Title:
ZOOM LENS HAVING VIBRATIONPROOF FUNCTION
Document Type and Number:
Japanese Patent JP3536128
Kind Code:
B2
Abstract:
PURPOSE: To provide a high-performance zoom lens which is applicable as a lens for general photography by assuring a required back focus and zoom ratio, has a vibrationproof function and permits internal focusing as well.
CONSTITUTION: This zoom lens has, successively from an object side, at least a first lens group G1 having a positive refracting power, a second lens group G2 having a negative refracting power and a third lens group G3 having a positive refracting power. The spacing between the first lens group G1 and the second lens group G2 increases and the spacing between the second lens group G2 and the third lens group G3 changes at the time of variable magnification from a wide angle end to a telephoto end. The second lens group G2 has, successively from the object side, at least a lens group G21 having a negative refracting power and a lens group G22 having a negative refracting power. The zoom lens has a displacement means for proofing vibration by moving the lens group G22 in the second lens group in a direction nearly orthogonal with the optical axis. The zoom lens is so constituted as to satisfy conditions 1.0 < f22/f2 < 5.0 when the focal length of the second lens group G2 is defined as f2 and the focal length of the lens group G22 in the second lens group as f22.
Inventors:
Suzuki, Kenzaburo
Application Number:
JP14078694A
Publication Date:
June 07, 2004
Filing Date:
May 31, 1994
Export Citation:
Assignee:
NIKON CORP
International Classes:
G02B15/16; G02B15/167; G02B15/173; G02B27/64; (IPC1-7): G02B15/16; G02B15/167
Attorney, Agent or Firm:
山口 孝雄