Mobile device and optical imaging lens thereof

Abstract

Present embodiments provide for a mobile device and an optical imaging lens thereof. The optical imaging lens comprises five lens elements positioned sequentially from an object side to an image side. Through controlling the convex or concave shape of the surfaces and/or the refracting power of the lens elements, the optical imaging lens shows better optical characteristics and the total length of the optical imaging lens is shortened.

What is claimed is: 
     
         1 . An optical imaging lens, sequentially from an object side to an image side, comprising first, second, third, fourth and fifth lens elements, each of the first, second, third, fourth and fifth 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 positive refracting power, and the image-side surface of the first lens element comprises a concave portion in a vicinity of a periphery of the first lens element;   the image-side surface of the third lens element comprises a convex portion in a vicinity of a periphery of the third lens element;   the object-side surface of the fourth lens element comprises a concave portion in a vicinity of an optical axis;   the object-side surface of the fifth lens element comprises a concave portion in a vicinity of the optical axis;   the optical imaging lens as a whole has only the five lens elements having refracting power; and a sum of thicknesses of all five lens elements along the optical axis is ALT, a back focal length of the optical imaging lens is BFL, and ALT and BFL satisfy the equation:
   ALT/BFL≤2.0.
 
   
     
     
         2 . The optical imaging lens according to  claim 1 , wherein a sum of all air gaps from the first lens element to the fifth lens element along the optical axis is AAG, a central thickness of the fifth lens element along the optical axis is CT 5 , and AAG and CT 5  satisfy the equation:
   3.0≤ AAG/CT   5 .
   
     
     
         3 . The optical imaging lens according to  claim 1 , wherein a central thickness of the fourth lens element along the optical axis is CT 4 , an air gap between the second lens element and the third lens element along the optical axis is AGL 23 , and CT 4  and AGL 23  satisfy the equation:
     CT   4   /AGL   23 ≤3.0.
   
     
     
         4 . The optical imaging lens according to  claim 1 , wherein an effective focal length thereof is EFL, and EFL and ALT satisfy the equation:
   1.8≤ EFL/ALT.  
   
     
     
         5 . The optical imaging lens according to  claim 1 , wherein a central thickness of the fourth lens element along the optical axis is CT 4 , and CT 4  and BFL satisfy the equation:
     CT   4   /BFL≤ 0.7.   
     
     
         6 . The optical imaging lens according to  claim 1 , wherein ALT and BFL further satisfy the equation:
     ALT/BFL≤ 1.5.   
     
     
         7 . The optical imaging lens according to  claim 1 , wherein an Abbe number of the first lens element is larger than a sum of an Abbe number of the second lens element and an Abbe number of the third lens element. 
     
     
         8 . An optical imaging lens, sequentially from an object side to an image side, comprising first, second, third, fourth and fifth lens elements, each of the first, second, third, fourth and fifth 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 positive refracting power, and the image-side surface of said first lens element comprises a concave portion in a vicinity of a periphery of the first lens element;   the object-side surface of the fourth lens element comprises a concave portion in a vicinity of an optical axis;   the object-side surface of the fifth lens element comprises a concave portion in a vicinity of the optical axis, and the object-side surface of the fifth lens element comprises a concave portion in a vicinity of a periphery of the fifth lens element;   the optical imaging lens as a whole has only the five lens elements having refracting power; and a sum of thicknesses of all five lens elements along the optical axis is ALT, a back focal length of the optical imaging lens is BFL, and ALT and BFL satisfy the equation:
     ALT/BFL≤ 2.0. 
   
     
     
         9 . The optical imaging lens according to  claim 8 , wherein an effective focal length of the optical imaging lens is EFL, and EFL and ALT satisfy the equation:
   1.9≤ EFL/ALT.  
   
     
     
         10 . The optical imaging lens according to  claim 8 , wherein a central thickness of the fourth lens element along the optical axis is CT 4 , and CT 4  and BFL satisfy the equation:
     CT   4   /BFL≤ 0.5.   
     
     
         11 . The optical imaging lens according to  claim 8 , wherein a central thickness of the first lens element along the optical axis is CT 1 , a central thickness of the fifth lens element along the optical axis is CT 5 , an air gap between the second lens element and the third lens element along the optical axis is AGL 23 , an air gap between the third lens element and the fourth lens element along the optical axis is AGL 34 , an air gap between the fourth lens element and the fifth lens element along the optical axis is AGL 45 , and CT 1 , CT 5 , AGL 23 , AGL 34 , and AGL 45  satisfy the equation:
   2.7≤( CT   1   +AGL   34   +AGL   45   +CT   5 )/ AGL   23 ≤4.1.
   
