Patent Publication Number: US-2022236521-A1

Title: Lens assembly and electronic device including the same

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to Korean Patent Application No. 10-2021-0011820 filed on Jan. 27, 2021, Korean Patent Application No. 10-2021-0050056 filed on Apr. 16, 2021, and Korean Patent Application No. 10-2021-0084453 filed on Jun. 29, 2021, in the Korean Intellectual Property Office, the disclosures of which are incorporated by reference herein in their entireties. 
     BACKGROUND 
     1. Field 
     Example embodiments of the present disclosure relate to a lens assembly and an electronic device including the lens assembly. 
     2. Description of Related Art 
     The development of an optical technology and an image processing technology has brought the widespread use of capturing devices in various fields such as multimedia contents, security, recognition, and the like. A capturing device may be provided in, for example, a mobile device, a camera, a vehicle, and a computer, to capture an image or obtain data for recognizing an object or controlling such a device. The volume of the capturing device may be determined based on the size of a lens, a focal length of the lens, and the size of a sensor. In a limited space where the volume of the capturing device is limited, the focal length increased by a change in a lens structure may be provided. 
     SUMMARY 
     Example embodiments provide a lens assembly and an electronic device including the lens assembly. 
     Example embodiments may address at least the above problems and/or disadvantages and other disadvantages not described above. Also, the example embodiments are not required to overcome the disadvantages described above, and an example embodiment may not overcome any of the problems described above. 
     According to an aspect of an example embodiment, there is provided a lens assembly including a first reflector configured to rotate around a first rotation axis, a second reflector configured to rotate around a second rotation axis, a plurality of lenses, and an image sensor configured to generate a plurality of captured images having different capturing angles based on a rotation of at least one of the first reflector and the second reflector, wherein the first reflector, the second reflector, the plurality of lenses, and the image sensor are provided in sequential order, wherein the plurality of lenses includes a first lens, a second lens, a third lens, a fourth lens, and a fifth lens, which are provided in sequential order, and wherein a distance from the first lens to an upper surface is TTL, a synthetic focal length of the lens assembly is f′, a focal length of the first lens is f1, a focal length of the second lens is f2, and the lens assembly satisfy TTL/f′&lt;1.0, and 0&lt;(f1+f2)/f′&lt;0.03. 
     A focal length of the third lens may be f3 and a focal length of the fourth lens may be f4, and the lens assembly may satisfy 0.04&lt;(f3+f4)/f′&lt;0.06. 
     An Abbe number of the third lens may be L3Ab and an Abbe number of the fourth lens may be L4Ab, the lens assembly may satisfy 19&lt;L3Ab&lt;25, and 19&lt;L4Ab&lt;25. 
     The first lens may have positive refractive power with a convex form, wherein the second lens may have negative refractive power, wherein the third lens may have positive refractive power with a biconvex form, wherein the fourth lens may have negative refractive power, and wherein the fifth lens may have positive refractive power. 
     Each of the plurality of captured images may correspond to a high-resolution telephoto image. 
     The plurality of captured images may be synthesized into a single high-resolution wide-angle image, and the plurality of captured images may form different regions corresponding to the different capturing angles in the high-resolution wide-angle image. 
     The lens assembly may further include an aperture stop provided between the second reflector and the plurality of lenses, the aperture stop being configured to adjust an amount of light. 
     An aperture circle of each of the lenses included in the plurality of lenses may be smaller than an image circle of the image sensor. 
     An aperture height of each of the lenses included in the plurality of lenses corresponding to positions through which rays provided in an image formation range corresponding to a short side of the image sensor pass the lenses respectively may be less than or equal to the short side of the image sensor. 
     A short side of the image sensor may be less than or equal to 7 millimeters (mm). 
     According to another aspect of an example embodiment, there is provided an electronic device including an imaging assembly configured to sense visual information of an object by a lens assembly, the image assembly being configured to generate a captured image based on the visual information, and a display configured to display the captured image, wherein the lens assembly includes a first reflector configured to rotate around a first rotation axis, a second reflector configured to rotate around a second rotation axis, a plurality of lenses, and an image sensor configured to generate a plurality of partially captured images having different capturing angles based on a rotation of at least one of the first reflector or the second reflector, wherein the first reflector, the second reflector, the plurality of lenses, and the image sensor are provided in sequential order from a side of the object, wherein the partially captured images are synthesized into the captured image, and wherein the plurality of lenses includes a first lens, a second lens, a third lens, a fourth lens, and a fifth lens, which are provided in sequential order from the side of the object, and wherein a distance from the first lens to an upper surface is TTL, a synthetic focal length of the lens assembly is f′, a focal length of the first lens is f1, a focal length of the second lens is f2, and the lens assembly satisfies TTL/f′&lt;1.0, and 0&lt;(f1+f2)/f′&lt;0.03. 
