Abstract:
An imaging lens includes an aperture and a first to a fifth lenses in order from an object side to an image side. The first lens is a positive meniscus lens made of glass, which has at least one aspheric surface. The Abbe number of the first lens is no less than 60. The second lens is a negative meniscus lens made of plastic, which has at least one aspheric surface. The third lens is a positive meniscus lens made of plastic, which has at least one aspheric surface. The fourth lens is a positive meniscus lens made of plastic, which has at least one aspheric surface. The fifth lens is a negative lens made of plastic, and both surfaces thereof are aspherical. A diopter of the fifth lens gradually turns from negative to positive from where an optical axis passes through to a margin thereof.

Description:
[0001]    The current application claims a foreign priority to the patent application of Taiwan No. 103142579 filed on Dec. 8, 2014. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Technical Field 
         [0003]    The present invention relates generally to optics, and more particularly to an imaging lens. 
         [0004]    2. Description of Related Art 
         [0005]    With the recent development of mobile devices, the market demand for lens modules rises. In consideration of convenience and portability, the market prefers mobile devices to be miniature and lightweight, and as a result, various industries such as automotive industry, video game industry, household appliances industry, etc. also start using miniature optical module to develop more convenient functions. 
         [0006]    It&#39;s needless to say that the size of the imaging lenses applied in miniature mobile devices is also greatly reduced in recent years, and since customers would like the image resolution of photos taken by such mobile devices to be satisfying high, the imaging lenses must be able to provide high optical performance. Therefore, miniature size and high optical performance are two key requirements for imaging lenses in modern days. 
         [0007]    In addition, the imaging lenses applied in mobile devices nowadays are getting wide angle; however, a wide angle system often has problems of limited view angle, distortion, and chromatic aberration, which affects the output image quality. In light of this, there is still room for improvement for the design of imaging lenses. 
       BRIEF SUMMARY OF THE INVENTION 
       [0008]    In view of the above, the primary objective of the present invention is to provide an imaging lens which satisfies the requirements of miniature size, high optical performance, and wider view angle for a wide angle system. 
         [0009]    The present invention provides an imaging lens, which includes, in order from an object side to an image side along an optical axis, an aperture, a first lens, a second lens, a third lens, a fourth lens, and a fifth lens. The first lens is made of glass, and is a positive meniscus lens, wherein a convex surface thereof faces the object side, and a concave surface thereof faces the image side; at least one of the surfaces of the first lens is aspheric; an Abbe number of first lens is no less than 60. The second lens is made of plastic, and is a negative meniscus lens, wherein a convex surface thereof faces the object side, and a concave surface thereof faces the image side; at least one of the surfaces of the second lens is aspheric. The third lens is made of plastic, and is a positive meniscus lens, wherein a convex surface thereof faces the image side, and a concave surface thereof faces the object side; at least one of the surfaces of the third lens is aspheric. The fourth lens is made of plastic, and is a positive meniscus lens, wherein a convex surface thereof faces the image side, and a concave surface thereof faces the object side; at least one of the surfaces of the fourth lens is aspheric. The fifth lens is made of plastic, and both surfaces thereof are aspheric; a diopter of the fifth lens gradually turns from negative to positive from where the optical axis passes through to a margin of the fifth lens. 
         [0010]    In an embodiment, both surfaces of the first lens are aspheric. 
         [0011]    In an embodiment, both surfaces of the second lens are aspheric. 
         [0012]    In an embodiment, both surfaces of the third lens are aspheric. 
         [0013]    In an embodiment, both surfaces of the fourth lens are aspheric. 
         [0014]    In an embodiment, the surface of the fifth lens which faces the object side is concave at where the optical axis passes through; a radius of curvature of the surface of the fifth lens which faces the object side is negative at where the optical axis passes through, and gradually turns from negative to positive from where the optical axis passes through to the margin of the fifth lens. 
         [0015]    In an embodiment, the surface of the fifth lens which faces the object side is convex at where the optical axis passes through; a radius of curvature of the surface of the fifth lens which faces the object side is positive at where the optical axis passes through, and gradually turns from positive to negative and positive again from where the optical axis passes through to the margin of the fifth lens. 
         [0016]    In an embodiment, a surface of the fifth lens which faces the image side is concave at where the optical axis passes through; a radius of curvature of the surface of the fifth lens which faces the image side is p positive at where the optical axis passes through, and the radius of curvature gradually turns from positive to negative from where the optical axis passes through to the margin of the fifth lens. 
         [0017]    In an embodiment, the imaging lens further satisfies: 0.74≦f1/f≦0.85; where f1 is a focal length of the first lens; f is a focal length of the imaging lens. 
         [0018]    In an embodiment, the imaging lens further satisfies: −1.6≦f2/f≦−1.3; where f2 is a focal length of the second lens; f is a focal length of the imaging lens. 
         [0019]    In an embodiment, the imaging lens further satisfies: 3.8≦f3/f≦5.1; where f3 is a focal length of the third lens; f is a focal length of the imaging lens. 
         [0020]    In an embodiment, the imaging lens further satisfies: 0.75≦f4/f≦0.96; where f4 is a focal length of the fourth lens; f is a focal length of the imaging lens. 
         [0021]    In an embodiment, the imaging lens further satisfies: −0.70≦f5/f≦−0.54; where f5 is a focal length of the fifth lens; f is a focal length of the imaging lens. 
         [0022]    In an embodiment, the imaging lens further satisfies: 1.16≦TTL/f≦1.20; where f is a focal length of the imaging lens; TTL is a total length of the image lens. 
         [0023]    In an embodiment, the imaging lens further satisfies: 0.69≦IMH/TTL≦0.78; where IMH is a height of an imaging plane of the imaging lens; TTL is a total length of the image lens. 
         [0024]    In an embodiment, the imaging lens further satisfies: 1.9≦f1/R 1 ≦2.2; where f1 is a focal length of the first lens; R 1  is a radius of curvature of the surface of the first lens which faces the object side at where the optical axis passes through. 
