Patent Publication Number: US-2021191091-A1

Title: Wide-Angle Lens Assembly

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The invention relates to a wide-angle lens assembly. 
     Description of the Related Art 
     The current development trend of a wide-angle lens assembly is toward miniaturization and large field of view. Additionally, the wide-angle lens assembly is developed to have high resolution and resistance to severe environment temperature variation in accordance with different application requirements. However, the known wide-angle lens assembly can&#39;t satisfy such requirements. Therefore, the wide-angle lens assembly needs a new structure to meet the requirements of miniaturization, large field of view, high resolution, and resistance to severe environment temperature variation at the same time. 
     BRIEF SUMMARY OF THE INVENTION 
     The invention provides a wide-angle lens assembly to solve the above problems. The wide-angle lens assembly of the invention is provided with characteristics of a shortened total lens length, a larger field of view, a high resolution, a resistance to severe environment temperature variation, and still has a good optical performance. 
     The wide-angle lens assembly in accordance with an exemplary embodiment of the invention includes a first lens, a second lens, a third lens, a fourth lens, and a fifth lens. The first lens is a meniscus lens with negative refractive power. The second lens is a meniscus lens with positive refractive power. The third lens is with positive refractive power and comprises a convex surface facing an object side. The fourth lens is with positive refractive power. The fifth lens is with negative refractive power. The first lens, the second lens, the third lens, the fourth lens, and the fifth lens are arranged in order from the object side to an image side along an optical axis. The wide-angle lens assembly satisfies: 3&lt;TTL/BFL&lt;3.5: wherein TTL is an interval from an object side surface of the first lens to an image plane along the optical axis and BFL is an interval from an image side surface of the fifth lens to the image plane along the optical axis. 
     In another exemplary embodiment, the first lens further includes a convex surface facing the object side and a concave surface facing the image side, the second lens further includes a concave surface facing the object side and a convex surface facing the image side, the third lens further includes a convex surface facing the image side, and the fourth lens further includes a convex surface facing the object side and a convex surface facing the image side, the fifth lens further includes a concave surface or a convex surface facing the object side and a concave surface facing the image side. 
     In yet another exemplary embodiment, the wide-angle lens assembly satisfies: −3&lt;f 2 /f 1 &lt;−1, wherein f 1  is an effective focal length of the first lens and f 2  is an effective focal length of the second lens. 
     In another exemplary embodiment, the wide-angle lens assembly satisfies: 1&lt;f 2 /f 4 &lt;3, wherein f 2  is an effective focal length of the second lens and f 4  is an effective focal length of the fourth lens. 
     In yet another exemplary embodiment, the wide-angle lens assembly satisfies: 0.5&lt;f 1 /f 5 &lt;1.5, wherein f 1  is an effective focal length of the first lens and f 5  is an effective focal length of the fifth lens. 
     In yet another exemplary embodiment, the wide-angle lens assembly satisfies: 3&lt;R 11 /R 12 &lt;5; −11&lt;R 31 /R 32 &lt;−3; wherein R 11  is a radius of curvature of the object side surface of the first lens, R 12  is a radius of curvature of the image side surface of the first lens, R 31  is a radius of curvature of the object side surface of the third lens, and R 32  is a radius of curvature of the image side surface of the third lens. 
     In yet another exemplary embodiment, the wide-angle lens assembly satisfies: 20&lt;TTL/T 1 &lt;21.5, wherein T 1  is a thickness of the first lens along the optical axis. 
     In yet another exemplary embodiment, the wide-angle lens assembly satisfies: 8&lt;TTL/T 3 &lt;10, T 3  is a thickness of the third lens along the optical axis. 
     In yet another exemplary embodiment, the wide-angle lens assembly satisfies: 10&lt;TTL/T 4 &lt;13, T 4  is a thickness of the fourth lens along the optical axis. 
     In yet another exemplary embodiment, the wide-angle lens assembly satisfies: 72.08&lt;TTL/AT 34 &lt;114.31; 106.3&lt;TTL/AT 45 &lt;115.7; wherein AT 34  is an air-interval between the third lens and the fourth lens along the optical axis and AT 45  is an air-interval between the fourth lens and the fifth lens along the optical axis. 
     In yet another exemplary embodiment, the wide-angle lens assembly further comprises a sixth lens located between the third lens and the fourth lens. The sixth lens with negative refractive power has a concave surface facing the object side and another concave surface facing the image side. 
     A detailed description is given in the following embodiments with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein: 
         FIG. 1  is a lens layout diagram and an optical path of a wide-angle lens assembly in accordance with a first embodiment of the invention; 
         FIG. 2A  depicts a longitudinal aberration diagram of the wide-angle lens assembly in accordance with the first embodiment of the invention; 
         FIG. 2B  is a field curvature diagram of the wide-angle lens assembly in accordance with the first embodiment of the invention; 
         FIG. 2C  is a distortion diagram of the wide-angle lens assembly in accordance with the first embodiment of the invention: 
         FIG. 2D  is a through focus modulation transfer function diagram of the wide-angle lens assembly at −10° C., 20° C., and 70° C. in accordance with the first embodiment of the invention; 
