Zoom lens and image capturing apparatus including the same
AssigneeCanon Kabushiki Kaisha
InventorYuichi Gyoda
Life of this patent
Estimating the term…
Abstract
A zoom lens B0 includes a first lens unit B1 having negative refractive, a second lens unit B2 having positive refractive power, and a third lens unit B3 having negative refractive power in order from an object side to an image side. The first lens unit B1 moves during zooming. The first lens unit B1 includes a negative lens G1 disposed closest to the object side and at least one positive lens. Lenses included in the second lens unit B2 all have positive refractive power. The number of lenses included in the third lens unit B3 is two or less. The third lens unit B3 moves toward the image side during focusing from infinity to close range.
Claims24
A zoom lens comprising:
- a first lens unit having negative refractive power,
- a second lens unit having positive refractive power and lenses included in the second lens unit are all positive single lenses, and
- a third lens unit having negative refractive power in order from an object side to an image side,
- wherein a distance between the first lens unit and the second lens unit and a distance between the second lens unit and the third lens unit change during at least one of zooming and focusing,
- wherein the first lens unit moves during zooming,
- wherein the first lens unit includes a negative lens G1 disposed closest to the object side and at least one positive lens,
- wherein the second lens unit consists of an aperture stop, a first positive lens, a second positive lens, and lenses included in the second lens unit are all positive single lenses,
- wherein a number of lenses included in the third lens unit is two or less,
- wherein the third lens unit moves toward the image side during focusing from infinity to close range, and
- wherein the following inequalities are satisfied:
- 1.40<Nd_G1<1.80
- 18<vd_B3n≤24.8
- where Nd_G1 is a refractive index of the negative lens G1, and vd_B3n is an Abbe number of a negative lens having strongest refractive power among negative lenses included in the third lens unit.
An image capturing apparatus comprising:
- a zoom lens;
- and
- an image sensor configured to capture an optical image formed by the zoom lens,
- wherein the zoom lens comprises:
- a first lens unit having negative refractive power,
- a second lens unit having positive refractive power, and
- a third lens unit having negative refractive power in order from an object side to an image side,
- wherein a distance between the first lens unit and the second lens unit and a distance between the second lens unit and the third lens unit change during at least one of zooming and focusing,
- wherein the first lens unit moves during zooming,
- wherein the first lens unit includes a negative lens G1 disposed closest to the object side and at least one positive lens,
- wherein the second lens unit consists of an aperture stop, a first positive lens, a second positive lens, and lenses included in the second lens unit are all positive single lenses,
- wherein a number of lenses included in the third lens unit is two or less,
- wherein the third lens unit moves toward the image side during focusing from infinity to close range, and
- wherein the following inequalities are satisfied:
- 1.40<Nd_G1<1.80
- 18<vd_B3n≤24.8
- where Nd_G1 is a refractive index of the negative lens G1, and vd_B3n is an Abbe number of a negative lens having strongest refractive power among negative lenses included in the third lens unit.
Dependencies are inferred from the claim text.