Abstract:
An optical imaging lens assembly includes an aperture stop and an optical assembly, the optical assembly includes, in order from the object side to the image side: a first lens element with a positive refractive power; a second lens element with a negative refractive power; a third lens element with a positive refractive power; a fourth lens element with a refractive power; wherein a radius of curvature of an object-side surface of the second lens element is R3, a radius of curvature of an image-side surface of the second lens element is R4, a radius of curvature of an object-side surface of the third lens element is R5, a radius of curvature of an image-side surface of the third lens element is R6, and the following conditions are satisfied: −0.62&lt;(R3−R4)/(R3+R4)&lt;−0.51; 0.54&lt;(R5−R6)/(R5+R6)&lt;0.67.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an optical lens system, and more particularly to a miniaturized optical imaging lens assembly applicable to electronic products. 
     2. Description of the Prior Art 
     In recent years, with the rapid development of devices, such as, smartphone, tablet computer and so on, small optical lens system applied to mobile devices has been indispensable. In addition, as the advanced semiconductor manufacturing technologies have allowed the image sensors with smaller size and higher pixel, small optical lens systems have increasingly higher pixel, there&#39;s an increasing demand for an optical lens system with better image quality. 
     A conventional optical lens system used in mobile phone camera usually consists of three lens elements, such as the optical lens system described in U.S. Pat. No. 7,145,736. However, the angle of view cannot be improved due to the limitation of the lens elements. In addition, as the pixel size of image sensors is allow to be reduced and compact, the requirement for image quality of the compact optical lens system increases significantly. However, the conventional optical lens systems cannot satisfy the requirement of the compact optical lens systems. 
     The present invention has been made in order to solve the above-mentioned problems. 
     SUMMARY OF THE INVENTION 
     The primary objective of the present invention is to provide an optical imaging lens assembly having high resolution, wider angle of view, and is favorable to be used in mobile devices under the condition that image quality and small size can be taken into account synchronously by good configuration of the lens thickness. 
     According to one aspect of the present invention, an optical imaging lens assembly comprises an aperture stop and an optical assembly, the optical assembly comprises, in order from the object side to the image side: a first lens element with a positive refractive power having an aspheric object-side surface being convex near the optical axis and an aspheric image-side surface, the first lens element being made of plastic material; a second lens element with a negative refractive power having an aspheric object-side surface being concave near the optical axis and an aspheric image-side surface being convex near the optical axis; a third lens element with a positive refractive power having an aspheric object-side surface and an aspheric image-side surface being convex near the optical axis, the third lens element being made of plastic material; a fourth lens element with a refractive power having an aspheric object-side surface being convex near the optical axis and an aspheric image-side surface being concave near the optical axis, the fourth lens element being made of plastic material, at least one inflection point being formed on the object-side surface and the image-side surface of the fourth lens element. 
     Wherein the radius of curvature of the object-side surface of the second lens element is R3, the radius of curvature of the image-side surface of the second lens element is R4, the radius of curvature of the object-side surface of the third lens element is R5, the radius of curvature of the image-side surface of the third lens element is R6, and the following conditions are satisfied:
 
−0.62&lt;( R 3− R 4)/( R 3+ R 4)&lt;−0.51;
 
0.54&lt;( R 5− R 6)/( R 5+ R 6)&lt;0.67.
 
     If (R3−R4)/(R3+R4) satisfies the above condition, it will be favorable to correct the spherical aberration of the optical imaging lens assembly. 
     If (R5−R6)/(R5+R6) satisfies the above condition, it will be favorable to correct the aberrations and reduce the track length of the optical imaging lens assembly. 
     Preferably, the central thickness of the first lens element is CT1, the central thickness of the third lens element is CT3, the distance along the optical axis between the object-side surface of the first lens element and the image-side surface of the fourth lens element is TD, and the following condition is satisfied: 0.49&lt;(CT1+CT3)/TD&lt;0.61, so that the thickness of the lens elements will be more proper, which can distribute the positive refractive power of the optical imaging lens assembly effectively, so as to balance the image quality and the sensitivity. 
     Preferably, the central thickness of the second lens element is CT2, the central thickness of the fourth lens element is CT4, the distance along the optical axis between the object-side surface of the first lens element and the image-side surface of the fourth lens element is TD, and the following condition is satisfied: 0.25&lt;(CT2+CT4)/TD&lt;0.32, it can maintain the objective of miniaturization of the optical imaging lens assembly and it will be favorable to reduce the peripheral astigmatism and distortion. 
     Preferably, the f-number of the optical imaging lens assembly is Fno, and the following condition is satisfied: 2.0≦Fno≦2.4, it can increase the incident light with respect to the lens elements, so as to improve the image contrast. 
     Preferably, the focal length of the first lens element is f1, the focal length of the second lens element is f2, and the following condition is satisfied: −0.76&lt;f1/f2&lt;−0.61, it will be favorable to enlarge the field of view and can better control the aberrations of the optical imaging lens assembly. 
     Preferably, the focal length of the second lens element is f2, the focal length of the fourth lens element is f4, and the following condition is satisfied: 1.25&lt;f2/f4&lt;2.29, which can balance the refractive power of the optical imaging lens assembly, so that it will be favorable to reduce the sensitivity to tolerance. 
     Preferably, the Abbe number of the second lens element is V2, the Abbe number of the fourth lens element is V4, and the following condition is satisfied: 18&lt;V4−V2&lt;38, it will be favorable to correct the chromatic aberration of the optical imaging lens assembly. 
     Preferably, half of the maximal field of view of the optical imaging lens assembly is HFOV, and the following condition is satisfied: 1/|tan(HFOV)|&lt;1.19, which can obtain larger shooting range by providing wider angle of view. 
     Preferably, the distance from the object-side surface of the first lens element to the image plane along the optical axis is TTL, half of the maximum diagonal imaging height of the optical imaging lens assembly is ImgH, and the following condition is satisfied: TTL/ImgH&lt;1.68, it can maintain the objective of miniaturization of the optical imaging lens assembly, so as to be used in light-weight portable electronic products. 
     According to another aspect of the present invention, an optical imaging lens assembly comprises an aperture stop and an optical assembly, the optical assembly comprises, in order from the object side to the image side: a first lens element with a positive refractive power having an aspheric object-side surface being convex near the optical axis and an aspheric image-side surface being convex near the optical axis, the first lens element being made of plastic material; a second lens element with a negative refractive power having an aspheric object-side surface being concave near the optical axis and an aspheric image-side surface being convex near the optical axis; a third lens element with a positive refractive power having an aspheric object-side surface being concave near the optical axis and an aspheric image-side surface being convex near the optical axis, the third lens element being made of plastic material; a fourth lens element with a negative refractive power having an aspheric object-side surface being convex near the optical axis and an aspheric image-side surface being concave near the optical axis, the fourth lens element being made of plastic material, at least one inflection point being formed on the object-side surface and the image-side surface of the fourth lens element. 
     Wherein the radius of curvature of the object-side surface of the second lens element is R3, the radius of curvature of the image-side surface of the second lens element is R4, the radius of curvature of the object-side surface of the third lens element is R5, the radius of curvature of the image-side surface of the third lens element is R6, and the following conditions are satisfied:
 
−0.65&lt;( R 3− R 4)/( R 3+ R 4)&lt;−0.57;
 
0.51&lt;( R 5− R 6)/( R 5+ R 6)&lt;0.71.
 