         FIG. 3  is a lens layout diagram and an optical path of a wide-angle lens assembly in accordance with a second embodiment of the invention: 
         FIG. 4A  depicts a longitudinal aberration diagram of the wide-angle lens assembly in accordance with the second embodiment of the invention; 
         FIG. 4B  is a field curvature diagram of the wide-angle lens assembly in accordance with the second embodiment of the invention; 
         FIG. 4C  is a distortion diagram of the wide-angle lens assembly in accordance with the second embodiment of the invention; 
         FIG. 4D  is a through focus modulation transfer function diagram of the wide-angle lens assembly at −10° C., 20° C., and 70° C. in accordance with the second embodiment of the invention; 
         FIG. 5  is a lens layout diagram and an optical path of a wide-angle lens assembly in accordance with a third embodiment of the invention; 
         FIG. 6A  depicts a longitudinal aberration diagram of the wide-angle lens assembly in accordance with the third embodiment of the invention; 
         FIG. 6B  is a field curvature diagram of the wide-angle lens assembly in accordance with the third embodiment of the invention: 
         FIG. 6C  is a distortion diagram of the wide-angle lens assembly in accordance with the third embodiment of the invention: 
         FIG. 6D  is a through focus modulation transfer function diagram of the wide-angle lens assembly at −10° C., 20° C., and 70° C. in accordance with the third embodiment of the invention: and 
         FIG. 7  is a lens layout diagram of a wide-angle lens assembly in accordance with a fourth embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The following description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by reference to the appended claims. 
     The invention provides a wide-angle lens including a first lens which is a meniscus lens with negative refractive power, a second lens which is a meniscus lens with positive refractive power, a third lens with positive refractive power, a fourth lens with positive refractive power, and a fifth lens with negative refractive power. The first lens, the second lens, the third lens, the fourth lens, and the fifth lens are arranged in order from an object side to an image side along an optical axis. The wide-angle lens assembly satisfies: 3&lt;TTL/BFL&lt;3.5: wherein TTL is an interval from an object side surface of the first lens to an image plane along the optical axis and BFL is an interval from an image side surface of the fifth lens to the image plane along the optical axis. 
     Referring to Table 1, Table 2, Table 3, Table 4, Table 5, Table 6, Table 7, Table 8, Table 9, Table 10, Table 11 and Table 12, wherein Table 1, Table 4, Table 7, and Table 10 show the parameters of the lenses in accordance with the first embodiment to the fourth embodiment of the invention respectively. Table 2, Table 5, Table 8, and Table 11 show the parameters of aspheric surfaces of each aspheric lenses in Table 1, Table 4, Table 7, and Table 10 respectively. 
       FIG. 1 ,  FIG. 3 , and  FIG. 5  are the lens layout diagram and the optical path of the wide-angle lens assembly in accordance with the first embodiment, the second embodiment, and the third embodiment of the invention respectively.  FIG. 7  is the lens layout diagram of the wide-angle lens assembly in accordance with the fourth embodiment. The first lenses L 11 , L 21 , L 31 , L 41  are meniscus lenses with negative refractive power and are made of glass. The objective surfaces of the first lenses S 11 , S 21 , S 31 , S 41  are convex. The image surfaces of the first lenses S 12 , S 22 , S 32 , S 42  are concave. Both of the objective surfaces S 11 , S 21 , S 31 , S 41  and the image surfaces S 12 , S 22 , S 32 , S 42  are spherical surfaces. 
     The second lenses L 12 , L 22 , L 32 , L 42  are meniscus lenses with positive refractive power. In accordance with the first to the third embodiment, the second lenses L 12 , L 22 , L 32  are made of plastic. In accordance with the fourth embodiment, the second lens L 42  is made of glass. The objective surfaces thereof S 13 , S 23 , S 33 , S 43  are concave. The image surfaces thereof S 14 , S 24 , S 34 , S 44  are convex. Both the objective surfaces S 13 , S 23 , S 33 , S 43  and the image surface S 14 , S 24 , S 34 , S 44  are aspherical surface. 
     The third lenses L 13 , L 23 , L 33 , L 43  are biconvex lenses with positive refractive power and are made of glass. Both the objective surfaces S 16 , S 26 , S 36 , S 46  and the image surfaces thereof S 17 , S 27 , S 37 , S 47  are convex and spherical surfaces. 
     The fourth lenses L 14  L 24 , L 34 , L 44  are biconvex lenses with positive refractive power. In accordance with the first to the third embodiment, the fourth lenses L 14 , L 24 , L 34  are made of plastic. In accordance with the fourth embodiment, the fourth lens L 44  is made of glass. Both the objective surfaces S 18 , S 28 , S 38 , S 410  and the image surfaces thereof S 17 . S 27 , S 37 , S 411  are convex and aspherical surfaces. 
     The fifth lenses L 15 , L 25 . L 35 , L 45  are with negative refractive power. In accordance with the first to the third embodiment, the fifth lenses L 15 , L 25 , L 35  are made of plastic. In accordance with the fourth embodiment, the fifth lens L 45  is made of glass. The objective surfaces S 110 , S 210 , S 310 , S 412  thereof are concave or convex. The image surfaces thereof S 111 , S 211 , S 311 , S 413  are concave. Both the objective surfaces S 110 , S 210 , S 310 , S 412  and image surfaces thereof S 111 , S 211 , S 311 , S 413  are aspherical surfaces. 
     The sixth lenses L 46  is with negative refractive power and are made of glass. Both the objective surface S 48  and the image surface thereof S 49  are concave and aspherical surfaces. 
     In addition, the lens assemblies  1 ,  2 ,  3 ,  4  satisfy at least one of the following conditions: 
       3&lt; TTL/BFL&lt; 3.5  (1)
 
