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US 2006/0187323 A1Published application
Zoom optical system and electronic equipment using the same
AssigneeOlympus Corporation
InventorsYuko Kobayashi, Noriyuki Iyama, Ayami Imamura
Life of this patent
Estimating the term…
Abstract
A zoom optical system that comprising: a first lens unit having a negative refractive power; a second lens unit having a positive refractive power; and a third lens unit having a positive refractive power which are arranged in order from an object side, a space between the lens units being changed to perform variation of magnification, the first lens unit includes a negative lens, the second lens unit includes a positive lens and a negative lens in order from the object side, the third lens unit includes a positive lens, and an electronic equipment provided with the zoom optical system.
Claims22
A zoom optical system comprising:
- a first lens unit having a negative refractive power;
- a second lens unit having a positive refractive power;
- and a third lens unit having a positive refractive power which are arranged in order from an object side, at least the first and second lens units being moved to change spaces between the lens units, thereby varying magnification,
- wherein the first lens unit includes a negative lens, the second lens unit includes a positive lens and a negative lens in order from the object side, the third lens unit includes a positive lens, a total number of lenses included in the first through third lens units is four, and the following condition is satisfied:
- −5.0<(r5+r6)/(r5−r6)<2.0 (1)
- wherein r5 denotes a radius of curvature of an image-side surface of the positive lens in the second lens unit on an optical axis, and r6 denotes a radius of curvature of an object-side surface of the negative lens in the second lens unit on the optical axis.
3 more elements
A zoom optical system comprising:
- a first lens unit having a negative refractive power;
- a second lens unit having a positive refractive power;
- and a third lens unit having a positive refractive power which are arranged in order from an object side, at least the first and second lens units being moved to change a space between the lens units, thereby varying magnification,
- wherein the first lens unit includes a negative lens, the second lens unit includes a positive lens and a negative lens in order from the object side, the third lens unit includes a positive lens, a total number of lenses included in the first through third lens units is four, and the following condition is satisfied:
- −0.1<(r6+r7)/(r6−r7)<5.0 (2)
- wherein r6 denotes a radius of curvature of an object-side surface of the negative lens in the second lens unit on an optical axis, and r7 denotes a radius of curvature of an image-side surface of the negative lens in the second lens unit on the optical axis.
3 more elements
A zoom optical system comprising:
- a first lens unit having a negative refractive power;
- a second lens unit having a positive refractive power, and a third lens unit having a positive refractive power which are arranged in order from an object side, an interval between the lens units being changed to vary magnification,
- wherein distortion of the zoom optical system satsfies the following condition:
- −35(%)≦DTmin≦−10(%)
- wherein DTmin is a minimum value (%) of distortion.
2 more elements
A three-unit zoom lens system comprising:
- a first lens unit having a negative refractive power;
- a second lens unit having a positive refractive power;
- and a third lens unit having a positive refractive power which are arranged in order from an object side, a space between the lens units being changed to vary magnification,
- wherein the first lens unit includes a double-concave negative lens, the second lens unit includes a positive lens and a negative lens in order from the object side, the third lens unit includes a positive lens, a total number of lenses included in the first through third lens units is four, and the following condition is satisfied:
- 1.2 mm≦D12t≦3.0 mm,
- wherein D12t denotes a space between the first lens unit and the second lens unit at a telephoto end.
3 more elements
A three-unit zoom lens system comprising:
- a first lens unit having a negative refractive power, an aperture stop;
- a second lens unit having a positive refractive power;
- and a third lens unit having a positive refractive power which are arranged in order from an object side, a space between the lens units being changed to vary magnification,
- wherein the first lens unit includes a double-concave negative lens, the second lens unit includes a positive lens and a negative lens in order from the object side, the third lens unit includes a positive lens, a total number of lenses included in the first through third lens units is four, and the following condition is satisfied:
- 0.3 mm≦Ds2t≦1.2 mm,
- wherein Ds2t denotes a space between the aperture stop and the second lens unit at a telephoto end.
3 more elements
Dependencies are inferred from the claim text.