Patent Publication Number: US-11022779-B2

Title: Optical imaging lens

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to an optical imaging lens. Specifically speaking, the present invention is directed to an optical imaging lens for use in a portable electronic device such as a mobile phone, a camera, a tablet personal computer, or a personal digital assistant (PDA) for taking pictures or for recording videos. 
     2. Description of the Prior Art 
     In recent years, the popularity of mobile phones and digital cameras makes the camera module, including an optical imaging lens, a holder and a sensor, develop quickly. The camera module also has greater and greater demands to be smaller with the reducing sizes of the mobile phones and digital cameras. With the development and shrinkage of a charge coupled device (CCD) or a complementary metal oxide semiconductor element (CMOS), the optical imaging lens set which is installed in the camera module shrinks as well to meet the demands. 
     As far as an optical imaging lens of six lens elements is concerned, a distance from the object-side surface of the first lens element to an image plane along the optical axis is large and such a large distance is unfavorable for the size reduction of a mobile phone and of a digital camera. In addition, it is also important to enlarge a field of view as well as to satisfy the higher and higher demands for the imaging quality. Therefore, it is still needed to provide a novel optical imaging lens with good imaging quality and a shorter system length in this field. 
     SUMMARY OF THE INVENTION 
     In the light of the above, various embodiments of the present invention propose an optical imaging lens of six lens elements which has reduced system length, ensured imaging quality, a larger field of view, good optical performance and is technically possible. The optical imaging lens of six lens elements of the present invention from an object side to an image side in order along an optical axis has a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element and a sixth lens element. Each first lens element, second lens element, third lens element, fourth lens element, fifth lens element and sixth lens element respectively has an object-side surface which faces toward the object side and allows imaging rays to pass through as well as an image-side surface which faces toward the image side and allows the imaging rays to pass through. 
     In order to facilitate clearness of the parameters represented by the present invention and the drawings, it is defined in this specification and the drawings: T1 is a thickness of the first lens element along the optical axis; T2 is a thickness of the second lens element along the optical axis; T3 is a thickness of the third lens element along the optical axis; T4 is a thickness of the fourth lens element along the optical axis; T5 is a thickness of the fifth lens element along the optical axis; and T6 is a thickness of the sixth lens element along the optical axis. G12 is an air gap between the first lens element and the second lens element along the optical axis; G23 is an air gap between the second lens element and the third lens element along the optical axis; G34 is an air gap between the third lens element and the fourth lens element along the optical axis; G45 is an air gap between the fourth lens element and the fifth lens element along the optical axis; G56 is an air gap between the fifth lens element and the sixth lens element along the optical axis. ALT is a sum of thicknesses of all the six lens elements along the optical axis. AAG is a sum of five air gaps from the first lens element to the sixth lens element along the optical axis. In addition, TTL is a distance from the object-side surface of the first lens element to an image plane along the optical axis, and that is the system length of the optical imaging lens; EFL is an effective focal length of the optical imaging lens; TL is a distance from the object-side surface of the first lens element to the image-side surface of the sixth lens element along the optical axis. BFL is a distance from the image-side surface of the sixth lens element to the image plane along the optical axis. 
     In one embodiment, an optical axis region of the object-side surface of the first lens element is convex. An optical axis region of the image-side surface of the second lens element is convex. An optical axis region of the object-side surface of the third lens element is convex. The fourth lens element has negative refracting power and an optical axis region of the object-side surface of the fourth lens element is concave. A periphery region of the object-side surface of the fifth lens element is concave. An optical axis region of the object-side surface of the sixth lens element is convex and an optical axis region of the image-side surface of the sixth lens element is concave. Only the above-mentioned six lens elements of the optical imaging lens have refracting power and the optical imaging lens satisfies the conditional formula (G12+T3+G34+T4+G45+T5)/EFL≥1.200. 
     In the optical imaging lens of the present invention, the embodiments may also selectively satisfy the following optical conditions: 
     BFL/(T2+G56)≥1.000; 
     ALT/(G23+T3+G34)≤3.100; 
     ALT/EFL≤2.300; 
     AAG/(T4+G45)≥3.900; 
     (T6+BFL)/T1≥3.300; 
     TL/(T4+T5)≤5.100; 
     (T3+G34)/T1≤2.800; 
     TTL/(G12+G34)≤5.700; 
     (G23+T3)/T6≤3.100; 
     (T3+T5)/T1≤4.000; 
     EFL/(G12+G56)≥1.500; 
     (T5+T6)/T4≤4.900; 
     TL/BFL≤4.200; 
     (G12+G23)/T2≥1.200; 
     G12/(G34+G45+G56)≤3.000; 
     (G12+G45)/T4≤4.600; 
     (T2+T3+T5)/(T1+T4)≤3.400; 
     (G12+G34)/T6≥2.400; 
     (T5+G56)/T6≤2.700. 
     These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1-5  illustrate the methods for determining the surface shapes and for determining an optical axis region and a periphery region of one lens element. 
         FIG. 6  illustrates a first embodiment of the optical imaging lens of the present invention. 
         FIG. 7A  illustrates the longitudinal spherical aberration on the image plane of the first embodiment. 
         FIG. 7B  illustrates the field curvature aberration on the sagittal direction of the first embodiment. 
         FIG. 7C  illustrates the field curvature aberration on the tangential direction of the first embodiment. 
         FIG. 7D  illustrates the distortion aberration of the first embodiment. 
         FIG. 8  illustrates a second embodiment of the optical imaging lens of the present invention. 
         FIG. 9A  illustrates the longitudinal spherical aberration on the image plane of the second embodiment. 
         FIG. 9B  illustrates the field curvature aberration on the sagittal direction of the second embodiment. 
         FIG. 9C  illustrates the field curvature aberration on the tangential direction of the second embodiment. 
         FIG. 9D  illustrates the distortion aberration of the second embodiment. 
         FIG. 10  illustrates a third embodiment of the optical imaging lens of the present invention. 
         FIG. 11A  illustrates the longitudinal spherical aberration on the image plane of the third embodiment. 
         FIG. 11B  illustrates the field curvature aberration on the sagittal direction of the third embodiment. 