       −3&lt; f   2   /f   1 &lt;−1  (2)
 
       1&lt; f   2   /f   4 &lt;3  (3)
 
       0.5&lt; f   1   /f   5 &lt;1.5  (4)
 
       3&lt; R   11   /R   12 &lt;5  (5)
 
       −11&lt; R   31   /R   12 &lt;−3  (6)
 
       20&lt; TTL/T   1 &lt;21.5  (7)
 
       8&lt; TTL/T   3 &lt;10  (8)
 
       10&lt; TTL/T   4 &lt;13  (9)
 
       72.08&lt; TTL/AT   34 &lt;114.31  (10)
 
       106.3&lt; TTL/AT   45 &lt;115.7  (11)
 
     For the first embodiment to the fourth embodiment, TTL is an interval from the object side surfaces S 11 . S 21 , S 31 , S 41  of the first lenses L 11 , L 21 , L 31 , L 41  to the image planes IMA 1 , IMA 2 , IMA 3 , IMA 4  along the optical axes OA 1 , OA 2 , OA 3 , OA 4  respectively. BFL is an interval from the image side surface S 111 , S 211 , S 311 , S 413  of the fifth lenses L 15 , L 25 , L 35 , L 45  to the image planes IMA 1 , IMA 2 , IMA 3 , IMA 4  along the optical axes OA 1 , OA 2 , OA 3 , OA 4  respectively, f 1  is an effective focal length of the first lenses L 11 , L 21 , L 31 , L 41 , f 2  is an effective focal length of the second lenses L 12 , L 22 , L 32 , L 42 , f 4  is an effective focal length of the fourth lenses L 14 , L 24 , L 34 , L 44 , f 5  is an effective focal length of the fifth lenses L 15 , L 25 , L 35 , L 45 . R 11  is a radius of curvature of the object side surfaces S 11 , S 21 , S 31 , S 41  of the first lenses L 11 , L 21 , L 31 , L 41 . R 12  is a radius of curvature of the image side surfaces S 12 , S 22 , S 32 , S 42  of the first lenses L 11 , L 21 , L 31 , L 41 . R 31  is a radius of curvature of the objective side surfaces S 16 , S 26 , S 36 , S 46  of the third lenses L 13 , L 23 , L 33 , L 43 . R 32  is a radius of curvature of the image side surfaces S 17 , S 27 , S 37 , S 47  of the third lenses L 13 , L 23 , L 33 , L 43 . T 1  is a thickness of the first lenses L 11 , L 21 , L 31 , L 41  along the optical axes OA 1 , OA 2 , OA 3 , OA 4 . T 3  is a thickness of the third lenses L 13 , L 23 , L 33 , L 43  along the optical axes OA 1 , OA 2 , OA 3 , OA 4 . T 4  is a thickness of the fourth lenses L 14 , L 24 , L 34 , L 44  along the optical axes OA 1 , OA 2 , OA 3 , OA 4 . AT 34  is an air-interval from the third lenses L 13 , L 23 , L 33 , L 43  to each fourth lenses L 14 , L 24 , L 34 , L 44  along the optical axes OA 1 , OA 2 , OA 3 , OA 4 . With the lens assemblies  1 ,  2 ,  3 ,  4  satisfying at least one of the above conditions (1)-(11), total lens length can be effectively shorten, the field of view can be effectively increased, the resolution can be effectively increased, the environmental temperature change can be effectively resisted, and the aberration can be effectively corrected. 
     A detailed description of the lens assembly in accordance with the first embodiment of the invention is as follows. Referring to  FIG. 1 , the lens assembly  1  includes a first lens L 11 , a second lens L 12 , a stop ST 1 , a third lens L 13 , a fourth lens L 14 , a fifth lens L 15 , an optical filter OF 1 , and a cover glass CG 1 , all of which are arranged in order from an object side to an image side along an optical axis OA 1 . In operation, an image of light rays from the object side is formed at an image plane IMA 1 . 
     According to paragraphs [0034]-[0041], wherein both an objective surface S 112  and an image surface S 113  of the optical filter OF 1  are flat surfaces; 
     Both an objective surface S 114  and an image surface S 115  of the cover glass CG 1  are flat surfaces: 
     With the above design of the lenses and stop ST 1  and at least any one of the conditions (1)-(11) satisfied, the lens assembly  1  can have an effective shorter total lens length, an effective increased field of view, an effective increased resolution, an effective resisted environmental temperature change, and is capable of an effective corrected aberration. 
     Table 1 shows the optical specification of the lens assembly  1  in  FIG. 1 . 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Effective Focal Length = 2.31706 mm 
               
               
                 F-number = 2.24 
               
               
                 Total Lens Length = 10.50 mm 
               
               
                 Field Of View = 134.5 Degrees 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                   
                   
                   
                   
                 Effective 
                   
               
               
                   
                 Radius of 
                   
                   
                   
                 Focal 
               
               
                 Surface 
                 Curvature 
                 Thickness 
                   
                   
                 Length 
               
               
                 Number 
                 (mm) 
                 (mm) 
                 Nd 
                 Vd 
                 (mm) 
                 Remark 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                 S11 
                 9.00 
                 0.51 
                 1.788001 
                 47.3685 
                 −3.5488 
                 The First Lens L11 
               
               
                 S12 
                 2.09 
                 1.48 
               
               
                 S13 
                 −3.28 
                 1.93 
                 1.543915 
                 55.9512 
                 7.9227 
                 The Second Lens L12 
               
               
                 S14 
                 −2.25 
                 0.38 
               
               
                 S15 
                 ∞ 
                 −0.01 
                   
                   
                   
