Zoom lens and imaging apparatus including the same
AssigneeCanon Kabushiki Kaisha
InventorTakahiro Hatada
Life of this patent
Estimating the term…
Abstract
A zoom lens L0 includes a first lens group L1 and a rear group LR disposed in order from an object side to an image side, the first lens group L1 having a negative refractive power and the rear group LR having a positive refractive power as a whole. The rear group LR includes a partial group LP, a partial group LN, and two or more lens groups between which distances change in zooming. When image blur is corrected, the partial group LN moves in a direction including a component of a direction perpendicular to an optical axis. A lens surface closest to the object side among lens surfaces of the partial group LN and a lens surface closest to the image side among the lens surfaces of the partial group LN are both concave surfaces.
Claims29
A zoom lens comprising:
- a first lens unit and a rear group disposed in order from an object side to an image side, wherein the first lens unit has a negative refractive power and the rear group includes four or more lens units and has a positive refractive power as a whole,
- wherein a distance between adjacent lens units changes in zooming,
- wherein a lens unit arranged on a most object side in the rear group includes a lens subunit LP having a positive refractive power,
- wherein the lens subunit LP consists of one or two positive lenses and one or two negative lenses,
- wherein the rear group includes a lens subunit LN arranged adjacent to the lens subunit LP on the image side and having a negative refractive power,
- wherein when image blur is corrected, the lens subunit LN moves in a direction including a component of a direction perpendicular to an optical axis,
- wherein a focus unit is disposed closer to the image side than the lens units including the lens subunit LN in the rear group, and the focus unit is moved in focusing,
- wherein the first lens unit includes two or more negative meniscus lenses each having a convex surface directed to the object side,
- wherein the zoom lens includes an aperture stop disposed on the object side of the lens subunit LP or within the lens subunit LP, and
- wherein a lens surface of the lens subunit LN closest to the object side is a concave surface directed to the object side, and a lens surface of the lens subunit LN closest to the image side is a concave surface directed to the image side,
- wherein the following inequality is satisfied:
- −2.3<fLN/fLP≤−1.81,
- where fLN is a focal length of the lens subunit LN, and fLP is a focal length of the lens subunit LP.
An imaging apparatus comprising:
- a zoom lens, and
- an image sensor configured to receive light of an image formed by the lens,
- wherein the zoom lens includes a first lens unit and a rear group disposed in order from an object side to an image side, wherein the first lens unit has a negative refractive power and the rear group includes four or more lens units and has a positive refractive power as a whole,
- wherein a distance between adjacent lens units changes in zooming,
- wherein a lens unit arranged on a most object side in the rear group includes a lens subunit LP having a positive refractive power,
- wherein the lens subunit LP consists of one or two positive lenses and one or two negative lenses,
- wherein the rear group includes a lens subunit LN arranged adjacent to the lens subunit LP on the image side and having a negative refractive power,
- wherein when image blur is corrected, the lens subunit LN moves in a direction including a component of a direction perpendicular to an optical axis,
- wherein a focus unit is disposed closer to the image side than the lens units including the lens subunit LN in the rear group, and the focus unit is moved in focusing,
- wherein the first lens unit includes two or more negative meniscus lenses each having a convex surface directed to the object side,
- wherein the zoom lens includes an aperture stop disposed on the object side of the lens subunit LP or within the lens subunit LP, and
- wherein a lens surface closest to the object side among lens surfaces of the lens subunit LN and a lens surface closest to the image side among the lens the surfaces of the lens subunit LN are both concave surfaces,
- wherein the following inequality is satisfied:
- −2.3<fLN/fLP≤−1.81,
- where fLN is a focal length of the lens subunit LN, and fLP is a focal length of the lens subunit LP.
Dependencies are inferred from the claim text.