     If (R3−R4)/(R3+R4) satisfies the above condition, it will be favorable to correct the spherical aberration of the optical imaging lens assembly. 
     If (R5−R6)/(R5+R6) satisfies the above condition, it will be favorable to correct the aberrations and reduce the track length of the optical imaging lens assembly. 
     Preferably, the central thickness of the first lens element is CT1, the central thickness of the third lens element is CT3, the distance along the optical axis between the object-side surface of the first lens element and the image-side surface of the fourth lens element is TD, and the following condition is satisfied: 0.45&lt;(CT1+CT3)/TD&lt;0.67, so that the thickness of the lens elements will be more proper, which can distribute the positive refractive power of the optical imaging lens assembly effectively, so as to balance the image quality and the sensitivity. 
     Preferably, the central thickness of the second lens element is CT2, the central thickness of the fourth lens element is CT4, the distance along the optical axis between the object-side surface of the first lens element and the image-side surface of the fourth lens element is TD, and the following condition is satisfied: 0.23&lt;(CT2+CT4)/TD&lt;0.35, it can maintain the objective of miniaturization of the optical imaging lens assembly and it will be favorable to reduce the peripheral astigmatism and distortion. 
     Preferably, the f-number of the optical imaging lens assembly is Fno, and the following condition is satisfied: 2.0≦Fno≦2.4, it can increase the incident light with respect to the lens elements, so as to improve the image contrast. 
     Preferably, the focal length of the first lens element is f1, the focal length of the second lens element is f2, and the following condition is satisfied: −0.82&lt;f1/f2&lt;−0.58, it will be favorable to enlarge the field of view and can better control the aberrations of the optical imaging lens assembly. 
     Preferably, the focal length of the second lens element is f2, the focal length of the fourth lens element is f4, and the following condition is satisfied: 1.21&lt;f2/f4&lt;2.42, which can balance the refractive power of the optical imaging lens assembly, so that it will be favorable to reduce the sensitivity to tolerance. Preferably, the Abbe number of the second lens element is V2, the Abbe number of the fourth lens element is V4, and the following condition is satisfied: 18&lt;V4−V2&lt;38, it will be favorable to correct the chromatic aberration of the optical imaging lens assembly. 
     Preferably, half of the maximal field of view of the optical imaging lens assembly is HFOV, and the following condition is satisfied: 1/|tan(HFOV)|&lt;1.19, which can obtain larger shooting range by providing wider angle of view. 
     Preferably, the distance from the object-side surface of the first lens element to the image plane along the optical axis is TTL, half of the maximum diagonal imaging height of the optical imaging lens assembly is ImgH, and the following condition is satisfied: TTL/ImgH&lt;1.68, it can maintain the objective of miniaturization of the optical imaging lens assembly, so as to be used in light-weight portable electronic products. 
     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 
         FIG. 1A  shows an optical imaging lens assembly in accordance with a first embodiment of the present invention; 
         FIG. 1B  shows the longitudinal spherical aberration curve, the astigmatic field curve and the distortion curve of the first embodiment of the present invention; 
         FIG. 2A  shows an optical imaging lens assembly in accordance with a second embodiment of the present invention; 
         FIG. 2B  shows the longitudinal spherical aberration curve, the astigmatic field curve and the distortion curve of the second embodiment of the present invention; 
         FIG. 3A  shows an optical imaging lens assembly in accordance with a third embodiment of the present invention; 
         FIG. 3B  shows the longitudinal spherical aberration curve, the astigmatic field curve and the distortion curve of the third embodiment of the present invention; 
         FIG. 4A  shows an optical imaging lens assembly in accordance with a fourth embodiment of the present invention; 
         FIG. 4B  shows the longitudinal spherical aberration curve, the astigmatic field curve and the distortion curve of the fourth embodiment of the present invention; 
         FIG. 5A  shows an optical imaging lens assembly in accordance with a fifth embodiment of the present invention; 
         FIG. 5B  shows the longitudinal spherical aberration curve, the astigmatic field curve and the distortion curve of the fifth embodiment of the present invention; 
         FIG. 6A  shows an optical imaging lens assembly in accordance with a sixth embodiment of the present invention; 
         FIG. 6B  shows the longitudinal spherical aberration curve, the astigmatic field curve and the distortion curve of the sixth embodiment of the present invention; 
         FIG. 7A  shows an optical imaging lens assembly in accordance with a seventh embodiment of the present invention; 
         FIG. 7B  shows the longitudinal spherical aberration curve, the astigmatic field curve and the distortion curve of the seventh embodiment of the present invention; 
         FIG. 8A  shows an optical imaging lens assembly in accordance with an eighth embodiment of the present invention; and 
         FIG. 8B  shows the longitudinal spherical aberration curve, the astigmatic field curve and the distortion curve of the eighth embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1A  shows an optical imaging lens assembly in accordance with a first embodiment of the present invention, and  FIG. 1B  shows, in order from left to right, the longitudinal spherical aberration curves, the astigmatic field curves, and the distortion curve of the first embodiment of the present invention. An optical imaging lens assembly in accordance with the first embodiment of the present invention comprises an aperture stop  100  and an optical assembly. The optical assembly comprises, in order from an object side to an image side: a first lens element  110 , a second lens element  120 , a third lens element  130 , a fourth lens element  140 , an IR cut filter  170  and an image plane  180 , wherein the optical imaging lens assembly has a total of four lens elements with refractive power. The aperture stop  100  is located between an image-side surface  112  of the first lens element  110  and an object to be photographed. 
     The first lens element  110  with a positive refractive power has an object-side surface  111  being convex near an optical axis  190  and the image-side surface  112  being convex near the optical axis  190 , both the object-side and image-side surfaces  111 ,  112  are aspheric, and the first lens element  110  is made of plastic material. 
     The second lens element  120  with a negative refractive power has an object-side surface  121  being concave near the optical axis  190  and an image-side surface  122  being concave near the optical axis  190 , both the object-side and image-side surfaces  121 ,  122  are aspheric, and the second lens element  120  is made of plastic material. 
     The third lens element  130  with a positive refractive power has an object-side surface  131  being concave near the optical axis  190  and an image-side surface  132  being convex near the optical axis  190 , both the object-side and image-side surfaces  131 ,  132  are aspheric, the third lens element  130  is made of plastic material. 
     The fourth lens element  140  with a negative refractive power has an object-side surface  141  being convex near the optical axis  190  and an image-side surface  142  being concave near the optical axis  190 , both the object-side and image-side surfaces  141 ,  142  are aspheric, the fourth lens element  140  is made of plastic material, and more than one inflection point is formed on the object-side surface  141  and the image-side surface  142  of the fourth lens element  140 . 
     The IR cut filter  170  made of glass is located between the fourth lens element  140  and the image plane  180  and has no influence on the focal length of the optical imaging lens assembly. 
     The equation for the aspheric surface profiles of the first embodiment is expressed as follows: 
     
       
         
           
             
               z 
               ⁡ 
               
                 ( 
                 h 
                 ) 
               
             
             = 
             
               
                 
                   ch 
                   2 
                 
                 
                   1 
                   + 
                   
                     
                       1 
                       - 
                       
                         
                           ( 
                           
                             1 
                             + 
                             k 
                           
                           ) 
                         
                         ⁢ 
                         
                           c 
                           2 
                         
                         ⁢ 
                         
                           h 
                           2 
                         
                       
                     
                   
                 
               
               + 
               
                 
                   A 
                   4 
                 
                 ⁢ 
                 
                   h 
                   4 
                 
               
               + 
               
                 
                   A 
                   6 
                 
                 ⁢ 
                 
                   h 
                   6 
                 
               
               + 
               
                 
                   A 
                   8 
                 
                 ⁢ 
                 
                   h 
                   8 
                 
               
               + 
               
                 
                   A 
                   10 
                 
                 ⁢ 
                 
                   h 
                   10 
                 
               
               + 
               
                 
                   A 
                   12 
                 
                 ⁢ 
                 
                   h 
                   12 
                 
               
               + 
               
                 
                   A 
                   14 
                 
                 ⁢ 
                 
                   h 
                   14 
                 
               
               + 
               … 
             
           
         
       
     
     z represents the distance of a point on the aspheric surface at a height h from the optical axis  190  relative to a plane perpendicular to the optical axis at the vertex of the aspheric surface; 
     c is a paraxial curvature equal to 1/R (R: a paraxial radius of curvature); 
     h represents a vertical distance from the point on the curve of the aspheric surface to the optical axis  190 ; 
     k represents the conic constant; 
     A 4 , A 6 , A 8 , A 10 , A 12 , A 14  . . . : represent the high-order aspheric coefficients. 
     In the first embodiment of the present optical imaging lens assembly, the focal length of the optical imaging lens assembly is f, the f-number of the optical imaging lens assembly is Fno, half of the maximal field of view of the optical imaging lens assembly is HFOV, and the following conditions are satisfied: 
     f=1.96 mm, Fno=2.07, and HFOV=42.2 degrees. 
     In the first embodiment of the present optical imaging lens assembly, the radius of curvature of the object-side surface  121  of the second lens element  120  is R3, the radius of curvature of the image-side surface  122  of the second lens element  120  is R4, and the following condition is satisfied:
 
( R 3− R 4)/( R 3+ R 4)=−0.60.
 
     In the first embodiment of the present optical imaging lens assembly, the radius of curvature of the object-side surface  131  of the third lens element  130  is R5, the radius of curvature of the image-side surface  132  of the third lens element  130  is R6, and the following condition is satisfied:
 
( R 5− R 6)/( R 5+ R 6)=0.60.
 
     In the first embodiment of the present optical imaging lens assembly, the central thickness of the first lens element  110  is CT1, the central thickness of the third lens element  130  is CT3, the distance along the optical axis between the object-side surface  111  of the first lens element  110  and the image-side surface  142  of the fourth lens element  140  is TD, and the following condition is satisfied:
 
(CT1+CT3)/ TD= 0.56.
 
     In the first embodiment of the present optical imaging lens assembly, the central thickness of the second lens element  120  is CT2, the central thickness of the fourth lens element  140  is CT4, the distance along the optical axis between the object-side surface  111  of the first lens element  110  and the image-side surface  142  of the fourth lens element  140  is TD, and the following condition is satisfied:
 
(CT2+CT4)/ TD= 0.27.
 
     In the first embodiment of the present optical imaging lens assembly, the focal length of the first lens element  110  is f1, the focal length of the second lens element  120  is f2, and the following condition is satisfied:
 
 f 1/ f 2=−0.70.
 
     In the first embodiment of the present optical imaging lens assembly, the focal length of the second lens element  120  is f2, the focal length of the fourth lens element  140  is f4, and the following condition is satisfied:
 
 f 2/ f 4=1.54.
 
     In the first embodiment of the present optical imaging lens assembly, the Abbe number of the second lens element  120  is V2, the Abbe number of the fourth lens element  140  is V4, and the following condition is satisfied:
 
 V 4− V 2=33.3.
 
     In the first embodiment of the present optical imaging lens assembly, half of the maximal field of view of the optical imaging lens assembly is HFOV, and the following condition is satisfied:
 
1/|tan(HFOV)|=1.10.
 
     In the first embodiment of the present optical imaging lens assembly, the distance from the object-side surface  111  of the first lens element  110  to the image plane  180  along the optical axis  190  is TTL, half of the maximum diagonal imaging height of the optical imaging lens assembly is ImgH, and the following condition is satisfied:
 
 TTL /ImgH=1.643.
 
     The detailed optical data of the first embodiment is shown in Table 1, and the aspheric surface data is shown in Table 2. 
     
       
         
               
             
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 1 
               
             
             
               
                   
               
               
                 (Embodiment 1) 
               
               
                 f(focal length) = 1.96 mm, Fno = 2.07, HFOV = 42.2 deg. 
               