                 Stop ST1 
               
               
                 S16 
                 13.28 
                 1.29 
                 1.58913 
                 61.135 
                 4.03 
                 The Third Lens L13 
               
               
                 S17 
                 −2.80 
                 0.14 
               
               
                 S18 
                 25.00 
                 0.87 
                 1.543915 
                 55.9512 
                 5.20 
                 The Fourth Lens L14 
               
               
                 S19 
                 −3.17 
                 0.10 
               
               
                 S110 
                 −6.27 
                 0.48 
                 1.661342 
                 20.3729 
                 −3.70 
                 The Fifth Lens L15 
               
               
                 S111 
                 4.20 
                 0.52 
               
               
                 S112 
                 ∞ 
                 0.210 
                 1.517 
                 64.167 
                   
                 Optical Filter OF1 
               
               
                 S113 
                 ∞ 
                 2.169 
               
               
                 S114 
                 ∞ 
                 0.400 
                 1.517 
                 64.167 
                   
                 Cover Glass CG1 
               
               
                 S115 
                 ∞ 
                 0.045 
               
               
                   
               
            
           
         
       
     
     The aspheric surface sag z of each aspheric lens in table 1 can be calculated by the following formula: 
         z=ch   2 /{1+[1−( k+ 1) c   2   h   2 ] 1/2   }+Ah   4   +Bh   6   +Ch   8   +Dh   10   +Eh   12  
 
     where c is curvature, h is the vertical distance from the lens surface to the optical axis, k is conic constant and A, B, C, D, and E are aspheric coefficients. 
     In the first embodiment, the conic constant k and the aspheric coefficients A, B, C, D, E of each aspheric lens are shown in Table 2. 
     
       
         
           
               
               
               
               
               
               
               
             
               
                 TABLE 2 
               
               
                   
               
               
                 Surface 
                   
                   
                   
                   
                   
                   
               
               
                 Number 
                 k 
                 A 
                 B 
                 C 
                 D 
                 E 
               
               
                   
               
             
            
               
                 S13 
                 −3.477E+00 
                 −4.269E−02 
                 7.835E−03 
                 −1.784E−03 
                  1.559E−03 
                 −3.282E−04  
               
               
                 S14 
                 −4.516E+00 
                 −2.090E−02 
                 1.038E−02 
                  3.261E−03 
                 −2.936E−03 
                 9.569E−04 
               
               
                 S18 
                  2.607E+02 
                  2.511E−02 
                 −5.997E−03  
                 −1.175E−03 
                  1.002E−03 
                 −1.626E−04  
               
               
                 S19 
                  9.208E−01 
                 −6.636E−04 
                 7.895E−03 
                 −2.561E−03 
                 −7.430E−04 
                 4.924E−04 
               
               
                 S110 
                  1.482E+01 
                 −3.621E−02 
                 2.399E−02 
                 −4.329E−03 
                 −3.049E−03 
                 1.309E−03 
               
               
                 S111 
                 −4.636E−01 
                 −1.920E−03 
                 1.558E−02 
                 −5.311E−03 
                 −3.125E−04 
                 2.603E−04 
               
               
                   
               
            
           
         
       
     
     Table 3 shows the parameters and condition values for conditions (1)-(11) in accordance with the first embodiment of the invention. It can be seen from Table 3 that the lens assembly  1  of the first embodiment satisfies the conditions (1)-(11). 
     
       
         
           
               
               
               
               
               
               
             
               
                 TABLE 3 
               
               
                   
               
             
            
               
                 BFL 
                 3.34 mm 
                   
                   
                   
                   
               
               
                 TTL/BFL 
                 3.144 
                 f 2 /f 1   
                 −2.233 
                 f 2 /f 4   
                 1.523 
               
               
                 f 1 /f 5   
                 0.959 
                 R 11 /R 12   
                 4.313 
                 R 31 /R 32   
                 −4.749 
               
               
                 TTL/T 1   
                 20.657 
                 TTL/T 3   
                 8.142 
                 TTL/T 4   
                 12.118 
               
               
                 TTL/AT 34   
                 74.001 
                 TTL/AT 45   
                 106.552 
               
               
                   
               
            
           
         
       
     
     By the above arrangements of the lenses and stop ST 1 , the lens assembly  1  of the first embodiment can meet the requirements of optical performance. 
     It can be seen from  FIG. 2A  that the longitudinal aberration in the lens assembly  1  of the first embodiment ranges from −0.02 mm to 0.02 mm. 
     It can be seen from  FIG. 2B  that the field curvature of tangential direction and sagittal direction in the lens assembly  1  of the first embodiment ranges from −0.02 mm to 0.08 mm. 
     It can be seen from  FIG. 2C  that the distortion in the lens assembly  1  of the first embodiment ranges from −1% to 1%. 
     It can be seen from  FIG. 2D  that when the temperature is at −10° C., 20° C., or 70° C. the focus offset in the lens assembly  1  of the first embodiment ranges from −0.03 mm to 0.03 mm, and the modulation transfer function in the lens assembly  1  of the first embodiment ranges from 0.0 to 0.83. 
     It is obvious that the longitudinal aberration, the field curvature, and the distortion of the lens assembly  1  of the first embodiment can be corrected effectively. The resolution and the depth of focus of the lens assembly  1  of the first embodiment can also meet the requirements. Therefore, the lens assembly  1  of the first embodiment is capable of good optical performance. 
     Referring to  FIG. 3 ,  FIG. 3  is the lens layout diagram and the optical path of the wide-angle lens assembly in accordance with the second embodiment, the lens assembly  2  includes a first lens L 21 , a second lens L 22 , a stop ST 2 , a third lens L 23 , a fourth lens L 24 , a fifth lens L 25 , an optical filter OF 2 , and cover glass CG 2 , all of which are arranged in order from an object side to an image side along an optical axis A 2 . In operation, an image of light rays from the object side is formed at an image plane IMA 2 . 
     According to paragraphs[0034]-[0041], wherein both an objective surface  212  and an image surface  213  of the optical filter OF 2  are flat surfaces; 
     Both an objective surface S 214  and an image surface S 215  of the cover glass CG 2  are flat surfaces; 
     With the above design of the lenses and stop ST 2  and at least anyone of the conditions (1)-(11) satisfied, the lens assembly  2  can have an effective shorter total lens length an effective increased field of view, an effective increased resolution, an effective resisted environmental temperature change and is capable of an effective corrected aberration. 
     Table 4 shows the optical specification of the lens assembly  2  in  FIG. 3 . 
     
