Title:
ZOOM LENS
Document Type and Number:
Japanese Patent JPH0255308
Kind Code:
A
Abstract:
PURPOSE:To obtain a compact and highly efficient zoom lens having about 1.4F and about 8 times of a zooming ratio and reducing the number of lenses by constituting a lens system of 4 groups of lenses and satisfying the lens system with specific conditions. CONSTITUTION:The lens system is constituted of a 1st group 1 consisting of a conjugated lens and a meniscus lens having positive refractive power, a 2nd group 2 consisting of a meniscus lens having negative refractive power and a conjugated lens a 3rd group 3 consisting of two single lenses having positive refractive power and a single lens having negative refractive power, and a 4th group 4 consisting of a conjugated lens and a single lens having positive refractive power arranged successively from the object side in order. When it is defined that fw is the focal distance of the whole system at a wide angle end, fi (i=1 to 4) is the focal distance of the i-th group, d16 is the 16th air space counted from the object side, and rj (j=12, 13, 15, 18, 20) is the radius of curvature of the j-th lens, the lens system is satisfied with conditional inequalities 1-10.
Inventors:
ONO SHUSUKE
ISHIGURO KEIZO
HIRAMOTO RIEKO
NAKAJIMA YASUO
ISHIGURO KEIZO
HIRAMOTO RIEKO
NAKAJIMA YASUO
Application Number:
JP20760288A
Publication Date:
February 23, 1990
Filing Date:
August 22, 1988
Export Citation:
Assignee:
MATSUSHITA ELECTRIC IND CO LTD
International Classes:
G02B15/16; (IPC1-7): G02B15/16
Attorney, Agent or Firm:
Shigetaka Awano (1 person outside)
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