         FIG. 11C  illustrates the field curvature aberration on the tangential direction of the third embodiment. 
         FIG. 11D  illustrates the distortion aberration of the third embodiment. 
         FIG. 12  illustrates a fourth embodiment of the optical imaging lens of the present invention. 
         FIG. 13A  illustrates the longitudinal spherical aberration on the image plane of the fourth embodiment. 
         FIG. 13B  illustrates the field curvature aberration on the sagittal direction of the fourth embodiment. 
         FIG. 13C  illustrates the field curvature aberration on the tangential direction of the fourth embodiment. 
         FIG. 13D  illustrates the distortion aberration of the fourth embodiment. 
         FIG. 14  illustrates a fifth embodiment of the optical imaging lens of the present invention. 
         FIG. 15A  illustrates the longitudinal spherical aberration on the image plane of the fifth embodiment. 
         FIG. 15B  illustrates the field curvature aberration on the sagittal direction of the fifth embodiment. 
         FIG. 15C  illustrates the field curvature aberration on the tangential direction of the fifth embodiment. 
         FIG. 15D  illustrates the distortion aberration of the fifth embodiment. 
         FIG. 16  illustrates a sixth embodiment of the optical imaging lens of the present invention. 
         FIG. 17A  illustrates the longitudinal spherical aberration on the image plane of the sixth embodiment. 
         FIG. 17B  illustrates the field curvature aberration on the sagittal direction of the sixth embodiment. 
         FIG. 17C  illustrates the field curvature aberration on the tangential direction of the sixth embodiment. 
         FIG. 17D  illustrates the distortion aberration of the sixth embodiment. 
         FIG. 18  illustrates a seventh embodiment of the optical imaging lens of the present invention. 
         FIG. 19A  illustrates the longitudinal spherical aberration on the image plane of the seventh embodiment. 
         FIG. 19B  illustrates the field curvature aberration on the sagittal direction of the seventh embodiment. 
         FIG. 19C  illustrates the field curvature aberration on the tangential direction of the seventh embodiment. 
         FIG. 19D  illustrates the distortion aberration of the seventh embodiment. 
         FIG. 20  illustrates an eighth embodiment of the optical imaging lens of the present invention. 
         FIG. 21A  illustrates the longitudinal spherical aberration on the image plane of the eighth embodiment. 
         FIG. 21B  illustrates the field curvature aberration on the sagittal direction of the eighth embodiment. 
         FIG. 21C  illustrates the field curvature aberration on the tangential direction of the eighth embodiment. 
         FIG. 21D  illustrates the distortion aberration of the eighth embodiment. 
         FIG. 22  illustrates a ninth embodiment of the optical imaging lens of the present invention. 
         FIG. 23A  illustrates the longitudinal spherical aberration on the image plane of the ninth embodiment. 
         FIG. 23B  illustrates the field curvature aberration on the sagittal direction of the ninth embodiment. 
         FIG. 23C  illustrates the field curvature aberration on the tangential direction of the ninth embodiment. 
         FIG. 23D  illustrates the distortion aberration of the ninth embodiment. 
         FIG. 24  illustrates a tenth embodiment of the optical imaging lens of the present invention. 
         FIG. 25A  illustrates the longitudinal spherical aberration on the image plane of the tenth embodiment. 
         FIG. 25B  illustrates the field curvature aberration on the sagittal direction of the tenth embodiment. 
         FIG. 25C  illustrates the field curvature aberration on the tangential direction of the tenth embodiment. 
         FIG. 25D  illustrates the distortion aberration of the tenth embodiment. 
         FIG. 26  shows the optical data of the first embodiment of the optical imaging lens. 
         FIG. 27  shows the aspheric surface data of the first embodiment. 
         FIG. 28  shows the optical data of the second embodiment of the optical imaging lens. 
         FIG. 29  shows the aspheric surface data of the second embodiment. 
         FIG. 30  shows the optical data of the third embodiment of the optical imaging lens. 
         FIG. 31  shows the aspheric surface data of the third embodiment. 
         FIG. 32  shows the optical data of the fourth embodiment of the optical imaging lens. 
         FIG. 33  shows the aspheric surface data of the fourth embodiment. 
         FIG. 34  shows the optical data of the fifth embodiment of the optical imaging lens. 
         FIG. 35  shows the aspheric surface data of the fifth embodiment. 
         FIG. 36  shows the optical data of the sixth embodiment of the optical imaging lens. 
         FIG. 37  shows the aspheric surface data of the sixth embodiment. 
         FIG. 38  shows the optical data of the seventh embodiment of the optical imaging lens. 
         FIG. 39  shows the aspheric surface data of the seventh embodiment. 
         FIG. 40  shows the optical data of the eighth embodiment of the optical imaging lens. 
         FIG. 41  shows the aspheric surface data of the eighth embodiment. 
         FIG. 42  shows the optical data of the ninth embodiment of the optical imaging lens. 
         FIG. 43  shows the aspheric surface data of the ninth embodiment. 
         FIG. 44  shows the optical data of the tenth embodiment of the optical imaging lens. 
         FIG. 45  shows the aspheric surface data of the tenth embodiment. 
         FIG. 46  shows some important parameters in the embodiments. 
         FIG. 47  shows some important ratios in the embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     In the present disclosure, the optical system may comprise at least one lens element to receive imaging rays that are incident on the optical system over a set of angles ranging from parallel to an optical axis to a half field of view (HFOV) angle with respect to the optical axis. The imaging rays pass through the optical system to produce an image on an image plane. The term “a lens element having positive refracting power (or negative refracting power)” means that the paraxial refracting power of the lens element in Gaussian optics is positive (or negative). The term “an object-side (or image-side) surface of a lens element” refers to a specific region of that surface of the lens element at which imaging rays can pass through that specific region. Imaging rays include at least two types of rays: a chief ray Lc and a marginal ray Lm (as shown in  FIG. 1 ). An object-side (or image-side) surface of a lens element can be characterized as having several regions, including an optical axis region, a periphery region, and, in some cases, one or more intermediate regions, as discussed more fully below. 
