Zoom lens and imaging apparatus
AssigneeFUJIFILM Corporation
InventorRyoko Tomioka
Life of this patent
Estimating the term…
Abstract
A zoom lens includes a positive first lens group, a negative second lens group, a positive third lens group, and a positive fourth lens group in order from an object side. In a case of magnification, the first lens group, the second lens group, and the third lens group move. The third lens group consists of a third a lens group that does not move in a case of image shake correction, a third b lens group that moves in the case of the image shake correction, and a third c lens group that does not move in the case of the image shake correction in order from the object side. The third b lens group consists of a positive lens and a negative lens. A predetermined conditional expression related to the third b lens group is satisfied.
Claims19
A zoom lens comprising:
- only four lens groups consisting of a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a fourth lens group having a positive refractive power in order from an object side to an image side as lens groups,
- wherein in a case of magnification, at least the first lens group, the second lens group, and the third lens group move along an optical axis by changing all intervals between adjacent lens groups in an optical axis direction,
- the third lens group consists of a third a lens group that is fixed with respect to an image plane in a case of image shake correction, a third b lens group that moves in a direction intersecting with the optical axis in the case of the image shake correction, and a third c lens group that is fixed with respect to the image plane in the case of the image shake correction in order from the object side to the image side,
- a stop is arranged between a lens surface of the second lens group closest to the image side and a lens surface of the third c lens group closest to the image side,
- the third b lens group consists of one positive lens and one negative lens,
- in a case where a thickness of the positive lens of the third b lens group on the optical axis is denoted by D3 bp, and a thickness of the negative lens of the third b lens group on the optical axis is denoted by D3bn, Conditional Expression (1) represented by
- 0.2<D3bp/D3bn<2 (1)
- is satisfied,
- a lens of the third c lens group closest to the image side is a meniscus lens that has a convex surface toward the image side and has a negative refractive power, and
- the fourth lens group consists of one positive lens.
A zoom lens comprising:
- only four lens groups consisting of a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a fourth lens group having a positive refractive power in order from an object side to an image side as lens groups,
- wherein in a case of magnification, at least the first lens group, the second lens group, and the third lens group move along an optical axis by changing all intervals between adjacent lens groups in an optical axis direction,
- the third lens group consists of a third a lens group that is fixed with respect to an image plane in a case of image shake correction, a third b lens group that moves in a direction intersecting with the optical axis in the case of the image shake correction, and a third c lens group that is fixed with respect to the image plane in the case of the image shake correction in order from the object side to the image side,
- a stop is arranged between a lens surface of the second lens group closest to the image side and a lens surface of the third c lens group closest to the image side,
- the third b lens group consists of one positive lens and one negative lens,
- in a case where a thickness of the positive lens of the third b lens group on the optical axis is denoted by D3 bp, and a thickness of the negative lens of the third b lens group on the optical axis is denoted by D3bn, Conditional Expression (1) represented by
- 0.2<D3bp/D3bn<2 (1)
- is satisfied, and
- in a case where a focal length of the third lens group is denoted by f3, and a focal length of the fourth lens group is denoted by f4, Conditional Expression (14) represented by
- 0.1<f3/f4<0.35 (14)
- is satisfied.
Dependencies are inferred from the claim text.