         [0025]    With the aforementioned structure and materials of the lenses, the purpose of getting miniature size and high optical performance can be achieved. In addition, the visible angle of a wide angle system can be effectively widened as well. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0026]    The present invention will be best understood by referring to the following detailed description of some illustrative embodiments in conjunction with the accompanying drawings, in which 
           [0027]      FIG. 1  is a schematic diagram of a first preferred embodiment of the present invention; 
           [0028]      FIG. 2A  is a diagram showing the field curvature of the imaging lens of the first preferred embodiment of the present invention; 
           [0029]      FIG. 2B  is a diagram showing the distortion of the imaging lens of the first preferred embodiment of the present invention; 
           [0030]      FIG. 2C  is a diagram showing the spherical aberration of the imaging lens of the first preferred embodiment of the present invention; 
           [0031]      FIG. 2D  is a diagram showing the chromatic difference of magnification of the imaging lens of the first preferred embodiment of the present invention; 
           [0032]      FIG. 3  is a schematic diagram of a second preferred embodiment of the present invention; 
           [0033]      FIG. 4A  is a diagram showing the field curvature of the imaging lens of the second preferred embodiment of the present invention; 
           [0034]      FIG. 4B  is a diagram showing the distortion of the imaging lens of the second preferred embodiment of the present invention; 
           [0035]      FIG. 4C  is a diagram showing the spherical aberration of the imaging lens of the second preferred embodiment of the present invention; 
           [0036]      FIG. 4D  is a diagram showing the chromatic difference of magnification of the imaging lens of the second preferred embodiment of the present invention; 
           [0037]      FIG. 5  is a schematic diagram of a third preferred embodiment of the present invention; 
           [0038]      FIG. 6A  is a diagram showing the field curvature of the imaging lens of the third preferred embodiment of the present invention; 
           [0039]      FIG. 6B  is a diagram showing the distortion of the imaging lens of the third preferred embodiment of the present invention; 
           [0040]      FIG. 6C  is a diagram showing the spherical aberration of the imaging lens of the third preferred embodiment of the present invention; 
           [0041]      FIG. 6D  is a diagram showing the chromatic difference of magnification of the imaging lens of the third preferred embodiment of the present invention; 
           [0042]      FIG. 7  is a schematic diagram of a fourth preferred embodiment of the present invention; 
           [0043]      FIG. 8A  is a diagram showing the field curvature of the imaging lens of the fourth preferred embodiment of the present invention; 
           [0044]      FIG. 8B  is a diagram showing the distortion of the imaging lens of the fourth preferred embodiment of the present invention; 
           [0045]      FIG. 8C  is a diagram showing the spherical aberration of the imaging lens of the fourth preferred embodiment of the present invention; and 
           [0046]      FIG. 8D  is a diagram showing the chromatic difference of magnification of the imaging lens of the fourth preferred embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0047]    Image lenses  1 - 4  of the first to the fourth preferred embodiments of the present invention are respectively shown in  FIG. 1 ,  FIG. 3 ,  FIG. 5 , and  FIG. 7 . Each of the imaging lenses  1 - 4  includes, in order from an object side to an image side along an optical axis Z, an aperture ST, a first lens L 1 , a second lens L 2 , a third lens L 3 , a fourth lens L 4 , and a fifth lens L 5 , wherein a diopter of each lens L 1 -L 5  is respectively positive, negative, positive, positive, and negative at where the optical axis goes through. Surfaces S 2 -S 11  of the lenses L 1 -L 5  are all aspheric. In addition, an optical filter CF is provided between the fifth lens L 5  and the image side to filter out unwanted stray light if necessary, which helps to enhance optical performance. 
         [0048]    In the imaging lenses  1 - 4  of the first to the fourth preferred embodiments of the present invention, the first lens L 1  is a meniscus lens with the convex surface S 2  facing the object side and the concave surface S 3  facing the image side; the second lens L 2  is a meniscus lens with the convex surface S 4  facing the object side and the concave surface S 5  facing the image side; the third lens L 3  is a meniscus lens with the concave surface S 6  facing the object side and the convex surface S 7  facing the image side; the fourth lens L 4  is a meniscus lens with the concave surface S 8  facing the object side and the convex surface S 9  facing the image side. 
         [0049]    The difference between each preferred embodiment is about a radius of curvature of the fifth lens L 5  at where the optical axis passes through. In the first preferred embodiment, the surface S 10  of the fifth lens L 5  of the imaging lens  1  which faces the object side is convex (i.e., the radius of curvature is positive) at where the optical axis passes through. Therefore, the radius of curvature of the surface S 10  gradually turns from positive to negative and positive again from where the optical axis passes through to a margin of the fifth lens L 5 . The surface S 11  of the fifth lens L 5  of the imaging lens  1  which faces the image side is concave (i.e., the radius of curvature is negative) at where the optical axis passes through. Therefore, the radius of curvature of the surface S 11  gradually turns from positive to negative from where the optical axis passes through to the margin of the fifth lens L 5 . Specifically, the surfaces S 10 , S 11  are designed in a way that the diopter of the fifth lens L 5  gradually turns from negative to positive from where the optical axis passes through to the margin of the fifth lens L 5 . 
         [0050]    In the second, third, and fourth preferred embodiments, the surface S 10  of the fifth lens L 5  which faces the object side is concave (i.e., the radius of curvature is negative) at where the optical axis passes through. Therefore, the radius of curvature of the surface S 10  gradually turns from negative to positive from where the optical axis passes through to a margin of the fifth lens L 5 . Similarly, the surfaces S 10 , S 11  in these preferred embodiments are also designed in a way that the diopter of the fifth lens L 5  gradually turns from negative to positive from where the optical axis passes through to the margin of the fifth lens L 5 . 
         [0051]    The following Tables 1-4 respectively list a system focal length f of each of the imaging lenses  1 - 4  in the first to the fourth preferred embodiments, along with the radius of curvature R of each surface S 2 -S 11  at where the optical axis Z passes through, a distance D between each surface S 2 -S 11  and the next surface S 2 -S 11  (or an imaging plane) along the optical axis Z, a material of each lens L 1 -L 5 , a refractive index Nd of each lens L 1 -L 5 , an Abbe number Vd of each lens L 1 -L 5 , and a focal length of each lens L 1 -L 5 . With these figures listed in Tables 1-4, the imaging lenses  1 - 4  of the first to the fourth preferred embodiments can effectively enhance optical performance. 
         [0000]    
       
