Optical imaging lens

Abstract

Present embodiments relate to an optical imaging lens. The optical imaging lens may include a first lens element, a second lens element, a third lens element, a fourth lens element, and a fifth lens element positioned sequentially from an object side to an image side. Through arrangement of convex or concave surfaces of the five lens elements, the length of the optical imaging lens may be shortened while providing improved optical characteristics and imaging quality.

What is claimed is: 
     
         1 . An optical imaging lens, comprising first, second, third, fourth, and fifth lens elements as five frontmost lens elements arranged sequentially in ascending order from an object side to an image side along an optical axis, an object-side surface facing toward the object side, an image-side surface facing toward the image side, wherein:
 the image-side surface of the first lens element comprises a concave portion in a vicinity of the optical axis;   the object-side surface of the second lens element comprises a convex portion in a vicinity of a periphery of the second lens element;   the image-side surface of the second lens element comprises a concave portion in a vicinity of a periphery of the second lens element;   the object-side surface of the fifth lens element comprises a convex portion in a vicinity of the optical axis;   a sum of all air gaps from the first lens element to the fifth lens element along the optical axis is represented by AAG;   a central thickness of the fifth lens element along the optical axis is represented by T5;   a central thickness of the first lens element along the optical axis is represented by T1;   a central thickness of the second lens element along the optical axis is represented by T2;   a distance from the object-side surface of the first lens element to an image plane along the optical axis is represented by TTL;   a distance from the image-side surface of the fifth lens element to the image plane along the optical axis is represented by BFL; and   the optical imaging lens further satisfies inequalities: (AAG+T5)/T1≤3.01, AAG/T2≤4.71 and TTL/BFL≤3.61.   
     
     
         2 . The optical imaging lens according to  claim 1 , wherein a sum of central thicknesses from the first to the fifth lens elements along the optical axis is represented by ALT, a central thickness of the third lens element along the optical axis is represented by T3, a central thickness of the fourth lens element along the optical axis is represented by T4, and the optical imaging lens further satisfies an inequality: ALT/(T1+T3+T4)≤1.8. 
     
     
         3 . The optical imaging lens according to  claim 1 , wherein an air gap between the second lens element and the third lens element along the optical axis is represented by G23, and the optical imaging lens further satisfies an inequality: (AAG+T5)/(T2+G23)≤4.2. 
     
     
         4 . The optical imaging lens according to  claim 1 , wherein an air gap between the second lens element and the third lens element along the optical axis is represented by G23, an air gap between the third lens element and the fourth lens element along the optical axis is represented by G34, an air gap between the fourth lens element and the fifth lens element along the optical axis is represented by G45, and the optical imaging lens further satisfies an inequality:
   ( T 2+ G 23+ G 34+ G 45+ T 5)/ T 1≤3.3.
   
     
     
         5 . The optical imaging lens according to  claim 1 , wherein a central thickness of the fourth lens element along the optical axis is represented by T4, and the optical imaging lens further satisfies an inequality: (AAG+T2)/T4≤8.51. 
     
     
         6 . The optical imaging lens according to  claim 1 , wherein the object-side surface of the third lens element comprises a convex portion in a vicinity of a periphery of the third lens element. 
     
     
         7 . The optical imaging lens according to  claim 1 , wherein the image-side surface of the fifth lens element comprises a concave portion in a vicinity of the optical axis. 
     
     
         8 . An optical imaging lens, comprising first, second, third, fourth, and fifth lens elements as five frontmost lens elements arranged sequentially in ascending order from an object side to an image side along an optical axis, an object-side surface facing toward the object side, an image-side surface facing toward the image side, wherein:
 the image-side surface of the first lens element comprises a concave portion in a vicinity of the optical axis;   the second lens element has negative refracting power;   the object-side surface of the fifth lens element comprises a convex portion in a vicinity of the optical axis;   a sum of all air gaps from the first lens element to the fifth lens element along the optical axis is represented by AAG;   a central thickness of the fifth lens element along the optical axis is represented by T5;   a central thickness of the first lens element along the optical axis is represented by T1;   a central thickness of the second lens element along the optical axis is represented by T2;   a distance from the object-side surface of the first lens element to an image plane along the optical axis is represented by TTL;   a distance from the image-side surface of the fifth lens element to the image plane along the optical axis is represented by BFL; and   the optical imaging lens further satisfies inequalities: (AAG+T5)/T1≤3.01, AAG/T2≤4.71 and TTL/BFL≤3.61.   
     
