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US 12,405,455 B2Granted
Zoom lens and image pickup apparatus
AssigneeCanon Kabushiki Kaisha
InventorMasaru Sakamoto
Life of this patent
Estimating the term…
Abstract
A zoom lens includes, from an object side to an image side, a positive first lens unit configured not to move for zooming, at least three movable lens units configured to move for zooming, and a positive final lens unit closest to the image side in lens units and configured not to move for zooming. In the at least three movable lens units, a lens unit closest to the image side has a positive power, and a lens unit second closest to the image side has a negative power. The first lens unit includes a first sub unit closest to the object side and configured not to move for focusing and a second sub unit configured to move for focusing. The final lens unit includes a positive lens closest to the image side in elements having a refractive power in the final lens unit. Predetermined inequalities are satisfied.
Claims18
A zoom lens comprising, in order from an object side to an image side:
- a first lens unit having a positive refractive power and configured not to move for zooming;
- at least three movable lens units configured to move so that a distance between each pair of adjacent lens units therein changes for zooming;
- and
- a final lens unit disposed closest to the image side in lens units included in the zoom lens, having a positive refractive power, and configured not to move for zooming,
- wherein a movable lens unit closest to the image side in the at least three movable lens units has a positive refractive power, and a movable lens unit second closest to the image side in the at least three movable lens units has a negative refractive power,
- wherein the first lens unit includes:
- a first sub unit closest to the object side and configured not to move for focusing;
- and
- a second sub unit configured to move for focusing,
- wherein the final lens unit includes a positive lens closest to the image side in elements having a refractive power in the final lens unit, and
- wherein following inequalities are satisfied:
- 80≤vdp≤81.54,
- 2.24≤Ndp+0.01vdp,
- 4≤Z≤50, and
- 2.5≤Le/fw≤5.46
- where vdp represents an Abbe number with respect to a d-line of the positive lens, Ndp represents a refractive index with respect to the d-line of the positive lens, Z represents a zoom ratio of the zoom lens, Le represents a distance on an optical axis from a lens surface closest to the object side in the final lens unit to an image side surface of the positive lens in the final lens unit, and fw represents a focal length of the zoom lens at a wide-angle end.
13 more elements
An apparatus comprising:
- a zoom lens;
- and
- a pickup element configured to pick up an image formed by the zoom lens,
- wherein the zoom lens includes, in order from an object side to an image side:
- a first lens unit having a positive refractive power and configured not to move for zooming;
- at least three movable lens units configured to move so that a distance between each pair of adjacent lens units therein changes for zooming;
- and
- a final lens unit disposed closest to the image side in lens units included in the zoom lens, having a positive refractive power, and configured not to move for zooming,
- wherein a movable lens unit closest to the image side in the at least three movable lens units has a positive refractive power, and a movable lens unit second closest to the image side in the at least three movable lens units has a negative refractive power,
- wherein the first lens unit includes:
- a first sub unit closest to the object side and configured not to move for focusing;
- and
- a second sub unit configured to move for focusing,
- wherein the final lens unit includes a positive lens closest to the image side in elements having a refractive power in the final lens unit,
- wherein following inequalities are satisfied:
- 80≤vdp≤81.54,
- 2.24≤Ndp+0.01vdp,
- 4≤Z≤50, and
- 2.5≤Le/fw≤5.46
- where vdp represents an Abbe number with respect to a d-line of the positive lens, Ndp represents a refractive index with respect to the d-line of the positive lens, Z represents a zoom ratio of the zoom lens, Le represents a distance on an optical axis from a lens surface closest to the object side in the final lens unit to an image side surface of the positive lens in the final lens unit, and fw represents a focal length of the zoom lens at a wide-angle end.
17 more elements
A zoom lens comprising, in order from an object side to an image side:
- a first lens unit having a positive refractive power and configured not to move for zooming;
- at least three movable lens units configured to move so that a distance between each pair of adjacent lens units therein changes for zooming;
- and
- a final lens unit disposed closest to the image side in lens units included in the zoom lens, having a positive refractive power, and configured not to move for zooming,
- wherein a movable lens unit closest to the image side in the at least three movable lens units has a positive refractive power, and a movable lens unit second closest to the image side in the at least three movable lens units has a negative refractive power,
- wherein a movable lens unit having a strongest negative refractive power in the at least three movable lens units includes two negative lenses and one positive lens,
- wherein the first lens unit includes:
- a first sub unit closest to the object side and configured not to move for focusing;
- and
- a second sub unit configured to move for focusing,
- wherein the final lens unit includes a positive lens closest to the image side in elements having a refractive power in the final lens unit, and
- wherein following inequalities are satisfied:
- 62≤vdp≤81.54,
- 2.24≤Ndp+0.01vdp,
- 4≤Z≤50, and
- 2.5≤Le/fw≤5.46
- where vdp represents an Abbe number with respect to a d-line of the positive lens, Ndp represents a refractive index with respect to the d-line of the positive lens, Z represents a zoom ratio of the zoom lens, Le represents a distance on an optical axis from a lens surface closest to the object side in the final lens unit to an image side surface of the positive lens in the final lens unit, and fw represents a focal length of the zoom lens at a wide-angle end.
14 more elements
An apparatus comprising:
- a zoom lens;
- and
- a pickup element configured to pick up an image formed by the zoom lens,
- wherein the zoom lens includes, in order from an object side to an image side:
- a first lens unit having a positive refractive power and configured not to move for zooming;
- at least three movable lens units configured to move so that a distance between each pair of adjacent lens units therein changes for zooming;
- and
- a final lens unit disposed closest to the image side in lens units included in the zoom lens, having a positive refractive power, and configured not to move for zooming,
- wherein a movable lens unit closest to the image side in the at least three movable lens units has a positive refractive power, and a movable lens unit second closest to the image side in the at least three movable lens units has a negative refractive power,
- wherein a movable lens unit having a strongest negative refractive power in the at least three movable lens units includes two negative lenses and one positive lens,
- wherein the first lens unit includes:
- a first sub unit closest to the object side and configured not to move for focusing;
- and
- a second sub unit configured to move for focusing,
- wherein the final lens unit includes a positive lens closest to the image side in elements having a refractive power in the final lens unit,
- wherein following inequalities are satisfied:
- 62≤vdp≤81.54,
- 2.24≤Ndp+0.01vdp,
- 4≤Z≤50, and
- 2.5≤Le/fw≤5.46ere vdp represents an Abbe number with respect to a d-line of the positive lens, Ndp represents a refractive index with respect to the d-line of the positive lens, Z represents a zoom ratio of the zoom lens, Le represents a distance on an optical axis from a lens surface closest to the object side in the final lens unit to an image side surface of the positive lens in the final lens unit, and fw represents a focal length of the zoom lens at a wide-angle end.
17 more elements
Dependencies are inferred from the claim text.