       FIG. 1  is a radial cross-sectional view of a lens element  100 . Two referential points for the surfaces of the lens element  100  can be defined: a central point, and a transition point. The central point of a surface of a lens element is a point of intersection of that surface and the optical axis I. As illustrated in  FIG. 1 , a first central point CP 1  may be present on the object-side surface  110  of lens element  100  and a second central point CP 2  may be present on the image-side surface  120  of the lens element  100 . The transition point is a point on a surface of a lens element, at which the line tangent to that point is perpendicular to the optical axis I. The optical boundary OB of a surface of the lens element is defined as a point at which the radially outermost marginal ray Lm passing through the surface of the lens element intersects the surface of the lens element. All transition points lie between the optical axis I and the optical boundary OB of the surface of the lens element. If multiple transition points are present on a single surface, then these transition points are sequentially named along the radial direction of the surface with reference numerals starting from the first transition point. For example, the first transition point, e.g., TP 1 , (closest to the optical axis I), the second transition point, e.g., TP 2 , (as shown in  FIG. 4 ), and the Nth transition point (farthest from the optical axis I). 
     The region of a surface of the lens element from the central point to the first transition point TP 1  is defined as the optical axis region, which includes the central point. The region located radially outside of the farthest Nth transition point from the optical axis I to the optical boundary OB of the surface of the lens element is defined as the periphery region. In some embodiments, there may be intermediate regions present between the optical axis region and the periphery region, with the number of intermediate regions depending on the number of the transition points. 
     The shape of a region is convex if a collimated ray being parallel to the optical axis I and passing through the region is bent toward the optical axis I such that the ray intersects the optical axis I on the image side A 2  of the lens element. The shape of a region is concave if the extension line of a collimated ray being parallel to the optical axis I and passing through the region intersects the optical axis I on the object side A 1  of the lens element. 
     Additionally, referring to  FIG. 1 , the lens element  100  may also have a mounting portion  130  extending radially outward from the optical boundary OB. The mounting portion  130  is typically used to physically secure the lens element to a corresponding element of the optical system (not shown). Imaging rays do not reach the mounting portion  130 . The structure and shape of the mounting portion  130  are only examples to explain the technologies, and should not be taken as limiting the scope of the present disclosure. The mounting portion  130  of the lens elements discussed below may be partially or completely omitted in the following drawings. 
     Referring to  FIG. 2 , optical axis region Z 1  is defined between central point CP and first transition point TP 1 . Periphery region Z 2  is defined between TP 1  and the optical boundary OB of the surface of the lens element. Collimated ray  211  intersects the optical axis I on the image side A 2  of lens element  200  after passing through optical axis region Z 1 , i.e., the focal point of collimated ray  211  after passing through optical axis region Z 1  is on the image side A 2  of the lens element  200  at point R in  FIG. 2 . Accordingly, since the ray itself intersects the optical axis I on the image side A 2  of the lens element  200 , optical axis region Z 1  is convex. On the contrary, collimated ray  212  diverges after passing through periphery region Z 2 . The extension line EL of collimated ray  212  after passing through periphery region Z 2  intersects the optical axis I on the object side A 1  of lens element  200 , i.e., the focal point of collimated ray  212  after passing through periphery region Z 2  is on the object side A 1  at point M in  FIG. 2 . Accordingly, since the extension line EL of the ray intersects the optical axis I on the object side A 1  of the lens element  200 , periphery region Z 2  is concave. In the lens element  200  illustrated in  FIG. 2 , the first transition point TP 1  is the border of the optical axis region and the periphery region, i.e., TP 1  is the point at which the shape changes from convex to concave. 
     Alternatively, there is another way for a person having ordinary skill in the art to determine whether an optical axis region is convex or concave by referring to the sign of “Radius” (the “R” value), which is the paraxial radius of shape of a lens surface in the optical axis region. The R value is commonly used in conventional optical design software such as Ze max and CodeV. The R value usually appears in the lens data sheet in the software. For an object-side surface, a positive R value defines that the optical axis region of the object-side surface is convex, and a negative R value defines that the optical axis region of the object-side surface is concave. Conversely, for an image-side surface, a positive R value defines that the optical axis region of the image-side surface is concave, and a negative R value defines that the optical axis region of the image-side surface is convex. The result found by using this method should be consistent with the method utilizing intersection of the optical axis by rays/extension lines mentioned above, which determines surface shape by referring to whether the focal point of a collimated ray being parallel to the optical axis I is on the object-side or the image-side of a lens element. As used herein, the terms “a shape of a region is convex (concave),” “a region is convex (concave),” and “a convex- (concave-) region,” can be used alternatively. 
       FIG. 3 ,  FIG. 4  and  FIG. 5  illustrate examples of determining the shape of lens element regions and the boundaries of regions under various circumstances, including the optical axis region, the periphery region, and intermediate regions as set forth in the present specification. 
       FIG. 3  is a radial cross-sectional view of a lens element  300 . As illustrated in  FIG. 3 , only one transition point TP 1  appears within the optical boundary OB of the image-side surface  320  of the lens element  300 . Optical axis region Z 1  and periphery region Z 2  of the image-side surface  320  of lens element  300  are illustrated. The R value of the image-side surface  320  is positive (i.e., R&gt;0). Accordingly, the optical axis region Z 1  is concave. 
     In general, the shape of each region demarcated by the transition point will have an opposite shape to the shape of the adjacent region(s). Accordingly, the transition point will define a transition in shape, changing from concave to convex at the transition point or changing from convex to concave. In  FIG. 3 , since the shape of the optical axis region Z 1  is concave, the shape of the periphery region Z 2  will be convex as the shape changes at the transition point TP 1 . 
       FIG. 4  is a radial cross-sectional view of a lens element  400 . Referring to  FIG. 4 , a first transition point TP 1  and a second transition point TP 2  are present on the object-side surface  410  of lens element  400 . The optical axis region Z 1  of the object-side surface  410  is defined between the optical axis I and the first transition point TP 1 . The R value of the object-side surface  410  is positive (i.e., R&gt;0). Accordingly, the optical axis region Z 1  is convex. 