             
          
           
               
                   
                   
                 Curvature 
                   
                   
                   
                   
                 Focal 
               
               
                 Surface 
                   
                 Radius 
                 Thickness 
                 Material 
                 index 
                 Abbe # 
                 length 
               
               
                   
               
             
          
           
               
                 0 
                 Object 
                 Plane 
                 Infinity 
                   
                   
                   
                   
               
               
                 1 
                 Aperture 
                 Plane 
                 −0.03 
                   
                   
                   
                   
               
               
                   
                 stop 
                   
                   
                   
                   
                   
                   
               
               
                 2 
                 Lens 1 
                   1.675(ASP) 
                 0.521 
                 Plastic 
                 1.544 
                 55.9 
                 2.02 
               
               
                 3 
                   
                 −2.863(ASP) 
                 0.242 
                   
                   
                   
                   
               
               
                 4 
                 Lens 2 
                 −1.354(ASP) 
                 0.220 
                 Plastic 
                 1.641 
                 22.6 
                 −2.88 
               
               
                 5 
                   
                 −5.417(ASP) 
                 0.061 
                   
                   
                   
                   
               
               
                 6 
                 Lens 3 
                 −2.330(ASP) 
                 0.568 
                 Plastic 
                 1.544 
                 55.9 
                 1.29 
               
               
                 7 
                   
                 −0.586(ASP) 
                 0.030 
                   
                   
                   
                   
               
               
                 8 
                 Lens 4 
                   1.064(ASP) 
                 0.307 
                 Plastic 
                 1.544 
                 55.9 
                 −1.87 
               
               
                 9 
                   
                   0.467(ASP) 
                 0.334 
                   
                   
                   
                   
               
               
                 10 
                 IR-filter 
                 Plane 
                 0.21 
                 Glass 
                 1.517 
                 64.2 
                 — 
               
               
                 11 
                   
                 Plane 
                 0.49 
                   
                   
                   
                   
               
               
                 12 
                 Image 
                 Plane 
               
               
                   
               
             
          
         
       
     
     
       
         
               
             
               
               
             
               
               
               
               
               
             
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 2 
               
               
                   
               
               
                 Aspheric Coefficients 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Surface # 
               
             
          
           
               
                   
                 2 
                 3 
                 4 
                 5 
               
               
                   
               
               
                 K = 
                  9.0774E+00 
                  5.4019E+00 
                  2.5828E+00 
                  1.5763E+00 
               
               
                 A4 = 
                 −3.8675E−01 
                 −4.9383E−01 
                 −1.0155E+00 
                 −3.9558E−01 
               
               
                 A6 = 
                 −1.3423E+00 
                  1.3729E−01 
                  2.3223E+00 
                  7.1735E−01 
               
               
                 A8 = 
                  1.3510E+01 
                 −1.2249E+00 
                 −4.6145E−01 
                 −9.1076E−02 
               
               
                 A10 = 
                 −1.5530E+02 
                  7.4748E−01 
                  5.2054E+00 
                  7.5475E−02 
               
               
                 A12 = 
                  6.8126E+02 
                  5.0834E+00 
                 −1.6720E+01 
                 −9.8254E−01 
               
               
                 A14 = 
                 −1.2385E+03 
                 −9.9423E+00 
                  1.8969E+01 
                  1.0543E+00 
               
               
                   
               
             
          
           
               
                   
                 Surface # 
               
             
          
           
               
                   
                 6 
                 7 
                 8 
                 9 
               
               
                   
               
               
                 K = 
                  6.1002E+00 
                 −4.0384E+00 
                 −8.2663E−01 
                 −3.7633E+00 
               
               
                 A4 = 
                  7.5047E−01 
                 −4.0471E−01 
                 −7.2555E−01 
                 −2.6994E−01 
               
               
                 A6 = 
                 −1.7292E+00 
                  8.4506E−01 
                  3.2656E−01 
                  1.6378E−01 
               
               
                 A8 = 
                  1.6367E+00 
                 −1.1488E+00 
                  3.8321E−02 
                 −9.2497E−02 
               
               
                 A10 = 
                  1.0298E+00 
                  2.0128E−01 
                 −4.4994E−01 
                  3.0534E−02 
               
               
                 A12 = 
                 −3.1069E+00 
                  1.2217E+00 
                  5.4729E−01 
                 −2.1498E−03 
               
               
                 A14 = 
                  2.4622E+00 
                 −5.7702E−01 
                 −2.2192E−01 
                 −1.4386E−03 
               
               
                   
               
             
          
         
       
     
     The units of the radius of curvature, the thickness and the focal length in table 1 are expressed in mm, in the tables 1 and 2, the surface numbers 2-9 represent the surfaces sequentially arranged from the object-side to the image-side along the optical axis, and in table 2, k represents the conic coefficient of the equation of the aspheric surface profiles, and A 4 , A 6 , A 8 , A 10 , A 12 , A 14  . . . : represent the high-order aspheric coefficients arranging from the 4th order to the 14th order. The tables presented below for each embodiment are the corresponding schematic parameter and aberration curves, and the definitions of the tables are the same as Table 1 and Table 2 of the first embodiment. Therefore, an explanation in this regard will not be provided again. 
       FIG. 2A  shows an optical imaging lens assembly in accordance with a second embodiment of the present invention, and  FIG. 2B  shows, in order from left to right, the longitudinal spherical aberration curves, the astigmatic field curves, and the distortion curve of the second embodiment of the present invention. An optical imaging lens assembly in accordance with the second embodiment of the present invention comprises an aperture stop  200  and an optical assembly. The optical assembly comprises, in order from an object side to an image side: a first lens element  210 , a second lens element  220 , a third lens element  230 , a fourth lens element  240 , an IR cut filter  270  and an image plane  280 , wherein the optical imaging lens assembly has a total of four lens elements with refractive power. The aperture stop  200  is located between an image-side surface  212  of the first lens element  210  and an object to be photographed. 
     The first lens element  210  with a positive refractive power has an object-side surface  211  being convex near an optical axis  290  and the image-side surface  212  being convex near the optical axis  290 , both the object-side and image-side surfaces  211 ,  212  are aspheric, and the first lens element  210  is made of plastic material. 
     The second lens element  220  with a negative refractive power has an object-side surface  221  being concave near the optical axis  290  and an image-side surface  222  being concave near the optical axis  290 , both the object-side and image-side surfaces  221 ,  222  are aspheric, and the second lens element  220  is made of plastic material. 
     The third lens element  230  with a positive refractive power has an object-side surface  231  being concave near the optical axis  290  and an image-side surface  232  being convex near the optical axis  290 , both the object-side and image-side surfaces  231 ,  232  are aspheric, the third lens element  230  is made of plastic material. 
     The fourth lens element  240  with a negative refractive power has an object-side surface  241  being convex near the optical axis  290  and an image-side surface  242  being concave near the optical axis  290 , both the object-side and image-side surfaces  241 ,  242  are aspheric, the fourth lens element  240  is made of plastic material, and more than one inflection point is formed on the object-side surface  241  and the image-side surface  242  of the fourth lens element  240 . 
     The IR cut filter  270  made of glass is located between the fourth lens element  240  and the image plane  280  and has no influence on the focal length of the optical imaging lens assembly. 
     The detailed optical data of the second embodiment is shown in Table 3 and the aspheric surface data is shown in Table 4 below. 
     
       
         
               
             
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 3 
               
             
             
               
                   
               
               
                 (Embodiment 2) 
               
               
                 f(focal length) = 1.98 mm, Fno = 2.1, HFOV = 41.8 deg. 
               
             
          
           
               
                   
                   
                   
                   
                   
                   
                   
                 Focal 
               
               
                 Surface 
                   
                 Curvature Radius 
                 Thickness 
                 Material 
                 index 
                 Abbe # 
                 length 
               
               
                   
               
             
          
           
               
                 0 
                 Object 
                 Plane 
                 Infinity 
                   
                   
                   
                   
               
               
                 1 
                 Aperture 
                 Plane 
                 −0.045 
                   
                   
                   
                   
               
               
                   
                 stop 
                   
                   
                   
                   
                   
                   
               
               
                 2 
                 Lens 1 
                   1.675(ASP) 
                 0.509 
                 Plastic 
                 1.544 
                 55.9 
                 2.09 
               
               
                 3 
                   
                 −3.167(ASP) 
                 0.251 
                   
                   
                   
                   
               
               
                 4 
                 Lens 2 
                 −1.347(ASP) 
                 0.220 
                 Plastic 
                 1.641 
                 22.6 
                 −3.25 
               
               
                 5 
                   
                 −4.042(ASP) 
                 0.058 
                   
                   
                   
                   
               
               
                 6 
                 Lens 3 
                 −2.249(ASP) 
                 0.568 
                 Plastic 
                 1.544 
                 55.9 
                 1.33 
               
               
                 7 
                   
                 −0.596(ASP) 
                 0.037 
                   
                   
                   
                   
               
               
                 8 
                 Lens 4 
                   1.085(ASP) 
                 0.311 
                 Plastic 
                 1.535 
                 56.3 
                 −1.86 
               
               
                 9 
                   
                   0.471(ASP) 
                 0.336 
                   
                   
                   
                   
               
               
                 10 
                 IR-filter 
                 Plane 
                 0.21 
                 Glass 
                 1.517 
                 64.2 
                 — 
               
               
                 11 
                   
                 Plane 
                 0.49 
                   
                   
                   
                   
               
               
                 12 
                 Image 
                 Plane 
               
               
                   
               
             
          
         
       
     
     
       
         
               
             
               
               
             
               
               
               
               
               
             
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 4 
               
               
                   
               
               
                 Aspheric Coefficients 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Surface # 
               
             
          
           
               
                   
                 2 
                 3 
                 4 
                 5 
               
               
                   
               
               
                 K = 
                  9.0425E+00 
                  5.8101E+00 
                  2.5337E+00 
                  7.9106E+00 
               
               
                 A4 = 
                 −3.8038E−01 
                 −4.8451E−01 
                 −1.0110E+00 
                 −3.8246E−01 
               
               
                 A6 = 
                 −1.3446E+00 
                  1.2673E−01 
                  2.2920E+00 
                  7.3739E−01 
               
               
                 A8 = 
                  1.3553E+01 
                 −1.2872E+00 
                 −4.9530E−01 
                 −7.1824E−02 
               
               
                 A10 = 
                 −1.5488E+02 
                  7.1141E−01 
                  5.2400E+00 
                  7.4569E−02 
               
               
                 A12 = 
                  6.8126E+02 
                  5.1500E+00 
                 −1.6681E+01 
                 −9.9133E−01 
               
               
                 A14 = 
                 −1.2385E+03 
                 −9.9423E+00 
                  1.8969E+01 
                  1.0546E+00 
               
               
                   
               
             
          
           
               
                   
                 Surface # 
               
             
          
           
               
                   
                 6 
                 7 
                 8 
                 9 
               
               
                   
               
               
                 K = 
                  5.6523E+00 
                 −4.1066E+00 
                 −8.8061E−01 
                 −3.7748E+00 
               
               
                 A4 = 
                  7.7067E−01 
                 −3.9717E−01 
                 −7.3201E−01 
                 −2.7248E−01 
               
               
                 A6 = 
                 −1.7237E+00 
                  8.4106E−01 
                  3.3784E−01 
                  1.6867E−01 
               
               
                 A8 = 
                  1.6371E+00 
                 −1.1519E+00 
                  3.6457E−02 
                 −8.9784E−02 
               
               
                 A10 = 
                  1.0412E+00 
                  2.0018E−01 
                 −4.4849E−01 
                  2.8915E−02 
               
