Abstract:
A five-piece optical lens system comprises, in order from the object side to the image side: a stop, a first lens element with a positive refractive power having a convex image-side surface, one of the object-side surface and an image-side surface being aspheric; a second lens element with a negative refractive power having a concave image-side surface, one of the object-side surface and an image-side surface being aspheric; a third lens element with a positive refractive power having a convex image-side surface, one of an object-side surface and the image-side surface being aspheric; a fourth lens element having a concave object-side surface, one of the object-side surface and an image-side surface being aspheric; a fifth lens element with a negative refractive power having a convex image-side surface, one of an object-side surface and the image-side surface being aspheric. The total track length of the system will not be too long.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to an optical lens system, and more particularly to a five-piece optical lens system. 
         [0003]    2. Description of the Prior Art 
         [0004]    In recent years, with the popularity of the mobile phone cameras, the optical lens system has become smaller in size, and the electronic sensor of a general digital camera is typically a CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor) sensor. Due to advances in semiconductor manufacturing, the pixel size of sensor has been reduced continuously, and miniaturized optical lens systems have increasingly higher resolution. Therefore, there&#39;s an increasing demand for an imaging lens system with better image quality. 
         [0005]    Conventional miniaturized lens systems used in portable electronic products mostly consist of four lens elements, however, the resolution of the mobile phone camera has been improved rapidly. As the pixel size of electronic imaging sensors gradually becomes smaller and smaller, the system requires higher image quality, and miniaturization and high performance have become the trend of modern electronic products. The conventional optical lens system comprising four lens elements cannot satisfy the requirements of higher resolution optical lens systems. 
         [0006]    The present invention mitigates and/or obviates the aforementioned disadvantages. 
       SUMMARY OF THE INVENTION 
       [0007]    The primary objective of the present invention is to provide a five-piece optical lens system capable of being applied to the electronic imaging sensors with high pixel sizes without make the total track length of the optical lens system too long. 
         [0008]    A five-piece optical lens system in accordance with the present invention comprises, in order from the object side to the image side: a stop; a first lens element with a positive refractive power having a convex image-side surface, at least one of an object-side and the image-side surfaces of the first lens element being aspheric; a second lens element with a negative refractive power having a concave image-side surface, at least one of an object-side and the image-side surfaces of the second lens element being aspheric; a third lens element with a positive refractive power having a convex image-side surface, at least one of an object-side and the image-side surfaces of the third lens element being aspheric; a fourth lens element having a concave object-side surface, at least one of the object-side and an image-side surfaces of the fourth lens element being aspheric; a fifth lens element with a negative refractive power having a convex image-side surface, at least one of an object-side and the image-side surfaces of the fifth lens element being aspheric. 
         [0009]    According to one aspect of the present invention five-piece optical lens system, the focal length of the first lens element is f1, the focal length of the second lens element is f2, and they satisfy the relation: 0.3&lt;|f1|/|f2|&lt;1.0. If |f1|/|f2| satisfies the above relation, a wide field of view can be provided and the resolution can be improved evidently. Contrarily, If ∥f1|/|f2| exceeds the above range, the performance and resolution of the optical lens system with a wide field of view will be reduced, and the yield rate will be low. 
         [0010]    According to another aspect of the present invention five-piece optical lens system, the focal length of the second lens element is f2, the focal length of the third lens element is f3, and they satisfy the relation: 0.5&lt;|f2|/|f3|&lt;2.2. If |f2|/|f3| satisfies the above relation, a wide field of view can be provided and the resolution can be improved evidently. Contrarily, If |f2|/|f3| exceeds the above range, the performance and resolution of the optical lens system with a wide field of view will be reduced, and the yield rate will be low. 
         [0011]    According to another aspect of the present invention five-piece optical lens system, the focal length of the third lens element is f3, the focal length of the fourth lens element is f4, and they satisfy the relation: |f3|/|f4|&lt;1.2. If |f3|/|f4| satisfies the above relation, a wide field of view can be provided and the resolution can be improved evidently. Contrarily, If |f3|/|f4| exceeds the above range, the performance and resolution of the optical lens system with a wide field of view will be reduced, and the yield rate will be low. 
         [0012]    According to another aspect of the present invention five-piece optical lens system, the focal length of the fourth lens element is f4, the focal length of the fifth lens element is f5, and they satisfy the relation: 1.0&lt;|f4|/|f5|&lt;5.5. If |f4|/|f5| satisfies the above relation, a wide field of view can be provided and the resolution can be improved evidently. Contrarily, If |f4|/|f5| exceeds the above range, the performance and resolution of the optical lens system with a wide field of view will be reduced, and the yield rate will be low. According to another aspect of the present invention five-piece optical lens system, the refractive index of the second lens element is N2, the Abbe number of the second lens element is V2, and they satisfy the relations: N2&gt;1.57; V2&lt;40. If N2 and V2 satisfy the above relations, the volume of the optical lens system can be reduced and the edge of an image can be effectively flattened, thus improving the image quality of the periphery of the image (namely, the limb darkening). In addition, the arrangement of the lens elements can make the optical lens system have a relatively short total track length and provide enough space for the IR cut filter. 
         [0013]    According to another aspect of the present invention five-piece optical lens system, the focal length of the first lens element is f1, the focal length of the second lens element, the third lens element, the fourth lens element and the fifth lens element combined is f2345, and they satisfy the relation: |f1|/|f2345|&lt;1.1. If |f1|/|f2345| satisfies the above relation, a wide field of view can be provided and the resolution can be improved evidently. Contrarily, If |f1|/|f2345| exceeds the above range, the performance and resolution of the optical lens system with a wide field of view will be reduced, and the yield rate will be low. 
         [0014]    According to another aspect of the present invention five-piece optical lens system, the focal length of the first lens element and the second lens element combined is f12, the focal length of the third lens element, the fourth lens element and the fifth lens element combined is f345, and they satisfy the relation: |f12|/|f345|&lt;2.5. If |f12|/|f345| satisfies the above relation, a wide field of view can be provided and the resolution can be improved evidently. Contrarily, If |f12|/|f345| exceeds the above range, the performance and resolution of the optical lens system with a wide field of view will be reduced, and the yield rate will be low. 
         [0015]    According to another aspect of the present invention five-piece optical lens system, the focal length of the first lens element, the second lens element and the third lens element combined is f123, the focal length of the fourth lens element and the fifth lens element combined is f45, and they satisfy the relation: |f123|/|f45|&lt;1.2. If |f123|/|f45| satisfies the above relation, a wide field of view can be provided and the resolution can be improved evidently. Contrarily, If |f123|/|f45| exceeds the above range, the performance and resolution of the optical lens system with a wide field of view will be reduced, and the yield rate will be low. 
         [0016]    According to another aspect of the present invention five-piece optical lens system, the focal length of the five-piece optical lens system is f, the distance between the object-side surface of the first lens element and the image plane is TL, and they satisfy the relation: 0.5&lt;|f/TL|&lt;0.9. If |f/TL| satisfies the above relation, the total track length of the optical lens system can be relatively short, and the requirement of miniaturization can be satisfied. 
         [0017]    The present invention will be presented in further details from the following descriptions with the accompanying drawings, which show, for purpose of illustrations only, the preferred embodiments in accordance with the present invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]      FIG. 1A  shows an optical lens system in accordance with a first embodiment of the present invention; 
           [0019]      FIG. 1B  shows the longitudinal spherical aberration curve, the astigmatic field curve, and the distortion curve of the first embodiment of the present invention; 
           [0020]      FIG. 2A  shows an optical lens system in accordance with a second embodiment of the present invention; 
           [0021]      FIG. 2B  shows the longitudinal spherical aberration curve, the astigmatic field curve, and the distortion curve of the second embodiment of the present invention; 
           [0022]      FIG. 3A  shows an optical lens system in accordance with a third embodiment of the present invention; 
           [0023]      FIG. 3B  shows the longitudinal spherical aberration curve, the astigmatic field curve, and the distortion curve of the third embodiment of the present invention; 
           [0024]      FIG. 4A  shows an optical lens system in accordance with a fourth embodiment of the present invention; and 
           [0025]      FIG. 4B  shows the longitudinal spherical aberration curve, the astigmatic field curve, and the distortion curve of the fourth embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0026]    Referring to  FIG. 1A , which shows a five-piece optical lens system in accordance with a first embodiment of the present invention, and  FIG. 1B  shows the longitudinal spherical aberration curves, the astigmatic field curves, and the distortion curve of the first embodiment of the present invention. A five-piece optical lens system in accordance with the first embodiment of the present invention comprises, in order from the object side A to the image side B: 
         [0027]    A stop  100 . 
         [0028]    A first lens element  110  with a positive refractive power made of plastic has a convex object-side surface  111  and a convex image-side surface  112 , and the object-side surface  111  and the image-side surface  112  of the first lens element  110  are aspheric. 
         [0029]    A second lens element  120  with a negative refractive power made of plastic has a convex object-side surface  121  and a concave image-side surface  122 , and the object-side surface  121  and the image-side surface  122  of the second lens element  120  are aspheric. 
         [0030]    A third lens element  130  with a positive refractive power made of plastic has a concave object-side surface  131  and a convex image-side surface  132 , and the object-side surface  131  and the image-side surface  132  of the third lens element  130  are aspheric. 
         [0031]    A fourth lens element  140  with a negative refractive power made of plastic has a concave object-side surface  141  and a convex image-side surface  142 , and the object-side surface  141  and the image-side surface  142  of the fourth lens element  140  are aspheric. 
         [0032]    A fifth lens element  150  with a negative refractive power made of plastic has a convex object-side surface  151  and a concave image-side surface  152 , and the object-side surface  151  and the image-side surface  152  of the fifth lens element  150  are aspheric. 
         [0033]    An IR cut filter  160  made of glass is located between the image-side surface  152  of the fifth lens element  150  and an image plane  170  and has no influence on the focal length of the five-piece optical lens system. 
         [0034]    The equation for the aspheric surface profiles of the first embodiment is expressed as follows: 
         [0000]    
       
