Patent Publication Number: US-2023152557-A1

Title: Optical imaging system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a Continuation Application of U.S. Pat. Application No. 16/890,036, filed on Jun. 2, 2020, which is a Divisional Application of U.S. Pat. Application No. 16/114,514, now U.S. Pat. No. 11,474,326, filed on Aug. 28, 2018, which claims the benefit under 35 USC 119(a) of Korean Patent Application No. 10-2017-0137676 filed on Oct. 23, 2017, in the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference for all purposes. 
    
    
     BACKGROUND 
     1. Field 
     This application relates to a telescopic optical imaging system including six lenses. 
     2. Description of Related Art 
     A telescopic optical system designed capture an image of a subject at a long distance has a significant size. For example, a ratio (TL/f) of a total length (TL) of the telescopic optical system to an overall focal length (f) of the telescopic optical system is 1 or more. Therefore, it is difficult to mount a telescopic optical system in a small electronic product such as a mobile communications terminal or other portable device. 
     SUMMARY 
     This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. 
     In one general aspect, an optical imaging system includes a first lens having an object-side surface that is convex; a second lens having a refractive power; a third lens having a refractive power; a fourth lens having a refractive power; a fifth lens having a refractive power and an object-side surface that is concave; and a sixth lens having a refractive power and an object-side surface that is concave, wherein the first lens through the sixth lens are sequentially disposed in numerical order from an object side of the optical imaging system toward an imaging plane of the optical imaging system so that there is a first air gap between the first lens and the second lens, a second air gap between the second lens and the third lens, a third air gap between the third lens and the fourth lens, a fourth air gap between the fourth lens and the fifth lens, and a fifth air gap between the fifth lens and the sixth lens, and the optical imaging system satisfies the conditional expressions 0.7 &lt; TL/f &lt; 1.0 and TL/2 &lt; f1, where TL is a distance from the object-side surface of the first lens to the imaging plane, f is an overall focal length of the optical imaging system, and f1 is a focal length of the first lens. 
     The first lens may have a positive refractive power. 
     The second lens may have a negative refractive power. 
     The fifth lens may have a negative refractive power. 
     An object-side surface of the second lens may be convex. 
     An object-side surface of the fourth lens may be concave. 
     An image-side surface of the fifth lens may be concave. 
     There may be an inflection point on either one or both of the object-side surface of the fifth lens and an image-side surface of the fifth lens. 
     An image-side surface of the sixth lens may be convex. 
     An object-side surface of the third lens or an object-side surface of the fourth lens may be spherical. 
     In another general aspect, an optical imaging system includes a first lens having an image-side surface that is concave; a second lens having a refractive power; a third lens having a refractive power; a fourth lens having a refractive power; a fifth lens having a refractive power; and a sixth lens having a refractive power and an object-side surface that is concave, wherein the first lens through the sixth lens are sequentially disposed in numerical order from an object side of the optical imaging system toward an imaging plane of the optical imaging system so that there is a first air gap between the first lens and the second lens, a second air gap between the second lens and the third lens, a third air gap between the third lens and the fourth lens, a fourth air gap between the fourth lens and the fifth lens, and a fifth air gap between the fifth lens and the sixth lens, and the optical imaging system satisfies the conditional expression 0.7 &lt; TL/f &lt; 1.0, where TL is a distance from an object-side surface of the first lens to the imaging plane, and f is an overall focal length of the optical imaging system. 
     The optical imaging system may further satisfy the conditional expression 0 &lt; D45/TL &lt; 0.2, where D45 is a distance from an image-side surface of the fourth lens to an object-side surface of the fifth lens. 
     The optical imaging system may further satisfy the conditional expression 1.5 &lt; Nd6 &lt; 1.7, where Nd6 is a refractive index of the sixth lens. 
     The optical imaging system may further satisfy the conditional expression f2/f &lt; -0.6, where f2 is a focal length of the second lens. 
     The optical imaging system may further satisfy the conditional expression 2.0 &lt; f/EPD &lt; 2.7, where EPD is an entrance pupil diameter of the optical imaging system. 
     The optical imaging system may further satisfy the conditional expression |f2/f3| &lt; 1.3, where f2 is a focal length of the second lens, and f3 is a focal length of the third lens. 
     In another general aspect, a optical imaging system includes a first lens having a refractive power; a second lens having a refractive power; a third lens having a refractive power; a fourth lens having a refractive power; a fifth lens having a refractive power; and a sixth lens having a refractive power; wherein the first lens through the sixth lens are sequentially disposed in numerical order from an object side of the optical imaging system toward an imaging plane of the optical imaging system, the refractive power of the second lens and the refractive power of the fifth lens have a same sign that is opposite to a sign of the refractive power of the first lens, the optical imaging system satisfies the conditional expression 0.7 &lt; TL/f &lt; 1.0, where TL is a distance from the object-side surface of the first lens to the imaging plane, and f is an overall focal length of the optical imaging system. 
     The first lens may have a positive refractive power, and the second lens and the fifth lens each may have a negative refractive power. 
     An object-side surface of the first lens may be convex, an object-side surface of the fifth lens may be concave, and an object-side surface of the sixth lens may be concave. 
     An image-side surface of the second lens may be concave, and an image-side surface of the sixth lens may be concave. 
     Other features and aspects will be apparent from the following detailed description, the drawings, and the claims. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a view illustrating a first example of an optical imaging system. 
         FIG.  2    illustrates aberration curves of the optical imaging system illustrated in  FIG.  1   . 
         FIG.  3    is a view illustrating a second example of an optical imaging system. 
         FIG.  4    illustrates aberration curves of the optical imaging system illustrated in  FIG.  3   . 
         FIG.  5    is a view illustrating a third example of an optical imaging system. 
         FIG.  6    illustrates aberration curves of the optical imaging system illustrated in  FIG.  5   . 
         FIG.  7    is a view illustrating a fourth example of an optical imaging system. 
         FIG.  8    illustrates aberration curves of the optical imaging system illustrated in  FIG.  7   . 
         FIG.  9    is a rear view of an example of a mobile communications terminal in which an optical imaging system described in this application is mounted. 
         FIG.  10    is a cross-sectional view of the mobile communications terminal illustrated in  FIG.  9    taken along the line X-X′ in  FIG.  9   . 
     