     The periphery region Z 2  of the object-side surface  410 , which is also convex, is defined between the second transition point TP 2  and the optical boundary OB of the object-side surface  410  of the lens element  400 . Further, intermediate region Z 3  of the object-side surface  410 , which is concave, is defined between the first transition point TP 1  and the second transition point TP 2 . Referring once again to  FIG. 4 , the object-side surface  410  includes an optical axis region Z 1  located between the optical axis I and the first transition point TP 1 , an intermediate region Z 3  located between the first transition point TP 1  and the second transition point TP 2 , and a periphery region Z 2  located between the second transition point TP 2  and the optical boundary OB of the object-side surface  410 . Since the shape of the optical axis region Z 1  is designed to be convex, the shape of the intermediate region Z 3  is concave as the shape of the intermediate region Z 3  changes at the first transition point TP 1 , and the shape of the periphery region Z 2  is convex as the shape of the periphery region Z 2  changes at the second transition point TP 2 . 
       FIG. 5  is a radial cross-sectional view of a lens element  500 . Lens element  500  has no transition point on the object-side surface  510  of the lens element  500 . For a surface of a lens element with no transition point, for example, the object-side surface  510  the lens element  500 , the optical axis region Z 1  is defined as the region between 0-50% of the distance between the optical axis I and the optical boundary OB of the surface of the lens element and the periphery region is defined as the region between 50%-100% of the distance between the optical axis I and the optical boundary OB of the surface of the lens element. Referring to lens element  500  illustrated in  FIG. 5 , the optical axis region Z 1  of the object-side surface  510  is defined between the optical axis I and 50% of the distance between the optical axis I and the optical boundary OB. The R value of the object-side surface  510  is positive (i.e., R&gt;0). Accordingly, the optical axis region Z 1  is convex. For the object-side surface  510  of the lens element  500 , because there is no transition point, the periphery region Z 2  of the object-side surface  510  is also convex. It should be noted that lens element  500  may have a mounting portion (not shown) extending radially outward from the periphery region Z 2 . 
     As shown in  FIG. 6 , the optical imaging lens  1  of six lens elements of the present invention, sequentially located from an object side A 1  (where an object is located) to an image side A 2  along an optical axis I, has a first lens element  10 , an aperture stop  80 , a second lens element  20 , a third lens element  30 , a fourth lens element  40 , a fifth lens element  50 , a sixth lens element  60 , a filter  90  and an image plane  91 . Generally speaking, the first lens element  10 , the second lens element  20 , the third lens element  30 , the fourth lens element  40 , the fifth lens element  50  and the sixth lens element  60  may be made of a transparent plastic material but the present invention is not limited to this, and each lens element has an appropriate refracting power. In the present invention, lens elements having refracting power included by the optical imaging lens  1  are only the six lens elements (the first lens element  10 , the second lens element  20 , the third lens element  30 , the fourth lens element  40 , the fifth lens element  50  and the sixth lens element  60 ) described above. The optical axis I is the optical axis of the entire optical imaging lens  1 , and the optical axis of each of the lens elements coincides with the optical axis of the optical imaging lens  1 . 
     Furthermore, the optical imaging lens  1  includes an aperture stop (ape. stop)  80  disposed in an appropriate position. In  FIG. 6 , the aperture stop  80  is disposed between the first lens element  10  and the second lens element  20 . When light emitted or reflected by an object (not shown) which is located at the object side A 1  enters the optical imaging lens  1  of the present invention, it forms a clear and sharp image on the image plane  91  at the image side A 2  after passing through the first lens element  10 , the aperture stop  80 , the second lens element  20 , the third lens element  30 , the fourth lens element  40 , the fifth lens element  50 , the sixth lens element  60 , and the filter  90 . In one embodiment of the present invention, the filter  90  may be a filter of various suitable functions to filter out light of a specific wavelength, for embodiment, the filter  90  may be an infrared cut filter (infrared cut-off filter), placed between the sixth lens element  60  and the image plane  91  to keep the infrared in the imaging rays from reaching the image plane  91  to jeopardize the imaging quality. 
     The first lens element  10 , the second lens element  20 , the third lens element  30 , the fourth lens element  40 , the fifth lens element  50  and the sixth lens element  60  of the optical imaging lens  1  each has an object-side surface  11 ,  21 ,  31 ,  41 ,  51  and  61  facing toward the object side A 1  and allowing imaging rays to pass through as well as an image-side surface  12 ,  22 ,  32 ,  42 ,  52  and  62  facing toward the image side A 2  and allowing the imaging rays to pass through. Furthermore, each object-side surface and image-side surface of lens elements in the optical imaging lens of present invention has optical axis region and periphery region. 
     Each lens element in the optical imaging lens  1  of the present invention further has a thickness T along the optical axis I. For embodiment, the first lens element  10  has a first lens element thickness T1, the second lens element  20  has a second lens element thickness T2, the third lens element  30  has a third lens element thickness T3, the fourth lens element  40  has a fourth lens element thickness T4, the fifth lens element  50  has a fifth lens element thickness T5, and the sixth lens element  60  has a sixth lens element thickness T6. Therefore, a sum of thicknesses of all the six lens elements in the optical imaging lens  1  along the optical axis I is ALT=T1+T2+T3+T4+T5+T6. 
     In addition, between two adjacent lens elements in the optical imaging lens  1  of the present invention there may be an air gap along the optical axis I. In embodiments, there is an air gap G12 between the first lens element  10  and the second lens element  20 , an air gap G23 between the second lens element  20  and the third lens element  30 , an air gap G34 between the third lens element  30  and the fourth lens element  40 , an air gap G45 between the fourth lens element  40  and the fifth lens element  50  as well as an air gap G56 between the fifth lens element  50  and the sixth lens element  60 . Therefore, a sum of five air gaps from the first lens element  10  to the sixth lens element  60  along the optical axis I is AAG=G12+G23+G34+G45+G56. 