         
               
             
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 1 
               
             
             
               
                   
               
               
                 (the first preferred embodiment) 
               
               
                 f = 4.60 mm 
               
             
          
           
               
                   
                   
                   
                   
                   
                   
                 Focal 
                   
               
               
                 Surface 
                 R (mm) 
                 D (mm) 
                 Material 
                 Nd 
                 Vd 
                 Length 
                 Component 
               
               
                   
               
             
          
           
               
                 S1 
                 ∞ 
                 −0.2825728 
                   
                   
                   
                   
                 Aperture ST 
               
               
                 S2 
                 1.712824 
                 0.5740615 
                 glass 
                 1.516 
                 64.1 
                 3.418 
                 First Lens L1 
               
               
                 S3 
                 46.75763 
                 0.1323232 
                   
                   
                   
                   
                   
               
               
                 S4 
                 6.241833 
                 0.25 
                 plastic 
                 1.642 
                 22.4 
                 −6.381 
                 Second Lens L2 
               
               
                 S5 
                 2.447412 
                 0.4742351 
                   
                   
                   
                   
                   
               
               
                 S6 
                 −9.613208 
                 0.518274 
                 plastic 
                 1.531 
                 55.7 
                 23.15 
                 Third Lens L3 
               
               
                 S7 
                 −5.504177 
                 0.5868162 
                   
                   
                   
                   
                   
               
               
                 S8 
                 −3.180978 
                 0.57529 
                 plastic 
                 1.531 
                 55.7 
                 3.96 
                 Fourth Lens L4 
               
               
                 S9 
                 −1.348511 
                 0.4113892 
                   
                   
                   
                   
                   
               
               
                 S10 
                 80.11441 
                 0.6403799 
                 plastic 
                 1.531 
                 55.7 
                 −2.849 
                 Fifth Lens L5 
               
               
                 S11 
                 1.486164 
                 0.8159251 
                   
                   
                   
                   
                   
               
               
                 S12 
                 ∞ 
                 0.21 
                 glass 
                 1.5163 
                 64.1 
                   
                 Optical Filter CF 
               
               
                 S13 
                 ∞ 
                 0.199182 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 2 
               
             
             
               
                   
               
               
                 (the second preferred embodiment) 
               
               
                 f = 4.08 mm 
               
             
          
           
               
                   
                   
                   
                   
                   
                   
                 Focal 
                   
               
               
                 Surface 
                 R (mm) 
                 D (mm) 
                 Material 
                 Nd 
                 Vd 
                 Length 
                 Component 
               
               
                   
               
             
          
           
               
                 S1 
                 ∞ 
                 −0.2937448 
                   
                   
                   
                   
                 Aperture ST 
               
               
                 S2 
                 1.515445 
                 0.5496945 
                 glass 
                 1.516 
                 64.1 
                 3.14 
                 First Lens L1 
               
               
                 S3 
                 19.5664 
                 0.08711894 
                   
                   
                   
                   
                   
               
               
                 S4 
                 9.096886 
                 0.25 
                 plastic 
                 1.642 
                 22.4 
                 −5.667 
                 Second Lens L2 
               
               
                 S5 
                 2.587006 
                 0.3660841 
                   
                   
                   
                   
                   
               
               
                 S6 
                 −29.49261 
                 0.3622795 
                 plastic 
                 1.531 
                 55.7 
                 18.268 
                 Third Lens L3 
               
               
                 S7 
                 −7.350098 
                 0.5733299 
                   
                   
                   
                   
                   
               
               
                 S8 
                 −3.709758 
                 0.6293488 
                 plastic 
                 1.531 
                 55.7 
                 3.161 
                 Fourth Lens L4 
               
               
                 S9 
                 −1.226788 
                 0.4465162 
                   
                   
                   
                   
                   
               
               
                 S10 
                 −13.71921 
                 0.4204823 
                 plastic 
                 1.531 
                 55.7 
                 −2.312 
                 Fifth Lens L5 
               
               
                 S11 
                 1.368213 
                 0.6633252 
                   
                   
                   
                   
                   
               
               
                 S12 
                 ∞ 
                 0.21 
                 glass 
                 1.516 
                 64.1 
                   