     A focal length of the third lens may be f3 and a focal length of the fourth lens may be f4, and the lens assembly may satisfy 0.04&lt;(f3+f4)/f′&lt;0.06. 
     An Abbe number of the third lens may be L3Ab, an Abbe number of the fourth lens may be L4Ab, and the lens assembly may satisfy 19&lt;L3Ab&lt;25, and 19&lt;L4Ab&lt;25. 
     The first lens may have positive refractive power with a convex form on the side of the object, wherein the second lens may have negative refractive power, wherein the third lens may have positive refractive power with a biconvex form, wherein the fourth lens may have negative refractive power, and wherein the fifth lens may have positive refractive power. 
     Each of the plurality of partially captured images may correspond to a high-resolution telephoto image, wherein the captured image may correspond to a high-resolution wide-angle image, and wherein the plurality of partially captured images may form different regions corresponding to the different capturing angles in the captured image. 
     The lens assembly may further include an aperture stop provided between the second reflector and the plurality of lenses, the aperture stop being configured to adjust an amount of light. 
     According to yet another aspect of an example embodiment, there is provided a capturing method including generating a plurality of partially captured images having different capturing angles while adjusting a capturing angle by rotating at least one of a first reflector configured to rotate around a first rotation axis or a second reflector configured to rotate around a second rotation axis, and generating a single synthesized image based on the plurality of partially captured images. 
     Each of the plurality of partially captured images may correspond to a high-resolution telephoto image, and wherein the synthesized image may correspond to a high-resolution wide-angle image. 
     The plurality of partially captured images may form different regions corresponding to the different capturing angles in the synthesized image. 
     According to yet another aspect of an example embodiment, there is provided a non-transitory computer-readable storage medium storing instructions that are executable by a processor to perform a capturing method, the capturing method including generating a plurality of partially captured images having different capturing angles while adjusting a capturing angle by rotating at least one of a first reflector configured to rotate around a first rotation axis or a second reflector configured to rotate around a second rotation axis, and generating a single synthesized image based on the plurality of partially captured images. 
     According to yet another aspect of an example embodiment, there is provided a lens assembly including a first reflector configured to rotate around a first rotation axis, a second reflector configured to rotate around a second rotation axis, a plurality of lenses including one or more lenses, and an image sensor configured to generate a plurality of captured images having different capturing angles, wherein the first reflector, the second reflector, the plurality of lenses, and the image sensor are provided in sequential order from an object&#39;s side, and wherein the capturing angles of the plurality of captured images are adjusted based on a rotation of at least one of the first reflector and the second reflector. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and/or other aspects will be more apparent by describing certain example embodiments, taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a diagram illustrating an example of a structure of a lens assembly according to an example embodiment; 
         FIG. 2  is a diagram illustrating an example of adjusting an angle of a capturing view by rotating reflectors according to an example embodiment; 
         FIG. 3  is a diagram illustrating an example of a height of reflectors according to an example embodiment; 
         FIG. 4  is a diagram illustrating an example of an arrangement between an aperture of lenses and an image circle of an image sensor according to an example embodiment; 
         FIG. 5  is a diagram illustrating an example of an arrangement between a height of an aperture of lenses and a height of an image sensor according to an example embodiment; 
         FIG. 6  is a diagram illustrating an example of compensating for a hand movement according to an example embodiment; 
         FIG. 7  is a diagram illustrating an example of generating a high-resolution wide-angle image according to an example embodiment; 
         FIG. 8  is a diagram illustrating an example of a structure of lenses of a lens assembly according to an example embodiment; 
         FIG. 9  is a diagram illustrating an example of generating a captured image by an electronic device according to an example embodiment; 
         FIG. 10  is a diagram illustrating an example of an electronic device in which imaging assemblies are provided according to an example embodiment; 
         FIG. 11  is a diagram illustrating an example of a configuration of an electronic device according to an example embodiment; and 
