Abstract:
A rectangular stacked lens module and a manufacturing method thereof are disclosed. The rectangular stacked lens module is produced by cutting straight lines through a stacked lens module array. Firstly, it produces at least two lens arrays. Each lens array includes a plurality of optical lenses by multi-cavity glass molding and at least one alignment member disposed on the non-optical area of the lens array. Then at least the two lens arrays are assembled by the alignment members and are stacked with other optical elements so as to form a stacked lens module array. The optical axis of each optical lens is aligned easily with each other so as to meet requirements for optical precision. Moreover, the manufacturing processes are simplified and the purposes of mass-production and low cost are achieved.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to a stacked glass lens module with alignment member and a manufacturing method thereof, especially to a rectangular stacked glass lens module with alignment member and a manufacturing method thereof that are applied to assembled lenses of light emitting diode (LED) light sources, assembled lenses of solar energy conversion systems and optical lenses of cameras and phone cameras. 
         [0002]    Glass precision molding technology has been widely applied to manufacture aspherical molded glass lens with high resolution, good stability and low cost such as lens revealed in US2006/0107695, US2007/0043463, TW095101830, TW095133807, and JP63-295448 etc. A glass preform is set into a mold having an upper mold and a lower mold to be heated and softening. Then the upper mold and the lower mold are assembled correspondingly and apply pressure on the upper mold and the lower mold so as to make the soft glass perform have the same optical surfaces as that of the upper mold and the lower mold. After cooling, a molded glass lens with mold surfaces of the upper mold and the lower mold is released. In order to reduce manufacturing cost, prior arts—JP63-304201 and US2005/041215 reveal a lens array formed by glass molding. As to a single lens-called a lens element hereunder, JP02-044033 revealed that a lens blank having a plurality of lenses is manufactured by movement of glass materials and multiple molding ways. Then the lens blank is cut into a plurality of lens elements. 
         [0003]    The optical lens formed by glass molding is widely applied to assembled lenses of LED light sources, lenses of solar energy conversion systems, and optical lenses of mobile phone cameras. The assembled lens or optical lens is formed by a plurality of optical lenses with different lens power assembled with other optical elements such as a shade, an infrared (IR)-cut lens, an aperture, an image capture device (ICD) or photo-electronic device (PED) arranged at a certain interval between one another. Thus while assembling, an optical axis of each optical lens must be aligned precisely so as to avoid the reduction of resolution. Moreover, the distance between two adjacent optical lenses (interval) is fixed. Thus the assembling requires a plurality of processes and precise correction. Therefore, the yield rate is unable to increase and the cost reduction is difficult. 
         [0004]    For mass production, the manufacturing of the optical lens array has received more attention. As to the manufacturing of the optical lens array, JP2001194508 discloses a manufacturing method of plastic optical lens array. Taiwanese patent No. M343166 reveals a manufacturing method of glass optical lens array. In manufacturing of arrayed optical lens modules, wafer level lens modules are revealed in U.S. Pat. No. 7,183,643, US2007/0070511, WO2008011003, WO2008094499 and so on. Refer to  FIG. 1 , a tri-piece arrayed optical lens module  70  generally includes an aperture  701 , a cover glass  702 , a plurality of optical lenses and an infrared (IR) cut lens  717 . As shown in figure, the plurality of optical lenses forms a three piece type optical lens set having a first optical lens  704 , a second optical lens  705  and a third optical lens  706  and an IR cut lens  707 . Two adjacent optical lenses are separated by a spacer  713 . After being assembled, a lens module array  70  is formed. 
         [0005]    However, in a lens module array, while assembling a lens array with plurality of optical lenses, the alignment of the lens array has effects on resolution of the lens module. In US20060249859, imaging techniques are used to determine if stacked wafers are in proper alignment. Fiducial marks that were previously patterned on each wafer of the stack are exposed in an image produced by the captured infrared radiation. The degree of alignment of the wafers can be measured using the fiducial marks exposed in the image. In assembling of plastic optical lens arrays, JP2000-321526 and JP2000-227505 revealed bi-convex type optical lens arrays formed by combination of heights with crevices. As to U.S. Pat. No. 7,187,501, cone-shaped projections are used to form a resin lens array by stacking the resin lenses one over another. Refer to US2008/0007623, a camera module having an array with multiple colors is revealed. As shown in  FIG. 2 , a wafer scale camera device is disclosed in 2006/0044450. A substrate  711  is arranged with a first lens array and a second lens array  712 ,  713  respectively, separated by a spacer substrate  714  to form a lens module array  71 . Then cut the lens array  71  to get a lens module  72 . Refer to  FIG. 3 , as shown in WO2008094499, two lenses  731 ,  732 , and an image capture device (ICD)  733  are disposed on a circuit board  735  by glue  734  to form a lens module  73 . The lens arrays or lens modules shown from  FIG. 1  to  FIG. 3  still got problems in alignment of optical axes of the lenses. Thus the improvement of resolution is difficult to achieve. 
         [0006]    As to the lens module used in cameras and phone cameras, it generally includes a plurality of lens with various concave or convex optical surfaces. Such lens modules have higher requirements of the alignment of the optical axis, and the location precision of optical surfaces. In the conventional assembling way of projections and holes to form plastic optical lens array, material shrinkage after the plastic injection molding will lead to size change of the projections and the holes. Thus the location precision is affected and the alignment of the optical axis is difficult. Therefore, the applications of the plastic optical lens array is limited, especially during manufacturing of small-size lens module, the complicated processes cause cost increase. The molded glass has better reflective index than the plastic and also with better thermostability so that the molded glass has been applied to various optical systems. Moreover, the optical lens array made from molded glass exhibit less shrinkage. 
