Image pickup lens
View Patent ↗An image pickup lens includes in order from an object side, a front lens unit having a positive refractive power, one focusing lens unit having a positive refractive power, and a rear lens unit having a negative refractive power, wherein at the time of focusing, the focusing lens moves on an optical axis, and a single lens having a positive refractive power is disposed nearest to an object in the rear lens unit.
1. An image pickup lens comprising in order from an object side:
a front lens unit having a positive refractive power;
a single focusing lens having a positive refractive power; and
a rear lens unit having a negative refractive power, wherein
at the time of focusing, only the single focusing lens moves on an optical axis, and
a single lens having a positive refractive power is disposed nearest to an object in the rear lens unit,
wherein the image pickup lens satisfies the following conditional expression (2)
1.0< f r1 /f fo ≤4.46 (2)
where,
f r1 denotes a focal length of the single lens having a positive refractive power which is disposed nearest to an object in the rear lens unit, and
f fo denotes a focal length of the single focusing lens.
2. The image pickup lens according to claim 1 , wherein the image pickup lens satisfies the following conditional expression (1)
1.0< f f /f fo (1)
where,
f f denotes a focal length of the front lens unit, and
f fo denotes a focal length of the single focusing lens.
3. The image pickup lens according to claim 1 , wherein the image pickup lens satisfies the following conditional expression (3)
0.5<(1− mg Fo 2 )×( mg R ) 2 (3)
where,
mg Fo denotes a lateral magnification of the single focusing lens, and
mg R denotes a lateral magnification of the rear lens unit.
4. The image pickup lens according to claim 1 , wherein the image pickup lens satisfies the following conditional expression (4)
v dFo ≥40.0 (4)
where,
v dFo denotes Abbe's number for the single focusing lens.
5. The image pickup lens according to claim 1 , wherein the image pickup lens satisfies the following conditional expression (5)
( r Rfof +r Rfor )/( r Rfof −r Rfor )<0.0 (5)
where,
r Rfof denotes a radius of curvature of an object-side surface of the single focusing lens, and
r Rfor denotes a radius of curvature of an image-side surface of the single focusing lens.
6. The image pickup lens according to claim 1 , wherein the image pickup lens satisfies the following conditional expression (6)
0.0< F no/( f× 21.633/ Y )<0.08 (6)
where,
f denotes a focal length of the overall lens system,
Fno denotes an F-number of the overall lens system, and
Y denotes a maximum image height on image forming surface of the lens.