         FIG. 12  is a flowchart illustrating an example of a capturing method according to an example embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Example embodiments are described in greater detail below with reference to the accompanying drawings. 
     In the following description, like drawing reference numerals are used for like elements, even in different drawings. The matters defined in the description, such as detailed construction and elements, are provided to assist in a comprehensive understanding of the example embodiments. However, it is apparent that the example embodiments can be practiced without those specifically defined matters. Also, well-known functions or constructions are not described in detail since they would obscure the description with unnecessary detail. 
     Although terms of “first” or “second” are used to explain various components, the components are not limited to the terms. These terms should be used only to distinguish one component from another component. For example, a “first” component may be referred to as a “second” component, or similarly, and the “second” component may be referred to as the “first” component within the scope of the right according to the concept of the present disclosure. 
     It will be understood that when a component is referred to as being “connected to” another component, the component can be directly connected or coupled to the other component or intervening components may be present. 
     As used herein, the singular forms are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should be further understood that the terms “comprises,” “comprising,” “includes,” and/or “including,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, components or a combination thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. Expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list. For example, the expression, “at least one of a, b, and c,” should be understood as including only a, only b, only c, both a and b, both a and c, both b and c, or all of a, b, and c. 
     Unless otherwise defined herein, all terms used herein including technical or scientific terms have the same meanings as those generally understood by one of ordinary skill in the art. Terms defined in dictionaries generally used should be construed to have meanings matching with contextual meanings in the related art and are not to be construed as an ideal or excessively formal meaning unless otherwise defined herein. 
     Hereinafter, examples will be described in detail with reference to the accompanying drawings, and like reference numerals in the drawings refer to like elements throughout. Also, in the description of example embodiments, detailed description of structures or functions that are thereby known after an understanding of the disclosure of the present application will be omitted when it is deemed that such description will cause ambiguous interpretation of the example embodiments. 
       FIG. 1  is a diagram illustrating an example of a structure of a lens assembly according to an example embodiment. Referring to  FIG. 1 , a lens assembly  100  may include reflectors  110  and  120 , for example, the first reflector  110  and the second reflector  120 , a lens group  130 , a filter  140 , and an image sensor  150 . The lens assembly  100  may further include an aperture stop  160  configured to adjust an amount of light. The aperture stop  160  may be disposed between the second reflector  120  and the lens group  130 . 
     The first reflector  110  may change a traveling path of light incident in a first direction D1 to a second direction D2. The second reflector  120  may change a traveling path of light incident in the second direction D2 to a third direction D3. For example, the first reflector  110  may be configured to bend the path of the light incident in the first direction D1 to the second direction D2 by an angle of 90 degrees (°). The second reflector  120  may be configured to bend the path of the light incident in the second direction D2 to the third direction D3 by an angle of 90°. According to an example embodiment, each of the reflectors  110  and  120  may include a first surface on which light is incident, a second surface by which the light is reflected, and a third surface from which the light is emitted. For example, each of the first reflector  110  and the second reflector  120  may correspond to a prism or include a mirror on the second surface. 
     The lens group  130  may include one or more lenses. For example, the lens group  130  may form a telephoto field of view (FOV) with five or more lenses. For example, the lens group  130  may include first through fifth lenses that are arranged in sequential order from the side of an object toward the side of the image sensor  150 . In this example, the first lens, the third lens, and the fifth lens may have positive refractive power. The second lens and the fourth lens may have negative refractive power. For example, the first lens may have a positive refractive power with a convex form toward the object, and the third lens may have a positive refractive power with a biconvex form. The lens group  130  may refract a traveling path of light provided from the second reflector  120  and provide the refracted light to the image sensor  150 . 