         
           
             z 
             = 
             
               
                 
                   ch 
                   2 
                 
                 
                   1 
                   + 
                   
                     
                       [ 
                       
                         1 
                         - 
                         
                           
                             ( 
                             
                               k 
                               + 
                               1 
                             
                             ) 
                           
                            
                           
                             c 
                             2 
                           
                            
                           
                             h 
                             2 
                           
                         
                       
                       ] 
                     
                     0.5 
                   
                 
               
               + 
               
                 A 
                  
                 
                     
                 
                  
                 
                   h 
                   4 
                 
               
               + 
               
                 Bh 
                 6 
               
               + 
               
                 Ch 
                 8 
               
               + 
               
                 Dh 
                 10 
               
               + 
               
                 Eh 
                 12 
               
               + 
               
                 Gh 
                 14 
               
               + 
               … 
             
           
         
       
     
         [0035]    wherein: 
         [0036]    z represents the value of a reference position with respect to a vertex of the surface of a lens and a position with a height h along the optical axis  180   
         [0037]    k represents the conic constant; 
         [0038]    c represents the reciprocal of the radius of curvature; 
         [0039]    A, B, C, D, E, G, . . . : represent the high-order aspheric coefficients. 
         [0040]    In the first embodiment of the present optical lens system, the focal length of the five-piece optical lens system is f, and it satisfies the relation: 
         [0000]        f= 3.69. 
         [0041]    In the first embodiment of the present five-piece optical lens system, the f-number of the five-piece optical lens system is Fno, and it satisfies the relation: 
         [0000]        Fno= 2.2. 
         [0042]    In the first embodiment of the present five-piece optical lens system, the field of view of the optical lens system is 2ω, and it satisfies the relation: 
         [0000]      2ω=75°.
 
         [0043]    In the first embodiment of the present five-piece optical lens system, the refractive index of the second lens element  120  is N2, the Abbe number of the second lens element  120  is V2, and they satisfy the relations: 
         [0000]        N 2=1.632; 
         [0000]        V 2=23. 
         [0044]    In the first embodiment of the present five-piece optical lens system, the focal length of the first lens element  110  is f1, the focal length of the second lens element  120  is f2, and they satisfy the relation: 
         [0000]      | f 1 |/|f 2|=0.5141. 
         [0045]    In the first embodiment of the present five-piece optical lens system, the focal length of the second lens element  120  is f2, the focal length of the third lens element  130  is f3, and they satisfy the relation: 
         [0000]      | f 2 |/|f 3|=1.8163. 
         [0046]    In the first embodiment of the present five-piece optical lens system, the focal length of the third lens element  130  is f3, the focal length of the fourth lens element  140  is f4, and they satisfy the relation: 
         [0000]      | f 3 |/|f 4|=0.2049. 
         [0047]    In the first embodiment of the present five-piece optical lens system, the focal length of the fourth lens element  140  is f4, the focal length of the fifth lens element  150  is f5, and they satisfy the relation: 
         [0000]      | f 4 |/|f 5|=3.9554. 
         [0048]    In the first embodiment of the present five-piece optical lens system, the focal length of the first lens element  110  is f1, the focal length of the second lens element  120 , the third lens element  130 , the fourth lens element  140  and the fifth lens element  150  combined is f2345, and they satisfy the relation: 
         [0000]      | f 1 |/|f 2345|=0.5012. 
         [0049]    In the first embodiment of the present five-piece optical lens system, the focal length of the first lens element  110  and the second lens element  120  combined is f12, the focal length of the third lens element  130 , the fourth lens element  140  and the fifth lens element  150  combined is f345, and they satisfy the relation: 
         [0000]      | f 12 |/|f 345|=0.1175. 
         [0050]    In the first embodiment of the present five-piece optical lens system, the focal length of the first lens element  110 , the second lens element  120  and the third lens element  130  combined is f123, the focal length of the fourth lens element  140  and the fifth lens element  150  combined is f45, and they satisfy the relation: 
         [0000]      | f 123 |/|f 45|=0.9422. 
         [0051]    In the first embodiment of the present five-piece optical lens system, the focal length of the five-piece optical lens system is f, the distance between the object-side surface  111  of the first lens element  110  and the image plane  170  is TL, and they satisfy the relation: 
         [0000]      | f/TL|= 0.7432. 
         [0052]    The detailed optical data of the first embodiment is shown in table 1, and the aspheric surface data is shown in table 2, wherein the units of the radius of curvature, the thickness and the focal length are expressed in mm. In the tables 1 and 2, the surfaces 2 and 3 represent the object-side surface  111  and the image-side surface  112  of the first lens element  110 , respectively, the surfaces 4 and 5 represent the object-side surface  121  and the image-side surface  122  of the second lens element  120 , respectively, the surfaces 6 and 7 represent the object-side surface  131  and the image-side surface  132  of the third lens element  130 , respectively, the surfaces 8 and 9 represent the object-side surface  141  and the image-side surface  142  of the fourth lens element  140 , respectively, and the surfaces 10 and 11 represent the object-side surface  151  and the image-side surface  152  of the fifth lens element  150 , respectively. 
         [0000]    
       
