US 12,253,655 B2
Optical system, lens module, and terminal device
Wenyan Zhang, Jiangxi (CN); Ming Li, Jiangxi (CN); Jian Yang, Jiangxi (CN); and Hairong Zou, Jiangxi (CN)
Assigned to JIANGXI JINGCHAO OPTICAL CO., LTD., Jiangxi (CN)
Filed by JIANGXI JINGCHAO OPTICAL CO., LTD., Jiangxi (CN)
Filed on Sep. 9, 2021, as Appl. No. 17/470,606.
Application 17/470,606 is a continuation of application No. PCT/CN2020/083348, filed on Apr. 3, 2020.
Prior Publication US 2021/0405331 A1, Dec. 30, 2021
Int. Cl. G02B 9/60 (2006.01); G02B 13/00 (2006.01)
CPC G02B 13/0045 (2013.01) [G02B 9/60 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An optical system, comprising a plurality of lenses arranged in order from an object side to an image side, the plurality of lenses consisting of:
a first lens with a positive refractive power, the first lens having an object-side surface which is convex at an optical axis;
a second lens with a refractive power;
a third lens with a refractive power, the third lens having an object-side surface which is concave at the optical axis;
a fourth lens with a positive refractive power, the fourth lens having an image-side surface which is convex at the optical axis; and
a fifth lens with a refractive power, the fifth lens having an object-side surface which is concave at the optical axis and an image-side surface which is convex at the optical axis;
wherein the optical system satisfies the following expressions:
0.25<ftgtl3/ftltl3<0.8, wherein ftgtl3 represents a shortest distance from the object-side surface of the third lens to an image-side surface of the third lens in a direction parallel to the optical axis, and ftltl3 represents a longest distance from the object-side surface of the third lens to the image-side surface of the third lens in the direction parallel to the optical axis; and
7 mm<FNO*L1SD/tan FOV<15 mm,
wherein FNO represents an F-number of the optical system, L1SD represents an effective diameter of the first lens, and tan FOV represents a tangent value of a maximum angle of view of the optical system.