    
    
     Throughout the drawings and the detailed description, the same reference numerals refer to the same elements. The drawings may not be to scale, and the relative size, proportions, and depiction of elements in the drawings may be exaggerated for clarity, illustration, and convenience. 
     DETAILED DESCRIPTION 
     The following detailed description is provided to assist the reader in gaining a comprehensive understanding of the methods, apparatuses, and/or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatuses, and/or systems described herein will be apparent after an understanding of the disclosure of this application. For example, the sequences of operations described herein are merely examples, and are not limited to those set forth herein, but may be changed as will be apparent after an understanding of the disclosure of this application, with the exception of operations necessarily occurring in a certain order. Also, descriptions of features that are known in the art may be omitted for increased clarity and conciseness. 
     The features described herein may be embodied in different forms, and are not to be construed as being limited to the examples described herein. Rather, the examples described herein have been provided merely to illustrate some of the many possible ways of implementing the methods, apparatuses, and/or systems described herein that will be apparent after an understanding of the disclosure of this application. 
     Throughout the specification, when an element, such as a layer, region, or substrate, is described as being “on,” “connected to,” or “coupled to” another element, it may be directly “on,” “connected to,” or “coupled to” the other element, or there may be one or more other elements intervening therebetween. In contrast, when an element is described as being “directly on,” “directly connected to,” or “directly coupled to” another element, there can be no other elements intervening therebetween. 
     As used herein, the term “and/or” includes any one and any combination of any two or more of the associated listed items. 
     Although terms such as “first,” “second,” and “third” may be used herein to describe various members, components, regions, layers, or sections, these members, components, regions, layers, or sections are not to be limited by these terms. Rather, these terms are only used to distinguish one member, component, region, layer, or section from another member, component, region, layer, or section. Thus, a first member, component, region, layer, or section referred to in examples described herein may also be referred to as a second member, component, region, layer, or section without departing from the teachings of the examples. 
     Spatially relative terms such as “above,” “upper,” “below,” and “lower” may be used herein for ease of description to describe one element’s relationship to another element as shown in the figures. Such spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, an element described as being “above” or “upper” relative to another element will then be “below” or “lower” relative to the other element. Thus, the term “above” encompasses both the above and below orientations depending on the spatial orientation of the device. The device may also be oriented in other ways (for example, rotated 90 degrees or at other orientations), and the spatially relative terms used herein are to be interpreted accordingly. 
     The terminology used herein is for describing various examples only, and is not to be used to limit the disclosure. The articles “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “includes,” and “has” specify the presence of stated features, numbers, operations, members, elements, and/or combinations thereof, but do not preclude the presence or addition of one or more other features, numbers, operations, members, elements, and/or combinations thereof. 
     In this application, a first lens is a lens closest to an object (or a subject), while a sixth lens is a lens closest to an imaging plane (or an image sensor). In addition, radii of curvature, thicknesses of lenses, TL, an IMG HT (a half of a diagonal length of the imaging plane), and focal lengths of the lenses are expressed in millimeters (mm). Further, thicknesses of the lenses, gaps between the lenses, and TL are distances measured along optical axes of the lenses. Further, in a description of the shapes of the lenses, a statement that a surface of a lens is convex means that at least a paraxial region of the surface is convex, and a statement that a surface of a lens is concave means that at least a paraxial region of the surface is concave. A paraxial region of a lens surface is a central portion of the lens surface surrounding the optical axis of the lens in which light rays incident to the lens surface make a small angle θ to the optical axis and the approximations sin θ ≈ θ, tan θ ≈ θ, and cos θ ≈ 1 are valid. Therefore, although it may be stated that a surface of a lens is convex, an edge portion of the surface may be concave. Likewise, although it may be stated that a surface of a lens is concave, an edge portion of the surface may be convex. 
     In the examples described in this application, an optical imaging system includes six lenses. For example, the optical imaging system may include a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens sequentially disposed in numerical order from an object side of the optical imaging system toward an imaging plane of the optical imaging system. The first lens through the sixth lens may be disposed so that there is a first air gap between the first lens and the second lens, a second air gap between the second lens and the third lens, a third air gap between the third lens and the fourth lens, a fourth air gap between the fourth lens and the fifth lens, and a fifth air gap between the fifth lens and the sixth lens. Thus, an image-side surface of one lens may not be in contact with an object-side surface of a next lens closer to the imaging plane. 
     The first lens may have a refractive power. For example, the first lens may have a positive refractive power. One surface of the first lens may be convex. For example, an object-side surface of the first lens may be convex. 
     The first lens may have an aspherical surface. For example, both surfaces of the first lens may be aspherical. The first lens may be made of a material having a high light transmissivity and an excellent workability. For example, the first lens may be made of plastic. However, a material of the first lens is not limited to plastic. For example, the first lens may be made of glass. The first lens may have a small refractive index. For example, the refractive index of the first lens may be less than 1.6. 
     The second lens may have a refractive power. For example, the second lens may have negative refractive power. One surface of the second lens may be convex. For example, an object-side surface of the second lens may be convex. 
     The second lens may have an aspherical surface. For example, the object-side surface of the second lens may be aspherical. The second lens may be made of a material having a high light transmissivity and an excellent workability. For example, the second lens may be made of plastic. However, a material of the second lens is not limited to plastic. For example, the second lens may be made of glass. The second lens may have a refractive index greater than the refractive index of the first lens. For example, the refractive index of the second lens may be 1.65 or greater. 
     The third lens may have a refractive power. For example, the third lens may have a positive refractive power or a negative refractive power. The third lens may have a meniscus shape in which one surface is concave and the other surface is convex. For example, an object-side surface of the third lens may be convex and an image-side surface thereof may be concave, or the object-side surface of the third lens may be concave and the image-side surface thereof may be convex. 
     The third lens may have a spherical surface. For example, the object-side surface of the third lens may be spherical, and the image-side surface thereof may be aspherical. The third lens may be made of a material having a high light transmissivity and an excellent workability. For example, the third lens may be made of plastic. However, a material of the third lens is not limited to plastic. For example, the third lens may be made of glass. The third lens may have a refractive index greater than the refractive index of the first lens. For example, the refractive index of the third lens may be 1.6 or greater. 
     The fourth lens may have a refractive power. For example, the fourth lens may have a positive refractive power or a negative refractive power. One surface of the fourth lens may be concave. For example, the object-side surface of the fourth lens may be concave. 
     The fourth lens may have a spherical surface. For example, the object-side surface of the fourth lens may be spherical, and an image-side surface thereof may be aspherical. The fourth lens may be made of a material having a high light transmissivity and an excellent workability. For example, the fourth lens may be made of plastic. However, a material of the fourth lens is not limited to plastic. For example, the fourth lens may be made of glass. The fourth lens may have a refractive index that is substantially equal to the refractive index of the first lens. For example, the refractive index of the fourth lens may be less than 1.6. 
     The fifth lens may have a refractive power. For example, the fifth lens may have a negative refractive power. One surface of the fifth lens may be concave. For example, an object-side surface of the fifth lens may be concave. The fifth lens may have an inflection point. For example, either one or both of the object-side surface and an image-side surface of the fifth lens may have an inflection point. 
     The fifth lens may have an aspherical surface. For example, both surfaces of the fifth lens may be aspherical. The fifth lens may be made of a material having a high light transmissivity and an excellent workability. For example, the fifth lens may be made of plastic. However, a material of the fifth lens is not limited to plastic. For example, the fifth lens may be made of glass. The fifth lens may have a refractive index that is substantially equal to the refractive index of the first lens and the fourth lens. For example, the refractive index of the fifth lens may be less than 1.6. 
     The sixth lens may have a refractive power. For example, the sixth lens may have a positive refractive power or a negative refractive power. One surface of the sixth lens may be concave. For example, an object-side surface of the sixth lens may be concave. 
     The sixth lens may have an aspherical surface. For example, both surfaces of the sixth lens may be aspherical. The sixth lens may be made of a material having a high light transmissivity and an excellent workability. For example, the sixth lens may be made of plastic. However, a material of the sixth lens is not limited to plastic. For example, the sixth lens may be made of glass. The sixth lens may have a refractive index greater than the refractive index of the first lens. For example, the refractive index of the sixth lens may be 1.6 or greater. 
     The aspherical surfaces of the first to sixth lenses are represented by Equation 1 below. 
     