                 Optical Filter CF 
               
               
                 S13 
                 ∞ 
                 0.2259435 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 3 
               
             
             
               
                   
               
               
                 (the third preferred embodiment) 
               
               
                 f = 4.13 mm 
               
             
          
           
               
                   
                   
                   
                   
                   
                   
                 Focal 
                   
               
               
                 Surface 
                 R (mm) 
                 D (mm) 
                 Material 
                 Nd 
                 Vd 
                 Length 
                 Component 
               
               
                   
               
             
          
           
               
                 S1 
                 ∞ 
                 −0.2937448 
                   
                   
                   
                   
                 Aperture ST 
               
               
                 S2 
                 1.531015 
                 0.5455172 
                 glass 
                 1.516 
                 64.1 
                 3.16 
                 First Lens L1 
               
               
                 S3 
                 20.9112 
                 0.08448909 
                   
                   
                   
                   
                   
               
               
                 S4 
                 6.025987 
                 0.25 
                 plastic 
                 1.642 
                 22.4 
                 −5.55 
                 Second Lens L2 
               
               
                 S5 
                 2.214615 
                 0.3512173 
                   
                   
                   
                   
                   
               
               
                 S6 
                 −26.0582 
                 0.4031397 
                 plastic 
                 1.531 
                 55.7 
                 17.649 
                 Third Lens L3 
               
               
                 S7 
                 −6.947832 
                 0.5748782 
                   
                   
                   
                   
                   
               
               
                 S8 
                 −3.591832 
                 0.5040297 
                 plastic 
                 1.531 
                 55.7 
                 3.93 
                 Fourth Lens L4 
               
               
                 S9 
                 −1.387571 
                 0.5038518 
                   
                   
                   
                   
                   
               
               
                 S10 
                 −38.35617 
                 0.4828769 
                 plastic 
                 1.531 
                 55.7 
                 −2.85 
                 Fifth Lens L5 
               
               
                 S11 
                 1.588758 
                 0.6643534 
                   
                   
                   
                   
                   
               
               
                 S12 
                 ∞ 
                 0.21 
                 glass 
                 1.516 
                 64.1 
                   
                 Optical Filter CF 
               
               
                 S13 
                 ∞ 
                 0.2123471 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 4 
               
             
             
               
                   
               
               
                 (the fourth preferred embodiment) 
               
               
                 f = 4.20 mm 
               
             
          
           
               
                   
                   
                   
                   
                   
                   
                 Focal 
                   
               
               
                 Surface 
                 R (mm) 
                 D (mm) 
                 Material 
                 Nd 
                 Vd 
                 Length 
                 Component 
               
               
                   
               
             
          
           
               
                 S1 
                 ∞ 
                 −0.3572004 
                   
                   
                   
                   
                 Aperture ST 
               
               
                 S2 
                 1.63415 
                 0.6660115 
                 glass 
                 1.514 
                 63.3 
                 3.54 
                 First Lens L1 
               
               
                 S3 
                 13.17739 
                 0.08 
                   
                   
                   
                   
                   
               
               
                 S4 
                 7.71684 
                 0.25 
                 plastic 
                 1.642 
                 22.4 
                 −6.58 
                 Second Lens L2 
               
               
                 S5 
                 2.714637 
                 0.3454669 
                   
                   
                   
                   
                   
               
               
                 S6 
                 −32.75801 
                 0.3620568 
                 plastic 
                 1.544 
                 55.9 
                 16.14 
                 Third Lens L3 
               
               
                 S7 
                 −6.977679 
                 0.6659967 
                   
                   
                   
                   
                   
               
               
                 S8 
                 −3.811038 
                 0.5840767 
                 plastic 
                 1.544 
                 55.9 
                 3.167 
                 Fourth Lens L4 
               
               
                 S9 
                 −1.254656 
                 0.4463914 
                   
                   
                   
                   
                   
               
               
                 S10 
                 −9.844213 
                 0.5 
                 plastic 
                 1.544 
                 55.9 
                 −2.291 
                 Fifth Lens L5 
               
               
                 S11 
                 1.460712 
                 0.79 
                   
                   
                   
                   
                   
               
               
                 S12 
                 ∞ 
                 0.21 
                 glass 
                 1.516 
                 64.1 
                   
                 Optical Filter CF 
               
               
                 S13 
                 ∞ 
                 0.09661739 
               
               
                   
               
             
          
         
       
     
         [0052]    In addition, for the lenses L 1 -L 5  of the imaging lens  1 - 4  in the first to the fourth preferred embodiments, the surface concavities z of each aspheric surface S 2 -S 11  is defined by the following formula: 
         [0000]    
       
         
           
             z 
             = 
             
               
                 
                   ch 
                   2 
                 
                 
                   1 
                   + 
                   
                     
                       1 
                       - 
                       
                         
                           ( 
                           
                             1 
                             + 
                             k 
                           
                           ) 
                         
                          
                         
                           c 
                           2 
                         
                          
                         
                           h 
                           2 
                         
                       
                     
                   
                 
               
               + 
               
                 
                   α 
                   2 
                 
                  
                 
                   h 
                   4 
                 
               
               + 
               
                 
                   α 
                   3 
                 
                  
                 
                   h 
                   6 
                 
               
               + 
               
                 
                   α 
                   4 
                 
                  
                 
                   h 
                   8 
                 
               
               + 
               
                 
                   α 
                   5 
                 
                  
                 
                   h 
                   10 
                 
               
               + 
               
                 
                   α 
                   6 
                 
                  
                 
                   h 
                   12 
                 
               
               + 
               
                 
                   α 
                   7 
                 
                  
                 
                   h 
                   14 
                 
               
               + 
               
                 
                   α 
                   8 
                 
                  
                 
                   h 
                   16 
                 
               
             
           
         
       
     
         [0053]    where: 
         [0000]    z is the surface concavity;
 
c is the reciprocal of the radius of curvature;
 
h is half the off-axis height of the surface;
 
k is conic constant; and
 
α 2 -α 8  respectively represents different order coefficient of h.
 
