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US 8,477,427 B2Granted
Zoom lens system, optical apparatus equipped with zoom lens system and method for zooming zoom lens system
AssigneeNikon Corporation
InventorsMami Muratani, Haruo Sato
Life of this patent
Estimating the term…
Abstract
A zoom lens system ZL mounted in an electronic still camera 1 etc is constructed to include, in order from an object side, a first lens group G1 having negative refractive power and a second lens group G2 having positive refractive power, in which the second lens group G2 has two cemented lenses. A distance between the first lens group G1 and the second lens group G2 changes when a lens position state changes from a wide-angle end state to a telephoto end state, thereby providing the zoom lens system exhibiting preferable optical performance, an optical apparatus including the zoom lens system and a magnification varying method using the zoom lens system.
Claims32
A zoom lens system comprising, in order from an object side:
- a first lens group having negative refractive power;
- and
- a second lens group having positive refractive power,
- wherein said second lens group has two cemented lenses, and a distance between said first lens group and said second lens group varies upon zooming from a wide-angle end state to a telephoto end state, and the following conditional expression is satisfied:
- 0.229≦dn/ds<0.5
- where ds denotes a thickness along an optical axis of the two cemented lenses of the second lens group from a surface closest to the object to a surface closest to the image, and dn denotes a thickness along the optical axis of a negative lens of the cemented lens disposed on the object side in the two cemented lenses.
3 more elements
A method for manufacturing a zoom lens system including, in order from an object side, a first lens group and a second lens group, said method comprising steps of:
- disposing said first lens group so as to have negative refractive power, and disposing said second lens group including two cemented lenses so as to have positive refractive power on the whole,
- a distance between said first lens group and said second lens group varying upon zooming from a wide-angle end state to a telephoto end state;
- and
- satisfying the following conditional expression:
- 0.229≦dn/ds<0.5
- where ds denotes a thickness along an optical axis of the two cemented lenses of the second lens group from a surface closest to the object to a surface closest to the image, and dn denotes a thickness along the optical axis of a negative lens of the cemented lens disposed on the object side in the two cemented lenses.
3 more elements
A zoom lens system comprising, in order from an object side:
- a first lens group having negative refractive power;
- and
- a second lens group having positive refractive power, wherein said second lens group has two cemented lenses, and a distance between said first lens group and said second lens group varies upon zooming from a wide-angle end state to a telephoto end state, and the following conditional expressions are satisfied:
- 0. 1<do/ds<0.5
- 0.05<sp/dn<1.00
- where ds denotes a thickness along an optical axis of the two cemented lenses of the second lens group from a surface closest to the object to a surface closest to the image, do denotes a thickness along the optical axis of a negative lens of the cemented lens disposed on the object side in the two cemented lenses, and sp denotes a distance between the two cemented lenses.
3 more elements
A zoom lens system comprising, in order from an object side:
- a first lens group having negative refractive power;
- and
- a second lens group having positive refractive power, wherein said second lens group has two cemented lenses, and a distance between said first lens group and said second lens group varies upon zooming from a wide-angle end state to a telephoto end state, and the following conditional expressions are satisfied:
- 0.1<do/ds<0.5
- 0.03<sp/f2<0.20
- where ds denotes a thickness along an optical axis of the two cemented lenses of the second lens group from a surface closest to the object to a surface closest to the image, do denotes a thickness along the optical axis of a negative lens of the cemented lens disposed on the object side in the two cemented lenses, sp denotes a distance between the two cemented lenses, and f2 denotes a focal length of the second lens group G2.
3 more elements
A zoom lens system comprising, in order from an object side:
- a first lens group having negative refractive power;
- and
- a second lens group having positive refractive power,
- wherein said second lens group has two cemented lenses, and a distance between said first lens group and said second lens group varies upon zooming from a wide-angle end state to a telephoto end state, and the following conditional expressions are satisfied:
- 0.1<do/ds<0.5
- 0.05<sp/dp<0.20
- where ds denotes a thickness along an optical axis of the two cemented lenses of the second lens group from a surface closest to the object to a surface closest to the image, do denotes a thickness along the optical axis of a negative lens of the cemented lens disposed on the object side in the two cemented lenses, dp denotes a thickness along the optical axis of a positive lens of the cemented lens disposed on the image side in the two cemented lenses, and sp denotes a distance between the two cemented lenses.
4 more elements
A method for manufacturing a zoom lens system including, in order from an object side, a first lens group and a second lens group, said method comprising steps of:
- disposing said first lens group so as to have negative refractive power, and disposing said second lens group including two cemented lenses so as to have positive refractive power on the whole,
- a distance between said first lens group and said second lens group varying upon zooming from a wide-angle end state to a telephoto end state;
- and
- satisfying the following conditional expressions:
- 0.1<do/ds<0.5
- 0.05<sp/dn<1.00
- where ds denotes a thickness along an optical axis of the two cemented lenses of the second lens group from a surface closest to the object to a surface closest to the image, do denotes a thickness along the optical axis of a negative lens of the cemented lens disposed on the object side in the two cemented lenses, and sp denotes a distance between the two cemented lenses.
4 more elements
A method for manufacturing a zoom lens system including, in order from an object side, a first lens group and a second lens group, said method comprising steps of:
- disposing said first lens group so as to have negative refractive power, and disposing said second lens group including two cemented lenses so as to have positive refractive power on the whole,
- a distance between said first lens group and said second lens group varying upon zooming from a wide-angle end state to a telephoto end state;
- and
- satisfying the following conditional expressions:
- 0.1<dn/ds<0.5
- 0.03<sp/f2<0.20
- where ds denotes a thickness along an optical axis of the two cemented lenses of the second lens group from a surface closest to the object to a surface closest to the image, do denotes a thickness along the optical axis of a negative lens of the cemented lens disposed on the object side in the two cemented lenses, sp denotes a distance between the two cemented lenses, and f2 denotes a focal length of the second lens group G2.
4 more elements
A method for manufacturing a zoom lens system including, in order from an object side, a first lens group and a second lens group, said method comprising steps of:
- disposing said first lens group so as to have negative refractive power, and disposing said second lens group including two cemented lenses so as to have positive refractive power on the whole,
- a distance between said first lens group and said second lens group varying upon zooming from a wide-angle end state to a telephoto end state;
- and
- satisfying the following conditional expressions:
- 0.1<dn/ds<0.5
- 0.05<sp/dp<0.20
- where ds denotes a thickness along an optical axis of the two cemented lenses of the second lens group from a surface closest to the object to a surface closest to the image, do denotes a thickness along the optical axis of a negative lens of the cemented lens disposed on the object side in the two cemented lenses, dp denotes a thickness along the optical axis of a positive lens of the cemented lens disposed on the image side in the two cemented lenses, and sp denotes a distance between the two cemented lenses.
4 more elements
Dependencies are inferred from the claim text.