       
         
           
             
               
                 Z= 
                 
                   
                     
                       
                         cr 
                       
                       2 
                     
                   
                   
                     1 
                     + 
                     
                       
                         1 
                         − 
                         
                           
                             1 
                             + 
                             k 
                           
                         
                         
                           c 
                           2 
                         
                         
                           r 
                           2 
                         
                       
                     
                   
                 
                 + 
               
             
             
               
                 
                   Ar 
                   4 
                 
                 + 
                 
                   Br 
                   6 
                 
                 + 
                 
                   Cr 
                   8 
                 
                 + 
                 
                   Dr 
                   
                     10 
                   
                 
                 + 
                 
                   Er 
                   
                     12 
                   
                 
                 + 
                 
                   Fr 
                   
                     14 
                   
                 
                 + 
                 
                   Gr 
                   
                     16 
                   
                 
                 + 
                 
                   Hr 
                   
                     18 
                   
                 
                 + 
                 
                   Jr 
                   
                     20 
                   
                 
               
             
           
         
       
     
     In Equation 1, c is an inverse of a radius of curvature of the lens, k is a conic constant, r is a distance from a certain point on an aspherical surface of the lens to an optical axis of the lens, A to J are aspherical constants, and Z (or sag) is a distance between the certain point on the aspherical surface of the lens at the distance r and a tangential plane meeting the apex of the aspherical surface of the lens. 
     The optical imaging system may further include a filter, an image sensor, and a stop. 
     The filter may be disposed between the sixth lens and the image sensor. The filter may block some wavelengths of light. For example, the filter may block infrared wavelengths of light. 
     The image sensor may form the imaging plane. For example, a surface of the image sensor may form the imaging plane. 
     The stop may be disposed to control an amount of light incident to the image sensor. For example, the stop may be disposed between the second lens and the third lens, but is not limited to this position. 
     The optical imaging system may satisfy one or more of Conditional Expressions 1 through 7 below. 
     
       
         
           
             0.7 
             &lt; 
             
               
                 TL 
               
               / 
               
                 f&lt; 
                   
                 1 
                 .0 
               
             
           
         
       
     
     
       
         
           
             0 
             &lt; 
             
               
                 D 
                 45 
               
               / 
               
                 TL 
                   
                 &lt; 
                   
                 0 
                 .2 
               
             
           
         
       
     
     
       
         
           
             1.5 
               
             &lt; 
               
             Nd 
             6 
               
             &lt; 
               
             1.7 
           
         
       
     
     
       
         
           
             
               
                 f2 
               
               / 
               f 
             
             &lt; 
             - 
             0.6 
           
         
       
     
     
       
         
           
             2.0 
               
             &lt; 
               
             
               f 
               / 
               
                 EPD 
                   
                 &lt; 
                   
                 2 
                 .7 
               
             
           
         
       
     
     
       
         
           
             
               
                 
                   
                     f2 
                   
                   / 
                   
                     f3 
                   
                 
               
             
             &lt; 
             1.3 
           
         
       
     
     
       
         
           
             
               
                 TL 
               
               / 
               2 
             
               
               
             &lt; 
               
             f1 
           
         
       