     In addition, a distance from the object-side surface  11  of the first lens element  10  to the image plane  91 , namely a system length of the optical imaging lens  1  along the optical axis I is TTL; an effective focal length of the optical imaging lens is EFL; a distance from the object-side surface  11  of the first lens element  10  to the image-side surface  62  of the sixth lens element  60  along the optical axis I is TL. A distance from the image-side surface  62  of the sixth lens element  60  to the filter  90  along the optical axis I is G6F; a thickness of the filter  90  along the optical axis I is TF; a distance from the filter  90  to the image plane  91  along the optical axis I is GFP; and a distance from the image-side surface  62  of the sixth lens element  60  to the image plane  91  along the optical axis I is BFL. Therefore, BFL=G6F+TF+GFP. ImgH is an image height of the optical imaging lens  1 . 
     Furthermore, a focal length of the first lens element  10  is f1; a focal length of the second lens element  20  is f2; a focal length of the third lens element  30  is f3; a focal length of the fourth lens element  40  is f4; a focal length of the fifth lens element  50  is f5; a focal length of the sixth lens element  60  is f6; a refractive index of the first lens element  10  is n1; a refractive index of the second lens element  20  is n2; a refractive index of the third lens element  30  is n3; a refractive index of the fourth lens element  40  is n4; a refractive index of the fifth lens element  50  is n5; a refractive index of the sixth lens element  60  is n6; an Abbe number of the first lens element  10  is υ1; an Abbe number of the second lens element  20  is υ2; an Abbe number of the third lens element  30  is υ3; and an Abbe number of the fourth lens element  40  is υ4; an Abbe number of the fifth lens element  50  is υ5; and an Abbe number of the sixth lens element  60  is υ6. 
     First Embodiment 
     Please refer to  FIG. 6  which illustrates the first embodiment of the optical imaging lens  1  of the present invention. Please refer to  FIG. 7A  for the longitudinal spherical aberration on the image plane  91  of the first embodiment; please refer to  FIG. 7B  for the field curvature aberration on the sagittal direction; please refer to  FIG. 7C  for the field curvature aberration on the tangential direction; and please refer to  FIG. 7D  for the distortion aberration. The Y axis of the spherical aberration in each embodiment is “field of view” for 1.0. The Y axis of the field curvature aberration and the distortion aberration in each embodiment stands for the “image height” (ImgH), which is 3.325 mm. 
     Only the six lens elements  10 ,  20 ,  30 ,  40 ,  50  and  60  of the optical imaging lens  1  of the first embodiment have refracting power. The optical imaging lens  1  also has an aperture stop  80 , a filter  90 , and an image plane  91 . The aperture stop  80  is provided between the first lens element  10  and the second lens element  20 . The filter  90  may be used for preventing specific wavelength light (such as the infrared light) reaching the image plane  91  to adversely affect the imaging quality. 
     The first lens element  10  has negative refracting power. An optical axis region  13  and a periphery region  14  of the object-side surface  11  of the first lens element  10  are convex. An optical axis region  16  and a periphery region  17  of the image-side surface  12  of the first lens element  10  are concave. Besides, both the object-side surface  11  and the image-side surface  12  of the first lens element  10  are aspherical surfaces, but it is not limited thereto. 
     The second lens element  20  has positive refracting power. An optical axis region  23  and a periphery region  24  of the object-side surface  21  of the second lens element  20  are convex. An optical axis region  26  and a periphery region  27  of the image-side surface  22  of the second lens element  20  are convex. Besides, both the object-side surface  21  and the image-side surface  22  of the second lens element  20  are aspherical surfaces, but it is not limited thereto. 
     The third lens element  30  has positive refracting power. An optical axis region  33  and a periphery region  34  of the object-side surface  31  of the third lens element  30  are convex. An optical axis region  36  and a periphery region  37  of the image-side surface  32  of the third lens element  30  are convex. Besides, both the object-side surface  31  and the image-side surface  32  of the third lens element  30  are aspherical surfaces, but it is not limited thereto. 
     The fourth lens element  40  has negative refracting power. An optical axis region  43  and a periphery region  44  of the object-side surface  41  of the fourth lens element  40  are concave. An optical axis region  46  of the image-side surface  42  of the fourth lens element  40  is convex and a periphery region  47  of the image-side surface  42  of the fourth lens element  40  is concave. Besides, both the object-side surface  41  and the image-side surface  42  of the fourth lens element  40  are aspherical surfaces, but it is not limited thereto. 
     The fifth lens element  50  has positive refracting power. An optical axis region  53  and a periphery region  54  of the object-side surface  51  of the fifth lens element  50  are concave. An optical axis region  56  and a periphery region  57  of the image-side surface  52  of the fifth lens element  50  are convex. Besides, both the object-side surface  51  and the image-side surface  52  of the fifth lens element  50  are aspherical surfaces, but it is not limited thereto. 
     The sixth lens element  60  has positive refracting power. An optical axis region  63  of the object-side surface  61  of the sixth lens element  60  is convex and a periphery region  64  of the object-side surface  61  of the sixth lens element  60  is concave. An optical axis region  66  of the image-side surface  62  of the sixth lens element  60  is concave and a periphery region  67  of the image-side surface  62  of the sixth lens element  60  is convex. Besides, both the object-side surface  61  and the image-side surface  62  of the sixth lens element  60  are aspherical surfaces, but it is not limited thereto. The filter  90  is disposed between the image-side surface  62  of the sixth lens element  60  and the image plane  91 . 
     In the first lens element  10 , the second lens element  20 , the third lens element  30 , the fourth lens element  40 , the fifth lens element  50  and the sixth lens element  60  of the optical imaging lens element  1  of the present invention, there are 12 surfaces, such as the object-side surfaces  11 / 21 / 31 / 41 / 51 / 61  and the image-side surfaces  12 / 22 / 32 / 42 / 52 / 62 . If a surface is aspherical, these aspheric coefficients are defined according to the following formula: 
               Z   ⁡     (   Y   )       =           Y   2     R     ⁢     /     ⁢     (     1   +       1   -       (     1   +   K     )     ⁢       Y   2       R   2               )       +       ∑     i   =   1     n     ⁢           ⁢       a     2   ⁢           ⁢   i       ×     Y     2   ⁢           ⁢   i                   
In which:
 