         [0054]    The conic constant k and each order coefficient α 2 -α 8  of the imaging lenses  1 - 4  of the first to the fourth preferred embodiments of the present invention are respectively listed in the following Tables 5-8. 
         [0000]    
       
         
               
             
               
               
             
               
               
               
               
               
               
             
               
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 5 
               
               
                   
               
               
                 (the first preferred embodiment) 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Surface 
               
             
          
           
               
                   
                 S2 
                 S3 
                 S4 
                 S5 
                 S6 
               
               
                   
               
               
                 k 
                 5.9617E−01 
                 0.0000E+00 
                 −8.8321E+00 
                 −2.9481E+00 
                 2.8365E+01 
               
               
                 α 2   
                 −8.3308E−03 
                 1.4134E−02 
                 −2.9099E−02 
                 −1.4534E−02 
                 −7.2833E−02 
               
               
                 α 3   
                 6.2117E−03 
                 5.7061E−03 
                 4.5224E−02 
                 6.8389E−02 
                 −2.2024E−02 
               
               
                 α 4   
                 −1.8983E−02 
                 1.2890E−03 
                 −2.9620E−02 
                 −5.7993E−02 
                 6.8094E−03 
               
               
                 α 5   
                 1.9090E−02 
                 5.0054E−03 
                 3.3398E−03 
                 4.3876E−02 
                 4.7428E−03 
               
               
                 α 6   
                 1.0265E−03 
                 −8.2726E−03 
                 1.0722E−02 
                 1.7635E−02 
                 −4.5471E−03 
               
               
                 α 7   
                 −1.5311E−02 
                 9.1380E−03 
                 −1.0908E−02 
                 −3.8802E−02 
                 −8.0226E−03 
               
               
                 α 8   
                 9.3208E−03 
                 −3.8935E−03 
                 2.8963E−04 
                 2.2571E−02 
                 2.0204E−02 
               
               
                   
               
             
          
           
               
                   
                 Surface 
               
             
          
           
               
                   
                 S7 
                 S8 
                 S9 
                 S10 
                 S11 
               
               
                   
               
               
                 k 
                 −1.6192E+00 
                 −3.0815E−01 
                 −3.6278E+00 
                 0.0000E+00 
                 −7.2273E+00 
               
               
                 α 2   
                 −4.4792E−02 
                 4.7924E−02 
                 7.0162E−04 
                 −5.6445E−02 
                 −3.4428E−02 
               
               
                 α 3   
                 −2.8886E−02 
                 −2.9412E−02 
                 1.1146E−02 
                 1.3456E−02 
                 7.2546E−03 
               
               
                 α 4   
                 2.3744E−03 
                 3.9516E−03 
                 −4.4592E−03 
                 −1.0960E−03 
                 −1.1661E−03 
               
               
                 α 5   
                 7.6584E−03 
                 −2.9983E−04 
                 1.0441E−03 
                 −6.0624E−06 
                 9.6667E−05 
               
               
                 α 6   
                 −2.1962E−03 
                 9.5026E−05 
                 −7.1742E−05 
                 5.6638E−06 
                 4.3113E−06 
               
               
                 α 7   
                 −2.3912E−03 
                 7.9551E−05 
                 −1.8552E−05 
                 −1.8855E−07 
                 1.3449E−07 
               
               
                 α 8   
                 2.3485E−03 
                 −2.8944E−05 
                 1.8912E−06 
                 −5.4416E−09 
                 −2.9635E−09 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
             
               
               
               
               
               
               
             
               
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 6 
               
               
                   
               
               
                 (the second preferred embodiment) 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Surface 
               
             
          
           
               
                   
                 S2 
                 S3 
                 S4 
                 S5 
                 S6 
               
               
                   
               
               
                 k 
                 3.8381E−01 
                 −1.2681E+01 
                 −3.7909E−01 
                 −1.2993E+00 
                 0.0000E+00 
               
               
                 α 2   
                 −9.8681E−03 
                 9.6824E−03 
                 −2.6204E−02 
                 1.0894E−03 
                 −7.8040E−02 
               
               
                 α 3   
                 2.3450E−02 
                 1.4713E−02 
                 7.9711E−02 
                 1.2514E−01 
                 −5.5834E−02 
               
               
                 α 4   
                 −5.2355E−02 
                 1.8806E−02 
                 −7.5121E−02 
                 −1.6706E−01 
                 1.2446E−02 
               
               
                 α 5   
                 6.5775E−02 
                 9.3284E−05 
                 −1.3632E−02 
                 1.3391E−01 
                 6.3134E−02 
               
               
                 α 6   
                 1.5536E−02 
                 −7.9306E−02 
                 5.4592E−02 
                 1.0716E−01 
                 −2.6278E−02 
               
               
                 α 7   
                 −9.7962E−02 
                 8.5861E−02 
                 −2.2319E−02 
                 −2.1875E−01 
                 −8.6017E−02 
               
               
                 α 8   
                 6.3604E−02 
                 −2.2609E−02 
                 −2.2512E−02 
                 1.1140E−01 
                 1.0482E−01 
               