     The filter  140  may allow a predetermined wavelength band of light provided to the filter  140  from the first reflector  110 , the second reflector  120 , and the lens group  130  to pass therethrough and/or block the wavelength band of the light. The filter  140  may be, for example, an infrared filter configured to block light of an infrared band. The image sensor  150  may generate a captured image based on visual information of the object that is included in the light that passes through the first reflector  110 , the second reflector  120 , the lens group  130 , and the filter  140  in sequential order. 
     The first reflector  110  may rotate around a first rotation axis, and the second reflector  120  may rotate around a second rotation axis. The first rotation axis and the second rotation axis may be vertical to each other. The first direction D1, the second direction D2, and the third direction D3 may be vertical to one another. The first rotation axis may be stretched in the third direction D3, and the second rotation axis may be stretched in the first direction D1. A capturing angle of a captured image may be adjusted based on a rotation of at least one of the first reflector  110  or the second reflector  120 . An adjustment of an angle of a capturing view or capturing angle may be used for various applications. For example, the adjustment of an angle of a capturing view may be used to compensate for a hand movement and/or generate a high-resolution wide-angle image. However, the foregoing applications are provided merely as an example, and the adjustment may be used for other applications. 
     The lens assembly  100  may refract the visual information of the object received in the first direction D1 to the lens group  130  arranged in the third direction D3. Thus, the lens assembly  100  may have a high magnification with less space in the first direction D1. The lens assembly  100  may be provided in an electronic device requiring a small thickness, for example, a smartphone and a wearable device. In such a case, a height of the first reflector  110  and the second reflector  120 , a height of each lens of the lens group  130 , a height of the filter  140 , and a height of the image sensor  150 , which correspond to a length of the first direction D1, may be formed to have a small value. For example, the heights may each be formed to be 7 millimeters (mm) or less. As illustrated in  FIG. 3 , heights Ph1 and Ph2 of the first reflector  310  and the second reflector  320 , corresponding to the first reflector  110  and the second reflector  120 , may be formed to be less than or equal to 7 mm. In addition, each of the first reflector  110  and the second reflector  120  may be provided as a prism having a refractive index of 1.6 or greater. 
       FIG. 2  is a diagram illustrating an example of adjusting an angle of a capturing view by rotating reflectors according to an example embodiment. Referring to  FIG. 2 , a first reflector  210  may rotate on a first rotation axis  211  and a second reflector  220  may rotate on a second rotation axis  221 . For example, a lens assembly may further include at least one driver configured to rotate at least one of the first reflector  210  or the second reflector  220 . By a rotation of at least one of the first reflector  210  and the second reflector  220 , an angle of a capturing view may be adjusted. As the angle of the capturing view is adjusted, a capturing region may change. The angle of the capturing view may indicate a direction the first reflector  210  faces or views, and the capturing region may indicate a region from which an image is to be captured in the direction. The first reflector  210  and the second reflector  220  may correspond to the first reflector  110  and the second reflector  120  as illustrated in  FIG. 1 . 
     In the example of  FIG. 2 , a first FOV  230  may be a narrower FOV than a second FOV  240 . For example, the first FOV  230  may correspond to a telephoto, and the second FOV  240  may correspond to a wide angle. For example, when the first reflector  210  and the second reflector  220  are used in a telephoto lens assembly with the first FOV  230 , a capturing region of the first FOV  230  may move as the angle of the capturing view is adjusted. For example, the capturing region may move in a first direction  212  in response to the angle of the capturing view being adjusted based on the first rotation axis  211 . The capturing region may move in a second direction  222  in response to the angle of the capturing view being adjusted based on the second rotation axis  221 . The first rotation axis  211  and the second rotation axis  221  may be vertical to each other, and the first direction  212  and the second direction  222  may be vertical to each other. For example, the first direction  212  may be a vertical direction, and the second direction  222  may be a horizontal direction. 
     According to an example embodiment, an angle of a capturing view may be adjusted to compensate for a hand shaking-derived movement caused by shaking of the hand. For example, when a hand shaking-derived movement is sensed, at least one driver of the lens assembly may rotate at least one of the first reflector  210  or the second reflector  220  to compensate for the movement. When a capturing region is changed by a hand shaking, the driver may rotate at least one of the first reflector  210  or the second reflector  220  to restore the capturing region. When the lens assembly is used for telephoto video capturing, there may be severe hand shaking or swaying. Thus, such a compensating operation may be performed to allow the video capturing to be performed stably. 