     
     In the above Conditional Expressions 1 through 7, TL is a distance from the object-side surface of the first lens to the imaging plane, f is an overall focal length of the optical imaging system, D45 is a distance from the image-side surface of the fourth lens to the object-side surface of the fifth lens, Nd6 is a refractive index of the sixth lens, f1 is a focal length of the first lens, f2 is a focal length of the second lens, f3 is a focal length of the third lens, and EPD is an entrance pupil diameter of the optical imaging system. The f-number (F No.) of the optical imaging system is equal to f/EPD, and thus f/EPD in Conditional Expression 5 above is equal to the f-number (F No.) of the optical imaging system. Tables 1, 3, 5, and 7 that appear later in this application list the f-number (F No.) of first to fourth examples of an optical imaging system described later in this application. 
     Conditional Expression 1 is a condition for miniaturizing the optical imaging system. For example, when TL/f is outside of an upper limit value of Conditional Expression 1, it is difficult to miniaturize the optical imaging system, making it difficult to mount the optical imaging system in a mobile communications terminal, and when TL/f is outside of a lower limit value of Conditional Expression 1, it is difficult to manufacture the optical imaging system. 
     Conditional Expression 2 is a condition for ensuring both good telescopic characteristics of the optical imaging system and good resolution of the optical imaging system. For example, when D45/TL is outside of a lower limit value of Conditional Expression 2, it is difficult to maintain the resolution of the optical imaging system, and when D45/TL is outside of an upper limit value of Conditional Expression 2, the telescopic characteristics of the optical imaging system are deteriorated. 
     Conditional Expression 3 is a condition for improving aberration through the sixth lens. For example, when the refractive index of the sixth lens is outside of a numerical range of Conditional Expression 3, it is difficult to correct astigmatism, longitudinal chromatic aberration, and chromatic aberration of magnification. 
     Conditional Expression 4 is a condition for ensuring easy manufacturing of the second lens. For example, when f2/f is outside of an upper limit value of Conditional Expression 4, the second lens has a large optical sensitivity, making it difficult to manufacture the second lens. 
     Conditional Expression 5 is a condition for implementing a bright optical imaging system. 
     Conditional Expression 6 is a condition for significantly decreasing aberration through the second lens and the third lens. For example, when |f2/f3| is outside of an upper limit value of Conditional Expression 6, the aberration is increased, thereby decreasing the resolution of the optical imaging system. 
     Next, several examples of an optical imaging system will be described. 
       FIG.  1    is a view illustrating a first example of an optical imaging system. 
     Referring to  FIG.  1   , an optical imaging system  100  includes a first lens  110 , a second lens  120 , a third lens  130 , a fourth lens  140 , a fifth lens  150 , and a sixth lens  160 . 
     The first lens  110  has a positive refractive power, an object-side surface thereof is convex, and an image-side surface thereof is concave. The second lens  120  has a negative refractive power, an object-side surface thereof is convex, and an image-side surface thereof is concave. The third lens  130  has a positive refractive power, an object-side surface thereof is concave, and an image-side surface thereof is convex. The fourth lens  140  has a negative refractive power, an object-side surface thereof is concave, and an image-side surface thereof is concave. The fifth lens  150  has a negative refractive power, an object-side surface thereof is concave, and an image-side surface thereof is concave. Both surfaces of the fifth lens  150  have inflection points. The sixth lens  160  has a positive refractive power, an object-side surface thereof is concave, and an image-side surface thereof is convex. The optical imaging system  100  has a narrow field of view. For example, the optical imaging system  100  has a field of view of 40° or less. In detail, the field of view of the optical imaging system  100  is θ = 25.32. 
     The optical imaging system  100  further includes a filter  170 , an image sensor  180 , and a stop ST. The filter  170  is disposed between the sixth lens  160  and the image sensor  180 , and the stop ST is disposed between the second lens  120  and the third lens  130 , but is not limited to this position. 
       FIG.  2    illustrates aberration curves of the optical imaging system illustrated in  FIG.  1   . 
     Table 1 below lists characteristics of the optical imaging system illustrated in  FIG.  1   , and Table 2 below lists aspherical values of the lenses of the optical imaging system illustrated in  FIG.  1   . 
     
       
         
          TABLE 1
           
               
               
               
               
               
               
               
               
               
               
             
               
                 First Example 
               
               
                 f = 5.75 
                 F No. = 2.28 
                 θ = 25.32° 
                 TL = 5.240 
               
               
                 Surface No. 
                 Element 
                 Radius of Curvature 
                 Thickness/ Distance 
                 Refractive Index 
                 Abbe No. 
                 Focal Length 
               
             
            
               
                 S1 
                 First Lens 
                 1.4433 
                 0.9847 
                 1.544 
                 56.00 
                 2.645 
               
               
                 S2 
                 728.5499 
                 0.2000 
                   
                   
                   
               
               
                 S3 
                 Second Lens 
                 13.0590 
                 0.2336 
                 1.661 
                 20.40 
                 -3.805 
               
               
                 S4 
                 2.1141 
                 0.1285 
                   
                   
                   
               
               
                   
                 Stop 
                 Infinity 
                 0.1001 
                   
                   
                   
               
               
                 S5 
                 Third Lens 
                 -36.0676 
                 0.2356 
                 1.650 
                 21.47 
                 9.663 
               
               
                 S6 
                 -5.4150 
                 0.1000 
                   
                   
                   
               
               
                 S7 
                 Fourth Lens 
                 -12.1269 
                 0.2300 
                 1.544 
                 56.00 
                 -9.342 
               
               
                 S8 
                 8.8765 
                 0.6050 
                   
                   
                   
               
               
                 S9 
                 Fifth Lens 
                 -47.3505 
                 0.3875 
                 1.544 
                 56.00 
                 -6.767 
               
               
                 S10 
                 4.0230 
                 0.5563 
                   
                   
                   
               
               
                 S11 
                 Sixth Lens 
                 -10.5945 
                 0.6078 
                 1.650 
                 21.47 
                 32.233 
               
               
                 S12 
                 -7.2239 
                 0.1001 
                   
                   
                   
               
               
                 S13 
                 Filter 
                 Infinity 
                 0.2100 
                 1.519 
                 64.20 
                   
               
               
                 S14 
                 Infinity 
                 0.5804 
                   
                   
                   
               
               
                 S15 
                 Imaging Plane 
                 Infinity 
                 -0.0196 
                   
                   
                   
               
            
           
         
       
     
     
       
         
          TABLE 2
           
               
               
               
               
               
               
               
               
               
               
               
               
             
               
                 First Example 
                 Radius of Curvature 
                 K 
                 A 
                 B 
                 C 
                 D 
                 E 
                 F 
                 G 
                 H 
                 J 
               
             
            
               
                 S1 
                 1.443 
                 -0.365 
                 0.008 
                 0.017 
                 -0.054 
                 0.141 
                 -0.223 
                 0.197 
                 -0.090 
                 0.016 
                 0.000 
               
               
                 S2 
                 728.550 
                 0.000 
                 0.055 
                 -0.037 
                 -0.047 
                 0.123 
                 -0.151 
                 0.090 
                 -0.023 
                 0.002 
                 0.000 
               
               
                 S3 
                 13.059 
                 0.000 
                 0.015 
                 -0.047 
                 0.502 
                 -2.580 
                 7.960 
                 -14.586 
                 15.821 
                 -9.320 
                 2.307 
               
               
                 S4 
                 2.114 
                 -8.148 
                 -0.007 
                 0.163 
                 -1.304 
                 4.341 
                 -8.515 
                 9.083 
                 -2.452 
                 -3.068 
                 1.922 
               
               
                 S5 
                 -36.068 
                 84.363 
                 0.007 
                 -0.085 
                 -0.588 
                 1.002 
                 -1.184 
                 1.712 
                 -1.247 
                 0.000 
                 0.000 
               
               
                 S6 
                 -5.415 
                 -34.536 
                 0.225 
                 0.857 
                 -11.874 
                 91.722 
                 -436.916 
                 1301.853 
                 -2356.42 
                 2362.081 
                 -1003.98 
               
               
                 S7 
                 -12.127 
                 84.778 
                 0.112 
                 0.274 
                 -0.966 
                 6.410 
                 -19.477 
                 31.752 
                 -28.594 
                 11.168 
                 0.000 
               
               
                 S8 
                 8.877 
                 98.900 
                 -0.141 
                 0.282 
                 -0.566 
                 3.297 
                 -9.778 
                 16.220 
                 -14.129 
                 4.842 
                 0.000 
               