               
                   
               
             
          
           
               
                   
                 Surface 
               
             
          
           
               
                   
                 S7 
                 S8 
                 S9 
                 S10 
                 S11 
               
               
                   
               
               
                 k 
                 −5.3040E−01 
                 2.8035E−02 
                 −3.7255E+00 
                 1.8059E−01 
                 −7.3735E+00 
               
               
                 α 2   
                 −4.3371E−02 
                 4.8188E−02 
                 −1.5804E−02 
                 −9.0459E−02 
                 −5.9372E−02 
               
               
                 α 3   
                 −6.6218E−02 
                 −3.6134E−02 
                 2.2198E−02 
                 2.7115E−02 
                 1.5989E−02 
               
               
                 α 4   
                 1.3445E−02 
                 5.9783E−03 
                 −1.0830E−02 
                 −2.7336E−03 
                 −2.9951E−03 
               
               
                 α 5   
                 2.2898E−02 
                 −1.8707E−03 
                 3.5027E−03 
                 −2.6215E−05 
                 3.0082E−04 
               
               
                 α 6   
                 −1.3001E−02 
                 −1.6124E−04 
                 −3.4385E−04 
                 2.2851E−05 
                 −1.9067E−05 
               
               
                 α 7   
                 −1.1091E−02 
                 4.3226E−04 
                 −1.0518E−04 
                 −1.2019E−06 
                 8.2203E−07 
               
               
                 α 8   
                 1.5029E−02 
                 −4.3787E−05 
                 1.9582E−05 
                 3.4977E−09 
                 −1.6587E−08 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
             
               
               
               
               
               
               
             
               
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 7 
               
               
                   
               
               
                 (the third preferred embodiment) 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Surface 
               
             
          
           
               
                   
                 S2 
                 S3 
                 S4 
                 S5 
                 S6 
               
               
                   
               
               
                 k 
                 3.9150E−01 
                 0.0000E+00 
                 0.0000E+00 
                 −2.4546E+00 
                 0.0000E+00 
               
               
                 α 2   
                 −5.7779E−03 
                 1.6991E−02 
                 −3.9016E−02 
                 −8.3681E−03 
                 −7.8950E−02 
               
               
                 α 3   
                 2.3351E−02 
                 2.1196E−02 
                 8.3384E−02 
                 1.3016E−01 
                 −4.5572E−02 
               
               
                 α 4   
                 −5.4221E−02 
                 1.0720E−02 
                 −7.1320E−02 
                 −1.6012E−01 
                 1.3647E−02 
               
               
                 α 5   
                 6.8898E−02 
                 5.2705E−03 
                 −2.2895E−02 
                 1.1730E−01 
                 5.7308E−02 
               
               
                 α 6   
                 2.0136E−02 
                 −6.8084E−02 
                 5.3150E−02 
                 1.0781E−01 
                 −1.1311E−02 
               
               
                 α 7   
                 −9.6963E−02 
                 8.5647E−02 
                 −2.1844E−02 
                 −2.1746E−01 
                 −8.6087E−02 
               
               
                 α 8   
                 6.4042E−02 
                 −2.3459E−02 
                 −2.1584E−02 
                 1.1272E−01 
                 1.0250E−01 
               
               
                   
               
             
          
           
               
                   
                 Surface 
               
             
          
           
               
                   
                 S7 
                 S8 
                 S9 
                 S10 
                 S11 
               
               
                   
               
               
                 k 
                 0.0000E+00 
                 0.0000E+00 
                 −3.7647E+00 
                 0.0000E+00 
                 −7.5586E+00 
               
               
                 α 2   
                 −4.8208E−02 
                 4.1265E−02 
                 −1.2769E−02 
                 −9.4499E−02 
                 −5.5702E−02 
               
               
                 α 3   
                 −6.0929E−02 
                 −3.6661E−02 
                 2.1955E−02 
                 2.7143E−02 
                 1.4914E−02 
               
               
                 α 4   
                 1.3597E−02 
                 5.0974E−03 
                 −1.0931E−02 
                 −2.7193E−03 
                 −2.9782E−03 
               
               
                 α 5   
                 2.4117E−02 
                 −2.2340E−03 
                 3.4853E−03 
                 −2.4300E−05 
                 3.0673E−04 
               
               
                 α 6   
                 −1.1592E−02 
                 −2.2083E−04 
                 −3.4607E−04 
                 2.3050E−05 
                 −1.8865E−05 
               
               
                 α 7   
                 −1.2502E−02 
                 4.5259E−04 
                 −1.0511E−04 
                 −1.1879E−06 
                 8.0303E−07 
               
               
                 α 8   
                 1.4936E−02 
                 −1.9849E−05 
                 1.9798E−05 
                 2.7928E−09 
                 −1.6311E−08 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
             
               
               
               
               
               
               
             
               
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 8 
               
               
                   
               
               
                 (the fourth preferred embodiment) 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Surface 
               
             
          
           
               
                   
                 S2 
                 S3 
                 S4 
                 S5 
                 S6 
               
               
                   
               
               
                 k 
                 −3.8209E−01 
                 1.6118E+02 
                 2.0466E+01 
                 −4.3611E+00 
                 −2.5190E+02 
               
               
                 α 2   
                 7.7357E−03 
                 −4.4202E−02 
                 −1.0889E−01 
                 −4.8835E−02 
                 −9.1648E−02 
               