R represents the curvature radius of the lens element surface;
 
Z represents the depth of an aspherical surface (the perpendicular distance between the point of the aspherical surface at a distance Y from the optical axis I and the tangent plane of the vertex on the optical axis I of the aspherical surface);
 
Y represents a vertical distance from a point on the aspherical surface to the optical axis I;
 
K is a conic constant; and
 
a 2i  is the aspheric coefficient of the 2i th  order.
 
     The optical data of the first embodiment of the optical imaging lens  1  are shown in  FIG. 26  while the aspheric surface data are shown in  FIG. 27 . In the present embodiments of the optical imaging lens, the f-number of the entire optical imaging lens is Fno, EFL is the effective focal length, HFOV stands for the half field of view of the entire optical imaging lens, and the unit for the radius, the thickness and the focal length is in millimeters (mm). In this embodiment, EFL=2.012 mm; HFOV=60.079 degrees; TTL=5.512 mm; Fno=2.2; ImgH=3.325 mm. 
     Second Embodiment 
     Please refer to  FIG. 8  which illustrates the second embodiment of the optical imaging lens  1  of the present invention. It is noted that from the second embodiment to the following embodiments, in order to simplify the figures, only the components different from what the first embodiment has, and the basic lens elements will be labeled in figures. Other components that are the same as what the first embodiment has, such as a convex surface or a concave surface, are omitted in the following embodiments. Please refer to  FIG. 9A  for the longitudinal spherical aberration on the image plane  91  of the second embodiment, please refer to  FIG. 9B  for the field curvature aberration on the sagittal direction, please refer to  FIG. 9C  for the field curvature aberration on the tangential direction, and please refer to  FIG. 9D  for the distortion aberration. The components in this embodiment are similar to those in the first embodiment, but the optical data such as the refracting power, the radius, the lens thickness, the aspheric surface or the back focal length in this embodiment are different from the optical data in the first embodiment. Besides, in this embodiment, a periphery region  24  of the object-side surface  21  of the second lens element  20  is concave, a periphery region  34  of the object-side surface  31  of the third lens element  30  is concave, a periphery region  47  of the image-side surface  42  of the fourth lens element  40  is convex and an optical axis region  53  of the object-side surface  51  of the fifth lens element  50  is convex. 
     The optical data of the second embodiment of the optical imaging lens are shown in  FIG. 28  while the aspheric surface data are shown in  FIG. 29 . In this embodiment, EFL=1.524 mm; HFOV=60.107 degrees; TTL=6.097 mm; Fno=1.7; ImgH=2.520 mm. In particular, the field curvature aberration on the tangential direction of the optical imaging lens in this embodiment is better than that of the optical imaging lens in the first embodiment. 
     Third Embodiment 
     Please refer to  FIG. 10  which illustrates the third embodiment of the optical imaging lens  1  of the present invention. Please refer to  FIG. 11A  for the longitudinal spherical aberration on the image plane  91  of the third embodiment; please refer to  FIG. 11B  for the field curvature aberration on the sagittal direction; please refer to  FIG. 11C  for the field curvature aberration on the tangential direction; and please refer to  FIG. 11D  for the distortion aberration. The components in this embodiment are similar to those in the first embodiment, but the optical data such as the refracting power, the radius, the lens thickness, the aspheric surface or the back focal length in this embodiment are different from the optical data in the first embodiment. Besides, in this embodiment, a periphery region  24  of the object-side surface  21  of the second lens element  20  is concave and an optical axis region  53  of the object-side surface  51  of the fifth lens element  50  is convex. 
     The optical data of the third embodiment of the optical imaging lens are shown in  FIG. 30  while the aspheric surface data are shown in  FIG. 31 . In this embodiment, EFL=1.899 mm; HFOV=60.079 degrees; TTL=5.637 mm; Fno=2.1; ImgH=3.141 mm. 
     Fourth Embodiment 
     Please refer to  FIG. 12  which illustrates the fourth embodiment of the optical imaging lens  1  of the present invention. Please refer to  FIG. 13A  for the longitudinal spherical aberration on the image plane  91  of the fourth embodiment; please refer to  FIG. 13B  for the field curvature aberration on the sagittal direction; please refer to  FIG. 13C  for the field curvature aberration on the tangential direction; and please refer to  FIG. 13D  for the distortion aberration. The components in this embodiment are similar to those in the first embodiment, but the optical data such as the refracting power, the radius, the lens thickness, the aspheric surface or the back focal length in this embodiment are different from the optical data in the first embodiment. Besides, in this embodiment, a periphery region  24  of the object-side surface  21  of the second lens element  20  is concave and an optical axis region  53  of the object-side surface  51  of the fifth lens element  50  is convex. 
     The optical data of the fourth embodiment of the optical imaging lens are shown in  FIG. 32  while the aspheric surface data are shown in  FIG. 33 . In this embodiment, EFL=1.897 mm; HFOV=60.079 degrees; TTL=5.720 mm; Fno=2.1; ImgH=3.142 mm. 
     Fifth Embodiment 
     Please refer to  FIG. 14  which illustrates the fifth embodiment of the optical imaging lens  1  of the present invention. Please refer to  FIG. 15A  for the longitudinal spherical aberration on the image plane  91  of the fifth embodiment; please refer to  FIG. 15B  for the field curvature aberration on the sagittal direction; please refer to  FIG. 15C  for the field curvature aberration on the tangential direction, and please refer to  FIG. 15D  for the distortion aberration. The components in this embodiment are similar to those in the first embodiment, but the optical data such as the refracting power, the radius, the lens thickness, the aspheric surface or the back focal length in this embodiment are different from the optical data in the first embodiment. Besides, in this embodiment, a periphery region  24  of the object-side surface  21  of the second lens element  20  is concave, an optical axis region  46  of the image-side surface  42  of the fourth lens element  40  is concave and an optical axis region  53  of the object-side surface  51  of the fifth lens element  50  is convex. 
     The optical data of the fifth embodiment of the optical imaging lens are shown in  FIG. 34  while the aspheric surface data are shown in  FIG. 35 . In this embodiment, EFL=1.465 mm; HFOV=60.079 degrees; TTL=6.065 mm; Fno=1.6; ImgH=2.425 mm. In particular, the field curvature aberration on the tangential direction of the optical imaging lens in this embodiment is better than that of the optical imaging lens in the first embodiment. 
     Sixth Embodiment 
     Please refer to  FIG. 16  which illustrates the sixth embodiment of the optical imaging lens  1  of the present invention. Please refer to  FIG. 17A  for the longitudinal spherical aberration on the image plane  91  of the sixth embodiment; please refer to  FIG. 17B  for the field curvature aberration on the sagittal direction; please refer to  FIG. 17C  for the field curvature aberration on the tangential direction, and please refer to  FIG. 17D  for the distortion aberration. The components in this embodiment are similar to those in the first embodiment, but the optical data such as the refracting power, the radius, the lens thickness, the aspheric surface or the back focal length in this embodiment are different from the optical data in the first embodiment. Besides, in this embodiment, a periphery region  24  of the object-side surface  21  of the second lens element  20  is concave, an optical axis region  46  of the image-side surface  42  of the fourth lens element  40  is concave and an optical axis region  53  of the object-side surface  51  of the fifth lens element  50  is convex. 