               
                 A12 = 
                 −3.1193E+00 
                  1.2201E+00 
                  5.4749E−01 
                 −2.7625E−03 
               
               
                 A14 = 
                  2.4544E+00 
                 −5.8144E−01 
                 −2.2109E−01 
                 −9.4290E−04 
               
               
                   
               
             
          
         
       
     
     In the 2nd embodiment, the equation of the aspheric surface profiles of the aforementioned lens elements is the same as the equation of the 1st embodiment. Also, the definitions of these parameters shown in the following table are the same as those stated in the 1st embodiment with corresponding values for the 2nd embodiment, so an explanation in this regard will not be provided again. 
     Moreover, these parameters can be calculated from Table 3 and Table 4 as the following values and satisfy the following conditions: 
     
       
         
               
             
               
               
               
               
               
             
           
               
                   
               
               
                 Embodiment 2 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 f 
                 1.98 
                 (CT2 + CT4)/TD 
                 0.27 
               
               
                   
                 Fno 
                 2.10 
                 f1/f2 
                 −0.64 
               
               
                   
                 HFOV 
                 41.8 
                 f2/f4 
                 1.75 
               
               
                   
                 (R3 − R4)/(R3 + R4) 
                 −0.50 
                 V4 − V2 
                 33.7 
               
               
                   
                 (R5 − R6)/(R5 + R6) 
                 0.58 
                 1/|tan(HFOV)| 
                 1.12 
               
               
                   
                 (CT1 + CT3)/TD 
                 0.55 
                 TTL/ImgH 
                 1.647 
               
               
                   
                   
               
             
          
         
       
     
       FIG. 3A  shows an optical imaging lens assembly in accordance with a third embodiment of the present invention, and  FIG. 3B  shows, in order from left to right, the longitudinal spherical aberration curves, the astigmatic field curves, and the distortion curve of the third embodiment of the present invention. An optical imaging lens assembly in accordance with the third embodiment of the present invention comprises an aperture stop  300  and an optical assembly. The optical assembly comprises, in order from an object side to an image side: a first lens element  310 , a second lens element  320 , a third lens element  330 , a fourth lens element  340 , an IR cut filter  370  and an image plane  380 , wherein the optical imaging lens assembly has a total of four lens elements with refractive power. The aperture stop  300  is located between an image-side surface  312  of the first lens element  310  and an object to be photographed. 
     The first lens element  310  with a positive refractive power has an object-side surface  311  being convex near an optical axis  390  and the image-side surface  312  being convex near the optical axis  390 , both the object-side and image-side surfaces  311 ,  312  are aspheric, and the first lens element  310  is made of plastic material. 
     The second lens element  320  with a negative refractive power has an object-side surface  321  being concave near the optical axis  390  and an image-side surface  322  being concave near the optical axis  390 , both the object-side and image-side surfaces  321 ,  322  are aspheric, and the second lens element  320  is made of plastic material. 
     The third lens element  330  with a positive refractive power has an object-side surface  331  being concave near the optical axis  390  and an image-side surface  332  being convex near the optical axis  390 , both the object-side and image-side surfaces  331 ,  332  are aspheric, the third lens element  330  is made of plastic material. 
     The fourth lens element  340  with a negative refractive power has an object-side surface  341  being convex near the optical axis  390  and an image-side surface  342  being concave near the optical axis  390 , both the object-side and image-side surfaces  341 ,  342  are aspheric, the fourth lens element  340  is made of plastic material, and more than one inflection point is formed on the object-side surface  341  and the image-side surface  342  of the fourth lens element  340 . 
     The IR cut filter  370  made of glass is located between the fourth lens element  340  and the image plane  380  and has no influence on the focal length of the optical imaging lens assembly. 
     The detailed optical data of the third embodiment is shown in Table 5 and the aspheric surface data is shown in Table 6 below. 
     
       
         
               
             
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 5 
               
             
             
               
                   
               
               
                 (Embodiment 3) 
               
               
                 f(focal length) = 1.97 mm, Fno = 2.08, HFOV = 42.0 deg. 
               
             
          
           
               
                   
                   
                 Curvature 
                   
                   
                   
                   
                 Focal 
               
               
                 Surface 
                   
                 Radius 
                 Thickness 
                 Material 
                 index 
                 Abbe # 
                 length 
               
               
                   
               
             
          
           
               
                 0 
                 Object 
                 Plane 
                 Infinity 
                   
                   
                   
                   
               
               
                 1 
                 Aperture 
                 Plane 
                 −0.043 
                   
                   
                   
                   
               
               
                   
                 stop 
                   
                   
                   
                   
                   
                   
               
               
                 2 
                 Lens 1 
                   1.678(ASP) 
                 0.501 
                 Plastic 
                 1.544 
                 55.9 
                 2.01 
               
               
                 3 
                   
                 −2.836(ASP) 
                 0.239 
                   
                   
                   
                   
               
               
                 4 
                 Lens 2 
                 −1.370(ASP) 
                 0.220 
                 Plastic 
                 1.641 
                 22.6 
                 −2.99 
               
               
                 5 
                   
                 −5.089(ASP) 
                 0.071 
                 Plastic 
                 1.544 
                 55.9 
                 1.44 
               
               
                 6 
                 Lens 3 
                 −2.172(ASP) 
                 0.570 
                   
                   
                   
                   
               
               
                 7 
                   
                 −0.630(ASP) 
                 0.030 
                 Plastic 
                 1.535 
                 55.7 
                 −2.20 
               
               
                 8 
                 Lens 4 
                   0.968(ASP) 
                 0.313 
                   
                   
                   
                   
               
               
                 9 
                   
                   0.475(ASP) 
                 0.345 
                   
                   
                   
                   
               
               
                 10 
                 IR-filter 
                 Plane 
                 0.21 
                 Glass 
                 1.517 
                 64.2 
                 — 
               
               
                 11 
                   
                 Plane 
                 0.49 
                   
                   
                   
                   
               
               
                 12 
                 Image 
                 Plane 
               
               
                   
               
             
          
         
       
     
     
       
         
               
             
               
               
             
               
               
               
               
               
             
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 6 
               
               
                   
               
               
                 Aspheric Coefficients 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Surface # 
               
             
          
           
               
                   
                 2 
                 3 
                 4 
                 5 
               
               
                   
               
               
                 K = 
                  9.0652E+00 
                  7.2386E+00 
                  2.5474E+00 
                 −2.1848E−01 
               
               
                 A4 = 
                 −3.9410E−01 
                 −5.0730E−01 
                 −9.9748E−01 
                 −3.8348E−01 
               
               
                 A6 = 
                 −1.3843E+00 
                  1.3499E−01 
                  2.2818E+00 
                  7.5231E−01 
               
               
                 A8 = 
                  1.3452E+01 
                 −1.2440E+00 
                 −4.4276E−01 
                 −8.5089E−02 
               
               
                 A10 = 
                 −1.5519E+02 
                  8.2907E−01 
                  5.3296E+00 
                  4.3765E−02 
               
               
                 A12 = 
                  6.8126E+02 
                  4.7600E+00 
                 −1.6658E+01 
                 −9.8219E−01 
               
               
                 A14 = 
                 −1.2385E+03 
                 −9.9423E+00 
                  1.7906E+01 
                  1.1566E+00 
               
               
                   
               
             
          
           
               
                   
                 Surface # 
               
             
          
           
               
                   
                 6 
                 7 
                 8 
                 9 
               
               
                   
               
               
                 K = 
                  5.3088E+00 
                 −4.1683E+00 
                 −1.0957E+00 
                 −3.5058E+00 
               
               
                 A4 = 
                  7.7918E−01 
                 −3.9891E−01 
                 −7.4026E−01 
                 −2.7693E−01 
               
               
                 A6 = 
                 −1.7450E+00 
                  8.4426E−01 
                  3.7403E−01 
                  1.6853E−01 
               
               
                 A8 = 
                  1.6426E+00 
                 −1.1500E+00 
                  2.9463E−02 
                 −9.3039E−02 
               
               
                 A10 = 
                  1.0779E+00 
                  1.9614E−01 
                 −4.7061E−01 
                  2.9952E−02 
               
               
                 A12 = 
                 −3.0840E+00 
                  1.2065E+00 
                  5.4626E−01 
                 −2.0387E−03 
               
               
                 A14 = 
                  2.4938E+00 
                 −5.8137E−01 
                 −2.1060E−01 
                 −1.3616E−03 
               
               
                   
               
             
          
         
       
     
     In the 3rd embodiment, the equation of the aspheric surface profiles of the aforementioned lens elements is the same as the equation of the 1st embodiment. Also, the definitions of these parameters shown in the following table are the same as those stated in the 1st embodiment with corresponding values for the 3rd embodiment, so an explanation in this regard will not be provided again. 
     Moreover, these parameters can be calculated from Table 5 and Table 6 as the following values and satisfy the following conditions: 
     
       
         
               
             
               
               
               
               
               
             
           
               
                   
               
               
                 Embodiment 3 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 f 
                 1.97 
                 (CT2 + CT4)/TD 
                 0.27 
               
               
                   
                 Fno 
                 2.08 
                 f1/f2 
                 −0.67 
               
               
                   
                 HFOV 
                 42.0 
                 f2/f4 
                 1.36 
               
               
                   
                 (R3 − R4)/(R3 + R4) 
                 −0.58 
                 V4 − V2 
                 33.1 
               
               
                   
                 (R5 − R6)/(R5 + R6) 
                 0.55 
                 1/|tan(HFOV)| 
                 1.11 
               
               
                   
                 (CT1 + CT3)/TD 
                 0.55 
                 TTL/ImgH 
                 1.647 
               
               
                   
                   
               
             
          
         
       
     
       FIG. 4A  shows an optical imaging lens assembly in accordance with a fourth embodiment of the present invention, and  FIG. 4B  shows, in order from left to right, the longitudinal spherical aberration curves, the astigmatic field curves, and the distortion curve of the fourth embodiment of the present invention. An optical imaging lens assembly in accordance with the fourth embodiment of the present invention comprises an aperture stop  400  and an optical assembly. The optical assembly comprises, in order from an object side to an image side: a first lens element  410 , a second lens element  420 , a third lens element  430 , a fourth lens element  440 , an IR cut filter  470  and an image plane  480 , wherein the optical imaging lens assembly has a total of four lens elements with refractive power. The aperture stop  400  is located between an image-side surface  412  of the first lens element  410  and an object to be photographed. 
     The first lens element  410  with a positive refractive power has an object-side surface  411  being convex near an optical axis  490  and the image-side surface  412  being convex near the optical axis  490 , both the object-side and image-side surfaces  411 ,  412  are aspheric, and the first lens element  410  is made of plastic material. 
     The second lens element  420  with a negative refractive power has an object-side surface  421  being concave near the optical axis  490  and an image-side surface  422  being concave near the optical axis  490 , both the object-side and image-side surfaces  421 ,  422  are aspheric, and the second lens element  420  is made of plastic material. 
     The third lens element  430  with a positive refractive power has an object-side surface  431  being concave near the optical axis  490  and an image-side surface  432  being convex near the optical axis  490 , both the object-side and image-side surfaces  431 ,  432  are aspheric, the third lens element  430  is made of plastic material. 
     The fourth lens element  440  with a negative refractive power has an object-side surface  441  being convex near the optical axis  490  and an image-side surface  442  being concave near the optical axis  490 , both the object-side and image-side surfaces  441 ,  442  are aspheric, the fourth lens element  440  is made of plastic material, and more than one inflection point is formed on the object-side surface  441  and the image-side surface  442  of the fourth lens element  440 . 
     The IR cut filter  470  made of glass is located between the fourth lens element  440  and the image plane  480  and has no influence on the focal length of the optical imaging lens assembly. 
     The detailed optical data of the fourth embodiment is shown in Table 7 and the aspheric surface data is shown in Table 8 below. 
     
