Nikon Corporation

Nippon Steel Corporation

Atsushi Shibayama

Susumu Sato

Takeshi Suzuki

Tomoki Ito

Keiko Mizuguchi

Koichi Ohshita

Masatoshi Suzuki

Takeshi Umeda

Takanori Fujita

Shigemasa Sato

Kiyoshi Hayashi

Motoyuki Ohtake

Satoshi Yamaguchi

Hiroshi Yamamoto

Haruo Sato

Kosuke Machida

Masaru Muramatsu

Masato Yasuda

Nobusato Morishige

Kazumi Mizukami

Masahiro Nakatsuji

Takeru Ichie

Fuminobu Murakami

Yoko Kimura

Susumo Sato

Kouichi Oshita

Teruyoshi Tsunashima

Masahide Urago

Sueyuki Oishi

Daichi Hamada

Daisuke Itabashi

A zoom optical system (ZL) comprises a first negative lens group (G) having a negative refractive power; and a second negative lens group (G) disposed closer to an image than the first negative lens group (G), wherein a distance between the first negative lens group (G) and the second negative lens group (G) changes during zooming, at least part of the first negative lens group (G) is movable so as to have a displacement component in a direction perpendicular to an optical axis, at least part of the second negative lens group (G) is movable along the optical axis during focusing, and the following conditional expression,0.50<<2.60is satisfied,where,

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

There is provided a non-oriented electrical steel sheet in which, in a cross section of a base material in a sheet thickness direction, the number density Nof precipitates with an equivalent circle diameter of 50 to 500 nm present in a range of 2.0 to 5.0 μm from the surface of the base material in the sheet thickness direction is 0.30 pieces/μmor less, and the relationship between the number density Nand the number density Nof precipitates with an equivalent circle diameter of 50 to 500 nm present in a range from the surface of the base material to 2.0 μm satisfies Formula (1):()/()≤0.5  Formula (1).

Non-oriented electrical steel sheet and method for manufacturing non-oriented electrical steel sheet

A zoom optical system includes a positive first lens group, a negative second lens group disposed on an image side of the first lens group, a positive third lens group disposed on an image side of the second lens group, a negative fourth lens group disposed on an image side of the third lens group, and a final lens group disposed on an image side of the fourth lens group and closest to an image. During zooming, distances between lens groups change, and the first lens group moves along an optical axis. A negative focusing lens group is provided, and the final lens group is disposed on an image side of the focusing lens group. A negative vibration proof group of the second lens group may include, in order from an object, a negative lens, an air gap and a cemented lens of a negative lens and a positive lens. The final lens group may have negative refractive power.

Provided is a variable power optical system (ZL) used for an optical apparatus such as a camera (). The variable power optical system (ZL) includes, in order from an object: a first lens group having positive refractive power; a second lens group having negative refractive power; a third lens group having negative refractive power; a fourth lens group having positive refractive power; and a fifth lens group. Upon zooming from a wide-angle end state to a telephoto end state, a distance between each of the lens groups changes, and upon focusing from an object at infinity to an object at a close distance, the third lens group moves in the optical axis direction.

Variable power optical system, optical apparatus and manufacturing method for variable power optical system

A variable magnification optical system includes, in order from an object: a first lens group (G) having a negative refractive power; a second lens group (G); a third lens group (G); a fourth lens group (G) having a negative refractive power; and a fifth lens group (G) having a positive refractive power, the system performing varying magnification by changing the distance between the first and second lens groups, the distance between the second and third lens groups, the distance between the third and fourth lens groups, and the distance between the fourth and fifth lens groups, and the fourth lens group including a 42nd lens group (G) configured to be movable so as to have a component in a direction orthogonal to an optical axis and a 41st lens group (G) disposed at an object-side of the 42nd lens group.

Variable magnification optical system, optical apparatus, and method for manufacturing variable magnification optical system

A variable magnification optical system includes, in order from an object: a first lens group (G) having a negative refractive power; a second lens group (G) having a positive refractive power; a third lens group (G) having a negative refractive power; and a fourth lens group (G) having a positive refractive power. The system performs varying magnification by changing the distance between the first lens group and the second lens group, the distance between the second lens group and the third lens group, and the distance between the third lens group and the fourth lens group. The third lens group includes a 32nd lens group (G) configured to be movable so as to have a component in a direction orthogonal to an optical axis in order to correct image blur as a vibration-reduction lens group (VR) and a 31st lens group (G) disposed at an object-side of the 32nd lens group. The 32nd lens group has negative refractive power, and the system satisfies Conditional Expression (1) below.0.200&#x3c;1/3&#x3c;0.900&#x2003;&#x2003;(1)

A zoom optical system (ZL) comprises: a first lens group (G) disposed closest to an object and having a positive refractive power; an aperture stop (S) disposed closer to an image than the first lens group (G); a positive lens component disposed so as to oppose the image side of the aperture stop (S); and a lens group (G) having the positive lens component, wherein a distance between the first lens group (G) and the lens group (G) having the positive lens component changes during zooming, at least one lens surface of the positive lens component has an aspherical surface, and the following conditional expression,0.40&#x3c;&#x3c;3.60is satisfied,where

A zoom optical system (ZL) comprises a first negative lens group (G) having a negative refractive power; and a second negative lens group (G) disposed closer to an image than the first negative lens group (G), wherein a distance between the first negative lens group (G) and the second negative lens group (G) changes during zooming, at least part of the first negative lens group (G) is movable so as to have a displacement component in a direction perpendicular to an optical axis, at least part of the second negative lens group (G) is movable along the optical axis during focusing, and the following conditional expression,0.50&#x3c;&#x3c;2.60is satisfied,where,

In an optical system (ZL) capable of imaging in a plurality of object side media (for instance, air and water) whose refractive indexes are different from each other, the optical system is composed of, in order from an object, a front lens group (G) whose position in an optical axis fixed, and a rear lens group (for instance, Gto G), and the rear lens group comprises at least two moving lens groups (for instance, Gand G), and at least two moving lens groups in the rear lens group are moved along the optical axis upon changing between object side media.

Optical system, imaging device, and method for manufacturing the optical system

A zoom optical system has a first lens group having a positive refracting power; a second lens group having a negative refracting power; a third lens group having a positive refracting power; a fourth lens group having a negative refracting power; and a fifth lens group having a positive refracting power, in the order from the object side. The fourth lens group is composed of a cemented lens of a negative lens and a positive lens in the order from the object side, and a condition of the following expression is satisfied: &#x3bd;p&#x3e;30.0, where &#x3bd;p is an Abbe number of the positive lens.

Zoom optical system, optical instrument incorporating the zoom optical system, and method of manufacturing the zoom optical system

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

Providing a compact zoom lens system with high optical performance suitable for an SLR digital camera with a solid-state imaging device of the APS-C size. The zoom lens system includes, in order from an object, a first group having negative power, a second group having positive power, a third group having negative power, and a fourth group having positive power. Upon zooming from a wide-angle end state to a telephoto end state, the second, third and fourth groups are moved to the object such that a distance between the first and second groups decreases, a distance between the second and third groups increases, and a distance between the third and fourth groups decreases. Each of the first, second and fourth groups is composed of at least one positive lens and at least one negative lens. The third group consists of a single lens. Given conditional expressions are satisfied.

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Tokyo, Japan

Atsushi Shibayama