               
                 α 3   
                 8.5634E−02 
                 1.1795E−01 
                 1.5684E−01 
                 1.4657E−01 
                 −4.0292E−02 
               
               
                 α 4   
                 −1.8319E−01 
                 −1.3045E−01 
                 −7.3319E−02 
                 −1.6265E−01 
                 −3.5119E−02 
               
               
                 α 5   
                 2.0437E−01 
                 1.3145E−01 
                 −1.0495E−01 
                 7.2527E−02 
                 1.0417E−01 
               
               
                 α 6   
                 −1.3526E−02 
                 −1.2661E−01 
                 1.2278E−01 
                 1.2177E−01 
                 −4.8535E−02 
               
               
                 α 7   
                 −1.1899E−01 
                 8.5146E−02 
                 −2.1900E−02 
                 −2.1847E−01 
                 −9.9189E−02 
               
               
                 α 8   
                 6.3988E−02 
                 −2.3943E−02 
                 −2.2200E−02 
                 1.1218E−01 
                 1.0482E−01 
               
               
                   
               
             
          
           
               
                   
                 Surface 
               
             
          
           
               
                   
                 S7 
                 S8 
                 S9 
                 S10 
                 S11 
               
               
                   
               
               
                 k 
                 −9.5723E+00 
                 −2.0817E+00 
                 −3.7930E+00 
                 4.1990E+00 
                 −7.9121E+00 
               
               
                 α 2   
                 −5.6683E−02 
                 2.8871E−02 
                 −2.9847E−02 
                 −7.0513E−02 
                 −5.0001E−02 
               
               
                 α 3   
                 −3.9870E−02 
                 −2.3823E−02 
                 3.1231E−02 
                 2.2607E−02 
                 1.3518E−02 
               
               
                 α 4   
                 −2.2895E−02 
                 4.0957E−03 
                 −1.3362E−02 
                 −2.4760E−03 
                 −2.5504E−03 
               
               
                 α 5   
                 5.0332E−02 
                 −2.2113E−03 
                 3.4118E−03 
                 8.1762E−06 
                 2.7500E−04 
               
               
                 α 6   
                 −1.9482E−02 
                 −1.5640E−04 
                 −2.5116E−04 
                 2.1380E−05 
                 −2.0579E−05 
               
               
                 α 7   
                 −2.1199E−02 
                 4.4321E−04 
                 −8.2305E−05 
                 −1.7150E−06 
                 1.1779E−06 
               
               
                 α 8   
                 2.0366E−02 
                 −6.0892E−05 
                 1.3067E−05 
                 4.1424E−08 
                 −3.4018E−08 
               
               
                   
               
             
          
         
       
     
         [0055]    In addition, with the aperture ST and the aforementioned aspheric design for the lenses L 1 -L 5 , the problem of distortion which tends to happen in wide angle optical design can be effectively fixed. Moreover, the first lens L 1  is made of glass, and through the arrangement of diopters of the lenses L 1 -L 5  as positive, negative, positive, positive, and negative, the imaging lenses  1 - 4  can provide high imaging quality, which effectively achieves the purpose of getting miniature size, providing wide angle, and eliminating optical distortion. Specifically, the imaging lenses  1 - 4  satisfy the following rules: 
         [0000]      60≦ Vd 1;  (1)
 
         [0000]      0.74≦ f 1/ f≦ 0.85;  (2)
 
         [0000]      −1.6≦ f 2/ f≦− 1.3;  (3)
 
         [0000]      3.8≦ f 3/ f≦ 5.1;  (4)
 
         [0000]      0.75≦ f 4/ f≦ 0.96;  (5)
 
         [0000]      −0.70≦ f 5/ f≦− 0.54;  (6)
 
         [0000]      1.16≦TTL/ f ≦1.20;  (7)
 
         [0000]      0.69≦IMH/TTL≦0.78;  (8)
 
         [0000]      1.9≦ f 1/ R 1≦2.2;  (9)
 
         [0056]    where, Vd1 is the Abbe number of the first lens L 1 ; R 1  is the radius of curvature of the surface S 2  of the first lens L 1 , which faces the object side, at where the optical axis passes through; f is the focal length of the imaging lenses  1 - 4 ; f1 is the focal length of the first lens L 1 ; f2 is the focal length of the second lens L 2 ; f3 is the focal length of the third lens L 3 ; f4 is the focal length of the fourth lens L 4 ; f5 is the focal length of the fifth lens L 5 ; IMH is a height of the imaging plane of the imaging lenses  1 - 4 ; TTL is a total length of the imaging lenses  1 - 4 . 
         [0057]    When rules (1) to (3) are satisfied, field curvature of each of the imaging lenses  1 - 4  can be significantly improved; when rules (4) to (6) are satisfied, peripheral distortion, chromatic difference of magnification, and spherical aberration can be effectively eliminated. In addition, with the aspheric shape of the fifth lens L 5 , the light passing through the periphery of the fifth lens L 5  is effectively suppressed, and therefore the incidence angle is reduced, which eases the melange effect happens due to large incidence angle. When rules (7) to (9) are satisfied, the total length of the imaging lenses  1 - 4  can be greatly shortened. In other words, if the above rules are not satisfied, the problem of poor chromatic difference of magnification and low imaging quality would arise; furthermore, the size of the lens cannot be miniature either. 
         [0058]    The detailed figures of the imaging lenses  1 - 4  of the first to the fourth preferred embodiments of the present invention are listed in Table 9. 
         [0000]    
       
         
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                   
                 TABLE 9 
               
               
                   
                   
               
               
                   
                 First 
                 Second 
                 Third 
                 Fourth 
               
               
                   