         
               
             
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
             
           
               
                 TABLE 1 
               
             
             
               
                   
               
               
                 (Embodiment 1) 
               
               
                 f(focal length) = 3.69 mm, Fno = 2.2, 2ω = 75°. 
               
             
          
           
               
                 Surface # 
                   
                 Curvature Radius 
                 Thickness 
                 Material 
                 nd 
                 vd 
               
               
                   
               
             
          
           
               
                 0 
                 Object 
                 Infinity 
                 Infinity 
                   
                   
                   
               
               
                 1 
                 Stop 
                 Infinity 
                 0 
               
               
                 2 
                 Lens 1 
                 2.845499(ASP) 
                 0.997785 
                 Plastic 
                 1.535 
                 56 
               
               
                 3 
                   
                 −2.69737(ASP) 
                 0.031718 
               
               
                 4 
                 Lens 2 
                 4.709608(ASP) 
                 0.314456 
                 Plastic 
                 1.632 
                 23 
               
               
                 5 
                   
                 1.928305(ASP) 
                 0.615746 
               
               
                 6 
                 Lens 3 
                 −2.42354(ASP) 
                 0.740778 
                 Plastic 
                 1.535 
                 56 
               
               
                 7 
                   
                 −1.05964(ASP) 
                 0.034467 
               
               
                 8 
                 Lens 4 
                 −7.75401(ASP) 
                 0.406171 
                 Plastic 
                 1.632 
                 23 
               
               
                 9 
                   
                 −51.0272(ASP) 
                 0.041449 
               
               
                 10 
                 Lens 5 
                 1.901796(ASP) 
                 0.439878 
                 Plastic 
                 1.535 
                 56 
               
               
                 11 
                   
                 0.885483(ASP) 
                 0.40108 
               
               
                 12 
                 IR-filter 
                 Infinity 
                 0.21 
                 Glass 
                 1.5168 
                 64.167336 
               
               
                 13 
                   
                 Infinity 
                 0.73961 
               
               
                 14 
                 Image 
                 Infinity 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 2 
               
               
                   
               
               
                 Aspheric Coefficients 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 Surface # 
                 2 
                 3 
                 4 
                 5 
                 6 
               
               
                   
               
               
                 k = 
                 −5.55074 
                 0.954687 
                 11.89479 
                 −1.77103 
                 −8.48652 
               
               
                 A = 
                 −0.011793128 
                 −0.083408296 
                 −0.14644683 
                 −0.035648 
                 −0.008497149 
               
               
                 B = 
                 −0.008997465 
                 0.095396616 
                 0.103507 
                 0.001351734 
                 0.039390254 
               
               
                 C = 
                 −0.035703717 
                 −0.054189771 
                 −0.004745912 
                 0.042839424 
                 −0.023223567 
               
               
                 D = 
                 0.01 
                 0.002863388 
                 −0.013769836 
                 −0.015519036 
                 0.005723045 
               
               
                   
               
               
                 Surface # 
                 7 
                 8 
                 9 
                 10 
                 11 
               
               
                   
               
               
                 k = 
                 −2.80434 
                 −983.984 
                 678.4531 
                 −36.9833 
                 −5.76633 
               
               
                 A = 
                 0.00171236 
                 0.0365087 
                 0.0285167 
                 −0.06893151 
                 −0.065707402 
               
               
                 B = 
                 −0.021513569 
                 −0.039028705 
                 −0.031668274 
                 0.00010119 
                 0.014496323 
               
               
                 C = 
                 0.021212353 
                 0.007040743 
                 0.003283609 
                 0.00324649 
                 −0.001738823 
               
               
                 D = 
                 −0.00356209 
                 −0.000934125 
                 0.000413163 
                 −0.000308073 
                 4.28E−05 
               
               
                   
               
             
          
         
       
     
         [0053]    Referring to  FIG. 2A , which shows a five-piece optical lens system in accordance with a second embodiment of the present invention, and  FIG. 2B  shows the longitudinal spherical aberration curves, the astigmatic field curves, and the distortion curve of the second embodiment of the present invention. The second embodiment of the present invention comprises, in order from the object side A to the image side B: 
         [0054]    A stop  200 . 
         [0055]    A first lens element  210  with a positive refractive power made of plastic has a convex object-side surface  211  and a convex image-side surface  212 , and the object-side surface  211  and the image-side surface  212  of the first lens element  210  are aspheric. 
         [0056]    A second lens element  220  with a negative refractive power made of plastic has a convex object-side surface  221  and a concave image-side surface  222 , and the object-side surface  221  and the image-side surface  222  of the second lens element  220  are aspheric. 
         [0057]    A third lens element  230  with a positive refractive power made of plastic has a concave object-side surface  231  and a convex image-side surface  232 , and the object-side surface  231  and the image-side surface  232  of the third lens element  230  are aspheric. 
         [0058]    A fourth lens element  240  with a negative refractive power made of plastic has a concave object-side surface  241  and a convex image-side surface  242 , and the object-side surface  241  and the image-side surface  242  of the fourth lens element  240  are aspheric. 
         [0059]    A fifth lens element  250  with a negative refractive power made of plastic has a convex object-side surface  251  and a concave image-side surface  252 , and the object-side surface  251  and the image-side surface  252  of the fifth lens element  250  are aspheric. 
         [0060]    An IR cut filter  260  made of glass is located between the image-side surface  252  of the fifth lens element  250  and an image plane  270  and has no influence on the focal length of the five-piece optical lens system. 
         [0061]    The equation for the aspheric surface profiles of the second embodiment is expressed as follows: 
         [0000]    
       
