US 12,353,057 B2
Fixed-focus lens
Pei-Ching Liu, Hsinchu (TW); and Kuo-Chuan Wang, Hsinchu (TW)
Assigned to YOUNG OPTICS INC., Hsinchu Science Park (TW)
Filed by Young Optics Inc., Hsinchu (TW)
Filed on Apr. 15, 2022, as Appl. No. 17/721,810.
Claims priority of application No. 110114776 (TW), filed on Apr. 23, 2021.
Prior Publication US 2022/0342182 A1, Oct. 27, 2022
Int. Cl. G02B 9/64 (2006.01); G02B 3/00 (2006.01); G02B 13/14 (2006.01)
CPC G02B 9/64 (2013.01) [G02B 3/005 (2013.01); G02B 13/143 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A fixed-focus lens, comprising:
an anti-radiation first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens arranged in order in a direction, wherein the second lens has a negative refractive power; and
an aperture stop disposed between the first lens and the fourth lens, a ratio of a lens diameter of the first lens to an overall length being within a range of 0.4 to 0.5, where the overall length is an axial distance between an outer surface of the first lens and an outer surface of the seventh lens, and each of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens is a spherical glass lens.