US 11,940,598 B2
Lens system and electronic device
Chun-Che Hsueh, Taichung (TW); and Hsin-Hsuan Huang, Taichung (TW)
Assigned to LARGAN PRECISION CO., LTD., Taichung (TW)
Filed by LARGAN PRECISION CO., LTD., Taichung (TW)
Filed on Mar. 13, 2023, as Appl. No. 18/120,842.
Application 18/120,842 is a continuation of application No. 17/713,986, filed on Apr. 5, 2022, granted, now 11,640,046.
Application 17/713,986 is a continuation of application No. 16/734,134, filed on Jan. 3, 2020, granted, now 11,327,277, issued on May 10, 2022.
Claims priority of application No. 108143778 (TW), filed on Nov. 29, 2019.
Prior Publication US 2023/0213735 A1, Jul. 6, 2023
Int. Cl. G02B 9/34 (2006.01); G02B 13/00 (2006.01); G06V 40/13 (2022.01)
CPC G02B 13/004 (2013.01) [G02B 9/34 (2013.01); G06V 40/13 (2022.01)] 21 Claims
OG exemplary drawing
 
1. A lens system comprising four lens elements, the four lens elements being, in order from an object side to an image side, a first lens element, a second lens element, a third lens element and a fourth lens element, and each of the four lens elements having an object-side surface facing toward the object side and an image-side surface facing toward the image side;
wherein the first lens element has negative refractive power, at least one of the object-side surface and the image-side surface of the first lens element has at least one inflection point, the object-side surface of the fourth lens element is convex in a paraxial region thereof, the image-side surface of the fourth lens element is concave in a paraxial region thereof, the lens system further comprises an aperture stop disposed between the second lens element and the third lens element, a central thickness of the third lens element is a maximum among central thicknesses of all lens elements of the lens system, and a total number of lens elements in the lens system is four;
wherein a minimum value among Abbe numbers of all lens elements of the lens system is Vdmin, a focal length of the lens system is f, an entrance pupil diameter of the lens system is EPD, and the following conditions are satisfied:
13.0<Vdmin<21.0; and
1.25<f/EPD<2.50.