US 11,686,925 B2
Wide-angle lens assembly including five lenses of -+++-, or six lenses of -++-+- refractive powers
Yuan-Chen Chen, Taichung (TW)
Assigned to SINTAI OPTICAL (SHENZHEN) CO., LTD., Shenzhen (CN); and ASIA OPTICAL CO., INC., Taichung (TW)
Filed by Sintai Optical (Shenzhen) Co., Ltd., ShenZhen (CN); and Asia Optical Co., Inc., Taichung (TW)
Filed on Aug. 17, 2020, as Appl. No. 16/994,732.
Claims priority of application No. 201911320621.7 (CN), filed on Dec. 19, 2019.
Prior Publication US 2021/0191091 A1, Jun. 24, 2021
Int. Cl. G02B 13/06 (2006.01); G02B 9/62 (2006.01); G02B 13/18 (2006.01); G02B 9/60 (2006.01)
CPC G02B 13/06 (2013.01) [G02B 9/60 (2013.01); G02B 9/62 (2013.01); G02B 13/18 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A wide-angle lens assembly, comprising sequentially from an object side to an image side along an optical axis:
a first lens which is a meniscus lens with negative refractive power;
a second lens which is a meniscus lens with positive refractive power;
a third lens with positive refractive power, comprising a convex surface facing the object side;
a fourth lens with positive refractive power, comprising a convex surface facing the object side; and
a fifth lens with negative refractive power;
wherein the wide-angle lens assembly satisfies:
3<TTL/BFL<3.5,
wherein TTL is an interval from an object side surface of the first lens to an image plane along the optical axis and BFL is an interval from an image side surface of the fifth lens to the image plane along the optical axis;
wherein the wide-angle lens assembly further satisfies at least one of following conditions:
−3<f2/f1<−1,
1<f2/f4<3,
3<R11/R12<5,
−11<R31/R32<−3,
20<TTL/T1<21.5,
wherein f1 is an effective focal length of the first lens, f2 is an effective focal length of the second lens, f4 is an effective focal length of the fourth lens, T1 is a thickness of the first lens, R11 is a radius of curvature of the object side surface of the first lens, R12 is a radius of curvature of the image side surface of the first lens, R31 is a radius of curvature of the objective side surface of the third lens, and R32 is a radius of curvature of the image side surface of the third lens.