     
     
         12 . The optical imaging lens according to  claim 8 , wherein a central thickness of the first lens element along the optical axis is CT 1 , a largest distance of all air gaps from the first lens element to the fifth lens element along the optical axis is Gmax, a smallest thickness of all five lens elements along the optical axis is Tmin, an air gap between the third lens element and the fourth lens element along the optical axis is AGL 34 , and CT 1 , Gmax, Tmin, and AGL 34  satisfy the equation:
   3.2≤( CT   1   +Gmax+Tmin )/ AGL   34 ≤3.6.
   
     
     
         13 . The optical imaging lens according to  claim 8 , wherein a largest thickness of all five lens elements along the optical axis is Tmax, a largest distance of all air gaps from the first lens element to the fifth lens element along the optical axis is Gmax, an air gap between the fourth lens element and the fifth lens element along the optical axis is AGL 45 , and Tmax, Gmax, and AGL 45  further satisfy the equation:
   3.2≤( Tmax+Gmax )/ AGL   45 ≤4.9.
   
     
     
         14 . The optical imaging lens according to  claim 8 , wherein an Abbe number of the fourth lens element is larger than a sum of an Abbe number of the second lens element and an Abbe number of the third lens element. 
     
     
         15 . An optical imaging lens, sequentially from an object side to an image side, comprising first, second, third, fourth and fifth lens elements, each of the first, second, third, fourth and fifth lens elements having an object-side surface facing toward the object side and 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 a periphery of the first lens element;   the third lens element has negative refracting power;   the object-side surface of the fourth lens element comprises a concave portion in a vicinity of an optical axis;   the object-side surface of the fifth lens element comprises a concave portion in a vicinity of the optical axis;   the optical imaging lens as a whole has only the five lens elements having refracting power; and a sum of thicknesses of all five lens elements along the optical axis is ALT, a back focal length of the optical imaging lens is BFL, and ALT and BFL satisfy the equation:
     ALT/BFL≤ 2.0. 
   
     
     
         16 . The optical imaging lens according to  claim 15 , wherein a central thickness of the third lens element along the optical axis is CT 3 , a central thickness of the fourth lens element along the optical axis is CT 4 , a central thickness of the fifth lens element along the optical axis is CT 5 , an air gap between the second lens element and the third lens element along the optical axis is AGL 23 , and CT 3 , CT 4 , CT 5 , and AGL 23  satisfy the equation:
   2.4≤( CT   3   +CT   4   +CT   5 )/ AGL   23 ≤3.6.
   
     
     
         17 . The optical imaging lens according to  claim 15 , wherein a central thickness of the second lens element along the optical axis is CT 2 , an air gap between the first lens element and the second lens element along the optical axis is AGL 12 , an air gap between the second lens element and the third lens element along the optical axis is AGL 23 , an air gap between the fourth lens element and the fifth lens element along the optical axis is AGL 45 , and CT 2 , AGL 12 , AGL 23 , and AGL 45  satisfy the equation:
   2.3≤( AGL   12   +CT   2   +AGL   23 )/ AGL   45 ≤3.8.
   
     
     
         18 . The optical imaging lens according to  claim 15 , wherein a central thickness of the third lens element along the optical axis is CT 3 , a central thickness of the fourth lens element along the optical axis is CT 4 , an air gap between the second lens element and the third lens element along the optical axis is AGL 23 , an air gap between the third lens element and the fourth lens element along the optical axis is AGL 34 , and CT 3 , CT 4 , AGL 23 , and AGL 34  satisfy the equation:
   2.1≤( CT   3   +AGL   34   +CT   4 )/ AGL   23 ≤3.6.
   
     
     
         19 . The optical imaging lens according to  claim 15 , wherein a central thickness of the fourth lens element along the optical axis is CT 4 , a central thickness of the fifth lens element along the optical axis is CT 5 , an air gap between the second lens element and the third lens element along the optical axis is AGL 23 , an air gap between the third lens element and the fourth lens element along the optical axis is AGL 34 , and CT 4 , CT 5 , AGL 23 , and AGL 34 , satisfy the equation:
   3.8≤( AGL   23   +AGL   34   +CT   4 )/ CT   5 ≤4.9.
   
     
     
         20 . The optical imaging lens according to  claim 15 , wherein an Abbe number of the fifth lens element is larger than a sum of an Abbe number of the second lens element and an Abbe number of the third lens element.