US 12,228,714 B2
Optical system
Fang-Li Ma, ShenZhen (CN); Bin Liu, ShenZhen (CN); Fei Han, ShenZhen (CN); Ling-Wei Zhao, ShenZhen (CN); Yue-Ye Chen, ShenZhen (CN); and Hua-Tang Liu, 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., Guandong (CN); and Asia Optical Co., Inc., Taichung (TW)
Filed on Dec. 22, 2022, as Appl. No. 18/145,102.
Claims priority of application No. 202210248054.4 (CN), filed on Mar. 14, 2022.
Prior Publication US 2023/0288683 A1, Sep. 14, 2023
Int. Cl. G02B 15/14 (2006.01); G02B 13/00 (2006.01); G02B 15/173 (2006.01)
CPC G02B 15/1461 (2019.08) [G02B 13/006 (2013.01); G02B 15/173 (2013.01)] 18 Claims
OG exemplary drawing
 
1. An optical system comprising:
an objective lens module which is with refractive power and comprises a first lens group, a second lens group, a third lens group, a fourth lens group, and a fifth lens group;
an image inverting module; and
an eyepiece module;
wherein the objective lens module, the image inverting module, and the eyepiece module are arranged in order from an object side to an image side along an optical axis;
wherein the first lens group, the second lens group, the third lens group, the fourth lens group, and the fifth lens group are arranged in order from the object side to the image side along the optical axis;
wherein the optical system satisfies at least one of following conditions:
0.45≤LG4D/LG1D≤0.8;
0.015 mm−1≤1/fG3≤0.045 mm−1;
0.045 mm−1≤|1/fG4|≤0.07 mm−1;
0.35≤|fG4/fG3|≤0.75;
0.15≤fG1/f≤1.6;
wherein LG4D is an effective optical diameter of the fourth lens group, LG1D is an effective optical diameter of the first lens group, fG1 is an effective focal length of the first lens group, fG3 is an effective focal length of the third lens group, fG4 is an effective focal length of the fourth lens group, and f is an effective focal length of the objective lens module.