Nikon Corporation

Keiko Mizuguchi

Atsushi Shibayama

Hiroshi Yamamoto

Tomoki Ito

Kouichi Oshita

Providing a zoom lens system having a vibration reduction function capable of performing quick focusing with excellent optical performance even upon vibration reduction. The system including, in order from an object, a first lens group Ghaving positive refractive power, a second lens group Ghaving negative refractive power, a third lens group Ghaving positive refractive power, and a fourth lens group Ghaving positive refractive power. Upon zooming from a wide-angle end state to a telephoto end state, a distance between the first lens group Gand the second lens group Gvaries, and a distance between the second lens group Gand the third lens group Gvaries. The third lens group Gcarries out focusing from an infinity object to a close object. At least a portion of the fourth lens group Gmoves in a direction perpendicular to the optical axis.

Zoom lens system, optical apparatus, and method for manufacturing zoom lens system

A compact zoom lens system has a zoom ratio of about 3.5 or more, an angle of view of 29&#xb0; or more in a wide-angle end, and a vibration reduction function. The system includes, in order from an object, a first group having positive power, a second group having negative power, and a third group having positive power. Upon zooming from a wide-angle end to a telephoto end, a distance between the first and second groups increases, and a distance between the second and third groups decreases. The third group consists of, in order from the object, a 31 group having positive power, a 32 group having negative power, and a 33 group. Only the 32 group is moved perpendicularly to an optical axis for correcting image blur due to camera shake.

Zoom lens system with vibration reduction function

The invention provides a zoom lens system suitable for an image gathering system using a solid-state imaging device, having a zoom ratio of about three, a small lens length, and superb optical performance. The zoom lens system includes, in order from an object, a first lens group having negative refractive power, a second lens group having positive refractive power, and a third lens group having positive refractive power. The first lens group consists only of a negative lens and a positive lens. The second lens group includes at least two positive lenses and at least one negative lens. The third lens group consists of one lens. Zooming from a wide-angle end state to a telephoto end state is conducted by decreasing a distance between the first and second lens groups, increasing a distance between the second and third lens groups, and fixing the third lens group. Given conditions are satisfied.

Zoom lens system

Object is to provide an inner-focusing type zoom lens system carrying out focusing by moving a portion of a first lens group suitable for an auto-focus SLR camera. A zoom lens system includes, in order from an object, a first lens group having positive refractive power, a second lens group having negative refractive power, and a third lens group having positive refractive power. Upon zooming from a wide-angle end state to a telephoto end state, a distance between the first and the second lens groups increases, and a distance between the second and the third lens groups decreases. The first lens group is composed of, in order from the object, aA lens group GA having positive refractive power, and aB lens group GB having positive refractive power. Focusing from infinity to a close-range object is carried out by moving only theB lens group GB to the object.

Providing a compact zoom lens system having a high zoom ratio. The zoom lens system includes, in order from an object, a first lens group Ghaving positive refractive power, a second lens group Ghaving negative refractive power, and a third lens group Ghaving positive refractive power. When a state of lens group positions varies from a wide-angle end state W to a telephoto end state T, at least the first lens group Gand the third lens group Gare moved along the optical axis to the object. Given conditional expressions are satisfied.

Object is to provide an inner-focusing type zoom lens system carrying out focusing by moving a portion of a first lens group suitable for an auto-focus SLR camera. A zoom lens system includes, in order from an object, a first lens group having positive refractive power, a second lens group having negative refractive power, and a third lens group having positive refractive power. Upon zooming from a wide-angle end state to a telephoto end state, a distance between the first and the second lens groups increases, and a distance between the second and the third lens groups decreases. The first lens group is composed of, in order from the object, a 1A lens group GA having positive refractive power, and a 1B lens group GB having positive refractive power. Focusing from infinity to a close-range object is carried out by moving only the 1B lens group GB to the object.

An object of the present invention is to provide a fisheye lens, in spite of its compactness, having an angle of view of 180 degrees and a fast f-number of 2.8 with securing sufficient back focal length and suitable for a digital camera. The fisheye lens consists of a front lens group Ghaving negative refractive power and a rear lens group Ghaving positive refractive power locating with a space along the optical axis apart from the front lens group G. The front lens group Gincludes a plurality of negative lens components, Land L. The rear lens group Gincludes at least one cemented lens L, and given conditional expressions are satisfied.

Fisheye lens

The present invention provides a zoom lens system suitable for an image gathering system using a solid-state imaging device, having a zoom ratio of about three, a small total lens length, and superb optical performance. According to one aspect, in order from the object side, a first lens group having negative refractive power, a second lens group having positive refractive power, and a third lens group having positive refractive power. Zooming is carried out by varying distances between adjacent lens groups. The first lens group includes two negative lens elements and a positive lens element. The second lens group includes three lens elements consisting of a first positive lens element, a second positive lens element, and a negative lens element. The third lens group includes at least one positive lens element. Predetermined conditional expressions are satisfied.

A variable focal length lens system with low cost, suitable for use with a video camera or a digital still camera employing a solid-state imaging device, capable of assembling and adjusting with ease, and to provide an imaging apparatus equipped with the lens system is provided. According to an aspect, it is a variable focal length lens system comprising, in order from an object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a third lens group having a positive refractive power, wherein the first lens group consists of only one cemented negative lens element, the second lens group comprising at least two positive lens element and at least one negative lens element, and the third lens group consists of a single lens element, and wherein a space between the first and second lens group is decreased and a space between the second and third lens group is increased when a state of the lens group positions is changed from the wide-angle end state to the telephoto end state.

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Kawasaki, Japan

Keiko Mizuguchi