         [0007]    Thus there is a need to develop a method of manufacturing stacked optical glass lens arrays as well as stacked lens modules with simple structure and high precision so as to provide stacked lens modules for assembled lenses of light emitting diode (LED) light sources, assembled lenses of solar energy conversion systems and optical lenses of phone cameras. And the lens modules meet requirements of mass-production and yield rate. 
       SUMMARY OF THE INVENTION 
       [0008]    Therefore it is a primary object of the present invention to provide a rectangular stacked glass lens module with alignment member and a manufacturing method thereof in which the stacked glass lens module is formed by making straight cuts through the stacked lens module array. Each rectangular stacked glass lens module includes at least two optical glass lenses that are assembled with other optical elements at a preset interval. The stacked optical glass lens module array includes at least two optical glass lens arrays that are produced by multi-cavity glass molding and are disposed with a plurality of lenses arranged in an array. An alignment member is arranged at a periphery of a non-optical surface of the optical glass lens arrays. The alignment members of two adjacent lens arrays are connected and assembled with each other so as to make each lens thereof align the optical axis. 
         [0009]    It is another object of the present invention to provide a rectangular stacked glass lens module with alignment member and a manufacturing method thereof in which an alignment member is designed as a through hole for convenience of assembly when the stacked lens module array consists of a plurality of optical elements. The through hole is arranged at a non-optical surface of each lens array and a proper position of each optical element. While assembling, the through-hole of the lens array and the through hole of the optical element are positioned over a rod of a jig assembly so as to align the lens array and the optical elements. Thus convenient and precise assembling is achieved. 
         [0010]    In accordance with the above manufacturing method, a stacked lens module array is produced one at a time. Then the stacked lens module array is cut into a plurality of rectangular stacked lens modules. Thus the purposes of precise assembling and mass production are achieved. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIGS. 1 to 3  are schematic drawings showing a conventional optical glass lens array or lens module; 
           [0012]      FIG. 4  is a flow chart showing manufacturing process of an embodiment according to the present invention; 
           [0013]      FIG. 5  is a cross sectional view of an embodiment of a lens module array and an embodiment of a lens module after being cut; 
           [0014]      FIG. 6  is a cross sectional view of an embodiment of a lens module array having a conical alignment member; 
           [0015]      FIG. 7  is a cross sectional view sowing assembling of through-hole fixtures in a second embodiment of a lens module array according to the present invention; 
           [0016]      FIG. 8  is a flow chart showing manufacturing process of an embodiment of a lens module array with through-hole alignment member; 
           [0017]      FIG. 9  is a cross sectional view of an embodiment of a lens module array and a first embodiment of a lens module after being cut; 
           [0018]      FIG. 10  is a cross sectional view of a third embodiment of a lens module according to the present invention; 
           [0019]      FIG. 11  is a cross sectional view of a fourth embodiment of a lens module according to the present invention; 
           [0020]      FIG. 12  is a cross sectional view of a fifth embodiment of a lens module according to the present invention; 
           [0021]      FIG. 13  is a cross sectional view of a sixth embodiment of a lens module according to the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0022]    Refer to  FIG. 5 , an alignment member such as an alignment pin  1011  or an alignment cavity  1022  is arranged on a periphery of a non-optical surface of a first (optical glass) lens array  101 . A corresponding alignment member such as an alignment cavity  1022  or an alignment pin  1011  is disposed on a periphery of a non-optical surface of an adjacent second lens array  102 . The alignment member is molded together with the two lens arrays  101 ,  102  so that each alignment member and an optical axis  103  are fixed. After the first and the second lens arrays  101 ,  102  are assembled correspondingly, the optical axes  103  of each lens are aligned and then are fixed by glue  104  so as to form a lens module array  100  precisely. The other optical elements are stacked thereof. In  FIG. 5 , the optical elements of this embodiment includes an optical element  105  such as a circuit board, a plurality of optical elements  106  such as image sensors and a plurality of optical elements  107  with a preset thickness such as spacers for separating the lens module array  100  and the optical elements  106 . Next the lens module array  100  and the optical element  105  are attached with each other by glue  104 . After curing, a stacked lens module array  10  is produced. Then make straight cuts, a plurality of rectangular stacked lens modules  11  is generated. 
         [0023]    The alignment member includes a plurality of alignment pins  1011 / 1021  and a plurality of corresponding alignment cavities  1022 / 1012  assembled with each other. The shape of the alignment pins  1011 / 1021  is not limited and it can be a column, a rectangular prism or a cone, as shown in  FIG. 6  while the shape of the corresponding alignment cavities  1022 / 1012  is a columnar or conical receiving hole, corresponding to that of the alignment pins  1011 / 1021 . 
         [0000]    Refer to  FIG. 4 , a manufacturing method of the rectangular stacked lens module  11  includes following steps:
 