     The optical data of the sixth embodiment of the optical imaging lens are shown in  FIG. 36  while the aspheric surface data are shown in  FIG. 37 . In this embodiment, EFL=1.877 mm; HFOV=60.079 degrees; TTL=5.743 mm; Fno=2.1; ImgH=3.110 mm. 
     Seventh Embodiment 
     Please refer to  FIG. 18  which illustrates the seventh embodiment of the optical imaging lens  1  of the present invention. Please refer to  FIG. 19A  for the longitudinal spherical aberration on the image plane  91  of the seventh embodiment; please refer to  FIG. 19B  for the field curvature aberration on the sagittal direction; please refer to  FIG. 19C  for the field curvature aberration on the tangential direction, and please refer to  FIG. 19D  for the distortion aberration. The components in this embodiment are similar to those in the first embodiment, but the optical data such as the refracting power, the radius, the lens thickness, the aspheric surface or the back focal length in this embodiment are different from the optical data in the first embodiment. Besides, in this embodiment, a periphery region  24  of the object-side surface  21  of the second lens element  20  is concave, an optical axis region  46  of the image-side surface  42  of the fourth lens element  40  is concave and an optical axis region  53  of the object-side surface  51  of the fifth lens element  50  is convex. 
     The optical data of the seventh embodiment of the optical imaging lens are shown in  FIG. 38  while the aspheric surface data are shown in  FIG. 39 . In this embodiment, EFL=1.794 mm; HFOV=60.079 degrees; TTL=5.909 mm; Fno=2.0; ImgH=2.970 mm. 
     Eighth Embodiment 
     Please refer to  FIG. 20  which illustrates the eighth embodiment of the optical imaging lens  1  of the present invention. Please refer to  FIG. 21A  for the longitudinal spherical aberration on the image plane  91  of the eighth embodiment; please refer to  FIG. 21B  for the field curvature aberration on the sagittal direction; please refer to  FIG. 21C  for the field curvature aberration on the tangential direction, and please refer to  FIG. 21D  for the distortion aberration. The components in this embodiment are similar to those in the first embodiment, but the optical data such as the refracting power, the radius, the lens thickness, the aspheric surface or the back focal length in this embodiment are different from the optical data in the first embodiment. Besides, in this embodiment, an optical axis region  53  of the object-side surface  51  of the fifth lens element  50  is convex. 
     The optical data of the eighth embodiment of the optical imaging lens are shown in  FIG. 40  while the aspheric surface data are shown in  FIG. 41 . In this embodiment, EFL=1.881 mm; HFOV=60.079 degrees; TTL=5.713 mm; Fno=2.1; ImgH=3.116 mm. 
     Ninth Embodiment 
     Please refer to  FIG. 22  which illustrates the ninth embodiment of the optical imaging lens  1  of the present invention. Please refer to  FIG. 23A  for the longitudinal spherical aberration on the image plane  91  of the ninth embodiment; please refer to  FIG. 23B  for the field curvature aberration on the sagittal direction; please refer to  FIG. 23C  for the field curvature aberration on the tangential direction, and please refer to  FIG. 23D  for the distortion aberration. The components in this embodiment are similar to those in the first embodiment, but the optical data such as the refracting power, the radius, the lens thickness, the aspheric surface or the back focal length in this embodiment are different from the optical data in the first embodiment. Besides, in this embodiment, a periphery region  24  of the object-side surface  21  of the second lens element  20  is concave, an optical axis region  46  of the image-side surface  42  of the fourth lens element  40  is concave and an optical axis region  53  of the object-side surface  51  of the fifth lens element  50  is convex. 
     The optical data of the ninth embodiment of the optical imaging lens are shown in  FIG. 42  while the aspheric surface data are shown in  FIG. 43 . In this embodiment, EFL=1.693 mm; HFOV=60.079 degrees; TTL=5.505 mm; Fno=1.9; ImgH=2.803 mm. In particular, the field curvature aberration on the tangential direction of the optical imaging lens in this embodiment is better than that of the optical imaging lens in the first embodiment. 
     Tenth Embodiment 
     Please refer to  FIG. 24  which illustrates the tenth embodiment of the optical imaging lens  1  of the present invention. Please refer to  FIG. 25A  for the longitudinal spherical aberration on the image plane  91  of the tenth embodiment; please refer to  FIG. 25B  for the field curvature aberration on the sagittal direction; please refer to  FIG. 25C  for the field curvature aberration on the tangential direction, and please refer to  FIG. 25D  for the distortion aberration. The components in this embodiment are similar to those in the first embodiment, but the optical data such as the refracting power, the radius, the lens thickness, the aspheric surface or the back focal length in this embodiment are different from the optical data in the first embodiment. Besides, in this embodiment, a periphery region  24  of the object-side surface  21  of the second lens element  20  is concave and an optical axis region  53  of the object-side surface  51  of the fifth lens element  50  is convex. 
     The optical data of the tenth embodiment of the optical imaging lens are shown in  FIG. 44  while the aspheric surface data are shown in  FIG. 45 . In this embodiment, EFL=1.744 mm; HFOV=60.079 degrees; TTL=5.446 mm; Fno=1.9; ImgH=2.886 mm. In particular, the field curvature aberration on the tangential direction of the optical imaging lens in this embodiment is better than that of the optical imaging lens in the first embodiment. 
     Some important parameters and ratios in each embodiment are shown in  FIG. 46  and in  FIG. 47 . 
     The numeral value ranges within the maximum and minimum values obtained from the combination ratio relationships of the optical parameters disclosed in each embodiment of the invention can all be implemented accordingly. 
     The applicants found that by the following designs, the lens configuration of the present invention has the following features and corresponding advantages: 
     1. An optical axis region  13  of the object-side surface  11  of the first lens element  10  being convex is effectively to focus rays of light. This may also go with an optical axis region  26  of the image-side surface  22  of the second lens element  20  being convex and with an optical axis region  33  of the object-side surface  31  of the third lens element  30  being convex to correct the aberration of the first lens element  10 . These may further go with the fourth lens element  40  having negative refracting power, with an optical axis region  43  of the object-side surface  41  of the fourth lens element  40  being concave, with a periphery region  54  of the object-side surface  51  of the fifth lens element  50  being concave, with an optical axis region  63  of the object-side surface  61  of the sixth lens element  60  being convex and with an optical axis region  66  of the image-side surface  62  of the sixth lens element  60  being concave, to more effectively reduce the field curvature aberration and the distortion aberration in order to optimize the resultant imaging quality of the optical imaging lens system.
 