     According to another example embodiment, an angle of a capturing view may be adjusted to generate a high-resolution wide-angle image. For example, by capturing an image of a capturing region of the second FOV  240  several times with the first FOV  230  while adjusting an angle of a capturing view, a plurality of captured images may be generated and the captured images may be synthesized into a single high-resolution wide-angle image. Each of the captured images may be a high-resolution telephoto image, and the captured images may form different regions corresponding to different capturing views in the high-resolution wide-angle image. Each of the captured images may also be referred to herein as a partial image of a synthesized image or a partially captured image. For example, the capturing region of the second FOV  240  may be divided into 5*4 sub-capturing regions. In this example, by capturing each of the sub-capturing regions with the first FOV  230 , 20 captured images may be generated and the 20 captured images may be synthesized into a high-resolution wide-angle image. The synthesized image may have a relatively higher resolution compared to a single image of the second FOV  240 . 
       FIG. 4  is a diagram illustrating an example of an arrangement between an aperture of lenses and an image circle of an image sensor according to an example embodiment. Referring to  FIG. 4 , light corresponding to visual information of an object may be provided to an image sensor  430  through a lens group  410  and a filter  420 . The lens group  410  may include one or more lenses. For example, the lens group  410  may include a total of m lenses, for example, a first lens  411  through an mth lens  412 . For a telephoto lens, m may denote an integer greater than or equal to 5. In this example, an aperture circle of each lens of the lens group  410  may be smaller than an image circle  431  of the image sensor  430 . For example, a first aperture d1, a second aperture d2, . . . , and an nth aperture do may all be smaller than the image circle  431 . A diameter D of the image circle  431  may correspond to a diagonal length of the image sensor  430 . A width of the image sensor  430  may be indicated as Sh, and a height of the image sensor  430  may be indicated as Sv. The width Sh and the height Sv may also be referred to as a long side and a short side, respectively. As described above with reference to  FIG. 1 , the height Sv may be associated with a thickness of an electronic device. Thus, when the electronic device is required to be thin, the height Sv may be formed to have potentially a minimum value, for example, 7 mm or less. 
       FIG. 5  is a diagram illustrating an example of an arrangement between a height of an aperture of lenses and a height of an image sensor according to an example embodiment. Referring to  FIG. 5 , light corresponding to visual information of an object may be provided to an image sensor  530  through a lens group  510  and a filter  520 . A height of each lens of the lens group  510  may be formed to match a height Sv of the image sensor  530 . For example, when an image formation range corresponding to the height Sv is defined on the image sensor  530 , an aperture height of each lens of the lens group  510  corresponding to positions through which rays provided in the image formation range pass through each lens of the lens group  510  may be defined. In this example, the aperture height of each lens may be formed to be less than or equal to the sensor height Sv. For example, a first aperture height v1, a second aperture height v2, . . . , and an nth aperture height vn may all be formed to be less than or equal to the sensor height Sv. 
       FIG. 6  is a diagram illustrating an example of compensating for a shaking hand according to an example embodiment. A first block  601  of  FIG. 6  illustrates a situation in which an image of an object  610  is captured in a normal manner in which there is no hand shaking. Light including visual information of the object  610  may be provided to an image sensor  640  after passing through a reflector  620  and a lens  630 . The image sensor  640  may then generate a captured image  651  that shows the object  610 . Although the reflector  610  and the lens  630  are illustrated respectively as a single reflector and a single lens in  FIG. 6  as an example, the reflector  620  and the lens  630  may be provided respectively as a plurality of reflectors and a plurality of lenses. In addition, a filter may be added between the lens  630  and the image sensor  640 . 
     A second block  602  of  FIG. 6  illustrates a situation in which an image of the object  610  is not captured in a normal manner due to the hand shaking. For example, only a portion of the object  610  may be shown in a captured image  652  due to the hand shaking. In this example, such hand shaking may be compensated for by a rotation of the reflector  620  as illustrated in a third block  603  of  FIG. 6 . For example, the reflector  620  may include a first reflector  611  and a second reflector  613 , and the first reflector  611  and the second reflector  613  may rotate respectively on a first rotation axis  612  and a second rotation axis  614 . The first reflector  611  and the second reflector  613  may rotate through a rotation driver. A controller and/or processor may sense an angle of the hand shaking through a gyro sensor, and control the rotation driver of the first reflector  611  and/or the second reflector  613  by calculating horizontal and vertical angles required for the compensation for the hand shaking. The hand shaking may be compensated for by the rotation of the reflector  620 , and an image of the object  610  may thereby be captured in a normal manner. A captured image  653  may include the entire object  610 . 
