Zoom lens and image pickup apparatus
AssigneeCanon Kabushiki Kaisha
InventorKazuhiro TERADA
Life of this patent
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Abstract
A zoom lens includes in order from an object side to an image side, one or more negative lens units each having a negative refractive power, and a positive lens unit having a positive refractive power, in which the one or more negative lens units include a BN lens unit including at least one BN negative lens, in which a refractive index of the BN negative lens, an Abbe number of the BN negative lens, and a partial dispersion ratio of the BN negative lens are appropriately set.
Claims12
A zoom lens comprising in order from an object side to an image side, one or more negative lens units each having a negative refractive power, and a positive lens unit having a positive refractive power,
- wherein the one or more negative lens units include a BN lens unit including at least one BN negative lens,
- wherein the following inequalities are satisfied,
- 1.6
- <
- nd_BNn
- <
- 2
- .00
- 25.
- <
- ν
-
- d_BNn
- <
- 55.
- 0.4958
- <
- θ
-
- Ct_BNn
- -
- 0
- .
- 0
-
- 0
-
- 417
- ×
- ν
-
- d_BNn
- <
- 0
- .
- 5
-
- 5
-
- 0
-
- 8
- where nd_BNn represents a refractive index of the BN negative lens, vd_BNn represents an Abbe number of the BN negative lens, and θCt_BNn represents a partial dispersion ratio of the BN negative lens.
An image pickup apparatus comprising:
- a zoom lens, including in order from an object side to an image side, one or more negative lens units each having a negative refractive power, and a positive lens unit having a positive refractive power,
- wherein the one or more negative lens units include a BN lens unit including at least one BN negative lens,
- wherein the following inequalities are satisfied,
- 1.6
- <
- nd_BNn
- <
- 2
- .00
- 25.
- <
- νd_BNn
- <
- 55.
- 0.4958
- <
- θ
-
- Ct_BNn
- -
- 0
- .
- 0
-
- 0417
- ×
- νd_BNn
- <
- 0
- .
- 5
-
- 5
-
- 0
-
- 8
- where nd_BNn represents a refractive index of the BN negative lens, vd_BNn represents an Abbe number of the BN negative lens, and eCt_BNn represents a partial dispersion ratio of the BN negative lens;
- and
- an image pickup element that receives an image formed by the zoom lens.
Dependencies are inferred from the claim text.