       
         
               
             
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 7 
               
             
             
               
                   
               
               
                 (Embodiment 4) 
               
               
                 f(focal length) = 1.99 mm, Fno = 2.09, HFOV = 41.8 deg. 
               
             
          
           
               
                   
                   
                 Curvature  
                   
                   
                   
                   
                 Focal 
               
               
                 Surface 
                   
                 Radius 
                 Thickness 
                 Material 
                 index 
                 Abbe # 
                 length 
               
               
                   
               
             
          
           
               
                 0 
                 Object 
                 Plane 
                 Infinity 
                   
                   
                   
                   
               
               
                 1 
                 Aperture 
                 Plane 
                 −0.048 
                   
                   
                   
                   
               
               
                   
                 stop 
                   
                   
                   
                   
                   
                   
               
               
                 2 
                 Lens 1 
                   1.676(ASP) 
                 0.525 
                 Plastic 
                 1.544 
                 55.9 
                 2.03 
               
               
                 3 
                   
                 −2.898(ASP) 
                 0.258 
                   
                   
                   
                   
               
               
                 4 
                 Lens 2 
                 −1.379(ASP) 
                 0.220 
                 Plastic 
                 1.641 
                 22.6 
                 −2.82 
               
               
                 5 
                   
                 −5.770(ASP) 
                 0.059 
                   
                   
                   
                   
               
               
                 6 
                 Lens 3 
                 −2.497(ASP) 
                 0.582 
                 Plastic 
                 1.544 
                 55.9 
                 1.07 
               
               
                 7 
                   
                 −0.512(ASP) 
                 0.030 
                   
                   
                   
                   
               
               
                 8 
                 Lens 4 
                   1.177(ASP) 
                 0.281 
                 Plastic 
                 1.544 
                 55.9 
                 −1.36 
               
               
                 9 
                   
                   0.417(ASP) 
                 0.366 
                   
                   
                   
                   
               
               
                 10 
                 IR-filter 
                 Plane 
                 0.21 
                 Glass 
                 1.517 
                 64.2 
                 — 
               
               
                 11 
                   
                 Plane 
                 0.49 
                   
                   
                   
                   
               
               
                 12 
                 Image 
                 Plane 
               
               
                   
               
             
          
         
       
     
     
       
         
               
             
               
               
             
               
               
               
               
               
             
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 8 
               
               
                   
               
               
                 Aspheric Coefficients 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Surface # 
               
             
          
           
               
                   
                 2 
                 3 
                 4 
                 5 
               
               
                   
               
               
                 K = 
                  9.0363E+00 
                  3.9821E+00 
                  2.6019E+00 
                  8.8462E+00 
               
               
                 A4 = 
                 −3.8477E−01 
                 −4.7946E−01 
                 −1.0067E+00 
                 −4.0381E−01 
               
               
                 A6 = 
                 −1.3525E+00 
                  1.4370E−01 
                  2.3460E+00 
                  7.0791E−01 
               
               
                 A8 = 
                  1.3569E+01 
                 −1.2156E+00 
                 −4.5829E−01 
                 −8.6701E−02 
               
               
                 A10 = 
                 −1.5466E+02 
                  7.8839E−01 
                  5.1792E+00 
                  9.7930E−02 
               
               
                 A12 = 
                  6.8126E+02 
                  5.0834E+00 
                 −1.6746E+01 
                 −9.6332E−01 
               
               
                 A14 = 
                 −1.2385E+03 
                 −9.9423E+00 
                  1.8969E+01 
                  1.0464E+00 
               
               
                   
               
             
          
           
               
                   
                 Surface # 
               
             
          
           
               
                   
                 6 
                 7 
                 8 
                 9 
               
               
                   
               
               
                 K = 
                  6.7293E+00 
                 −4.1411E+00 
                 −6.2737E−01 
                 −4.0991E+00 
               
               
                 A4 = 
                  7.3392E−01 
                 −3.9934E−01 
                 −7.0441E−01 
                 −2.6822E−01 
               
               
                 A6 = 
                 −1.7345E+00 
                  8.4821E−01 
                  2.9182E−01 
                  1.6102E−01 
               
               
                 A8 = 
                  1.6180E+00 
                 −1.1537E+00 
                  3.8787E−02 
                 −9.1241E−02 
               
               
                 A10 = 
                  9.8328E−01 
                  1.9304E−01 
                 −4.2576E−01 
                  3.1466E−02 
               
               
                 A12 = 
                 −3.1320E+00 
                  1.2149E+00 
                  5.4781E−01 
                 −2.5309E−03 
               
               
                 A14 = 
                  2.4319E+00 
                 −5.8799E−01 
                 −2.3172E−01 
                 −1.5113E−03 
               
               
                   
               
             
          
         
       
     
     In the 4th embodiment, the equation of the aspheric surface profiles of the aforementioned lens elements is the same as the equation of the 1st embodiment. Also, the definitions of these parameters shown in the following table are the same as those stated in the 1st embodiment with corresponding values for the 4th embodiment, so an explanation in this regard will not be provided again. 
     Moreover, these parameters can be calculated from Table 7 and Table 8 as the following values and satisfy the following conditions: 
     
       
         
               
             
               
               
               
               
               
             
           
               
                   
               
               
                 Embodiment 4 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 f 
                 1.99 
                 (CT2 + CT4)/TD 
                 0.26 
               
               
                   
                 Fno 
                 2.09 
                 f1/f2 
                 −0.72 
               
               
                   
                 HFOV 
                 41.8 
                 f2/f4 
                 2.07 
               
               
                   
                 (R3 − R4)/(R3 + R4) 
                 −0.61 
                 V4 − V2 
                 33.3 
               
               
                   
                 (R5 − R6)/(R5 + R6) 
                 0.66 
                 1/|tan(HFOV)| 
                 1.12 
               
               
                   
                 (CT1 + CT3)/TD 
                 0.57 
                 TTL/ImgH 
                 1.647 
               
               
                   
                   
               
             
          
         
       
     
       FIG. 5A  shows an optical imaging lens assembly in accordance with a fifth embodiment of the present invention, and  FIG. 5B  shows, in order from left to right, the longitudinal spherical aberration curves, the astigmatic field curves, and the distortion curve of the fifth embodiment of the present invention. An optical imaging lens assembly in accordance with the fifth embodiment of the present invention comprises an aperture stop  500  and an optical assembly. The optical assembly comprises, in order from an object side to an image side: a first lens element  510 , a second lens element  520 , a third lens element  530 , a fourth lens element  540 , an IR cut filter  570  and an image plane  580 , wherein the optical imaging lens assembly has a total of four lens elements with refractive power. The aperture stop  500  is located between an image-side surface  512  of the first lens element  510  and an object to be photographed. 
     The first lens element  510  with a positive refractive power has an object-side surface  511  being convex near an optical axis  590  and the image-side surface  512  being convex near the optical axis  590 , both the object-side and image-side surfaces  511 ,  512  are aspheric, and the first lens element  510  is made of plastic material. 
     The second lens element  520  with a negative refractive power has an object-side surface  521  being concave near the optical axis  590  and an image-side surface  522  being concave near the optical axis  590 , both the object-side and image-side surfaces  521 ,  522  are aspheric, and the second lens element  520  is made of plastic material. 
     The third lens element  530  with a positive refractive power has an object-side surface  531  being concave near the optical axis  590  and an image-side surface  532  being convex near the optical axis  590 , both the object-side and image-side surfaces  531 ,  532  are aspheric, the third lens element  530  is made of plastic material. 
     The fourth lens element  540  with a negative refractive power has an object-side surface  541  being convex near the optical axis  590  and an image-side surface  542  being concave near the optical axis  590 , both the object-side and image-side surfaces  541 ,  542  are aspheric, the fourth lens element  540  is made of plastic material, and more than one inflection point is formed on the object-side surface  541  and the image-side surface  542  of the fourth lens element  540 . 
     The IR cut filter  570  made of glass is located between the fourth lens element  540  and the image plane  580  and has no influence on the focal length of the optical imaging lens assembly. 
     The detailed optical data of the fifth embodiment is shown in Table 9 and the aspheric surface data is shown in Table 10 below. 
     
       
         
               
             
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 9 
               
             
             
               
                   
               
               
                 (Embodiment 5) 
               
               
                 f(focal length) = 1.96 mm, Fno = 2.03, HFOV = 42.0 deg. 
               