     Such hand shaking compensation may provide an elaborate gimbal function. A method such as a lens shift method and a sensor shift method may provide a compensation range of 1° or less. However, the compensation method using two reflectors, for example, the first and second reflectors  611  and  613 , may provide a compensational angle of ±10° or greater and may thus respond to a stronger hand shaking. In addition, a rotation of an image may be minimized during an angle adjustment, and thus cropping and warping may not be necessary for an image synthesis. Thus, it is possible to improve a sensor utilization, reduce a processing complexity, and prevent or reduce the degradation of an image quality or resolution. 
       FIG. 7  is a diagram illustrating an example of generating a high-resolution wide-angle image according to an example embodiment. Referring to  FIG. 7 , a plurality of captured images  710 , which are images captured with different capturing views, may be generated by a rotation of a reflector. The captured images  710  may be synthesized into a first wide-angle image  720 . The captured images  710  may be generated through continuous capturing or discontinuous or divided capturing. 
     The captured images  710  may respectively correspond to broken line blocks in the first wide-angle image  720 . For example, the number of the captured images  710  included in the first wide-angle image  720  may be 5*4 as shown by the broken line blocks. In this example, the 5*4 captured images  710  may be generated by capturing 5*4 times while changing an angle of a capturing view in horizontal and vertical directions. However, the number is provided merely as an example, and other numbers of captured images and other numbers of times of capturing may be applied. When the number of captured images and/or the number of times of capturing increases, high-resolution capturing may be enabled. The first wide-angle image  720  may have a relatively higher resolution than a second wide-angle image  730  that is generated through single capturing. For example, when a portion of the first wide-angle image  720  is enlarged, an enlarged image  721  of the enlarged portion may have the same high resolution. 
     According to an example embodiment, the first wide-angle image  720  and the second wide-angle image  730  may be generated simultaneously, and at least a portion of the first wide-angle image  720  may be provided at the request of a user. For example, when the user performs telephoto capturing, the second wide-angle image  730  may be provided. By adjusting an angle of a capturing view in a short period of time in which the second wide-angle image  730  is generated, the captured images  710  may be generated. The captured images  710  may be synthesized into the first wide-angle image  720 . 
     The first wide-angle image  720  may be stored in a user terminal and/or a server. When the user enlarges the second wide-angle image  730  or requests the first wide-angle image  720 , at least a portion of the first wide-angle image  720  may be provided to the user. For example, when the user enlarges or zooms a portion of the second wide-angle image  730 , the second wide-angle image  730  may be enlarged or zoomed up to a resolution supported by a wide-angle camera, and the first wide-angle image  720  may be provided starting from a magnification at which an image quality starts to be degraded. When the user indicates a portion he/she desires to store, the portion may be cropped from the first wide-angle image  720 , and a final image of the cropped portion may be provided. In addition, when the user activates a high-resolution wide-angle capturing option, the first wide-angle image  720  may be entirely provided. Further, when the user sets a block that is not as indicated by the broken lines in the first wide-angle image  720 , a high-resolution wide-angle image may be captured by synthesizing images that are captured while a capturing angle is being adjusted according to the set block. 
       FIG. 8  is a diagram illustrating an example of a structure of lenses of a lens assembly according to an example embodiment. Referring to  FIG. 8 , a lens assembly  800  may include a lens group  810 , a filter  820 , and an image sensor  830 . The lens group  810  may include lenses  811  through  815 . The lens group  810  may include the first lens  811  having positive refractive power with a convex form toward an object O, the second lens  812  having negative refractive power, the third lens  813  having positive refractive power with a biconvex form, the fourth lens  814  having negative refractive power, and the fifth lens  815  having positive refractive power. An aperture stop (or STOP as indicated in the following tables) configured to adjust an amount of light may be disposed on an object side of the first lens  811 . For example, the aperture stop may be disposed as indicated by the following example numerical values. 
     Where a distance from the first lens  811  to an upper surface (or an image plane) is TTL, a synthetic focal length of the lens assembly  800  is f′, a focal length of the first lens  811  is f1, and a focal length of the second lens  812  is f2, the lens assembly  800  may satisfy the following Equations 1 and 2. 
         TTL/f ′&lt;1.0  [Equation 1]
 