S 1 : providing a rectangular sheet-like glass blank  21  and a molding mold  22  having an upper mold  221  and a lower mold  222  respectively disposed with a mold core of multi-cavity optical surfaces  227 / 228  and a mold pin/mold bushing  223 .  224 ;
 
S 2 : setting the glass blank  21  into the mold  22 , then heat the glass blank  21  by a heater  225  and apply pressure to run molding processes;
 
S 3 : molding a lens array  101  with alignment members such as alignment pins and alignment cavities; as shown in  FIG. 4 , there are 16 lenses arranged in an array;
 
S 4 : producing another lens array  102  according to the above steps from S 1  to S 3  and the two adjacent lens arrays  101 ,  102  have corresponding alignment members such as alignment cavities  1022 / 1012  and alignment pins  1011 / 1021 ;
 
S 5 : coating ultraviolet (UV) curing glue  104  on a non-optical area between the two adjacent optical glass lenses  101 ,  102 ;
 
S 6 : performing alignment and assembling; for example, the alignment cavities  1022 / 1012  and corresponding alignment pins  1011 / 1021  are connected correspondingly so that the two lens arrays  101 ,  102  are assembled along the optical axis  103 ;
 
S 7 : producing a lens module array  100  in which each optical axis  103  is aligned with one another;
 
S 8 : assembling and aligning other optical elements having a spacer  107  a circuit board  105 , and image sensors  106  by glue in a stacked way sequentially; each image sensor  106  is aligned with each optical axis  103  of the lens module array  100 ;
 
S 9 : curing the glue: for example, a semifinished product in the step S 8  is radiated by UV light so that the glue  104  is cured and a stacked lens module array  10  is formed.
 
S 10 : cutting straight lines through the stacked lens module array  10  to produce a plurality of rectangular stacked lens modules  11 . As shown in  FIG. 4 , there are 16 (4×4) rectangular stacked lens modules  11  and each rectangular stacked lens module  11  consists of two lenses  101 ,  102  and the image sensor  106  connected on the circuit board  105 . A stacked rectangular columnar lens module is produced.
 
         [0024]    As shown from  FIG. 4  to  FIG. 6 , the rectangular stacked lens module having at least two glass lenses  101 ,  102  and other optical elements can be applied to optical systems. The optical elements include aperture, cover glasses, spacers, IR cut lenses, image sensors, optoelectronic semiconductor devices, circuit board, etc. 
         [0025]    Refer to  FIG. 8 , a manufacturing method of a stacked lens module array  10  with through holes as alignment members includes following steps: 
         [0000]    SS 1 : providing a rectangular sheet-like glass blank  21  and a molding mold  24  having an upper mold  221  and a lower mold  222  respectively disposed with a mold core of optical surfaces  247 ,  248  and a mold bar and/or mold sleeve for molding four through holes as alignment members;
 
SS 2 : setting the glass blank  21  into the mold  24 , then heat the glass blank  21  by a heater  245  and apply pressure to run multi-cavity glass molding processes;
 
SS 3 : molding a first lens array  101 ;
 
SS 4 : producing at least another lens array  102  by repeating above steps; the lens arrays  101 ,  102  respectively include a plurality of lenses arranged in an array; through holes  108  for alignment are arranged on non-optical area of each lens array.
 
