US 12,436,371 B2
Zoom lens and imaging apparatus
Daiki Kawamura, Saitama (JP)
Assigned to FUJIFILM Corporation, Tokyo (JP)
Filed by FUJIFILM Corporation, Tokyo (JP)
Filed on Mar. 15, 2023, as Appl. No. 18/184,511.
Application 18/184,511 is a continuation of application No. 17/929,979, filed on Sep. 6, 2022, granted, now 11,640,049.
Application 17/929,979 is a continuation of application No. 17/139,202, filed on Dec. 31, 2020, granted, now 11,480,775, issued on Oct. 25, 2022.
Application 17/139,202 is a continuation of application No. 16/355,942, filed on Mar. 18, 2019, granted, now 10,914,929, issued on Dec. 9, 2021.
Claims priority of application No. 2018-064597 (JP), filed on Mar. 29, 2018.
Prior Publication US 2023/0213743 A1, Jul. 6, 2023
Int. Cl. G02B 15/163 (2006.01); G02B 13/02 (2006.01); G02B 15/14 (2006.01); G02B 15/177 (2006.01); G02B 5/00 (2006.01); G02B 9/34 (2006.01); G02B 9/60 (2006.01); G02B 9/62 (2006.01); G02B 13/00 (2006.01); G02B 13/04 (2006.01); G02B 13/18 (2006.01); G02B 15/20 (2006.01); G02B 27/00 (2006.01)
CPC G02B 15/163 (2013.01) [G02B 13/02 (2013.01); G02B 15/145523 (2019.08); G02B 15/177 (2013.01); G02B 5/005 (2013.01); G02B 9/34 (2013.01); G02B 9/60 (2013.01); G02B 9/62 (2013.01); G02B 13/0045 (2013.01); G02B 13/009 (2013.01); G02B 13/04 (2013.01); G02B 13/18 (2013.01); G02B 15/14 (2013.01); G02B 15/20 (2013.01); G02B 27/0025 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A zoom lens consisting of:
in order from an object side to an image side,
a first lens group having a negative refractive power;
a second lens group having a positive refractive power;
a third lens group having a positive refractive power;
a fourth lens group having a negative refractive power; and
a fifth lens group having a refractive power,
wherein mutual distances between the first lens group, the second lens group, the third lens group, the fourth lens group and the fifth lens group change due to movement of at least the first lens group, the second lens group, the third lens group and the fourth lens group during zooming,
the fourth lens group includes a focusing lens group which moves during focusing from an object at infinity from an object within a short range,
a negative meniscus lens of which a convex surface faces the object side is disposed closest to an object side in the first lens group,
a lens of which a convex surface faces the image side is disposed closest to an image side in the second lens group,
a lens of which a concave surface faces the object side is disposed closest to an object side in the fourth lens group,
a lens of which a concave surface faces the image side is disposed closest to an image side in the fourth lens group, and
assuming that an on-axis air-equivalent distance from a lens surface closest to the image side to an image plane in a state in which the object at infinity at the wide-angle end is in focus is BFw, a focal length of the zoom lens in a state in which the object at infinity at the wide-angle end is in focus is fw, and a maximum half-angle of view in a state in which the object at infinity at the wide-angle end is in focus is ωw, Conditional Expression (8-7) is satisfied,
0.5<BFw/(fw×tan ωw)<1.3  (8-7).