation:
Assignee:
Pentax Co., Ltd.
International Classes:
G02B13/04; G02B13/06; G02B13/18; (IPC1-7): G02B13/04; G02B13/18
Domestic Patent References:
| JP9211321A | ||||
| JP7261076A | ||||
| JP59216114A | ||||
| JP5273459A | ||||
| JP61123810A |
Attorney, Agent or Firm:
Kunio Miura