               
                 S9 
                 -47.351 
                 99.000 
                 -0.229 
                 -0.081 
                 0.695 
                 -2.066 
                 3.613 
                 -3.636 
                 2.059 
                 -0.604 
                 0.071 
               
               
                 S10 
                 4.023 
                 -63.019 
                 -0.088 
                 -0.035 
                 0.097 
                 -0.139 
                 0.137 
                 -0.082 
                 0.028 
                 -0.005 
                 0.000 
               
               
                 S11 
                 -10.595 
                 -99.000 
                 -0.102 
                 0.105 
                 -0.069 
                 0.019 
                 0.000 
                 0.001 
                 -0.001 
                 0.000 
                 0.000 
               
               
                 S12 
                 -7.224 
                 0.000 
                 -0.128 
                 0.124 
                 -0.120 
                 0.095 
                 -0.054 
                 0.020 
                 -0.005 
                 0.001 
                 0.000 
               
            
           
         
       
     
       FIG.  3    is a view illustrating a second example of an optical imaging system. 
     Referring to  FIG.  3   , an optical imaging system  200  includes a first lens  210 , a second lens  220 , a third lens  230 , a fourth lens  240 , a fifth lens  250 , and a sixth lens  260 . 
     The first lens  210  has a positive refractive power, an object-side surface thereof is convex, and an image-side surface thereof is convex. The second lens  220  has a negative refractive power, an object-side surface thereof is convex, and an image-side surface thereof is concave. The third lens  230  has a positive refractive power, an object-side surface thereof is concave, and an image-side surface thereof is convex. The fourth lens  240  has a negative refractive power, an object-side surface thereof is concave, and an image-side surface thereof is concave. The fifth lens  250  has a negative refractive power, an object-side surface thereof is concave, and an image-side surface thereof is concave. Both surfaces of the fifth lens  250  have inflection points. The sixth lens  260  has a positive refractive power, an object-side surface thereof is concave, and an image-side surface thereof is convex. The optical imaging system  200  has a narrow field of view. For example, the optical imaging system  200  has a field of view of 40° or less. In detail, the field of view of the optical imaging system  200  is θ = 24.89. 
     The optical imaging system  200  further includes a filter  270 , an image sensor  280 , and a stop ST. The filter  270  is disposed between the sixth lens  260  and the image sensor  280 , and the stop ST is disposed between the second lens  220  and the third lens  230 , but is not limited to this position. 
       FIG.  4    illustrates aberration curves of the optical imaging system illustrated in  FIG.  3   . 
     Table 3 below lists characteristics of the optical imaging system illustrated in  FIG.  3   , and Table 4 below lists aspherical values of the lenses of the optical imaging system illustrated in  FIG.  3   . 
     
       
         
          TABLE 3
           
               
               
               
               
               
               
               
               
               
               
             
               
                 Second Example 
               
               
                 f = 5.60 
                 F No. = 2.43 
                 θ = 24.89° 
                 TL = 5.000 
               
               
                 Surface No. 
                 Element 
                 Radius of Curvature 
                 Thickness/ Distance 
                 Refractive Index 
                 Abbe No. 
                 Focal Length 
               
             
            
               
                 S1 
                 First Lens 
                 1.4056 
                 0.9417 
                 1.544 
                 56.00 
                 2.510 
               
               
                 S2 
                 -43.4165 
                 0.1600 
                   
                   
                   
               
               
                 S3 
                 Second Lens 
                 11.0320 
                 0.2300 
                 1.661 
                 20.40 
                 -3.745 
               
               
                 S4 
                 2.0239 
                 0.1168 
                   
                   
                   
               
               
                   
                 Stop 
                 Infinity 
                 0.1000 
                   
                   
                   
               
               
                 S5 
                 Third Lens 
                 -31.2658 
                 0.2326 
                 1.6504 
                 21.47 
                 14.507533 
               
               
                 S6 
                 -7.3295 
                 0.1000 
                   
                   
                   
               
               
                 S7 
                 Fourth Lens 
                 -21.7194 
                 0.2300 
                 1.544 
                 56.00 
                 -11.052 
               
               
                 S8 
                 8.3983 
                 1.0848 
                   
                   
                   
               
               
                 S9 
                 Fifth Lens 
                 -3.8000 
                 0.2300 
                 1.544 
                 56.00 
                 -6.049 
               
               
                 S10 
                 25.9530 
                 0.1397 
                   
                   
                   
               
               
                 S11 
                 Sixth Lens 
                 -10.9009 
                 0.5845 
                 1.650 
                 21.47 
                 89.119 
               
               
                 S12 
                 -9.3863 
                 0.1002 
                   
                   
                   
               
               
                 S13 
                 Filter 
                 Infinity 
                 0.2000 
                 1.519 
                 64.20 
                   
               
               
                 S14 
                 Infinity 
                 0.5576 
                   
                   
                   
               
               
                 S15 
                 Imaging Plane 
                 Infinity 
                 -0.0078 
                   
                   
                   
               
            
           
         
       
     
     
       
         
          TABLE 4
           
               
               
               
               
               
               
               
               
               
               
               
               
             
               
                 Second Example 
                 Radius of Curvature 
                 K 
                 A 
                 B 
                 C 
                 D 
                 E 
                 F 
                 G 
                 H 
                 J 
               
             
            
               
                 S1 
                 1.406 
                 -0.350 
                 0.009 
                 0.025 
                 -0.076 
                 0.219 
                 -0.381 
                 0.371 
                 -0.186 
                 0.036 
                 0.000 
               
               
                 S2 
                 -43.416 
                 0.000 
                 0.074 
                 -0.048 
                 -0.066 
                 0.191 
                 -0.258 
                 0.170 
                 -0.048 
                 0.004 
                 0.000 
               
               
                 S3 
                 11.032 
                 0.000 
                 0.007 
                 -0.060 
                 0.701 
                 -4.005 
                 13.613 
                 -27.505 
                 32.899 
                 -21.361 
                 5.831 
               
               
                 S4 
                 2.024 
                 -8.405 
                 0.000 
                 0.211 
                 -1.845 
                 6.688 
                 -14.564 
                 17.127 
                 -5.097 
                 -7.031 
                 4.856 
               
               
                 S5 
                 -31.266 
                 -99.000 
                 0.001 
                 -0.151 
                 -0.819 
                 1.547 
                 -2.024 
                 3.228 
                 -2.592 
                 0.000 
                 0.000 
               
               
                 S6 
                 -7.330 
                 80.652 
                 0.208 
                 1.053 
                 -16.708 
                 142.469 
                 -747.274 
                 2454.835 
                 -4898.83 
                 5413.925 
                 -2537.00 
               