             
          
           
               
                   
                   
                   
                   
                   
                   
                   
                 Focal 
               
               
                 Surface 
                   
                 Curvature Radius 
                 Thickness 
                 Material 
                 index 
                 Abbe # 
                 length 
               
               
                   
               
             
          
           
               
                 0 
                 Object 
                 Plane 
                 Infinity 
                   
                   
                   
                   
               
               
                 1 
                 Aperture 
                 Plane 
                 −0.041 
                   
                   
                   
                   
               
               
                   
                 stop 
                   
                   
                   
                   
                   
                   
               
               
                 2 
                 Lens 1 
                   1.687(ASP) 
                 0.443 
                 Plastic 
                 1.544 
                 55.9 
                 2.01 
               
               
                 3 
                   
                 −2.835(ASP) 
                 0.242 
                   
                   
                   
                   
               
               
                 4 
                 Lens 2 
                 −1.361(ASP) 
                 0.225 
                 Plastic 
                 1.641 
                 22.6 
                 −2.88 
               
               
                 5 
                   
                 −5.501(ASP) 
                 0.093 
                   
                   
                   
                   
               
               
                 6 
                 Lens 3 
                 −2.320(ASP) 
                 0.516 
                 Plastic 
                 1.544 
                 55.9 
                 1.41 
               
               
                 7 
                   
                 −0.624(ASP) 
                 0.030 
                   
                   
                   
                   
               
               
                 8 
                 Lens 4 
                   1.187(ASP) 
                 0.369 
                 Plastic 
                 1.535 
                 55.7 
                 −2.06 
               
               
                 9 
                   
                   0.514(ASP) 
                 0.313 
                   
                   
                   
                   
               
               
                 10 
                 IR-filter 
                 Plane 
                 0.21 
                 Glass 
                 1.517 
                 64.2 
                 — 
               
               
                 11 
                   
                 Plane 
                 0.49 
                   
                   
                   
                   
               
               
                 12 
                 Image 
                 Plane 
               
               
                   
               
             
          
         
       
     
     
       
         
               
             
               
               
             
               
               
               
               
               
             
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 10 
               
               
                   
               
               
                 Aspheric Coefficients 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Surface # 
               
             
          
           
               
                   
                 2 
                 3 
                 4 
                 5 
               
               
                   
               
               
                 K = 
                  9.0927E+00 
                  8.6876E+00 
                  2.6325E+00 
                 −2.6193E+00 
               
               
                 A4 = 
                 −4.2540E−01 
                 −5.1798E−01 
                 −9.4563E−01 
                 −3.9125E−01 
               
               
                 A6 = 
                 −1.4805E+00 
                  7.6398E−02 
                  2.3547E+00 
                  7.4798E−01 
               
               
                 A8 = 
                  1.3207E+01 
                 −1.2839E+00 
                 −3.3513E−01 
                 −6.9831E−02 
               
               
                 A10 = 
                 −1.5499E+02 
                  6.3185E−01 
                  5.4777E+00 
                  6.6406E−02 
               
               
                 A12 = 
                  6.8126E+02 
                  4.8393E+00 
                 −1.6814E+01 
                 −1.0032E+00 
               
               
                 A14 = 
                 −1.2385E+03 
                 −9.9423E+00 
                  1.8969E+01 
                  1.1410E+00 
               
               
                   
               
             
          
           
               
                   
                 Surface # 
               
             
          
           
               
                   
                 6 
                 7 
                 8 
                 9 
               
               
                   
               
               
                 K = 
                  6.0082E+00 
                 −4.0458E+00 
                 −5.7212E−01 
                 −4.2103E+00 
               
               
                 A4 = 
                  7.9217E−01 
                 −3.5538E−01 
                 −7.0994E−01 
                 −2.5643E−01 
               
               
                 A6 = 
                 −1.7182E+00 
                  8.5775E−01 
                  3.4867E−01 
                  1.6656E−01 
               
               
                 A8 = 
                  1.6310E+00 
                 −1.1447E+00 
                  3.3745E−02 
                 −9.3994E−02 
               
               
                 A10 = 
                  1.0176E+00 
                  2.1408E−01 
                 −4.6576E−01 
                  2.9158E−02 
               
               
                 A12 = 
                 −3.1213E+00 
                  1.2252E+00 
                  5.3921E−01 
                 −2.1889E−03 
               
               
                 A14 = 
                  2.4333E+00 
                 −5.7671E−01 
                 −2.1226E−01 
                 −9.4370E−04 
               
               
                   
               
             
          
         
       
     
     In the 5th embodiment, the equation of the aspheric surface profiles of the aforementioned lens elements is the same as the equation of the 1st embodiment. Also, the definitions of these parameters shown in the following table are the same as those stated in the 1st embodiment with corresponding values for the 5th embodiment, so an explanation in this regard will not be provided again. 
     Moreover, these parameters can be calculated from Table 9 and Table 10 as the following values and satisfy the following conditions: 
     
       
         
               
             
               
               
               
               
               
             
           
               
                   
               
               
                 Embodiment 5 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 f 
                 1.96 
                 (CT2 + CT4)/TD 
                 0.31 
               
               
                   
                 Fno 
                 2.03 
                 f1/f2 
                 −0.70 
               
               
                   
                 HFOV 
                 42.0 
                 f2/f4 
                 1.39 
               
               
                   
                 (R3 − R4)/(R3 + R4) 
                 −0.60 
                 V4 − V2 
                 33.1 
               
               
                   
                 (R5 − R6)/(R5 + R6) 
                 0.58 
                 1/|tan(HFOV)| 
                 1.11 
               
               
                   
                 (CT1 + CT3)/TD 
                 0.50 
                 TTL/ImgH 
                 1.614 
               
               
                   
                   
               
             
          
         
       
     
       FIG. 6A  shows an optical imaging lens assembly in accordance with a sixth embodiment of the present invention, and  FIG. 6B  shows, in order from left to right, the longitudinal spherical aberration curves, the astigmatic field curves, and the distortion curve of the sixth embodiment of the present invention. An optical imaging lens assembly in accordance with the sixth embodiment of the present invention comprises an aperture stop  600  and an optical assembly. The optical assembly comprises, in order from an object side to an image side: a first lens element  610 , a second lens element  620 , a third lens element  630 , a fourth lens element  640 , an IR cut filter  670  and an image plane  680 , wherein the optical imaging lens assembly has a total of four lens elements with refractive power. The aperture stop  600  is located between an image-side surface  612  of the first lens element  610  and an object to be photographed. 
     The first lens element  610  with a positive refractive power has an object-side surface  611  being convex near an optical axis  690  and the image-side surface  612  being convex near the optical axis  690 , both the object-side and image-side surfaces  611 ,  612  are aspheric, and the first lens element  610  is made of plastic material. 
     The second lens element  620  with a negative refractive power has an object-side surface  621  being concave near the optical axis  690  and an image-side surface  622  being concave near the optical axis  690 , both the object-side and image-side surfaces  621 ,  622  are aspheric, and the second lens element  620  is made of plastic material. 
     The third lens element  630  with a positive refractive power has an object-side surface  631  being concave near the optical axis  690  and an image-side surface  632  being convex near the optical axis  690 , both the object-side and image-side surfaces  631 ,  632  are aspheric, the third lens element  630  is made of plastic material. 
     The fourth lens element  640  with a negative refractive power has an object-side surface  641  being convex near the optical axis  690  and an image-side surface  642  being concave near the optical axis  690 , both the object-side and image-side surfaces  641 ,  642  are aspheric, the fourth lens element  640  is made of plastic material, and more than one inflection point is formed on the object-side surface  641  and the image-side surface  642  of the fourth lens element  640 . 
     The IR cut filter  670  made of glass is located between the fourth lens element  640  and the image plane  680  and has no influence on the focal length of the optical imaging lens assembly. 
     The detailed optical data of the sixth embodiment is shown in Table 11 and the aspheric surface data is shown in Table 12 below. 
     
       
         
               
             
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 11 
               
             
             
               
                   
               
               
                 (Embodiment 6) 
               
               
                 f(focal length) = 1.94 mm, Fno = 2.04, HFOV = 42.5 deg. 
               
             
          
           
               
                   
                   
                   
                   
                   
                   
                   
                 Focal 
               
               
                 Surface 
                   
                 Curvature Radius 
                 Thickness 
                 Material 
                 index 
                 Abbe # 
                 length 
               
               
                   
               
             
          
           
               
                 0 
                 Object 
                 Plane 
                 Infinity 
                   
                   
                   
                   
               
               
                 1 
                 Aperture 
                 Plane 
                 −0.05 
                   
                   
                   
                   
               
               
                   
                 stop 
                   
                   
                   
                   
                   
                   
               
               
                 2 
                 Lens 1 
                   1.672(ASP) 
                 0.495 
                 Plastic 
                 1.544 
                 55.9 
                 2.00 
               
               
                 3 
                   
                 −2.822(ASP) 
                 0.248 
                   
                   
                   
                   
               
               
                 4 
                 Lens 2 
                 −1.386(ASP) 
                 0.232 
                 Plastic 
                 1.641 
                 22.6 
                 −2.80 
               
               
                 5 
                   
                 −5.300(ASP) 
                 0.058 
                   
                   
                   
                   
               
               
                 6 
                 Lens 3 
                 −2.562(ASP) 
                 0.590 
                 Plastic 
                 1.544 
                 55.9 
                 1.10 
               
               
                 7 
                   
                 −0.525(ASP) 
                 0.030 
                   
                   
                   
                   
               
               
                 8 
                 Lens 4 
                   1.284(ASP) 
                 0.321 
                 Plastic 
                 1.544 
                 55.9 
                 −1.40 
               
               
                 9 
                   
                   0.436(ASP) 
                 0.346 
                   
                   
                   
                   
               
               
                 10 
                 IR-filter 
                 Plane 
                 0.21 
                 Glass 
                 1.517 
                 64.2 
                 — 
               
               
                 11 
                   
                 Plane 
                 0.49 
                   
                   
                   
                   
               
               
                 12 
                 Image 
                 Plane 
               
               
                   
               
             
          
         
       
     
     
       
         
               
             
               
               
             
               
               
               
               
               
             
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 12 
               
               
                   
               
               
                 Aspheric Coefficients 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Surface # 
               
             
          
           
               
                   
                 2 
                 3 
                 4 
                 5 
               
               
                   
               
               
                 K = 
                  9.0150E+00 
                  5.6760E+00 
                  2.5449E+00 
                 −2.1960E+01 
               
               
                 A4 = 
                 −3.9900E−01 
                 −4.9516E−01 
                 −9.8468E−01 
                 −3.8484E−01 
               