       0&lt;( f 1+ f 2)/ f′&lt; 0.03  [Equation 2]
 
     Where a focal length of the third lens  813  is f3 and a focal length of the fourth lens  814  is f4, the lens assembly  800  may satisfy the following Equation 3. 
       0.04&lt;( f 3+ f 4)/ f′&lt; 0.06  [Equation 3]
 
     Where an Abbe number of the third lens  813  is L3Ab and an Abbe number of the fourth lens  814  is L4Ab, the lens assembly  800  may satisfy the following Equations 4 and 5. 
       19&lt; L 3 Ab&lt; 25  [Equation 4]
 
       19&lt; L 4 Ab&lt; 25  [Equation 5]
 
     Tables 1 and 2 below indicate example numerical values associated with the lens assembly  800 . In Tables 1 and 2, 1 through N denote the numbers of lens surfaces, in which N is a natural number. These are allocated in sequential order from a side of the object O toward a side of the image sensor  830 . 
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                   
                 Radius 
                 Thickness 
                 Index 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 First reflector 
                 infinity 
                 2.0 
                 8466.238 
               
               
                   
                   
                 infinity 
                 2.0 
                 8466.238 
               
               
                   
                   
                 infinity 
                 1.5 
                   
               
               
                   
                 Second reflector 
                 infinity 
                 3.4 
                 8466.238 
               
               
                   
                   
                 infinity 
                 3.4 
                 8466.238 
               
               
                   
                   
                 infinity 
                 2.008 
                   
               
               
                   
                 STOP 
                 infinity 
                 −0.808 
                   
               
               
                   
                  1 
                 4.8647196 
                 2.030 
                 5348.557 
               
               
                   
                  2 
                 −8.410408 
                 0.15 
                   
               
               
                   
                  3 
                 −12.07049 
                 0.955 
                 6144.259 
               
               
                   
                  4 
                 5.026249 
                 1.128 
                   
               
               
                   
                  5 
                 6.1433834 
                 0.985 
                 6707.192 
               
               
                   
                  6 
                 −68.49743 
                 0.188 
                   
               
               
                   
                  7 
                 8.2700876 
                 0.685 
                 6144.259 
               
               
                   
                  8 
                 2.8338054 
                 1.800 
                   
               
               
                   
                  9 
                 7.373176 
                 0.957 
                 5441.561 
               
               
                   
                 10 
                 11.680651 
                 6.307 
                   
               
               
                   
                 Filter 
                 infinity 
                 0.3 
                 5168.642 
               
               
                   
                   
                 infinity 
                 1.789 
                   
               
               
                   
                 Image sensor 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
               
               
             
               
                 TABLE 2 
               
               
                   
               
               
                   
                 dn 
                 vn 
               
               
                   
               
             
            
               
                 STOP 
                 2.700 
                 1.940 
               
               
                  1 
                 2.700 
                 1.940 
               
               
                  2 
                 2.524 
                 1.820 
               
               
                  3 
                 2.431 
                 1.777 
               
               
                  4 
                 2.148 
                 1.678 
               
               
                  5 
                 2.092 
                 1.744 
               
               
                  6 
                 2.000 
                 1.696 
               
               
                  7 
                 1.953 
                 1.644 
               
               
                  8 
                 1.811 
                 1.502 
               
               
                  9 
                 2.201 
                 1.650 
               
               
                 10 
                 2.228 
                 1.652 
               
               
                 Filter 
                 2.993 
                 1.873 
               
               
                   
                 3.017 
                 1.880 
               
               
                 Image sensor 
                 3.240 
                 1.944 
               
               
                   
               
            
           
         
       
     
     Tables 3 and 4 below indicate aspherical surface factors associated with the foregoing numerical values. 
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE 3 
               
               
                   
                   
               
               
                   
                   
                 K 
                 A 
                 B 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                  1 
                 −0.62317 
                  5.0256E−04 
                  2.8934E−05 
               
               
                   
                  2 
                 −6.406442 
                  1.0112E−03 
                 −4.8180E−05 
               
               
                   
                  3 
                 0 
                 −1.4801E−03 
                  2.3934E−04 
               
               
                   
                  4 
                 0.003552 
                 −4.2791E−03 
                  1.9551E−04 
               
               
                   