       
         
           
               
             
               
                 TABLE 4 
               
             
            
               
                   
               
               
                 Effective Focal Length = 2.41991 mm 
               
               
                 F-number = 2.24 
               
               
                 Total Lens Length = 10.50 mm 
               
               
                 Field Of View = 127.6 Degrees 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                   
                   
                   
                   
                 Effective 
                   
               
               
                   
                 Radius of 
                   
                   
                   
                 Focal 
               
               
                 Surface 
                 Curvature 
                 Thickness 
                   
                   
                 Length 
               
               
                 Number 
                 (mm) 
                 (mm) 
                 Nd 
                 Vd 
                 (mm) 
                 Remark 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                 S21 
                 9.74 
                 0.49 
                 1.834807 
                 42.7137 
                 −3.3617 
                 The First Lens L21 
               
               
                 S22 
                 2.14 
                 2.20 
               
               
                 S23 
                 −24.99 
                 1.21 
                 1.543915 
                 55.9512 
                 9.3628 
                 The Second Lens L22 
               
               
                 S24 
                 −4.32 
                 0.39 
               
               
                 S25 
                 ∞ 
                 0.12 
                   
                   
                   
                 Stop ST2 
               
               
                 S26 
                 27.78 
                 1.07 
                 1.583126 
                 59.3747 
                 4.01 
                 The Third Lens L23 
               
               
                 S27 
                 −2.53 
                 0.13 
               
               
                 S28 
                 5.91 
                 1.03 
                 1.535218 
                 56.1153 
                 4.15 
                 The Fourth Lens L24 
               
               
                 S29 
                 −3.36 
                 0.09 
               
               
                 S210 
                 −6.29 
                 0.59 
                 1.661342 
                 20.3729 
                 −3.09 
                 The Fifth Lens L25 
               
               
                 S211 
                 3.18 
                 0.52 
               
               
                 S212 
                 ∞ 
                 0.210 
                 1.517 
                 64.167 
                   
                 Optical Filter OF2 
               
               
                 S213 
                 ∞ 
                 2.000 
               
               
                 S214 
                 ∞ 
                 0.400 
                 1.517 
                 64.167 
                   
                 Cover Glass CG2 
               
               
                 S215 
                 ∞ 
                 0.045 
               
               
                   
               
            
           
         
       
     
     The definition of the aspheric surface sag z of each aspheric lens in table 4 is the same as that of in Table 1 and is not described here again. 
     In the second embodiment, the conic constant k and the aspheric coefficients A, B, C, D, E of each aspheric lens are shown in Table 5. 
     
       
         
           
               
               
               
               
               
               
               
             
               
                 TABLE 5 
               
               
                   
               
               
                 Surface 
                   
                   
                   
                   
                   
                   
               
               
                 Number 
                 k 
                 A 
                 B 
                 C 
                 D 
                 E 
               
               
                   
               
             
            
               
                 S23 
                 −1.881E+02 
                 −4.516E−02 
                 −2.633E−03  
                 −2.847E−04 
                 3.231E−04 
                 7.962E−05 
               
               
                 S24 
                 −1.388E+01 
                 −3.554E−02 
                 2.569E−03 
                  1.030E−02 
                 −6.456E−03  
                 1.697E−03 
               
               
                 S28 
                 −5.770E−02 
                 −1.360E−02 
                 −9.533E−04  
                 −8.888E−04 
                 6.158E−04 
                 2.006E−05 
               
               
                 S29 
                  2.988E+00 
                 −1.031E−02 
                 5.037E−03 
                  1.621E−03 
                 −4.936E−05  
                 1.831E−04 
               
               
                 S210 
                  1.467E+01 
                 −3.895E−02 
                 8.280E−03 
                  4.878E−04 
                 3.572E−04 
                 −5.878E−05  
               
               
                 S211 
                 −3.801E+00 
                 −1.328E−02 
                 3.386E−03 
                 −1.308E−03 
                 3.713E−04 
                 −5.493E−05  
               
               
                   
               
            
           
         
       
     
     Table 6 shows the parameters and condition values for conditions (1)-(11) in accordance with the second embodiment of the invention. It can be seen from Table 6 that the lens assembly  2  of the second embodiment satisfies the conditions (1)-(11). 
     