         
           
             z 
             = 
             
               
                 
                   ch 
                   2 
                 
                 
                   1 
                   + 
                   
                     
                       [ 
                       
                         1 
                         - 
                         
                           
                             ( 
                             
                               k 
                               + 
                               1 
                             
                             ) 
                           
                            
                           
                             c 
                             2 
                           
                            
                           
                             h 
                             2 
                           
                         
                       
                       ] 
                     
                     0.5 
                   
                 
               
               + 
               
                 A 
                  
                 
                     
                 
                  
                 
                   h 
                   4 
                 
               
               + 
               
                 Bh 
                 6 
               
               + 
               
                 Ch 
                 8 
               
               + 
               
                 Dh 
                 10 
               
               + 
               
                 Eh 
                 12 
               
               + 
               
                 Gh 
                 14 
               
               + 
               … 
             
           
         
       
     
         [0062]    wherein: 
         [0063]    z represents the value of a reference position with respect to a vertex of the surface of a lens and a position with a height h along the optical axis  280 ; 
         [0064]    k represents the conic constant; 
         [0065]    c represents the reciprocal of the radius of curvature; 
         [0066]    A, B, C, D, E, G, . . . : represent the high-order aspheric coefficients. 
         [0067]    In the second embodiment of the present five-piece optical lens system, the focal length of the five-piece optical lens system is f, and it satisfies the relation: 
         [0000]        f= 2.86. 
         [0068]    In the second embodiment of the present five-piece optical lens system, the f-number of the five-piece optical lens system is Fno, and it satisfies the relation: 
         [0000]        Fno= 2.4. 
         [0069]    In the second embodiment of the present five-piece optical lens system, the field of view of the five-piece optical lens system is 2ω, and it satisfies the relation: 
         [0000]      2ω=90°.
 
         [0070]    In the second embodiment of the present five-piece optical lens system, the refractive index of the second lens element  220  is N2, the Abbe number of the second lens element  220  is V2, and they satisfy the relations: 
         [0000]        N 2=1.632; 
         [0000]        V 2=23. 
         [0071]    In the second embodiment of the present five-piece optical lens system, the focal length of the first lens element  210  is f1, the focal length of the second lens element  220  is f2, and they satisfy the relation: 
         [0000]      | f 1 |/|f 2|=0.5715. 
         [0072]    In the second embodiment of the present five-piece optical lens system, the focal length of the second lens element  220  is f2, the focal length of the third lens element  230  is f3, and they satisfy the relation: 
         [0000]      | f 2 |/|f 3|=1.0748. 
         [0073]    In the second embodiment of the present five-piece optical lens system, the focal length of the third lens element  230  is f3, the focal length of the fourth lens element  240  is f4, and they satisfy the relation: 
         [0000]      | f 3 |/|f 4|=0.0627. 
         [0074]    In the second embodiment of the present five-piece optical lens system, the focal length of the fourth lens element  240  is f4, the focal length of the fifth lens element  250  is f5, and they satisfy the relation: 
         [0000]      | f 4 |/|f 5|=5.4373. 
         [0075]    In the second embodiment of the present five-piece optical lens system, the focal length of the first lens element  210  is f1, the focal length of the second lens element  220 , the third lens element  230 , the fourth lens element  240  and the fifth lens element  250  combined is f2345, and they satisfy the relation: 
         [0000]      | f 1 |/|f 2345|=0.0890. 
         [0076]    In the second embodiment of the present five-piece optical lens system, the focal length of the first lens element  210  and the second lens element  220  combined is f12, the focal length of the third lens element  230 , the fourth lens element  240  and the fifth lens element  250  combined is f345, and they satisfy the relation: 
         [0000]      | f 12 |/|f 345|=0.8478. 
         [0077]    In the second embodiment of the present five-piece optical lens system, the focal length of the first lens element  210 , the second lens element  220  and the third lens element  230  combined is f123, the focal length of the fourth lens element  240  and the fifth lens element  250  combined is f45, and they satisfy the relation: 
         [0000]      | f 123 |/|f 45|=0.2889. 
         [0078]    In the second embodiment of the present five-piece optical lens system, the focal length of the five-piece optical lens system is f, the distance between the object-side surface  211  of the first lens element  210  and the image plane  270  is TL, and they satisfy the relation: 
         [0000]      | f/TL|= 0.6526. 
         [0079]    The detailed optical data of the second embodiment is shown in table 3, and the aspheric surface data is shown in table 4, wherein the units of the radius of curvature, the thickness and the focal length are expressed in mm. In the tables 3 and 4, the surfaces 2 and 3 represent the object-side surface  211  and the image-side surface  212  of the first lens element  210 , respectively, the surfaces 4 and 5 represent the object-side surface  221  and the image-side surface  222  of the second lens element  220 , respectively, the surfaces 6 and 7 represent the object-side surface  231  and the image-side surface  232  of the third lens element  230 , respectively, the surfaces 8 and 9 represent the object-side surface  241  and the image-side surface  242  of the fourth lens element  240 , respectively, and the surfaces 10 and 11 represent the object-side surface  251  and the image-side surface  252  of the fifth lens element  250 , respectively. 
         [0000]    
       
         
               
             
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
             
           
               
                 TABLE 3 
               
             
             
               
                   
               
               
                 (Embodiment 2) 
               
               
                 f(focal length) = 2.86 mm, Fno = 2.4, 2ω = 90°. 
               