                 Preferred 
                 Preferred 
                 Preferred 
                 Preferred 
               
               
                   
                 Embodiment 
                 Embodiment 
                 Embodiment 
                 Embodiment 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                 f 
                 4.6 
                 4.08 
                 4.13 
                 4.2 
               
               
                 TTL 
                 5.4 
                 4.78 
                 4.8 
                 5 
               
               
                 IMH 
                 3.775 
                 3.7 
                 3.53 
                 3.7 
               
               
                 f1 
                 3.418 
                 3.14 
                 3.16 
                 3.54 
               
               
                 f2 
                 −6.382 
                 −5.66 
                 −5.54 
                 −6.58 
               
               
                 f3 
                 23.15 
                 18.26 
                 17.65 
                 16.14 
               
               
                 f4 
                 3.96 
                 3.16 
                 3.93 
                 3.16 
               
               
                 f5 
                 −2.845 
                 −2.31 
                 −2.85 
                 −2.29 
               
               
                 R1 
                 1.713 
                 1.515 
                 1.53 
                 1.63 
               
               
                 Vd1 
                 64.1 
                 64.1 
                 64.1 
                 63.3 
               
               
                 f1/f 
                 0.743 
                 0.769 
                 0.765 
                 0.842 
               
               
                 f2/f 
                 −1.387 
                 −1.387 
                 −1.341 
                 −1.566 
               
               
                 f3/f 
                 5.032 
                 4.475 
                 4.273 
                 3.842 
               
               
                 f4/f 
                 0.860 
                 0.774 
                 0.951 
                 0.752 
               
               
                 f5/f 
                 −0.618 
                 −0.566 
                 −0.690 
                 −0.545 
               
               
                 TTL/f 
                 1.173 
                 1.171 
                 1.162 
                 1.190 
               
               
                 IMH/TTL 
                 0.699 
                 0.7747 
                 0.735 
                 0.740 
               
               
                 f1/R 
                 1.995 
                 2.072 
                 2.065 
                 2.171 
               
               
                   
               
             
          
         
       
     
         [0059]    As shown in  FIG. 2A to 2D , the imaging lens  1  of the first preferred embodiment of the present invention is able to provide high imaging quality, wherein the maximum field curvature of the imaging lens  1  does not exceed −0.03 mm and 0.01 mm, which can be seen in  FIG. 2A ; the maximum distortion of the imaging lens  1  does not exceed −0.5% and 2.5%, which can be seen in  FIG. 2B ; the spherical aberration of the imaging lens  1  does not exceed −0.005 mm and 0.015 mm, which can be seen in  FIG. 2C ; the chromatic difference of magnification of the imaging lens  1  does not exceed −1 μm and 1.5 nm, which can be seen in  FIG. 2D . In other words, the imaging lens  1  provides high optical performance. 
         [0060]    Similarly, as shown in  FIG. 4A to 4D , the imaging lens  2  of the second preferred embodiment of the present invention is also able to provide high imaging quality, wherein the maximum field curvature of the imaging lens  2  does not exceed −0.01 mm and 0 mm, which can be seen in  FIG. 4A ; the maximum distortion of the imaging lens  2  does not exceed 0.5% and 2.5%, which can be seen in  FIG. 4B ; the spherical aberration of the imaging lens  2  does not exceed −0.04 mm and 0.015 mm, which can be seen in  FIG. 4C ; the chromatic difference of magnification of the imaging lens  2  does not exceed −1.5 nm and 1 μm, which can be seen in  FIG. 4D . In other words, the imaging lens  2  provides high optical performance. 
         [0061]    In addition, as shown in  FIG. 6A to 6D , the imaging lens  3  of the third preferred embodiment of the present invention is also able to provide high imaging quality, wherein the maximum field curvature of the imaging lens  3  does not exceed −0.06 mm and 0.01 mm, which can be seen in  FIG. 6A ; the maximum distortion of the imaging lens  3  does not exceed 0% and 3%, which can be seen in  FIG. 6B ; the spherical aberration of the imaging lens  3  does not exceed −0.005 mm and 0.02 mm, which can be seen in  FIG. 6C ; the chromatic difference of magnification of the imaging lens  3  does not exceed −2.5 nm and 1.5 nm, which can be seen in  FIG. 6D . In other words, the imaging lens  3  provides high optical performance. 
         [0062]    Finally, as shown in  FIG. 8A to 8D , the imaging lens  4  of the fourth preferred embodiment of the present invention is also able to provide high imaging quality, wherein the maximum field curvature of the imaging lens  4  does not exceed −0.04 mm and 0.04 mm, which can be seen in  FIG. 8A ; the maximum distortion of the imaging lens  4  does not exceed 0.5% and 2%, which can be seen in  FIG. 8B ; the spherical aberration of the imaging lens  4  does not exceed −0.015 mm and 0.02 mm, which can be seen in  FIG. 8C ; the chromatic difference of magnification of the imaging lens  4  does not exceed −1 μm and 1 μm, which can be seen in  FIG. 8D . In other words, the imaging lens  4  also provides high optical performance. 
         [0063]    In summary, with the imaging lenses  1 - 4  provided in the present invention, the purpose of getting miniature size and high optical performance can be effectively achieved. In addition, the visible angle of a wide angle system which uses any of the imaging lenses  1 - 4  can be broadened. 
         [0064]    It must be pointed out that the embodiments described above are only some preferred embodiments of the present invention. All equivalent structures which employ the concepts disclosed in this specification and the appended claims should fall within the scope of the present invention.