       
         
           
               
               
               
               
               
               
             
               
                 TABLE 6 
               
               
                   
               
             
            
               
                 BFL 
                 3.17 mm 
                   
                   
                   
                   
               
               
                 TTL/BFL 
                 3.313 
                 f 2 /f 1   
                 −2.785 
                 f 2 /f 4   
                 2.258 
               
               
                 f 1 /f 5   
                 1.088 
                 R 11 /R 12   
                 4.561 
                 R 31 /R 32   
                 −10.989 
               
               
                 TTL/T 1   
                 21.227 
                 TTL/T 3   
                 9.787 
                 TTL/T 4   
                 10.162 
               
               
                 TTL/AT 34   
                 81.647 
                 TTL/AT 45   
                 115.419 
               
               
                   
               
            
           
         
       
     
     By the above arrangements of the lenses and stop ST 2 , the lens assembly  2  of the second embodiment can meet the requirements of optical performance. 
     It can be seen from  FIG. 4A  that the longitudinal aberration in the lens assembly  2  of the second embodiment ranges from −0.02 mm to 0.03 mm. 
     It can be seen from  FIG. 4B  that the field curvature of tangential direction and sagittal direction in the lens assembly  2  of the second embodiment ranges from −0.08 mm to 0.06 mm. 
     It can be seen from  FIG. 4C  that the distortion in the lens assembly  2  of the second embodiment ranges from 0% to 1%. 
     It can be seen from  FIG. 4D  that when the temperature is at −10° C., 20° C., or 70° C. the focus offset in the lens assembly  2  of the second embodiment ranges from −0.03 mm to 0.03 mm, and the modulation transfer function in the lens assembly  2  of the second embodiment ranges from 0.0 to 0.82. 
     It is obvious that the longitudinal aberration, the field curvature, and the distortion of the lens assembly  2  of the second embodiment can be corrected effectively. The resolution and the depth of focus of the lens assembly  2  of the second embodiment can also meet the requirements. Therefore, the lens assembly  2  of the second embodiment is capable of good optical performance. 
     Referring to  FIG. 5 ,  FIG. 5  is the lens layout diagram and the optical path of the wide-angle lens assembly in accordance with the third embodiment, the lens assembly  3  includes a first lens L 31 , a second lens L 32 , a stop ST 3 , a third lens L 33 , a fourth lens L 34 , a fifth lens L 35 , an optical filter OF 3 , and a cover glass CG 3 , all of which are arranged in order from an object side to an image side along an optical axis OA 3 . In operation, an image of light rays from the object side is formed at an image plane IMA 3 . 
     According to paragraphs [0034]-[0041], wherein both an objective surface S 312  and an image surface S 313  of the optical filter OF 3  are flat surfaces. 
     Both an objective surface S 314  and an image surface S 315  of the cover glass CG 3  are flat surfaces; 
     With the above design of the lenses and stop ST 3  and at least any one of the conditions (1)-(11) satisfied, the lens assembly  3  can have an effective shorter total lens length, an effective increased field of view, an effective increased resolution, an effective resisted environmental temperature change, and is capable of an effective corrected aberration. 
     Table 7 shows the optical specification of the lens assembly  3  in  FIG. 5 . 
     
       
         
           
               
             
               
                 TABLE 7 
               
             
            
               
                   
               
               
                 Effective Focal Length = 2.26895 mm 
               
               
                 F-number = 2.24 
               
               
                 Total Lens Length = 10.50 mm 
               
               
                 Field Of View = 130.2 Degrees 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                   
                   
                   
                   
                 Effective 
                   
               
               
                   
                 Radius of 
                   
                   
                   
                 Focal 
               
               
                 Surface 
                 Curvature 
                 Thickness 
                   
                   
                 Length 
               
               
                 Number 
                 (mm) 
                 (mm) 
                 Nd 
                 Vd 
                 (mm) 
                 Remark 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                 S31 
                 7.01 
                 0.49 
                 1.788001 
                 47.3685 
                 −3.6729 
                 The First Lens L31 
               
               
                 S32 
                 1.99 
                 1.87 
               
               
                 S33 
                 −3.75 
                 1.92 
                 1.543915 
                 55.9512 
                 7.0049 
                 The Second Lens L32 
               
               
                 S34 
                 −2.24 
                 0.24 
               
               
                 S35 
                 ∞ 
                 −0.03 
                   
                   
                   
                 Stop ST3 
               
               
                 S36 
                 10.55 
                 1.26 
                 1.58913 
                 61.135 
                 4.08 
                 The Third Lens L33 
               
               
                 S37 
                 −2.98 
                 0.09 
               
               
                 S38 
                 25.00 
                 0.82 
                 1.543915 
                 55.9512 
                 5.63 
                 The Fourth Lens L34 
               
               
                 S39 
                 −3.47 
                 0.09 
               
               
                 S310 
                 −6.70 
                 0.47 
                 1.661342 
                 20.3729 
                 −3.64 
                 The Fifth Lens L35 
               
               
                 S311 
                 3.91 
                 0.67 
               
               
                 S312 
                 ∞ 
                 0.210 
                 1.517 
                 64.167 
                   
                 Optical liter OF3 
               
               
                 S313 
                 ∞ 
                 1.949 
               
               
                 S314 
                 ∞ 
                 0.400 
                 1.517 
                 64.167 
                   
                 Cover Glass CG3 
               
               
                 S315 
                 ∞ 
                 0.045 
               
               
                   
               
            
           
         
       
     
     The definition of the aspheric surface sag z of each aspheric lens in table 7 is the same as that of in Table 1 and is not described here again. 
     In the third embodiment, the conic constant k and the aspheric coefficients A, B, C, D, E of each aspheric lens are shown in Table 8. 
     