             
          
           
               
                 Surface # 
                   
                 Curvature Radius 
                 Thickness 
                 Material 
                 nd 
                 vd 
               
               
                   
               
             
          
           
               
                 0 
                 Object 
                 Infinity 
                 Infinity 
                   
                   
                   
               
               
                 1 
                 Stop 
                 Infinity 
                 0 
               
               
                 2 
                 Lens 1 
                 5.302978(ASP) 
                 0.643614 
                 Plastic 
                 1.535 
                 56 
               
               
                 3 
                   
                  −1.7093(ASP) 
                 0.039299 
               
               
                 4 
                 Lens 2 
                 5.376636(ASP) 
                 0.314262 
                 Plastic 
                 1.632 
                 23 
               
               
                 5 
                   
                 1.789442(ASP) 
                 0.4664 
               
               
                 6 
                 Lens 3 
                 −1.80154(ASP) 
                 0.601153 
                 Plastic 
                 1.535 
                 56 
               
               
                 7 
                   
                 −1.10007(ASP) 
                 0.032245 
               
               
                 8 
                 Lens 4 
                 −21.0133(ASP) 
                 0.339737 
                 Plastic 
                 1.531 
                 56 
               
               
                 9 
                   
                 −54.2549(ASP) 
                 0.033159 
               
               
                 10 
                 Lens 5 
                 1.077954(ASP) 
                 0.401075 
                 Plastic 
                 1.535 
                 56 
               
               
                 11 
                   
                 0.802195(ASP) 
                 0.602516 
               
               
                 12 
                 IR-filter 
                 Infinity 
                 0.3 
                 Glass 
                 1.5168 
                 64.167336 
               
               
                 13 
                   
                 Infinity 
                 0.559663 
               
               
                 14 
                 Image 
                 Infinity 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 4 
               
               
                   
               
               
                 Aspheric Coefficients 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 Surface # 
                 2 
                 3 
                 4 
                 5 
                 6 
               
               
                   
               
               
                 k = 
                 −41.4247 
                 2.269337 
                 9.09726 
                 −4.006414 
                 −6.610414 
               
               
                 A = 
                 −0.07333 
                 −0.029 
                 −0.16214 
                 −0.03565 
                 0.015736 
               
               
                 B = 
                 −0.12601 
                 0.072435 
                 0.128747 
                 0.015702 
                 0.077466 
               
               
                 C = 
                 −0.00675 
                 0.008939 
                 0.033801 
                 0.029103 
                 −0.02719 
               
               
                 D = 
                 −0.12047 
                 0.002318 
                 −0.05082 
                 −0.01822 
                 −4.95E−05 
               
               
                   
               
               
                 Surface # 
                 7 
                 8 
                 9 
                 10 
                 11 
               
               
                   
               
               
                 k = 
                 −2.54577 
                 158.8585 
                 795.8416 
                 −1.89099 
                 −2.26909 
               
               
                 A = 
                 −0.02006 
                 0.104513 
                 0.056716 
                 −0.10487 
                 −0.08117 
               
               
                 B = 
                 −0.0025 
                 −0.05751 
                 −0.02952 
                 0.000611 
                 0.011376 
               
               
                 C = 
                 0.035194 
                 0.012452 
                 0.00253 
                 0.003743 
                 −0.00043 
               
               
                 D = 
                 −0.008 
                 −0.00147 
                 0.000352 
                 −0.00035 
                 −6.37E−05 
               
               
                   
               
             
          
         
       
     
         [0080]    Referring to  FIG. 3A , which shows a five-piece optical lens system in accordance with a third embodiment of the present invention, and  FIG. 3B  shows the longitudinal spherical aberration curves, the astigmatic field curves, and the distortion curve of the third embodiment of the present invention. The third embodiment of the present invention comprises, in order from the object side A to the image side B: 
         [0081]    A stop  300 . 
         [0082]    A first lens element  310  with a positive refractive power made of plastic has a convex object-side surface  311  and a convex image-side surface  312 , and the object-side surface  311  and the image-side surface  312  of the first lens element  310  are aspheric. 
         [0083]    A second lens element  320  with a negative refractive power made of plastic has a concave object-side surface  321  and a concave image-side surface  322 , and the object-side surface  321  and the image-side surface  322  of the second lens element  320  are aspheric. 
         [0084]    A third lens element  330  with a positive refractive power made of plastic has a concave object-side surface  331  and a convex image-side surface  332 , and the object-side surface  331  and the image-side surface  332  of the third lens element  330  are aspheric. 
         [0085]    A fourth lens element  340  with a negative refractive power made of plastic has a concave object-side surface  341  and a convex image-side surface  342 , and the object-side surface  341  and the image-side surface  342  of the fourth lens element  340  are aspheric. 
         [0086]    A fifth lens element  350  with a negative refractive power made of plastic has a convex object-side surface  351  and a concave image-side surface  352 , and the object-side surface  351  and the image-side surface  352  of the fifth lens element  350  are aspheric. 
         [0087]    An IR cut filter  360  made of glass is located between the image-side surface  352  of the fifth lens element  350  and an image plane  370  and has no influence on the focal length of the optical lens system. 
         [0088]    A cover glass  390  made of glass is located between the IR cut filter  360  and the image plane  370  to protect a sensor (not shown), and has no influence on the focal length of the five-piece optical lens system. 
         [0089]    The equation for the aspheric surface profiles of the third embodiment is expressed as follows: 
         [0000]    
       
         
           
             z 
             = 
             
               
                 
                   ch 
                   2 
                 
                 
                   1 
                   + 
                   
                     
                       [ 
                       
                         1 
                         - 
                         
                           
                             ( 
                             
                               k 
                               + 
                               1 
                             
                             ) 
                           
                            
                           
                             c 
                             2 
                           
                            
                           
                             h 
                             2 
                           
                         
                       
                       ] 
                     
                     0.5 
                   
                 
               
               + 
               
                 A 
                  
                 
                     
                 
                  
                 
                   h 
                   4 
                 
               
               + 
               
                 Bh 
                 6 
               
               + 
               
                 Ch 
                 8 
               
               + 
               
                 Dh 
                 10 
               
               + 
               
                 Eh 
                 12 
               
               + 
               
                 Gh 
                 14 
               
               + 
               … 
             
           
         
       
     
         [0090]    wherein: 
         [0091]    z represents the value of a reference position with respect to a vertex of the surface of a lens and a position with a height h along the optical axis  380 ; 
         [0092]    k represents the conic constant; 
         [0093]    c represents the reciprocal of the radius of curvature; 
         [0094]    A, B, C, D, E, G, . . . : represent the high-order aspheric coefficients. 
         [0095]    In the third embodiment of the present five-piece optical lens system, the focal length of the five-piece optical lens system is f, and it satisfies the relation: 
         [0000]        f= 5.63. 
         [0096]    In the third embodiment of the present five-piece optical lens system, the f-number of the five-piece optical lens system is Fno, and it satisfies the relation: 
         [0000]        Fno= 2.8. 
         [0097]    In the third embodiment of the present five-piece optical lens system, the field of view of the five-piece optical lens system is 2ω, and it satisfies the relation: 
         [0000]      2ω=68°.
 