               
                 S7 
                 -21.719 
                 99.000 
                 0.122 
                 0.347 
                 -1.350 
                 9.952 
                 -33.312 
                 59.873 
                 -59.445 
                 25.598 
                 0.000 
               
               
                 S8 
                 8.398 
                 99.000 
                 -0.026 
                 0.283 
                 -0.780 
                 5.214 
                 -16.852 
                 30.585 
                 -29.373 
                 11.099 
                 0.000 
               
               
                 S9 
                 -3.800 
                 3.952 
                 0.064 
                 -1.153 
                 3.086 
                 -5.298 
                 6.160 
                 -4.674 
                 2.189 
                 -0.569 
                 0.062 
               
               
                 S10 
                 25.953 
                 70.469 
                 0.096 
                 -0.730 
                 1.856 
                 -2.874 
                 2.725 
                 -1.593 
                 0.561 
                 -0.110 
                 0.009 
               
               
                 S11 
                 -10.901 
                 -99.000 
                 -0.159 
                 0.496 
                 -0.585 
                 0.325 
                 -0.070 
                 -0.012 
                 0.009 
                 -0.002 
                 0.000 
               
               
                 S12 
                 -9.386 
                 0.000 
                 -0.233 
                 0.363 
                 -0.375 
                 0.295 
                 -0.177 
                 0.074 
                 -0.019 
                 0.003 
                 0.000 
               
            
           
         
       
     
       FIG.  5    is a view illustrating a third example of an optical imaging system. 
     Referring to  FIG.  5   , an optical imaging system  300  includes a first lens  310 , a second lens  320 , a third lens  330 , a fourth lens  340 , a fifth lens  350 , and a sixth lens  360 . 
     The first lens  310  has a positive refractive power, an object-side surface thereof is convex, and an image-side surface thereof is concave. The second lens  320  has a negative refractive power, an object-side surface thereof is convex, and an image-side surface thereof is concave. The third lens  330  has a negative refractive power, an object-side surface thereof is convex, and an image-side surface thereof is concave. One surface of the third lens  330  is a spherical surface and the other surface of the third lens is an aspherical surface. For example, an object-side surface of the third lens  330  is a spherical surface, and an image-side surface thereof is an aspherical surface. The fourth lens  340  has a positive refractive power, an object-side surface thereof is concave, and an image-side surface thereof is convex. The fifth lens  350  has a negative refractive power, an object-side surface thereof is concave, and an image-side surface thereof is concave. Both surfaces of the fifth lens  350  have inflection points. The sixth lens  360  has a positive refractive power, an object-side surface thereof is concave, and an image-side surface thereof is convex. The optical imaging system  300  has a narrow field of view. For example, the optical imaging system  300  has a field of view of 40° or less. In detail, the field of view of the optical imaging system  300  is θ = 24.41. 
     The optical imaging system  300  further includes a filter  370 , an image sensor  380 , and a stop ST. The filter  370  is disposed between the sixth lens  360  and the image sensor  380 , and the stop ST is disposed between the second lens  320  and the third lens  330 , but is not limited to this position. 
       FIG.  6    illustrates aberration curves of the optical imaging system illustrated in  FIG.  5   . 
     Table 5 below lists characteristics of the optical imaging system illustrated in  FIG.  5   , and Table 6 below lists aspherical values of the lenses of the optical imaging system illustrated in  FIG.  5   .  
     
       
         
          TABLE 5
           
               
               
               
               
               
               
               
               
               
               
             
               
                 Third Example 
               
               
                 f = 6.00 
                 F No. = 2.65 
                 θ = 24.41° 
                 TL = 5.290 
               
               
                 Surface No. 
                 Element 
                 Radius of Curvature 
                 Thickness/ Distance 
                 Refractive Index 
                 Abbe No. 
                 Focal Length 
               
             
            
               
                 S1 
                 First Lens 
                 1.4144 
                 0.8510 
                 1.544 
                 56.00 
                 2.657 
               
               
                 S2 
                 43.0741 
                 0.0500 
                   
                   
                   
               
               
                 S3 
                 Second Lens 
                 4.4611 
                 0.2390 
                 1.661 
                 20.40 
                 -8.0591 
               
               
                 S4 
                 2.3883 
                 0.1000 
                   
                   
                   
               
               
                   
                 Stop 
                 Infinity 
                 0.2000 
                   
                   
                   
               
               
                 S5 
                 Third Lens 
                 107.8754 
                 0.2400 
                 1.6504 
                 21.47 
                 -6.6326 
               
               
                 S6 
                 4.1871 
                 0.1674 
                   
                   
                   
               
               
                 S7 
                 Fourth Lens 
                 -89.6829 
                 0.2300 
                 1.544 
                 56.00 
                 206.347 
               
               
                 S8 
                 -50.0000 
                 1.0270 
                   
                   
                   
               
               
                 S9 
                 Fifth Lens 
                 -3.1691 
                 0.2900 
                 1.544 
                 56.00 
                 -4.7817 
               
               
                 S10 
                 15.3784 
                 0.2648 
                   
                   
                   
               
               
                 S11 
                 Sixth Lens 
                 -151.2417 
                 0.7458 
                 1.650 
                 21.47 
                 12.560 
               
               
                 S12 
                 -7.8450 
                 0.0400 
                   
                   
                   
               
               
                 S13 
                 Filter 
                 Infinity 
                 0.2100 
                 1.519 
                 64.20 
                   
               
               
                 S14 
                 Infinity 
                 0.6550 
                   
                   
                   
               
               
                 S15 
                 Imaging Plane 
                 Infinity 
                 -0.0200 
                   
                   
                   
               
            
           
         
       
     
     
       
         
          TABLE 6
           
               
               
               
               
               
               
               
               
               
               
               
               
             
               
                 Third Example 
                 Radius of Curvature 
                 K 
                 A 
                 B 
                 C 
                 D 
                 E 
                 F 
                 G 
                 H 
                 J 
               
             
            
               
                 S1 
                 1.414 
                 -0.351 
                 0.009 
                 0.020 
                 -0.070 
                 0.193 
                 -0.314 
                 0.290 
                 -0.142 
                 0.027 
                 0.000 
               
               
                 S2 
                 43.074 
                 0.000 
                 0.128 
                 -0.168 
                 -0.043 
                 0.424 
                 -0.775 
                 0.729 
                 -0.348 
                 0.066 
                 0.000 
               
               
                 S3 
                 4.461 
                 0.000 
                 0.096 
                 -0.159 
                 0.128 
                 -0.643 
                 2.682 
                 -5.660 
                 6.569 
                 -3.906 
                 0.930 
               