       
         
           
               
               
               
               
               
               
               
             
               
                 TABLE 8 
               
               
                   
               
               
                 Surface 
                   
                   
                   
                   
                   
                   
               
               
                 Number 
                 k 
                 A 
                 B 
                 C 
                 D 
                 E 
               
               
                   
               
             
            
               
                 S33 
                 −4.469E+00  
                 −4.473E−02 
                 4.412E−03 
                 −7.405E−04 
                  1.166E−03 
                 −2.291E−04  
               
               
                 S34 
                 −4.902E+00  
                 −2.797E−02 
                 8.660E−03 
                  6.569E−03 
                 −5.199E−03 
                 1.393E−03 
               
               
                 S38 
                 2.422E+02 
                  2.365E−02 
                 −3.532E−03  
                  1.011E−03 
                  1.908E−04 
                 2.049E−04 
               
               
                 S39 
                 1.196E+00 
                 −1.433E−03 
                 1.178E−02 
                 −3.368E−03 
                 −4.576E−04 
                 7.205E−04 
               
               
                 S310 
                 1.759E+01 
                 −1.749E−02 
                 8.925E−03 
                 −3.097E−03 
                 −1.345E−03 
                 6.549E−04 
               
               
                 S311 
                 1.958E+00 
                  1.062E−02 
                 −2.056E−03  
                 −1.531E−03 
                 −1.373E−04 
                 1.230E−04 
               
               
                   
               
            
           
         
       
     
     Table 9 shows the parameters and condition values for conditions (1)-(11) in accordance with the third embodiment of the invention. It can be seen from Table 9 that the lens assembly  3  of the third embodiment satisfies the conditions (1)-(11). 
     
       
         
           
               
               
               
               
               
               
             
               
                 TABLE 9 
               
               
                   
               
             
            
               
                 BFL 
                 3.27 mm 
                   
                   
                   
                   
               
               
                 TTL/BFL 
                 3.213 
                 f 2 /f 1   
                 −1.907 
                 f 2 /f 4   
                 1.243 
               
               
                 f 1 /f 5   
                 1.010 
                 R 11 /R 12   
                 3.521 
                 R 31 /R 32   
                 −3.539 
               
               
                 TTL/T 1   
                 21.260 
                 TTL/T 3   
                 8.314 
                 TTL/T 4   
                 12.787 
               
               
                 TTL/AT 34   
                 112.391 
                 TTL/AT 45   
                 110.821 
               
               
                   
               
            
           
         
       
     
     By the above arrangements of the lenses and stop ST 3 , the lens assembly  3  of the third embodiment can meet the requirements of optical performance. 
     It can be seen from  FIG. 6A  that the longitudinal aberration in the lens assembly  3  of the third embodiment ranges from −0.02 mm to 0.02 mm. 
     It can be seen from  FIG. 6B  that the field curvature of tangential direction and sagittal direction in the lens assembly  3  of the third embodiment ranges from −0.04 mm to 0.08 mm. 
     It can be seen from  FIG. 6C  that the distortion in the lens assembly  3  of the third embodiment ranges from 0% to 5.1%. 
     It can be seen from  FIG. 6D  that when the temperature is at −10° C., 20° C., or 70° C. the focus offset in the lens assembly  3  of the third embodiment ranges from −0.03 mm to 0.03 mm, and the modulation transfer function in the lens assembly  3  of the third embodiment ranges from 0.0 to 0.82. 
     It is obvious that the longitudinal aberration, the field curvature, and the distortion of the lens assembly  3  of the third embodiment can be corrected effectively. The resolution and the depth of focus of the lens assembly  3  of the third embodiment can also meet the requirements. Therefore, the lens assembly  3  of the third embodiment is capable of good optical performance. 
     Referring to  FIG. 7 ,  FIG. 7  is the lens layout diagram of the wide-angle lens assembly in accordance with the fourth embodiment, the lens assembly  4  includes a first lens L 41 , a second lens L 42 , a stop ST 4 , a third lens L 43 , a sixth lens L 46 , a fourth lens L 44 , a fifth lens L 45 , and an optical filter OF 4 , all of which are arranged in order from an object side to an image side along an optical axis OA 4 . In operation, an image of light rays from the object side is formed at an image plane IMA 4 . 
     According to paragraphs [0034]-[0041], wherein both an objective surface S 414  and an image surface S 415  of the optical filter OF 4  are flat surfaces. 
     With the above design of the lenses and stop ST 4  and at least one of the conditions (1)-(11) satisfied, the lens assembly  4  can have an effective shorter total lens length, an effective increased field of view, an effective increased resolution, an effective resisted environmental temperature change, and is capable of an effective corrected aberration. 
     Table 10 shows the optical specification of the lens assembly  4  in  FIG. 7 . 
     