               
                 A6 = 
                 −1.3922E+00 
                  1.2704E−01 
                  2.3519E+00 
                  7.1490E−01 
               
               
                 A8 = 
                  1.3463E+01 
                 −1.2699E+00 
                 −4.5754E−01 
                 −8.3307E−02 
               
               
                 A10 = 
                 −1.5539E+02 
                  6.6558E−01 
                  5.2014E+00 
                  9.7980E−02 
               
               
                 A12 = 
                  6.8126E+02 
                  5.0834E+00 
                 −1.6504E+01 
                 −9.7233E−01 
               
               
                 A14 = 
                 −1.2385E+03 
                 −9.9423E+00 
                  1.8969E+01 
                  9.9094E−01 
               
               
                   
               
             
          
           
               
                   
                 Surface # 
               
             
          
           
               
                   
                 6 
                 7 
                 8 
                 9 
               
               
                   
               
               
                 K = 
                  7.0085E+00 
                 −3.9966E+00 
                 −8.6885E−02 
                 −4.2557E+00 
               
               
                 A4 = 
                  7.4911E−01 
                 −3.7442E−01 
                 −6.2386E−01 
                 −2.1908E−01 
               
               
                 A6 = 
                 −1.7110E+00 
                  8.5381E−01 
                  2.4813E−01 
                  1.3971E−01 
               
               
                 A8 = 
                  1.6288E+00 
                 −1.1740E+00 
                  2.1768E−02 
                 −9.0180E−02 
               
               
                 A10 = 
                  9.7068E−01 
                  1.6940E−01 
                 −4.4956E−01 
                  3.1668E−02 
               
               
                 A12 = 
                 −3.1758E+00 
                  1.2015E+00 
                  5.4814E−01 
                 −2.6632E−03 
               
               
                 A14 = 
                  2.3481E+00 
                 −5.8380E−01 
                 −2.1139E−01 
                 −9.4706E−04 
               
               
                   
               
             
          
         
       
     
     In the 6th embodiment, the equation of the aspheric surface profiles of the aforementioned lens elements is the same as the equation of the 1st embodiment. Also, the definitions of these parameters shown in the following table are the same as those stated in the 1st embodiment with corresponding values for the 6th embodiment, so an explanation in this regard will not be provided again. 
     Moreover, these parameters can be calculated from Table 11 and Table 12 as the following values and satisfy the following conditions: 
     
       
         
               
             
               
               
               
               
               
             
           
               
                   
               
               
                 Embodiment 6 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 f 
                 1.94 
                 (CT2 + CT4)/TD 
                 0.28 
               
               
                   
                 Fno 
                 2.04 
                 f1/f2 
                 −0.71 
               
               
                   
                 HFOV 
                 42.5 
                 f2/f4 
                 2.01 
               
               
                   
                 (R3 − R4)/(R3 + R4) 
                 −0.59 
                 V4 − V2 
                 33.3 
               
               
                   
                 (R5 − R6)/(R5 + R6) 
                 0.66 
                 1/|tan(HFOV)| 
                 1.09 
               
               
                   
                 (CT1 + CT3)/TD 
                 0.55 
                 TTL/ImgH 
                 1.647 
               
               
                   
                   
               
             
          
         
       
     
       FIG. 7A  shows an optical imaging lens assembly in accordance with a seventh embodiment of the present invention, and  FIG. 7B  shows, in order from left to right, the longitudinal spherical aberration curves, the astigmatic field curves, and the distortion curve of the seventh embodiment of the present invention. An optical imaging lens assembly in accordance with the seventh embodiment of the present invention comprises an aperture stop  700  and an optical assembly. The optical assembly comprises, in order from an object side to an image side: a first lens element  710 , a second lens element  720 , a third lens element  730 , a fourth lens element  740 , an IR cut filter  770  and an image plane  780 , wherein the optical imaging lens assembly has a total of four lens elements with refractive power. The aperture stop  700  is located between an image-side surface  712  of the first lens element  710  and an object to be photographed. 
     The first lens element  710  with a positive refractive power has an object-side surface  711  being convex near an optical axis  790  and the image-side surface  712  being convex near the optical axis  790 , both the object-side and image-side surfaces  711 ,  712  are aspheric, and the first lens element  710  is made of plastic material. 
     The second lens element  720  with a negative refractive power has an object-side surface  721  being concave near the optical axis  790  and an image-side surface  722  being concave near the optical axis  790 , both the object-side and image-side surfaces  721 ,  722  are aspheric, and the second lens element  720  is made of plastic material. 
     The third lens element  730  with a positive refractive power has an object-side surface  731  being concave near the optical axis  790  and an image-side surface  732  being convex near the optical axis  790 , both the object-side and image-side surfaces  731 ,  732  are aspheric, the third lens element  730  is made of plastic material. 
     The fourth lens element  740  with a negative refractive power has an object-side surface  741  being convex near the optical axis  790  and an image-side surface  742  being concave near the optical axis  790 , both the object-side and image-side surfaces  741 ,  742  are aspheric, the fourth lens element  740  is made of plastic material, and more than one inflection point is formed on the object-side surface  741  and the image-side surface  742  of the fourth lens element  740 . 
     The IR cut filter  770  made of glass is located between the fourth lens element  740  and the image plane  780  and has no influence on the focal length of the optical imaging lens assembly. 
     The detailed optical data of the seventh embodiment is shown in Table 13 and the aspheric surface data is shown in Table 14 below. 
     
       
         
               
             
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 13 
               
             
             
               
                   
               
               
                 (Embodiment 7) 
               
               
                 f(focal length) = 1.97 mm, Fno = 2.05, HFOV = 42.1 deg. 
               
             
          
           
               
                   
                   
                 Curvature 
                   
                   
                   
                   
                 Focal 
               
               
                 Surface 
                   
                 Radius 
                 Thickness 
                 Material 
                 index 
                 Abbe # 
                 length 
               
               
                   
               
             
          
           
               
                 0 
                 Object 
                 Plane 
                 Infinity 
                   
                   
                   
                   
               
               
                 1 
                 Aperture 
                 Plane 
                 −0.048 
                   
                   
                   
                   
               
               
                   
                 stop 
                   
                   
                   
                   
                   
                   
               
               
                 2 
                 Lens 1 
                   1.681(ASP) 
                 0.509 
                 Plastic 
                 1.544 
                 55.9 
                 2.01 
               
               
                 3 
                   
                 −2.795(ASP) 
                 0.235 
                   
                   
                   
                   
               
               
                 4 
                 Lens 2 
                 −1.412(ASP) 
                 0.220 
                 Plastic 
                 1.641 
                 22.6 
                 −2.84 
               
               
                 5 
                   
                 −5.720(ASP) 
                 0.067 
                   
                   
                   
                   
               
               
                 6 
                 Lens 3 
                 −2.329(ASP) 
                 0.591 
                 Plastic 
                 1.544 
                 55.9 
                 1.22 
               
               
                 7 
                   
                 −0.565(ASP) 
                 0.030 
                   
                   
                   
                   
               
               
                 8 
                 Lens 4 
                   1.002(ASP) 
                 0.283 
                 Plastic 
                 1.535 
                 56.3 
                 −1.73 
               
               
                 9 
                   
                   0.437(ASP) 
                 0.354 
                   
                   
                   
                   
               
               
                 10 
                 IR-filter 
                 Plane 
                 0.21 
                 Glass 
                 1.517 
                 64.2 
                 — 
               
               
                 11 
                   
                 Plane 
                 0.49 
                   
                   
                   
                   
               
               
                 12 
                 Image 
                 Plane 
                   
                   
                   
                   
                   
               
               
                   
               
             
          
         
       
     
     
       
         
               
             
               
               
             
               
               
               
               
               
             
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 14 
               
               
                   
               
               
                 Aspheric Coefficients 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Surface # 
               
             
          
           
               
                   
                 2 
                 3 
                 4 
                 5 
               
               
                   
               
               
                 K = 
                  9.0492E+00 
                  6.6888E+00 
                  2.5641E+00 
                 −2.5278E+00 
               
               
                 A4 = 
                 −3.8567E−01 
                 −5.0410E−01 
                 −1.0037E+00 
                 −3.8391E−01 
               
               
                 A6 = 
                 −1.3921E+00 
                  1.3501E−01 
                  2.2892E+00 
                  7.2148E−01 
               
               
                 A8 = 
                  1.3479E+01 
                 −1.2073E+00 
                 −4.8955E−01 
                 −1.0971E−01 
               
               
                 A10 = 
                 −1.5444E+02 
                  8.3034E−01 
                  5.2049E+00 
                  3.2102E−02 
               
               
                 A12 = 
                  6.8126E+02 
                  4.5623E+00 
                 −1.6891E+01 
                 −9.9516E−01 
               
               
                 A14 = 
                 −1.2385E+03 
                 −9.9423E+00 
                  1.8969E+01 
                  1.1367E+00 
               
               
                   
               
             
          
           
               
                   
                 Surface # 
               
             
          
           
               
                   
                 6 
                 7 
                 8 
                 9 
               
               
                   
               
               
                 K = 
                  6.1125E+00 
                 −4.1840E+00 
                 −8.3226E−01 
                 −3.6840E+00 
               
               
                 A4 = 
                  7.5327E−01 
                 −3.9055E−01 
                 −7.2306E−01 
                 −2.5135E−01 
               
               
                 A6 = 
                 −1.7360E+00 
                  8.3879E−01 
                  3.5312E−01 
                  1.4865E−01 
               
               
                 A8 = 
                  1.6396E+00 
                 −1.1565E+00 
                  8.7076E−03 
                 −9.0562E−02 
               
               
                 A10 = 
                  1.0479E+00 
                  1.9102E−01 
                 −4.5982E−01 
                  3.1676E−02 
               
               
                 A12 = 
                 −3.1058E+00 
                  1.2159E+00 
                  5.4192E−01 
                 −2.0957E−03 
               
               
                 A14 = 
                  2.4362E+00 
                 −5.8183E−01 
                 −2.0463E−01 
                 −1.5484E−03 
               
               
                   
               
             
          
         
       
     
     In the 7th embodiment, the equation of the aspheric surface profiles of the aforementioned lens elements is the same as the equation of the 1st embodiment. Also, the definitions of these parameters shown in the following table are the same as those stated in the 1st embodiment with corresponding values for the 7th embodiment, so an explanation in this regard will not be provided again. 
     Moreover, these parameters can be calculated from Table 13 and Table 14 as the following values and satisfy the following conditions: 
     
