Title:
SMALL-SIZED ZOOM LENS
Document Type and Number:
Japanese Patent JPH01191114
Kind Code:
A
Abstract:
PURPOSE:To realize the compact zoom lens which has a >=X2 zoom ratio by satisfying specific conditions among the focal lengths of 1st and 2nd lens groups, and the front and rear groups of the 1st lens group. CONSTITUTION:This zoom lens consists of the 1st lens group G1 which has positive focal length and the 2nd lens group G2 which has negative focal length in order from the object side. Then the focal lengths of the 1st lens group G1 and 2nd lens group G2 are denoted as f1 and f2, the focal lengths of the front group GF and rear group GR are denoted as fF and fR, and the focal length at the wide-angle zoom position of the zoom lens is denoted as fW. In this case, inequalities I-III hold. Consequently, the zoom lens can be realized which maintains the compact shape with simple constitution, has the zoom ratio exceeding X2 and aberrations compensated excellently from the wide-angle end to the telephoto end, and secures excellent image formation performance.
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Inventors:
SHIBAYAMA ATSUSHI
HAYASHI KIYOSHI
TSUNASHIMA TERUYOSHI
HAYASHI KIYOSHI
TSUNASHIMA TERUYOSHI
Application Number:
JP1614288A
Publication Date:
August 01, 1989
Filing Date:
January 27, 1988
Export Citation:
Assignee:
NIKON CORP
International Classes:
G02B15/16; (IPC1-7): G02B15/16
Attorney, Agent or Firm:
Takao Watanabe