       
         
           
               
             
               
                 TABLE 10 
               
             
            
               
                   
               
               
                 Effective Focal Length = 2.025337613 mm 
               
               
                 F-number = 2.0054978995161 
               
               
                 Total Lens Length = 12.0463262938364 mm 
               
               
                 Field Of View = 150 Degrees 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                   
                   
                   
                   
                 Effective 
                   
               
               
                   
                 Radius of 
                   
                   
                   
                 Focal 
               
               
                 Surface 
                 Curvature 
                 Thickness 
                   
                   
                 Length 
               
               
                 Number 
                 (mm) 
                 (mm) 
                 Nd 
                 Vd 
                 (mm) 
                 Remark 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                 S41 
                 14.29364 
                 1 
                 1.696799 
                 55.521308 
                 −3.6665 
                 The First Lens L41 
               
               
                 S42 
                 2.11091 
                 1.2593665 
               
               
                 S43 
                 −15.7754 
                 3.981935 
                 1.544514 
                 56.003278 
                 5.5243 
                 The Second Lens L42 
               
               
                 S44 
                 −2.75914 
                 0.0039607 
               
               
                 S45 
                 ∞ 
                 0.0638947 
                   
                   
                   
                 Stop ST4 
               
               
                 S46 
                 3.271095 
                 1.6980371 
                 1.496999 
                 81.545888 
                 3.5936 
                 The Third Lens L43 
               
               
                 S47 
                 −3.27109 
                 0.2558871 
               
               
                 S48 
                 −24.6506 
                 0.4510033 
                 1.661316 
                 20.381513 
                 −4.4134 
                 The Sixth Lens L46 
               
               
                 S49 
                 3.367923 
                 0.2972975 
               
               
                 S410 
                 5.31317 
                 1.2814375 
                 1.544514 
                 56.003278 
                 7.9805 
                 The Fourth Lens L44 
               
               
                 S411 
                 −22.2224 
                 0.0661971 
               
               
                 S412 
                 4.477886 
                 0.4999124 
                 1.544514 
                 56.003278 
                 −11.1051 
                 The Fifth Lens L45 
               
               
                 S413 
                 2.474661 
                 0.6803079 
               
               
                 S414 
                 ∞ 
                 0.3 
                 1.5168 
                 64.167336 
                   
                 Optical Filter OF4 
               
               
                 S415 
                 ∞ 
                 0.2012054 
               
               
                 S416 
                 ∞ 
                 0.0058841 
               
               
                   
               
            
           
         
       
     
     The definition of the aspheric surface sag z of each aspheric lens in table 10 is the same as that of in Table 1 and is not described here again. 
     In the fourth embodiment, the conic constant k and the aspheric coefficients A, B, C, D, E of each aspheric lens are shown in Table 11. 
     
       
         
           
               
               
               
               
               
               
               
               
               
             
               
                 TABLE 11 
               
               
                   
               
               
                 Surface 
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 Number 
                 k 
                 A 
                 B 
                 C 
                 D 
                 E 
                 F 
                 G 
               
               
                   
               
             
            
               
                 S43 
                 −1.35E+01 
                 −1.36E−02 
                 −2.25E−04  
                 −3.28E−04 
                 −4.10E−05 
                 8.78E−05 
                 −2.41E−05 
                 2.30E−06 
               
               
                 S44 
                  1.48E+00 
                  2.19E−02 
                 2.46E−04 
                  3.33E−03 
                 −1.66E−03 
                 8.27E−04 
                 −3.29E−04 
                 8.25E−05 
               
               
                 S48 
                 −1.02E+02 
                  5.07E−02 
                 −4.05E−02  
                  3.30E−04 
                  1.23E−02 
                 −4.98E−03  
                  2.54E−06 
                 1.82E−04 
               
               
                 S49 
                  3.15E+00 
                  6.89E−02 
                 −5.23E−02  
                  4.89E−03 
                  7.24E−03 
                 −1.36E−03  
                 −1.05E−03 
                 2.42E−04 
               
               
                 S410 
                  4.32E+00 
                  9.00E−03 
                 1.84E−03 
                 −4.10E−03 
                  1.21E−03 
                 1.87E−04 
                 −1.15E−05 
                 −3.72E−05  
               
               
                 S411 
                  4.13E+01 
                 −1.18E−03 
                 1.18E−02 
                  5.27E−04 
                 −7.53E−04 
                 8.96E−06 
                  1.02E−05 
                 2.06E−07 
               
               
                 S412 
                 −1.47E+01 
                 −4.11E−02 
                 1.85E−02 
                 −1.82E−03 
                 −2.20E−04 
                 5.69E−05 
                 −5.24E−06 
                 −6.31E−07  
               
               
                 S413 
                 −1.16E+00 
                 −6.59E−02 
                 1.71E−02 
                 −3.00E−03 
                  9.89E−05 
                 7.10E−05 
                 −8.60E−06 
                 −5.82E−07  
               
               
                   
               
            
           
         
       
     
     Table 12 shows the parameters and condition values for conditions (1)-(11) in accordance with the fourth embodiment of the invention. 
     
       
         
           
               
               
               
               
               
               
             
               
                 TABLE 12 
               
               
                   
               
             
            
               
                 BFL 
                 1.187 mm 
                   
                   
                   
                   
               
               
                 TTL/BFL 
                 10.145 
                 f 2 /f 1   
                 −1.507 
                 f 2 /f 4   
                 0.692 
               
               
                 f 1 /f 5   
                 0.33 
                 R 11 /R 12   
                 6.771 
                 R 31 /R 32   
                 −1 
               
               
                 TTL/T 1   
                 12.046 
                 TTL/T 3   
                 7.094 
                 TTL/T 4   
                 9.4 
               
               
                 TTL/AT 34   
                 21.776 
                 TTL/AT 45   
                 181.977 
               
               
                   
               
            
           
         
       
     
     By the above arrangements of the lenses and stop ST 4 , the lens assembly  4  of the fourth embodiment can meet the requirements of optical performance. 
     While the invention has been described by way of example and in terms of the preferred embodiment(s), it is to be understood that the invention is not limited thereto. On the contrary, it is intended to cover various modifications and similar arrangements and procedures, and the scope of the appended claims therefore should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements and procedures.