Optical lens assembly

Abstract

An optical lens assembly includes first, second, third, and fourth lens elements arranged in order from an object side to an image side along an optical axis. Each lens element has an object-side surface and an image-side surface. The object-side surface of the first lens element has a convex portion in a vicinity of a periphery. The second lens element has negative refracting power. The object-side surface of the third lens element has a concave portion in a vicinity of a periphery. The image-side surface of the fourth lens element has a convex portion in a vicinity of a periphery.

What is claimed is: 
     
         1 . An optical lens assembly comprising a first lens element, a second lens element, a third lens element, and a fourth lens element in order from an object side to an image side along an optical axis, each of the first lens element to the fourth lens element comprising an object-side surface facing the object side and allowing an imaging ray to pass through and an image-side surface facing the image side and allowing the imaging ray to pass through;
 the object-side surface of the first lens element having a convex portion in a vicinity of a periphery;   the second lens element having negative refracting power;   the object-side surface of the third lens element having a concave portion in a vicinity of a periphery;   the image-side surface of the fourth lens element having a convex portion in a vicinity of a periphery,   wherein the optical lens assembly satisfies:
   ( TTL×Fno )/EFL≦2.2;
 
   2.8 mm≦ TTL≦ 8 mm; and
 
   HFOV≦25°,
 
   wherein TTL is a distance from the object-side surface of the first lens element to an image plane at the image side along the optical axis, Fno is an f-number of the optical lens assembly, EFL is an effective focal length of the optical lens assembly, and HFOV is a half field of view of the optical lens assembly.   
     
     
         2 . The optical lens assembly as recited in  claim 1 , further satisfying: 7.3≦EFL/T4, wherein T4 is a thickness of the fourth lens element along the optical axis. 
     
     
         3 . The optical lens assembly as recited in  claim 1 , further satisfying: 1.7≦G23/T4, wherein G23 is a distance from the second lens element to the third lens element along the optical axis, and T4 is a thickness of the fourth lens element along the optical axis. 
     
     
         4 . The optical lens assembly as recited in  claim 1 , further satisfying: 2.4≦AAG/T4, wherein AAG is a sum of a distance from the first lens element to the second lens element along the optical axis, a distance from the second lens element to the third lens element along the optical axis, and a distance from the third lens element to the fourth lens element along the optical axis, and T4 is a thickness of the fourth lens element along the optical axis. 
     
     
         5 . The optical lens assembly as recited in  claim 1 , further satisfying: 0.8≦G23/T1, wherein G23 is a distance from the second lens element to the third lens element along the optical axis, and T1 is a thickness of the first lens element along the optical axis. 
     
     
         6 . The optical lens assembly as recited in  claim 1 , further satisfying: EFL/G23≦7.1, wherein G23 is a distance from the second lens element to the third lens element along the optical axis. 
     
     
         7 . The optical lens assembly as recited in  claim 1 , further satisfying: 6.9≦EFL/T3, wherein T3 is a thickness of the third lens element along the optical axis. 
     
     
         8 . The optical lens assembly as recited in  claim 1 , further satisfying: EFL/AAG≦4.6, wherein AAG is a sum of a distance from the first lens element from the second lens element along the optical axis, a distance from the second lens element to the third lens element along the optical axis, and a distance from the third lens element to the fourth lens element along the optical axis. 
     
     
         9 . The optical lens assembly as recited in  claim 1 , further satisfying: 10.5≦AAG/G12, wherein AAG is a sum of a distance from the first lens element to the second lens element along the optical axis, a distance from the second lens element to the third lens element along the optical axis, and a distance from the third lens element to the fourth lens element along the optical axis, and G12 is the distance from the first lens element to the second lens element along the optical axis. 
     
     
         10 . The optical lens assembly as recited in  claim 1 , further satisfying: 7.5≦G23/G12, wherein G23 is a distance from the second lens element to the third lens element along the optical axis, and G12 is a distance from the first lens element to the second lens element along the optical axis. 
     
