US 12,276,864 B2
Optical system, lens module, and terminal device
Jian Yang, Jiangxi (CN); Wenyan Zhang, Jiangxi (CN); Ming Li, Jiangxi (CN); and Hairong Zou, Jiangxi (CN)
Assigned to JIANGXI JINGCHAO OPTICAL CO., LTD., Nanchang (CN)
Appl. No. 17/437,706
Filed by JIANGXI JINGCHAO OPTICAL CO., LTD., Jiangxi (CN)
PCT Filed Apr. 3, 2020, PCT No. PCT/CN2020/083347
§ 371(c)(1), (2) Date Sep. 9, 2021,
PCT Pub. No. WO2021/196223, PCT Pub. Date Oct. 7, 2021.
Prior Publication US 2022/0299736 A1, Sep. 22, 2022
Int. Cl. G02B 9/62 (2006.01); G02B 13/00 (2006.01)
CPC G02B 9/62 (2013.01) [G02B 13/0045 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An optical system comprising six lenses in total arranged in order from an object side to an image side, the six lenses comprise:
a first lens with a positive refractive power, wherein the first lens has an object-side surface which is convex at an optical axis;
a second lens with a negative refractive power, wherein the second lens has an image-side surface which is concave at the optical axis;
a third lens with a negative refractive power, wherein the third lens has an object-side surface which is convex at the optical axis and an image-side surface which is concave at the optical axis;
a fourth lens with a negative refractive power, wherein the fourth lens has an image-side surface which is concave at the optical axis;
a fifth lens with a refractive power; and
a sixth lens with a refractive power;
wherein the optical system satisfies the following expression:
1≤ftLtl4/ftGtl4<1.5,
wherein ftLtl4 represents a longest distance from the object-side surface of the fourth lens to the image-side surface of the fourth lens in a direction parallel to the optical axis, and ftGtl4 represents a shortest distance from the object-side surface of the fourth lens to the image-side surface of the fourth lens in the direction parallel to the optical axis.