         [0098]    In the third embodiment of the present five-piece optical lens system, the refractive index of the second lens element  320  is N2, the Abbe number of the second lens element  320  is V2, and they satisfy the relations: 
         [0000]        N 2=1.607; 
         [0000]        V 2=27. 
         [0099]    In the third embodiment of the present five-piece optical lens system, the focal length of the first lens element  310  is f1, the focal length of the second lens element  320  is f2, and they satisfy the relation: 
         [0000]      | f 1 |/|f 2|=0.6079. 
         [0100]    In the third embodiment of the present five-piece optical lens system, the focal length of the second lens element  320  is f2, the focal length of the third lens element  330  is f3, and they satisfy the relation: 
         [0000]      | f 2 |/|f 3|=0.6935. 
         [0101]    In the third embodiment of the present five-piece optical lens system, the focal length of the third lens element  330  is f3, the focal length of the fourth lens element  340  is f4, and they satisfy the relation: 
         [0000]      | f 3 |/|f 4|=0.2579. 
         [0102]    In the third embodiment of the present five-piece optical lens system, the focal length of the fourth lens element  340  is f4, the focal length of the fifth lens element  350  is f5, and they satisfy the relation: 
         [0000]      | f 4 |/|f 5|=3.8177. 
         [0103]    In the third embodiment of the present five-piece optical lens system, the focal length of the first lens element  310  is f1, the focal length of the second lens element  320 , the third lens element  330 , the fourth lens element  340  and the fifth lens element  350  combined is f2345, and they satisfy the relation: 
         [0000]      | f 1 |/|f 2345|=0.7966. 
         [0104]    In the third embodiment of the present five-piece optical lens system, the focal length of the first lens element  310  and the second lens element  320  combined is f12, the focal length of the third lens element  330 , the fourth lens element  340  and the fifth lens element  350  combined is f345, and they satisfy the relation: 
         [0000]      | f 12 |/|f 345|=0.1362. 
         [0105]    In the third embodiment of the present five-piece optical lens system, the focal length of the first lens element  310 , the second lens element  320  and the third lens element  330  combined is f123, the focal length of the fourth lens element  340  and the fifth lens element  350  combined is f45, and they satisfy the relation: 
         [0000]      | f 123 |/|f 45|=0.7710. 
         [0106]    In the third embodiment of the present five-piece optical lens system, the focal length of the five-piece optical lens system is f, the distance between the object-side surface  311  of the first lens element  310  and the image plane  370  is TL, and they satisfy the relation: 
         [0000]      | f/TL|= 0.8014. 
         [0107]    The detailed optical data of the third embodiment is shown in table 5, and the aspheric surface data is shown in table 6, wherein the units of the radius of curvature, the thickness and the focal length are expressed in mm. In the tables 5 and 6, the surfaces 2 and 3 represent the object-side surface  311  and the image-side surface  312  of the first lens element  310 , respectively, the surfaces 4 and 5 represent the object-side surface  321  and the image-side surface  322  of the second lens element  320 , respectively, the surfaces 6 and 7 represent the object-side surface  331  and the image-side surface  332  of the third lens element  330 , respectively, the surfaces 8 and 9 represent the object-side surface  341  and the image-side surface  342  of the fourth lens element  340 , respectively, and the surfaces 10 and 11 represent the object-side surface  351  and the image-side surface  352  of the fifth lens element  350 , respectively. 
         [0000]    
       
         
               
             
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
             
           
               
                 TABLE 5 
               
             
             
               
                   
               
               
                 (Embodiment 3) 
               
               
                 f(focal length) = 5.63 mm, Fno = 2.8, 2ω = 68°. 
               
             
          
           
               
                 Surface # 
                   
                 Curvature Radius 
                 Thickness 
                 Material 
                 nd 
                 vd 
               
               
                   
               
             
          
           
               
                 0 
                 Object 
                 Infinity 
                 Infinity 
                   
                   
                   
               
               
                 1 
                 Stop 
                 Infinity 
                 0.06 
               
               
                 2 
                 Lens 1 
                 2.934507(ASP) 
                 1.251576 
                 Plastic 
                 1.531 
                 56 
               
               
                 3 
                   
                 −3.65097(ASP) 
                 0.057732 
               
               
                 4 
                 Lens 2 
                 −43.3973(ASP) 
                 0.387851 
                 Plastic 
                 1.607 
                 27 
               
               
                 5 
                   
                  3.57248(ASP) 
                 0.77182 
               
               
                 6 
                 Lens 3 
                 −2.35536(ASP) 
                 0.73188 
                 Plastic 
                 1.514 
                 57 
               
               
                 7 
                   
                 −1.63916(ASP) 
                 0.06 
               
               
                 8 
                 Lens 4 
                 −13.3022(ASP) 
                 0.563425 
                 Plastic 
                 1.607 
                 27 
               
               
                 9 
                   
                 −48.8062(ASP) 
                 0.518976 
               
               
                 10 
                 Lens 5 
                 2.022648(ASP) 
                 0.602701 
                 Plastic 
                 1.531 
                 56 
               
               
                 11 
                   
                 1.223396(ASP) 
                 0.542734 
               
               
                 12 
                 IR-filter 
                 Infinity 
                 0.3 
                 Glass 
                 1.5168 
                 64.167336 
               
               
                 13 
                   
                 Infinity 
                 0.726281 
               
               
                 14 
                 Cover 
                 Infinity 
                 0.4 
                 Glass 
                 1.5168 
                 64.167336 
               
               
                 15 
                 Glass 
                 Infinity 
                 0.048205 
               
               
                 16 
                 Image 
                 Infinity 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 6 
               
               
                   
               
               
                 Aspheric Coefficients 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 Surface # 
                 2 
                 3 
                 4 
                 5 
                 6 
               
               
                   
               
               
                 k = 
                 −1.79007 
                 1.014251 
                 −428.018 
                 −0.07654 
                 −1.02436 
               
               
                 A = 
                 −0.00032 
                 −0.01208 
                 −0.01579 
                 −0.00687 
                 0.003291 
               
               
                 B = 
                 −0.00693 
                 −0.00579 
                 0.004587 
                 0.005291 
                 0.004976 
               
               
                 C = 
                 −8.09E−05 
                 −0.00022 
                 −0.00098 
                 0.001016 
                 0.002467 
               
               
                 D = 
                 −0.00167 
                 −0.00027 
                 0.000855 
                 −0.00019 
                 −9.62E−05 
               
               
                   
               
               
                 Surface # 
                 7 
                 8 
                 9 
                 10 
                 11 
               
               
                   
               
               
                 k = 
                 −1.05811 
                 −839.609 
                 404.1097 
                 −19.4234 
                 −6.13598 
               
               
                 A = 
                 0.031569 
                 0.006125 
                 −0.00032 
                 −0.03519 
                 −0.02203 
               
               
                 B = 
                 −0.00248 
                 −0.00524 
                 −0.00258 
                 0.00092 
                 0.001276 
               
               
                 C = 
                 0.000812 
                 0.000187 
                 −4.13E−05 
                 0.000291 
                 −3.48E−05 
               
               
                 D = 
                 0.000343 
                 −3.59E−05 
                  4.00E−05 
                 −1.59E−05 
                 −2.40E−06 
               
               
                   
               
             
          
         
       
     
