Zoom lens system, imaging apparatus, and method for zooming the zoom lens system

a technology of zoom lens and zoom lens system, which is applied in the field of zoom lens system, imaging apparatus and method for zooming lens system, can solve the problems of insufficient satisfaction of high zoom ratio and inability to achieve excellent optical performance, and achieve excellent optical performance and high zoom ratio
US20110194191A1Inactive Publication Date: 2011-08-11NIKON CORP
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Patent Information

Authority / Receiving Office
US · United States
Patent Type
Applications(United States)
Current Assignee / Owner
NIKON CORP
Publication Date
2011-08-11
Estimated Expiration
Not applicable · inactive patent

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Abstract

Providing a zoom lens system having excellent optical performance with a high zoom ratio, an imaging apparatus, and a method for zooming the zoom lens system. The system including, in order from an object, a first group G1 having negative refractive power, a second group G2 having positive refractive power, a third group G3 having negative refractive power, and a fourth group G4 having positive refractive power. An aperture stop S is disposed between the second group G2 and the fourth group G4. Upon zooming from a wide-angle end state to a telephoto end state, each group is moved such that a distance between the second group G2 and the third group G3 increases, a distance between the third group G3 and the fourth group G4 decreases, and the aperture stop S is moved together with the third group G3. Given conditions are satisfied.
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Description

TECHNICAL FIELD

[0001] The present invention relates to a zoom lens system, an imaging apparatus and a method for zooming the zoom lens system.BACKGROUND ART

[0002] A zoom lens system suitable for a film camera, an electronic still camera, and a video camera has been proposed (for example, Japanese Patent Application Laid-Open Nos. 2004-61910, and 11-174329).

[0003] However, conventional zoom lens system has a zoom ratio of about two, so that a requirement for a high zoom ratio cannot be sufficiently satisfied. Moreover, since the position of an aperture stop is not optimized, excellent optical performance cannot be accomplished.DISCLOSURE OF THE INVENTION

[0004] The present invention is made in view of the aforementioned problems and has an object to provide a zoom lens system having excellent optical performance with a high zoom ratio, an imaging apparatus, and a method for zooming the zoom lens system.

[0005] According to a first aspect of the present invention, there is provided a zoom...

Claims

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