     
         9 . The optical imaging lens according to  claim 8 , wherein an effective focal length of the optical imaging lens is represented by EFL, and the optical imaging lens further satisfies an inequality: EFL/BFL≤4.2. 
     
     
         10 . The optical imaging lens according to  claim 8 , wherein a central thickness of the fourth lens element along the optical axis is represented by T4, the optical imaging lens further satisfies an inequality: AAG/T4≤7.2. 
     
     
         11 . The optical imaging lens according to  claim 8 , wherein an air gap between the first lens element and the second lens element along the optical axis is represented by G12, an air gap between the fourth lens element and the fifth lens element along the optical axis is represented by G45, and the optical imaging lens further satisfies an inequality: (G12+T2+G45+T5)/T1≤2.2. 
     
     
         12 . The optical imaging lens according to  claim 8 , wherein the first lens element has positive refracting power, the third lens element has positive refracting power, the fourth lens element has negative refracting power, and the fifth lens element has positive refracting power. 
     
     
         13 . The optical imaging lens according to  claim 8 , wherein the object-side surface of the third lens element comprises a convex portion in a vicinity of the optical axis. 
     
     
         14 . The optical imaging lens according to  claim 8 , wherein the object-side surface of the fourth lens element comprises a concave portion in a vicinity of the optical axis. 
     
     
         15 . An optical imaging lens, comprising first, second, third, fourth, and fifth lens elements as five frontmost lens elements arranged sequentially in ascending order from an object side to an image side along an optical axis, an object-side surface facing toward the object side, an image-side surface facing toward the image side, wherein:
 the image-side surface of the first lens element comprises a concave portion in a vicinity of the optical axis;   a sum of all air gaps from the first to the fifth lens elements along the optical axis is represented by AAG;   a central thickness of the fifth lens element along the optical axis is represented by T5;   a central thickness of the first lens element along the optical axis is represented by T1;   an air gap between the second lens element and the third lens element along the optical axis is represented by G23;   the optical imaging lens further satisfies inequalities: (AAG+T5)/T1≤3.01 and AAG/G23≤4; and   all of the first, second, third, fourth, and fifth lens elements have an effective radius smaller than or equal to 2.5 mm.   
     
     
         16 . The optical imaging lens according to  claim 15 , wherein a sum of central thicknesses from the first to the fifth lens elements along the optical axis is represented by ALT, a central thickness of the third lens element along the optical axis is represented by T3, a central thickness of the fourth lens element along the optical axis is represented by T4, and the optical imaging lens further satisfies an inequality: ALT/(T1+T3+T4)≤1.8. 
     
     
         17 . The optical imaging lens according to  claim 15 , wherein a central thickness of the second lens element along the optical axis is represented by T2, and the optical imaging lens further satisfies an inequality: (AAG+T5)/(T2+G23)≤4.2. 
     
     
         18 . The optical imaging lens according to  claim 15 , wherein a central thickness of the second lens element along the optical axis is represented by T2, an air gap between the third lens element and the fourth lens element along the optical axis is represented by G34, an air gap between the fourth lens element and the fifth lens element along the optical axis is represented by G45, and the optical imaging lens further satisfies an inequality: (T2+G23+G34+G45+T5)/T1≤3.3. 
     
     
         19 . The optical imaging lens according to  claim 15 , wherein an air gap between the first lens element and the second lens element along the optical axis is represented by G12, a central thickness of the second lens element along the optical axis is represented by T2, an air gap between the fourth lens element and the fifth lens element along the optical axis is represented by G45, a central thickness of the third lens element along the optical axis is represented by T3, and the optical imaging lens further satisfies an inequality: (G12+T2+G45+T5)/T3≤4.1. 
     
     
         20 . The optical imaging lens according to  claim 15 , wherein the object-side surface of the second lens element comprises a convex portion in a vicinity of the optical axis.