               
                 S4 
                 2.388 
                 -2.596 
                 -0.020 
                 0.168 
                 -1.169 
                 4.180 
                 -8.515 
                 9.083 
                 -2.452 
                 -3.068 
                 1.922 
               
               
                 S5 
                 107.875 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 S6 
                 4.187 
                 -23.505 
                 0.104 
                 1.252 
                 -17.486 
                 152.975 
                 -818.990 
                 2735.879 
                 -5553.53 
                 6268.187 
                 -3016.83 
               
               
                 S7 
                 -89.683 
                 -99.000 
                 0.129 
                 -0.017 
                 0.103 
                 0.000 
                 0.000 
                 0.000 
                 0.000 
                 0.000 
                 0.000 
               
               
                 S8 
                 -50.000 
                 -99.000 
                 0.154 
                 0.000 
                 0.000 
                 0.000 
                 0.000 
                 0.000 
                 0.000 
                 0.000 
                 0.000 
               
               
                 S9 
                 -3.169 
                 -2.527 
                 -0.044 
                 0.217 
                 -0.907 
                 1.760 
                 -1.927 
                 1.269 
                 -0.500 
                 0.109 
                 -0.010 
               
               
                 S10 
                 15.378 
                 22.815 
                 -0.100 
                 0.422 
                 -0.991 
                 1.223 
                 -0.909 
                 0.424 
                 -0.122 
                 0.020 
                 -0.001 
               
               
                 S11 
                 -151.242 
                 -99.000 
                 -0.166 
                 0.427 
                 -0.594 
                 0.453 
                 -0.201 
                 0.051 
                 -0.007 
                 0.000 
                 0.000 
               
               
                 S12 
                 -7.845 
                 0.000 
                 -0.159 
                 0.198 
                 -0.154 
                 0.055 
                 -0.001 
                 -0.007 
                 0.002 
                 0.000 
                 0.000 
               
            
           
         
       
     
       FIG.  7    is a view illustrating a fourth example of an optical imaging system. 
     Referring to  FIG.  7   , an optical imaging system  400  includes a first lens  410 , a second lens  420 , a third lens  430 , a fourth lens  440 , a fifth lens  450 , and a sixth lens  460 . 
     The first lens  410  has a positive refractive power, an object-side surface thereof is convex, and an image-side surface thereof is concave. The second lens  420  has a negative refractive power, an object-side surface thereof is convex, and an image-side surface thereof is concave. The third lens  430  has a positive refractive power, an object-side surface thereof is convex, and an image-side surface thereof is concave. The fourth lens  440  has a positive refractive power, an object-side surface thereof is concave, and an image-side surface thereof is convex. One surface of the fourth lens  440  is a spherical surface, and the other surface of the fourth lens  440  is an aspherical surface. For example, an object-side surface of the fourth lens  440  is a spherical surface, and an image-side surface of the fourth lens  440  is an aspherical surface. The fifth lens  450  has a negative refractive power, an object-side surface thereof is concave, and an image-side surface thereof is convex. Both surfaces of the fifth lens  450  have inflection points. The sixth lens  460  has a negative refractive power, an object-side surface thereof is concave, and an image-side surface thereof is convex. The optical imaging system  400  has a narrow field of view. For example, the optical imaging system  400  has a field of view of 40° or less. In detail, the field of view of the optical imaging system  400  is θ = 25.07. 
     The optical imaging system  400  further includes a filter  470 , an image sensor  480 , and a stop ST. The filter  470  is disposed between the sixth lens  460  and the image sensor  480 , and the stop ST is disposed between the third lens  430  and the fourth lens  440 , but is not limited to this position. 
       FIG.  8    illustrates aberration curves of the optical imaging system illustrated in  FIG.  7   . 
     Table 7 below lists characteristics of the optical imaging system illustrated in  FIG.  7   , and Table 8 below lists aspherical values of the lenses of the optical imaging system illustrated in  FIG.  7   . 
     
       
         
          TABLE 7
           
               
               
               
               
               
               
               
               
               
               
             
               
                 Fourth Example 
               
               
                 f = 5.60 
                 F No. = 2.6 
                 θ = 25.07° 
                 TL = 5.280 
               
               
                 Surface No. 
                 Element 
                 Radius of Curvature 
                 Thickness/ Distance 
                 Refractive Index 
                 Abbe No. 
                 Focal Length 
               
             
            
               
                 S1 
                 First Lens 
                 1.4365 
                 0.7886 
                 1.544 
                 56.00 
                 2.645 
               
               
                 S2 
                 186.1834 
                 0.1998 
                   
                   
                   
               
               
                 S3 
                 Second Lens 
                 5.9143 
                 0.2341 
                 1.661 
                 20.40 
                 -3.780 
               
               
                 S4 
                 1.7431 
                 0.1564 
                   
                   
                   
               
               
                 S5 
                 Third Lens 
                 4.6972 
                 0.3376 
                 1.6504 
                 21.47 
                 27.295 
               
               
                 S6 
                 6.1815 
                 0.1677 
                   
                   
                   
               
               
                   
                 Stop 
                 Infinity 
                 0.1023 
                   
                   
                   
               
               
                 S7 
                 Fourth Lens 
                 -6.4326 
                 0.2527 
                 1.544 
                 56.00 
                 13.017 
               
               
                 S8 
                 -3.4249 
                 0.1284 
                   
                   
                   
               
               
                 S9 
                 Fifth Lens 
                 -2.0657 
                 0.3000 
                 1.544 
                 56.00 
                 -7.373 
               
               
                 S10 
                 -4.4563 
                 0.7231 
                   
                   
                   
               
               
                 S11 
                 Sixth Lens 
                 -5.0958 
                 0.6336 
                 1.650 
                 21.47 
                 -19.746 
               
               
                 S12 
                 -8.8027 
                 0.1001 
                   
                   
                   
               
               
                 S13 
                 Filter 
                 Infinity 
                 0.2100 
                 1.519 
                 64.20 
                   
               
               
                 S14 
                 Infinity 
                 0.9707 
                   
                   
                   
               
               
                 S15 
                 Imaging Plane 
                 Infinity 
                 -0.0250 
                   
                   
                   
               
            
           
         
       
     
     
       
         
          TABLE 8
           
               
               
               
               
               
               
               
               
               
               
               
               
             
               
                 Fourth Example 
                 Radius of Curvature 
                 K 
                 A 
                 B 
                 C 
                 D 
                 E 
                 F 
                 G 
                 H 
                 J 
               
             
            