2. If the condition of (G12+T3+G34+T4+G45+T5)/EFL≥1.200 can be satisfied, it is beneficial for enlarging the field of view of the optical imaging lens system. The preferable range of the above condition is 1.200≤(G12+T3+G34+T4+G45+T5)/EFL≤2.100.
 
3. In order to reduce the system length of the optical imaging lens  1  along the optical axis I and simultaneously to ensure the imaging quality, the thickness of each lens element or the air gaps should be appropriately adjusted. However, the assembly or the manufacturing difficulty should be taken into consideration. If the following numerical conditions are selectively satisfied, the optical imaging lens  1  of the present invention may have better optical arrangements:
 
1) BFL/(T2+G56)≥1.000, and the preferable range is 1.000≤BFL/(T2+G56)≤2.200;
 
2) ALT/(G23+T3+G34)≤3.100, and the preferable range is 2.500≤ALT/(G23+T3+G34)≤3.100;
 
3) ALT/EFL≤2.300, and the preferable range is 1.400≤ALT/EFL≤2.300;
 
4) AAG/(T4+G45)≥3.900, and the preferable range is 3.900≤AAG/(T4+G45)≤5.100;
 
5) (T6+BFL)/T1≥3.300, and the preferable range is 3.300≤(T6+BFL)/T1≤5.100;
 
6) TL/(T4+T5)≤5.100, and the preferable range is 4.200≤TL/(T4+T5)≤5.100;
 
7) (T3+G34)/T1≤2.800, and the preferable range is 1.800≤(T3+G34)/T1≤2.800;
 
8) TTL/(G12+G34)≤5.700, and the preferable range is 4.700≤TTL/(G12+G34)≤5.700;
 
9) (G23+T3)/T6≤3.100, and the preferable range is 1.700≤(G23+T3)/T6≤3.100;
 
10) (T3+T5)/T1≤4.000, and the preferable range is 2.900≤(T3+T5)/T1≤4.000;
 
11) EFL/(G12+G56)≥1.500, and the preferable range is 1.500≤EFL/(G12+G56)≤2.600;
 
12) (T5+T6)/T4≤4.900, and the preferable range is 4.000≤(T5+T6)/T4≤4.900;
 
13) TL/BFL≤4.200, and the preferable range is 3.000≤TL/BFL≤4.200;
 
14) (G12+G23)/T2≥1.200, and the preferable range is 1.200≤(G12+G23)/T2≤2.000;
 
15) G12/(G34+G45+G56)≤3.000, and the preferable range is 1.800≤G12/(G34+G45+G56)≤3.000;
 
16) (G12+G45)/T4≤4.600, and the preferable range is 3.200≤(G12+G45)/T4≤4.600;
 
17) (T2+T3+T5)/(T1+T4)≤3.400, and the preferable range is 2.800≤(T2+T3+T5)/(T1+T4)≤3.400;
 
18) (G12+G34)/T6≥2.400, and the preferable range is 2.400≤((G12+G34))/T6≤3.500;
 
19) (T5+G56)/T6≤2.700, and the preferable range is 1.900≤(T5+G56)/T6≤2.700.
 
     Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.