SS 5 : preparing a jig assembly  23  with at least one alignment rod  231  and optical elements having a circuit board  105  and a spacer  107 ; the circuit board  105  are preset with image sensors  106  and through holes corresponding to the through holes  108 ; then coating glue  104  on non-optical area of each component, setting these components  105 ,  107 ,  102 ,  101  on a jig assembly  23 , and positioning each through hole  108  over the alignment rod  231  in turn; One more spacer  107   a  can be disposed between two adjacent lens arrays  101 ,  102  according to users&#39; needs. Refer to  FIG. 7 , this embodiment is not disposed with the spacer  107   a.  
 
SS 6 : aligning the components by the alignment rod  231  of the jig assembly  23  and fixing them by glue  104 ; curing the glue  104  and releasing the jig assembly  23  so as to produce a stacked lens module array  10  in which each optical axis  103  is aligned.
 
SS 7 : making straight cuts through the stacked lens module array  10  to generate a plurality of rectangular stacked lens modules  11 ; each rectangular stacked lens module  11  includes at least two lenses  101 ,  102  and other optical elements  105 ,  106 ,  107  and aligned optical axes  103 .
 
       Embodiment 1 
       [0026]    Refer to  FIG. 9 , an embodiment of a rectangular stacked lens module  11  including two optical glass lenses  101 ,  102  is produced by cutting of a stacked lens module array  10 . The rectangular stacked lens module  11  generated through cutting of a center part of the stacked lens module array  10  is without alignment member such as columnar alignment pins  1011 / 1021  and corresponding alignment cavities  1022 / 1012 . A lens module array  100  includes two lens arrays  101 ,  102  and four sets of alignment members. The alignment member sets consist of a plurality of columnar alignment pins  1011 / 1021  and corresponding alignment cavities  1022 / 1012 . The four sets of alignment members are respectively disposed on four corners of the two lens arrays  101 ,  102 . In  FIG. 9 , only two sets are revealed. After being aligned by four sets of alignment members, each optical axis  103  of the two lens arrays  101 ,  102  is aligned. Then UV curing glue  104  is applied to attach and fix the assembly. The alignment members ( 1011 / 1021 ,  1022 / 1012 ) and each lens array  101 .  102  are molded by multi-cavity molds  22  once at a time. Thus each alignment member and each optical axis  103  are fixed. Therefore, after being assembled by the alignment members, each optical axis  103  of the two lens arrays  101 ,  102  are assembled according to a preset tolerance so as to achieve precise assembling. 
       Embodiment 2 
       [0027]    Refer to  FIG. 7 , an embodiment of a rectangular stacked lens module  11  is generated by making straight cutting through a stacked lens module array  10 . The stacked lens module array  10  consists of two lens arrays (the first array and the second lens array), four sets of alignment members, a circuit board (the first optical element)  105 , a plurality of image sensors (the second optical element)  106 , and a plurality of spacers (the third optical element)  107 . The four sets of alignment members are four sets of through holes  108 . There are only two sets of through holes  108  shown in  FIG. 7 . The image sensor  106  is corresponding to the optical area (lens) and is preset on the circuit board  105 . The circuit board  105  is aligned with the second lens array  102  at a preset interval (by the spacer  107 ) and is aligned with the first lens array  101  by the through holes  108 . After alignment of each optical axis  103  of the lens arrays  101 ,  102  with each image sensor  106 , glue  104  is applied to adhere and fix the assembly of the lens module. 
       Embodiment 3 
       [0028]    Refer to  FIG. 10 , this embodiment of a rectangular stacked lens module  30  is applied to an LED assembly. In an LED assembly, in order to concentrate light from LED chips  35  by optical glass lenses and project light to objectives with a preset distribution pattern, a plurality of optical glass lenses are stacked and spaced at a preset interval. In this embodiment, the rectangular stacked lens module  30  is composed of a first optical glass lens  31 , a second optical glass lens  32 , a circuit board  36 , a LED chip  35 , spacers  37  and a silicon layer  38 . The optical axes  103  of the two lenses  31 ,  32  are aligned and there is a certain distance between the two lenses  31 ,  32 . In this embodiment, along the optical axis  103 , the distance between a convex surface of the first lens  31  on the light source side and a concave surface of the second lens  32  on the object side is 0.65 mm. The distance between an image side convex surface of the second lens  32  and the LED chip  35  is 3.1 mm. The silicon layer  38  used as a wave length transmission layer is filled between the second lens  32  and the LED chip  35 . In  FIG. 10 , there are only one alignment pin  311 / 321  and one alignment cavity  312 / 322  shown in the two lens arrays  31 ,  32 . The manufacturing method of this embodiment is similar to that of the above embodiment. The lens module  30  is formed by cutting through dicing lines  301  and is used in LED assemblies. 
       Embodiment 4 
       [0029]    Refer to  FIG. 11 , this embodiment of a rectangular stacked lens module  40  is applied to mobile camera lenses. From the object side to the image side, the lens module  40  includes a first lens  41  that is a meniscus lens with a concave surface facing the image side, a second lens  42  that is a meniscus lens with a convex surface facing the image side, and a third lens  43  that is a M-shaped lens with optical elements. The optical elements consists of a cover glass  44 , an aperture  45 , three spacers  47 , an IR cut lens  48 , an image sensor  46  and a circuit board  36 . 
         [0030]    In the following list one, the number of the optical surfaces from the object side in turn, the optical surface type, the radius of curvature R (mm) of each optical surface on the optical axis, the on-axis surface spacing and lens materials. 
         [0031]    List one optical parameters of the embodiment 4 applied to mobile camera lenses: 
         [0000]    
       