               
                 S1 
                 1.436 
                 -0.372 
                 0.011 
                 0.013 
                 -0.047 
                 0.130 
                 -0.212 
                 0.192 
                 -0.093 
                 0.017 
                 0.000 
               
               
                 S2 
                 186.183 
                 0.000 
                 0.070 
                 -0.036 
                 -0.052 
                 0.137 
                 -0.174 
                 0.108 
                 -0.031 
                 0.003 
                 0.000 
               
               
                 S3 
                 5.914 
                 0.000 
                 0.029 
                 -0.042 
                 0.349 
                 -1.906 
                 6.217 
                 -11.726 
                 12.945 
                 -7.729 
                 1.938 
               
               
                 S4 
                 1.743 
                 -4.367 
                 -0.020 
                 0.168 
                 -1.169 
                 4.180 
                 -8.515 
                 9.083 
                 -2.452 
                 -3.068 
                 1.922 
               
               
                 S5 
                 4.697 
                 -62.851 
                 0.026 
                 -0.017 
                 -0.865 
                 2.811 
                 -6.313 
                 8.030 
                 -4.260 
                 0.000 
                 0.000 
               
               
                 S6 
                 6.181 
                 -99.000 
                 0.141 
                 0.892 
                 -12.279 
                 95.633 
                 -463.919 
                 1418.924 
                 -2656.30 
                 2773.752 
                 -1236.64 
               
               
                 S7 
                 -6.433 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 S8 
                 -3.425 
                 9.589 
                 0.037 
                 0.199 
                 -0.585 
                 3.521 
                 -10.093 
                 16.342 
                 -14.307 
                 5.023 
                 0.000 
               
               
                 S9 
                 -2.066 
                 -8.746 
                 -0.130 
                 0.396 
                 -0.247 
                 0.582 
                 -0.969 
                 0.485 
                 0.025 
                 -0.076 
                 0.015 
               
               
                 S10 
                 -4.456 
                 -58.287 
                 -0.171 
                 0.256 
                 -0.198 
                 0.078 
                 0.060 
                 -0.118 
                 0.068 
                 -0.017 
                 0.002 
               
               
                 S11 
                 -5.096 
                 -99.000 
                 -0.249 
                 0.187 
                 -0.171 
                 0.127 
                 -0.045 
                 0.003 
                 0.002 
                 -0.001 
                 0.000 
               
               
                 S12 
                 -8.803 
                 0.000 
                 -0.114 
                 0.012 
                 0.057 
                 -0.096 
                 0.080 
                 -0.038 
                 0.011 
                 -0.002 
                 0.000 
               
            
           
         
       
     
     Table 9 below lists values of Conditional Expressions 1 through 7 of the optical imaging systems of the first to fourth examples. 
     
       
         
          TABLE 9
           
               
               
               
               
               
             
               
                 Conditional Expression 
                 First Example 
                 Second Example 
                 Third Example 
                 Fourth Example 
               
             
            
               
                 TL/f 
                 0.9113 
                 0.8929 
                 0.8817 
                 0.9429 
               
               
                 D45/TL 
                 0.1155 
                 0.2170 
                 0.1941 
                 0.0243 
               
               
                 Nd6 
                 1.650 
                 1.650 
                 1.650 
                 1.650 
               
               
                 f2/f 
                 -0.6617 
                 -0.6688 
                 -1.3432 
                 -0.6750 
               
               
                 f/EPD 
                 2.28 
                 2.43 
                 2.65 
                 2.60 
               
               
                 | f2/f3 | 
                 -0.3938 
                 -0.2581 
                 1.2151 
                 -0.1385 
               
               
                 TL/2 
                 2.620 
                 2.500 
                 2.645 
                 2.640 
               
            
           
         
       
     
       FIG.  9    is a rear view of an example of a mobile communications terminal in which an optical imaging system described in this application is mounted.  FIG.  10    is a cross-sectional view of the mobile communications terminal illustrated in  FIG.  9    taken along the line X-X′ in  FIG.  9   . 
     Referring to  FIGS.  9  and  10   , a mobile communications terminal  10  includes a plurality of camera modules  30  and  40 . A first camera module  30  includes a first optical imaging system  500  configured to capture an image of a subject positioned at a short distance away from the mobile communications terminal  10 , and a second camera module  40  includes a second optical imaging system  100 ,  200 ,  300 , or  400  configured to capture an image of a subject positioned at a long distance away from the mobile communications terminal  10 . 
     The first optical imaging system  500  includes a plurality of lenses. For example, the first optical imaging system  500  may include four or more lenses. The first optical imaging system  500  is configured to an image of a subject positioned at a short distance away from the mobile communications terminal  10 . For example, the first optical imaging system  500  may have a wide field of view of 50° or more, and a ratio (h1/Cf) may be 1.0 or h1 is a height of the first optical imaging system  500  and is equal to a total length of the first optical imaging system  500 , and Cf is an overall focal length of the first optical imaging system  500 . 
     The second optical imaging system  100 ,  200 ,  300 , or  400  includes a plurality of lenses. For example, the second optical imaging system  100 ,  200 ,  300 , or  400  may include six lenses. The second optical imaging system  100 ,  200 ,  300 , or  400  is any one of the optical imaging systems of the first to fourth examples described above. The second optical imaging system  100 ,  200 ,  300 , or  400  is configured to capture an image of a subject positioned at a long distance away from the mobile communications terminal  10 . For example, the second optical imaging system  100 ,  200 ,  300 , or  400  may have a narrow field of view of 40° or less, and a ratio (h2/f) may be less than 1.0, where h2 is a height of the second optical imaging system  100 ,  200 ,  300 , or  400  and is equal to the total length TL of the second optical imaging system, and f is the overall focal length of the second optical imaging system  100 ,  200 ,  300 , or  400 . 
     The examples described above provide an optical imaging system capable of capturing an image of a subject at a long distance and being mounted in a small terminal. 
     While this disclosure includes specific examples, it will be apparent after an understanding of the disclosure of this application that various changes in form and details may be made in these examples without departing from the spirit and scope of the claims and their equivalents. The examples described herein are to be considered in a descriptive sense only, and not for purposes of limitation. Descriptions of features or aspects in each example are to be considered as being applicable to similar features or aspects in other examples. Suitable results may be achieved if the described techniques are performed in a different order, and/or if components in a described system, architecture, device, or circuit are combined in a different manner, and/or replaced or supplemented by other components or their equivalents. Therefore, the scope of the disclosure is defined not by the detailed description, but by the claims and their equivalents, and all variations within the scope of the claims and their equivalents are to be construed as being included in the disclosure.