     
         11 . An optical lens assembly comprising a first lens element, a second lens element, a third lens element, and a fourth lens element in order from an object side to an image side along an optical axis, each of the first lens element to the fourth lens element comprising an object-side surface facing the object side and allowing an imaging ray to pass through and an image-side surface facing the image side and allowing the imaging ray to pass through;
 the object-side surface of the first lens element having a convex portion in a vicinity of a periphery;   the second lens element having negative refracting power;   the object-side surface of the third lens element having a concave portion in a vicinity of a periphery;   the image-side surface of the fourth lens element having a convex portion in a vicinity of a periphery,   wherein the optical lens assembly satisfies:
   ( TTL×Fno )/EFL≦2.2;
 
   2.8 mm≦ TTL≦ 8 mm; and
 
   2.5≦EFL/ ALT≦ 4.75,
 
   wherein TTL is a distance from the object-side surface of the first lens element to an image plane at the image side along the optical axis, Fno is an f-number of the optical lens assembly, EFL is an effective focal length of the optical lens assembly, and ALT is a sum of a thickness of the first lens element along the optical axis, a thickness of the second lens element along the optical axis, a thickness of the third lens element along the optical axis, and a thickness of the fourth lens element along the optical axis.   
     
     
         12 . The optical lens assembly as recited in  claim 11 , further satisfying: 2.6≦G23/T3, wherein G23 is a distance from the second lens element to the third lens element along the optical axis, and T3 is the thickness of the third lens element along the optical axis. 
     
     
         13 . The optical lens assembly as recited in  claim 11 , further satisfying: 2≦AAG/T1≦5.1, wherein AAG is a sum of a distance from the first lens element to the second lens element along the optical axis, a distance from the second lens element to the third lens element along the optical axis, and a distance from the third lens element to the fourth lens element along the optical axis, and T1 is the thickness of the first lens element along the optical axis. 
     
     
         14 . The optical lens assembly as recited in  claim 11 , further satisfying: (T3+BFL)/T1≦2.2, wherein T3 is the thickness of the third lens element along the optical axis, BFL is a distance from the image-side surface of the fourth lens element to the image plane along the optical axis, and T1 is the thickness of the first lens element along the optical axis. 
     
     
         15 . The optical lens assembly as recited in  claim 11 , further satisfying: EFL/T2≦39, wherein T2 is the thickness of the second lens element along the optical axis. 
     
     
         16 . The optical lens assembly as recited in  claim 11 , further satisfying: 1.1≦G23/BFL, wherein G23 is a distance from the second lens element to the third lens element along the optical axis, and BFL is a distance from the image-side surface of the fourth lens element to the image plane along the optical axis. 
     
     
         17 . The optical lens assembly as recited in  claim 11 , further satisfying: AAG/T2≦19.5, wherein AAG is a sum of a distance from the first lens element to the second lens element along the optical axis, a distance from the second lens element to the third lens element along the optical axis, and a distance from the third lens element to the fourth lens element along the optical axis, and T2 is the thickness of the second lens element along the optical axis. 
     
     
         18 . The optical lens assembly as recited in  claim 11 , further satisfying: ALT/G23≦1.8, wherein ALT is the sum of the thickness of the first lens element along the optical axis, the thickness of the second lens element along the optical axis, the thickness of the third lens element along the optical axis, and the thickness of the fourth lens element along the optical axis, and G23 is a distance from the second lens element to the third lens element along the optical axis. 
     
     
         19 . The optical lens assembly as recited in  claim 11 , further satisfying: G23/T2≦19.5, wherein G23 is a distance from the second lens element to the third lens element along the optical axis, and T2 is the thickness of the second lens element along the optical axis. 
     
     
         20 . The optical lens assembly as recited in  claim 11 , further satisfying: ALT/T1≦3.2, wherein T1 is the thickness of the first lens element along the optical axis.