         
               
               
               
               
               
             
               
               
               
               
               
               
             
           
               
                   
               
               
                   
                   
                 radius of 
                 on-axis 
                   
               
               
                   
                   
                 curvature R 
                 surface 
               
               
                 Surf# 
                 optical surface type 
                 (mm) 
                 spacing 
                 lens materials 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1. 
                 (STO) aperture and 
                 aspheric surface 
                 1.0613 
                 0.625417 
                 SCHOTT_BAC2 
               
               
                   
                 first optical lens 
               
               
                 2. 
                 concave surface of the 
                 aspheric surface 
                 2.8968 
                 0.333 
               
               
                   
                 first optical lens 
               
               
                 3. 
                 concave surface of the 
                 aspheric surface 
                 −1.2031 
                 0.3 
                 OHARA_FTM16 
               
               
                   
                 second optical lens 
               
               
                 4. 
                 convex surface of the 
                 aspheric surface 
                 −1.4586 
                 0.71 
               
               
                   
                 second optical lens 
               
               
                 5. 
                 object side of the third 
                 aspheric surface 
                 7.6865 
                 0.635 
                 SCHOTT_BAC2 
               
               
                   
                 optical lens 
               
               
                 6. 
                 image side of the third 
                 aspheric surface. 
                 3.4879 
                 0.3 
               
               
                   
                 optical lens 
               
               
                 7. 
                 object side of the IR 
                   
                 ∞ 
                 0.3 
                 BK7 
               
               
                   
                 cut lens 
               
               
                 8. 
                 image side of the IR 
                   
                 ∞ 
                 0.6895 
               
               
                   
                 cut lens 
               
               
                 9. 
                 sensing surface of the 
                   
                 ∞ 
               
               
                   
                 image sensor 
               
               
                   
               
             
          
         
       
     