         [0108]    Referring to  FIG. 4A , which shows a five-piece optical lens system in accordance with a fourth embodiment of the present invention, and  FIG. 4B  shows the longitudinal spherical aberration curves, the astigmatic field curves, and the distortion curve of the fourth embodiment of the present invention. The fourth embodiment of the present invention comprises, in order from the object side A to the image side B: 
         [0109]    A stop  400 . 
         [0110]    A first lens element  410  with a positive refractive power made of plastic has a convex object-side surface  411  and a convex image-side surface  412 , and the object-side surface  411  and the image-side surface  412  of the first lens element  410  are aspheric. 
         [0111]    A second lens element  420  with a negative refractive power made of plastic has a convex object-side surface  421  and a concave image-side surface  422 , and the object-side surface  421  and the image-side surface  422  of the second lens element  420  are aspheric. 
         [0112]    A third lens element  430  with a positive refractive power made of plastic has a convex object-side surface  431  and a concave image-side surface  432 , and the object-side surface  431  and the image-side surface  432  of the third lens element  430  are aspheric. 
         [0113]    A fourth lens element  440  with a positive refractive power made of plastic has a concave object-side surface  441  and a convex image-side surface  442 , and the object-side surface  441  and the image-side surface  442  of the fourth lens element  440  are aspheric. 
         [0114]    A fifth lens element  450  with a negative refractive power made of plastic has a convex object-side surface  451  and a concave image-side surface  452 , and the object-side surface  451  and the image-side surface  452  of the fifth lens element  450  are aspheric. 
         [0115]    An IR cut filter  460  made of glass is located between the image-side surface  452  of the fifth lens element  450  and an image plane  470  and has no influence on the focal length of the optical lens system. 
         [0116]    A cover glass  490  made of glass is located between the IR cut filter  460  and the image plane  470  to protect a sensor (not shown), and has no influence on the focal length of the five-piece optical lens system. 
         [0117]    The equation for the aspheric surface profiles of the fourth embodiment is expressed as follows: 
         [0000]    
       
         
           
             z 
             = 
             
               
                 
                   ch 
                   2 
                 
                 
                   1 
                   + 
                   
                     
                       [ 
                       
                         1 
                         - 
                         
                           
                             ( 
                             
                               k 
                               + 
                               1 
                             
                             ) 
                           
                            
                           
                             c 
                             2 
                           
                            
                           
                             h 
                             2 
                           
                         
                       
                       ] 
                     
                     0.5 
                   
                 
               
               + 
               
                 A 
                  
                 
                     
                 
                  
                 
                   h 
                   4 
                 
               
               + 
               
                 Bh 
                 6 
               
               + 
               
                 Ch 
                 8 
               
               + 
               
                 Dh 
                 10 
               
               + 
               
                 Eh 
                 12 
               
               + 
               
                 Gh 
                 14 
               
               + 
               … 
             
           
         
       
     
         [0118]    wherein: 
         [0119]    z represents the value of a reference position with respect to a vertex of the surface of a lens and a position with a height h along the optical axis  480 ; 
         [0120]    k represents the conic constant; 
         [0121]    c represents the reciprocal of the radius of curvature; 
         [0122]    A, B, C, D, E, G, . . . : represent the high-order aspheric coefficients. 
         [0123]    In the fourth embodiment of the present five-piece optical lens system, the focal length of the five-piece optical lens system is f, and it satisfies the relation: 
         [0000]        f= 5.06. 
         [0124]    In the fourth embodiment of the present five-piece optical lens system, the f-number of the five-piece optical lens system is Fno, and it satisfies the relation: 
         [0000]        Fno= 2.8. 
         [0125]    In the fourth embodiment of the present five-piece optical lens system, the field of view of the five-piece optical lens system is 2ω, and it satisfies the relation: 
         [0000]      2ω=70°.
 
         [0126]    In the fourth embodiment of the present five-piece optical lens system, the refractive index of the second lens element  420  is N2, the Abbe number of the second lens element  420  is V2, and they satisfy the relations: 
         [0000]        N 2=1.607; 
         [0000]        V 2=27. 
         [0127]    In the fourth embodiment of the present five-piece optical lens system, the focal length of the first lens element  410  is f1, the focal length of the second lens element  420  is f2, and they satisfy the relation: 
         [0000]      | f 1 |/|f 2|=0.8434. 
         [0128]    In the fourth embodiment of the present five-piece optical lens system, the focal length of the second lens element  420  is f2, the focal length of the third lens element  430  is f3, and they satisfy the relation: 
         [0000]      | f 2 |/|f 3|=0.8238. 
         [0129]    In the fourth embodiment of the present five-piece optical lens system, the focal length of the third lens element  430  is f3, the focal length of the fourth lens element  440  is f4, and they satisfy the relation: 
         [0000]      | f 3 |/|f 4|=1.0301. 
         [0130]    In the fourth embodiment of the present five-piece optical lens system, the focal length of the fourth lens element  440  is f4, the focal length of the fifth lens element  450  is f5, and they satisfy the relation: 
         [0000]      | f 4 |/|f 5|=1.2249. 
         [0131]    In the fourth embodiment of the present five-piece optical lens system, the focal length of the first lens element  410  is f1, the focal length of the second lens element  420 , the third lens element  430 , the fourth lens element  440  and the fifth lens element  450  combined is f2345, and they satisfy the relation: 
         [0000]      | f 1 |/|f 2345|=0.1992. 
         [0132]    In the fourth embodiment of the present five-piece optical lens system, the focal length of the first lens element  410  and the second lens element  420  combined is f12, the focal length of the third lens element  430 , the fourth lens element  440  and the fifth lens element  450  combined is f345, and they satisfy the relation: 
         [0000]      | f 12 |/|f 345|=2.3910. 
         [0133]    In the fourth embodiment of the present five-piece optical lens system, the focal length of the first lens element  410 , the second lens element  420  and the third lens element  430  combined is f123, the focal length of the fourth lens element  440  and the fifth lens element  450  combined is f45, and they satisfy the relation: 
         [0000]      | f 123 |/|f 45|=0.0688. 
         [0134]    In the fourth embodiment of the present five-piece optical lens system, the focal length of the five-piece optical lens system is f, the distance between the object-side surface  411  of the first lens element  410  and the image plane  470  is TL, and they satisfy the relation: 
         [0000]      | f/TL|= 0.7617. 
         [0135]    The detailed optical data of the fourth embodiment is shown in table 7, and the aspheric surface data is shown in table 8, wherein the units of the radius of curvature, the thickness and the focal length are expressed in mm. In the tables 7 and 8, the surfaces 2 and 3 represent the object-side surface  411  and the image-side surface  412  of the first lens element  410 , respectively, the surfaces 4 and 5 represent the object-side surface  421  and the image-side surface  422  of the second lens element  420 , respectively, the surfaces 6 and 7 represent the object-side surface  431  and the image-side surface  432  of the third lens element  430 , respectively, the surfaces 8 and 9 represent the object-side surface  441  and the image-side surface  442  of the fourth lens element  440 , respectively, and the surfaces 10 and 11 represent the object-side surface  451  and the image-side surface  452  of the fifth lens element  450 , respectively. 
         [0000]    
       
         
               
             
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
             
           
               
                 TABLE 7 
               
             
             
               
                   
               
               
                 (Embodiment 4) 
               
               
                 f(focal length) = 5.06 mm, Fno = 2.8, 2ω = 70°. 
               