       
         
               
             
               
               
               
               
               
             
           
               
                   
               
               
                 Embodiment 7 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 f 
                 1.97 
                 (CT2 + CT4)/TD 
                 0.26 
               
               
                   
                 Fno 
                 2.05 
                 f1/f2 
                 −0.71 
               
               
                   
                 HFOV 
                 42.1 
                 f2/f4 
                 1.64 
               
               
                   
                 (R3 − R4)/(R3 + R4) 
                 −0.60 
                 V4 − V2 
                 33.7 
               
               
                   
                 (R5 − R6)/(R5 + R6) 
                 0.61 
                 1/|tan(HFOV)| 
                 1.11 
               
               
                   
                 (CT1 + CT3)/TD 
                 0.57 
                 TTL/ImgH 
                 1.646 
               
               
                   
                   
               
             
          
         
       
     
       FIG. 8A  shows an optical imaging lens assembly in accordance with an eighth embodiment of the present invention, and  FIG. 8B  shows, in order from left to right, the longitudinal spherical aberration curves, the astigmatic field curves, and the distortion curve of the eighth embodiment of the present invention. An optical imaging lens assembly in accordance with the eighth embodiment of the present invention comprises an aperture stop  800  and an optical assembly. The optical assembly comprises, in order from an object side to an image side: a first lens element  810 , a second lens element  820 , a third lens element  830 , a fourth lens element  840 , an IR cut filter  870  and an image plane  880 , wherein the optical imaging lens assembly has a total of four lens elements with refractive power. The aperture stop  800  is located between an image-side surface  812  of the first lens element  810  and an object to be photographed. 
     The first lens element  810  with a positive refractive power has an object-side surface  811  being convex near an optical axis  890  and the image-side surface  812  being convex near the optical axis  890 , both the object-side and image-side surfaces  811 ,  812  are aspheric, and the first lens element  810  is made of plastic material. 
     The second lens element  820  with a negative refractive power has an object-side surface  821  being concave near the optical axis  890  and an image-side surface  822  being concave near the optical axis  890 , both the object-side and image-side surfaces  821 ,  822  are aspheric, and the second lens element  820  is made of plastic material. 
     The third lens element  830  with a positive refractive power has an object-side surface  831  being concave near the optical axis  890  and an image-side surface  832  being convex near the optical axis  890 , both the object-side and image-side surfaces  831 ,  832  are aspheric, the third lens element  830  is made of plastic material. 
     The fourth lens element  840  with a negative refractive power has an object-side surface  841  being convex near the optical axis  890  and an image-side surface  842  being concave near the optical axis  890 , both the object-side and image-side surfaces  841 ,  842  are aspheric, the fourth lens element  840  is made of plastic material, and more than one inflection point is formed on the object-side surface  841  and the image-side surface  842  of the fourth lens element  840 . 
     The IR cut filter  870  made of glass is located between the fourth lens element  840  and the image plane  880  and has no influence on the focal length of the optical imaging lens assembly. 
     The detailed optical data of the eighth embodiment is shown in Table 15 and the aspheric surface data is shown in Table 16 below. 
     
       
         
               
             
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 15 
               
             
             
               
                   
               
               
                 (Embodiment 8) 
               
               
                 f(focal length) = 1.98 mm, Fno = 2.05, HFOV = 41.9 deg. 
               
             
          
           
               
                   
                   
                 Curvature 
                   
                   
                   
                   
                 Focal 
               
               
                 Surface 
                   
                 Radius 
                 Thickness 
                 Material 
                 index 
                 Abbe # 
                 Length 
               
               
                   
               
             
          
           
               
                 0 
                 Object 
                 Plane 
                 Infinity 
                   
                   
                   
                   
               
               
                 1 
                 Aperture 
                 Plane 
                 −0.045 
                   
                   
                   
                   
               
               
                   
                 stop 
                   
                   
                   
                   
                   
                   
               
               
                 2 
                 Lens 1 
                   1.681(ASP) 
                 0.479 
                 Plastic 
                 1.544 
                 55.9 
                 1.99 
               
               
                 3 
                   
                 −2.759(ASP) 
                 0.234 
                   
                   
                   
                   
               
               
                 4 
                 Lens 2 
                 −1.356(ASP) 
                 0.244 
                 Plastic 
                 1.641 
                 22.6 
                 −2.82 
               
               
                 5 
                   
                 −5.570(ASP) 
                 0.063 
                   
                   
                   
                   
               
               
                 6 
                 Lens 3 
                 −2.322(ASP) 
                 0.550 
                 Plastic 
                 1.544 
                 55.9 
                 1.44 
               
               
                 7 
                   
                 −0.636(ASP) 
                 0.030 
                   
                   
                   
                   
               
               
                 8 
                 Lens 4 
                   1.158(ASP) 
                 0.365 
                 Plastic 
                 1.535 
                 55.7 
                 −2.14 
               
               
                 9 
                   
                   0.517(ASP) 
                 0.325 
                   
                   
                   
                   
               
               
                 10 
                 IR-filter 
                 Plane 
                 0.21 
                 Glass 
                 1.517 
                 64.2 
                 — 
               
               
                 11 
                   
                 Plane 
                 0.49 
                   
                   
                   
                   
               
               
                 12 
                 Image 
                 Plane 
               
               
                   
               
             
          
         
       
     
     
       
         
               
             
               
               
             
               
               
               
               
               
             
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 16 
               
               
                   
               
               
                 Aspheric Coefficients 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Surface # 
               
             
          
           
               
                   
                 2 
                 3 
                 4 
                 5 
               
               
                   
               
               
                 K = 
                  9.0103E+00 
                  8.2030E+00 
                  2.5698E+00 
                 −8.0525E+00 
               
               
                 A4 = 
                 −4.0226E−01 
                 −5.1732E−01 
                 −9.7791E−01 
                 −3.8598E−01 
               
               
                 A6 = 
                 −1.4504E+00 
                  1.3512E−01 
                  2.3174E+00 
                  7.3199E−01 
               
               
                 A8 = 
                  1.3341E+01 
                 −1.2221E+00 
                 −4.2063E−01 
                 −8.8419E−02 
               
               
                 A10 = 
                 −1.5436E+02 
                  6.0029E−01 
                  5.3960E+00 
                  5.9182E−02 
               
               
                 A12 = 
                  6.8126E+02 
                  5.0834E+00 
                 −1.6713E+01 
                 −9.7091E−01 
               
               
                 A14 = 
                 −1.2385E+03 
                 −9.9423E+00 
                  1.8969E+01 
                  1.1454E+00 
               
               
                   
               
             
          
           
               
                   
                 Surface # 
               
             
          
           
               
                   
                 6 
                 7 
                 8 
                 9 
               
               
                   
               
               
                 K = 
                  6.0798E+00 
                 −4.0143E+00 
                 −6.1657E−01 
                 −3.9848E+00 
               
               
                 A4 = 
                  7.7963E−01 
                 −3.7086E−01 
                 −7.0106E−01 
                 −2.5169E−01 
               
               
                 A6 = 
                 −1.7144E+00 
                  8.5042E−01 
                  3.2335E−01 
                  1.5983E−01 
               
               
                 A8 = 
                  1.6487E+00 
                 −1.1570E+00 
                  2.4174E−02 
                 −8.9294E−02 
               
               
                 A10 = 
                  1.0407E+00 
                  1.9395E−01 
                 −4.5484E−01 
                  2.8460E−02 
               
               
                 A12 = 
                 −3.1158E+00 
                  1.2190E+00 
                  5.4887E−01 
                 −2.8083E−03 
               
               
                 A14 = 
                  2.4267E+00 
                 −5.7015E−01 
                 −2.1833E−01 
                 −6.8920E−04 
               
               
                   
               
             
          
         
       
     
     In the 8th embodiment, the equation of the aspheric surface profiles of the aforementioned lens elements is the same as the equation of the 1st embodiment. Also, the definitions of these parameters shown in the following table are the same as those stated in the 1st embodiment with corresponding values for the 8th embodiment, so an explanation in this regard will not be provided again. 
     Moreover, these parameters can be calculated from Table 15 and Table 16 as the following values and satisfy the following conditions: 
     
       
         
               
             
               
               
               
               
               
             
           
               
                   
               
               
                 Embodiment 8 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 f 
                 1.98 
                 (CT2 + CT4)/TD 
                 0.31 
               
               
                   
                 Fno 
                 2.05 
                 f1/f2 
                 −0.71 
               
               
                   
                 HFOV 
                 41.9 
                 f2/f4 
                 1.32 
               
               
                   
                 (R3 − R4)/(R3 + R4) 
                 −0.61 
                 V4 − V2 
                 33.1 
               
               
                   
                 (R5 − R6)/(R5 + R6) 
                 0.57 
                 1/|tan(HFOV)| 
                 1.11 
               
               
                   
                 (CT1 + CT3)/TD 
                 0.52 
                 TTL/ImgH 
                 1.647 
               
               
                   
                   
               
             
          
         
       
     
     In the present optical imaging lens assembly, the lens elements can be made of plastic or glass. If the lens elements are made of plastic, the cost will be effectively reduced. If the lens elements are made of glass, there is more freedom in distributing the refractive power of the optical imaging lens assembly. Plastic lens elements can have aspheric surfaces, which allow more design parameter freedom (than spherical surfaces), so as to reduce the aberration and the number of the lens elements, as well as the total track length of the optical imaging lens assembly. 
     In the present optical imaging lens assembly, if the object-side or the image-side surface of the lens elements with refractive power is convex and the location of the convex surface is not defined, the object-side or the image-side surface of the lens elements near the optical axis is convex. If the object-side or the image-side surface of the lens elements is concave and the location of the concave surface is not defined, the object-side or the image-side surface of the lens elements near the optical axis is concave. 
     The optical imaging lens assembly of the present invention can be used in focusing optical systems and can obtain better image quality. The optical imaging lens assembly of the present invention can also be used in electronic imaging systems, such as, 3D image capturing, digital camera, mobile device, digital flat panel or vehicle camera. 
     The embodiments depicted above and the appended drawings are exemplary and are not intended to be exhaustive or to limit the scope of the present disclosure to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings. 
     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.