         [0032]    The manufacturing processes of this embodiment are similar to that of the embodiment 3, first produce a glass lens module array having 16 first lenses and 16 second lenses. The number of the lenses is not limited to 16. The non-optical area of each lens array is disposed with alignment member such as an alignment cavity  412  on the first lens  41  and an alignment pin  421  on the second lens  42  so as to align optical axes  103  of each lens. Then produce a lens array having 16 (4×4) third lenses  43  by glass molding. Also produce optical element plate having 16 (4×4) apertures  45  and 16 (4×4) spacers  47 . Weld 16 (4×4) optical sensors  46  on preset positions of a circuit board  36 . Next use glue  49  such as UV curing glue to bind each optical element plate  45 ,  47 , a cover glass  4 , an IR cut lens  48 , a lens module array formed by the first lens array  41  and the second lens array  42 , with the third lens array  43  in a stacked way. After being radiated in an UV oven, a stacked lens module array with 16 camera lenses is formed and 16 rectangular stacked lens modules  40  are generated through cutting. By this method, the manufacturing processes are simplified, the cost is reduced and predetermined optical functions are achieved. 
       Embodiment 5 
       [0033]    Refer to  FIG. 12 , this embodiment of a rectangular stacked lens module  50  is applied to mobile camera lens, similar to the above embodiment. At least one through hole  515  is used as an alignment member, as the through hole  108  in  FIG. 7  (the second embodiment). The alignment members  412 ,  421  of the embodiment four in  FIG. 11  are replaced by through holes. The manufacturing method of this embodiment is similar to that of the above embodiment. An optical glass lens array respectively having 16 (4×4) first lenses  51 , second lenses  52  and third lenses  53  is produced. A through hole  515  is arranged at non-optical area of each corner of each lens array and there are four through holes  515  totally used as alignment members. Then produce an optical element plate having 16 (4×4) apertures  55  and an optical element plate having 16 (4×4) spacers  57 , both disposed with through holes  515  on corresponding positions. That means each optical element plate includes four through holes  515 . In  FIG. 12 , only one through hole  515  is shown. 16 (4×4) optical sensors  56  are welded on preset positions of the circuit board  36 . While assembling, use a jig assembly  23  (as shown in  FIG. 7 ) having an alignment rod  231  disposed on each of four corners thereof and through holes of above optical element plates and of each lens array are positioned over the alignment rod correspondingly. Then bind each optical element plate  55 ,  57 , a cover glass  54 , an IR cut lens  58 , the circuit board  36  and the lens arrays in a stacked way sequentially by glue. After curing of the glue, release the jig assembly and a stacked lens module array with 16 camera lenses is produced. 16 rectangular stacked lens module  50  are generated through cutting. By this method, 16 camera lenses are produced once and optical axes of the first lens  51 , the second lens  52  and the third lens  53  of each camera lens are aligned. There is a preset distance between the lens and each optical elements. Thus the manufacturing processes are simplified, the cost is down and the predetermined optical functions are achieved. 
       Embodiment 6 
       [0034]    Refer to  FIG. 13 , this embodiment of a rectangular stacked lens module  60  applied to camera zoom lenses includes a first optical group  61 , a second optical group  62 , a third optical group  63 , and a fourth optical group  64 . Each optical group  61 - 64  is a rectangular stacked lens module produced according to the manufacturing method of the present invention and is assembled with a lens holder  613 ,  623 ,  633 ,  643  and then is mounted in a lens barrel  601  so as to form a zoom lens. The first optical group  61  and the fourth optical group  64  are fixed on the lens barrel  601 , remaining static while zooming while the second optical group  62  and the third optical group  63  are mounted into sliding slots (not shown in figure) and moving upward and downward along the optical axis while zooming so as to achieve the purpose of zooming. 
         [0035]    The first optical group  61  consists of a cover glass  64   a , an aperture  65 , a first lens  611 , a second lens  612  and the lens holder  613 . The first lens  611  and the second lens  612  are made of optical glass and disposed with alignment members such as an alignment cavity  6112  and corresponding alignment pin  6121 . The manufacturing processes of this embodiment are similar to those of the embodiment 4. Firstly, a stacked lens module array having a cover glass  64   a , an aperture  65 , a first lens  611 , and a second lens  612  glued with one another by glue  69  is produced. Then the array is cut through straight lines into a plurality of rectangular stacked lens module. Each lens module is positioned into a lens holder  613 . The lens holder  613  is designed into a column with a rectangular hole therein so as to assemble with the columnar lens barrel  601 . Thus the rectangular stacked lens module is mounted into the rectangular hole to be assembled with the lens holder  613 . 
         [0036]    The second optical group  62  consists of a third lens  621 , a fourth lens  622  and the lens holder  623 . The third lens  621  and the fourth lens  622  are made of optical glass and disposed with alignment members such as an alignment cavity  6212  and corresponding alignment pin  6221 . The manufacturing processes of this embodiment are similar to those of the first optical group  61 . The lens holder  623  in this embodiment is similar to the lens holder  613 , a column with a rectangular hole therein. 
         [0037]    The third optical group  63  includes a fifth lens  631  made of optical plastic and a lens holder  633  that is a column with a hole for mounting the fifth lens  631 . 
         [0038]    The fourth optical group  64  includes an IR cut lens  68 , a spacer  67 , an image sensor  661 , a circuit board  662  and a lens holder  643 . The lens holder  643  is designed into a column with a hole for mounting each optical element in the fourth optical group  64 . 
         [0039]    Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, and representative devices shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.