             
          
           
               
                 Surface # 
                   
                 Curvature Radius 
                 Thickness 
                 Material 
                 nd 
                 vd 
               
               
                   
               
             
          
           
               
                 0 
                 Object 
                 Infinity 
                 Infinity 
                   
                   
                   
               
               
                 1 
                 Stop 
                 Infinity 
                 0 
               
               
                 2 
                 Lens 1 
                  2.83374(ASP) 
                 0.516371 
                 Plastic 
                 1.535 
                 56 
               
               
                 3 
                   
                 −33.5741(ASP) 
                 0.390597 
               
               
                 4 
                 Lens 2 
                 191.8077(ASP) 
                 0.334781 
                 Plastic 
                 1.607 
                 27 
               
               
                 5 
                   
                 3.482144(ASP) 
                 0.11527 
               
               
                 6 
                 Lens 3 
                 5.366991(ASP) 
                 0.742505 
                 Plastic 
                 1.535 
                 57 
               
               
                 7 
                   
                 −12.1643(ASP) 
                 0.66271 
               
               
                 8 
                 Lens 4 
                 −1.90714(ASP) 
                 0.656841 
                 Plastic 
                 1.531 
                 56 
               
               
                 9 
                   
                 −1.40164(ASP) 
                 0.315902 
               
               
                 10 
                 Lens 5 
                 4.063234(ASP) 
                 1.041432 
                 Plastic 
                 1.531 
                 56 
               
               
                 11 
                   
                 1.563888(ASP) 
                 0.645652 
               
               
                 12 
                 IR-filter 
                 Infinity 
                 0.3 
                 Glass 
                 1.5168 
                 64.167336 
               
               
                 13 
                   
                 Infinity 
                 0.566297 
               
               
                 14 
                 Cover 
                 Infinity 
                 0.318664 
                 Glass 
                 1.5168 
                 64.167336 
               
               
                 15 
                 Glass 
                 Infinity 
                 0.041506 
               
               
                 16 
                 Image 
                 Infinity 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 8 
               
               
                   
               
               
                 Aspheric Coefficients 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 Surface # 
                 2 
                 3 
                 4 
                 5 
                 6 
               
               
                   
               
               
                 k = 
                 −1.21071 
                 753.2901 
                 −1037.23 
                 −0.15723 
                 6.331358 
               
               
                 A = 
                 −0.00085 
                 −0.00658 
                 −0.01001 
                 −0.00012 
                 3.70E−07 
               
               
                 B = 
                 −0.00368 
                 −0.00041 
                 0.000148 
                 −0.00045 
                 −4.52E−08  
               
               
                 C = 
                 −0.00067 
                 −0.00285 
                 0.001259 
                 0.000214 
                 5.77E−07 
               
               
                 D = 
                 −0.00238 
                 −0.0011 
                 −3.56E−05 
                 0.00016 
                 5.18E−07 
               
               
                   
               
               
                 Surface # 
                 7 
                 8 
                 9 
                 10 
                 11 
               
               
                   
               
               
                 k = 
                 37.21635 
                 −0.63993 
                 −0.87743 
                 −33.4635 
                 −5.51178 
               
               
                 A = 
                 −3.22E−09  
                 0.012823 
                 0.018622 
                 −0.02305 
                 −0.01904 
               
               
                 B = 
                 3.33E−06 
                 0.001158 
                 0.004339 
                 0.000974 
                 0.002127 
               
               
                 C = 
                 7.27E−07 
                 0.000554 
                 0.000201 
                 0.000294 
                 −0.0002 
               
               
                 D = 
                 3.23E−08 
                 −0.0002 
                 0.000113 
                 −8.20E−05 
                 4.00E−06 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                   
                 TABLE 9 
               
               
                   
                   
               
               
                   
                 Embodiment 
                 Embodiment 
                 Embodiment 
                 Embodiment 
               
               
                   
                 1 
                 2 
                 3 
                 4 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                 f 
                 3.69 
                 2.86 
                 5.63 
                 5.06 
               
               
                 Fno 
                 2.2 
                 2.4 
                 2.8 
                 2.8 
               
               
                 2ω 
                 75 
                 90 
                 68 
                 70 
               
               
                 N2 
                 1.632 
                 1.632 
                 1.607 
                 1.607 
               
               
                 V2 
                 23 
                 23 
                 27 
                 27 
               
               
                 |f1|/|f2| 
                 0.5141 
                 0.5715 
                 0.6079 
                 0.8434 
               
               
                 |f2|/|f3| 
                 1.8163 
                 1.0748 
                 0.6935 
                 0.8238 
               
               
                 |f3|/|f4| 
                 0.2049 
                 0.0627 
                 0.2579 
                 1.0301 
               
               
                 |f4|/|f5| 
                 3.9554 
                 5.4373 
                 3.8177 
                 1.2249 
               
               
                 |f1|/|f2345| 
                 0.5012 
                 0.0890 
                 0.7966 
                 0.1992 
               
               
                 |f12|/|f345| 
                 0.1175 
                 0.8478 
                 0.1362 
                 2.3910 
               
               
                 |f123|/|f45| 
                 0.9422 
                 0.2889 
                 0.7710 
                 0.0688 
               
               
                 |f/TL| 
                 0.7432 
                 0.6526 
                 0.8014 
                 0.7617 
               
               
                   
               
             
          
         
       
     
         [0136]    It is to be noted that the tables 1-8 show different data from the different embodiments, however, the data of the different embodiments is obtained from experiments. Therefore, any product of the same structure is deemed to be within the scope of the present invention even if it uses different data. Table 9 lists the relevant data for the various embodiments of the present invention. 
         [0137]    In the present five-piece optical lens system, the lens elements can be made of glass or plastic. If the lens elements are made of glass, there is more freedom in distributing the refractive power of the five-piece optical lens system. If the lens elements are made of plastic, the cost will be effectively reduced. 
         [0138]    In the present five-piece optical lens system, if the object-side or the image-side surface of the lens elements is convex, the object-side or the image-side surface of the lens elements in proximity of the optical axis is convex. If the object-side or the image-side surface of the lens elements is concave, the object-side or the image-side surface of the lens elements in proximity of the optical axis is concave. 
         [0139]    While we have shown and described various embodiments in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.