                  5 
                 −1.822932 
                 −1.6071E−03 
                  2.5231E−04 
               
               
                   
                  6 
                 −99 
                 −2.0705E−03 
                  5.1234E−04 
               
               
                   
                  7 
                 −1.998207 
                 −4.0142E−03 
                  6.4186E−04 
               
               
                   
                  8 
                 −0.877361 
                 −4.2588E−03 
                  1.2933E−03 
               
               
                   
                  9 
                 1.9678733 
                 −7.6789E−03 
                  3.9460E−04 
               
               
                   
                 10 
                 −41.08265 
                 −3.4227E−03 
                 −2.1922E−04 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE 4 
               
               
                   
                   
               
               
                   
                   
                 C 
                 D 
                 E 
               
               
                   
                   
               
             
            
               
                   
                  1 
                 −6.8317E−08 
                  2.8819E−07 
                 −4.8854E−08 
               
               
                   
                  2 
                  1.1736E−06 
                 −1.0713E−06 
                  9.6365E−08 
               
               
                   
                  3 
                 −2.1684E−05 
                  1.2036E−06 
                  2.9074E−08 
               
               
                   
                  4 
                 −5.3448E−06 
                  3.9470E−06 
                 −2.1785E−07 
               
               
                   
                  5 
                 −5.6234E−05 
                  6.7174E−06 
                  1.3752E−07 
               
               
                   
                  6 
                 −9.7370E−05 
                  5.2445E−06 
                  3.0409E−07 
               
               
                   
                  7 
                  9.7963E−05 
                 −4.6148E−05 
                  2.6706E−06 
               
               
                   
                  8 
                  2.5837E−04 
                 −4.9576E−05 
                 −1.0761E−06 
               
               
                   
                  9 
                  1.3338E−04 
                 −4.7468E−07 
                 −7.8099E−07 
               
               
                   
                 10 
                  1.4584E−04 
                 −1.2427E−05 
                  9.9128E−07 
               
               
                   
                   
               
            
           
         
       
     
     An aspherical surface factor may be defined as represented by the following Equation 6. 
     
       
         
           
             
               
                 
                   
                     Z 
                     ⁡ 
                     
                       ( 
                       r 
                       ) 
                     
                   
                   = 
                   
                     
                       
                         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 
                     
                   
                 
               
               
                 
                   [ 
                   
                     Equation 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     6 
                   
                   ] 
                 
               
             
           
         
       
     
     In Equation 6 above, Z(r) denotes a distance in an optical axis (A) direction from an apex of a lens, c denotes an inverse number (1/R) of a curvature radius at the apex of the lens, r denotes a distance in a vertical direction from the optical axis A, and k denotes a conic constant, and A, B, C, D, E, and F denote aspherical surface factors. 
       FIG. 9  is a diagram illustrating an example of generating a captured image by an electronic device according to an example embodiment. Referring to  FIG. 9 , an electronic device  900  may include an imaging assembly  910 , a processor  920 , and a display  930 . The imaging assembly  910  may include an optical system  911 , an image sensor  912 , and an image signal processor (ISP)  913 . The optical system  911  may include reflectors, a lens group, and a filter. According to an example embodiment, the imaging assembly  910  may include the lens assembly  100  described above with reference to  FIG. 1 . The imaging assembly  910  may sense visual information of an object through the lens assembly  100 , and the processor  920  may generate a captured image based on the visual information. 
     The ISP  913  and the processor  920  may perform processing to convert the sensed information to the captured image. For example, the ISP  913  may perform preprocessing on the sensed information. The processor  920  may generate the captured image based on a result of the preprocessing. As another example, the ISP  913  or the processor  920  may perform all the processes required to generate the captured image. In this example, except for one of the ISP  913  and the processor  920  that performs the processes, the other one may be omitted. The imaging assembly  910  may generate a plurality of captured images having different capturing views based on a rotation of at least one of the reflectors. The processor  920  may then synthesize the captured images into a high-resolution wide-angle image. The imaging assembly  910  may include a rotation driver configured to rotate at least one of the reflectors, and the processor  920  may control the rotation driver to adjust an angle of a capturing view. The display  930  may display the captured image. 
       FIG. 10  is a diagram illustrating an example of an electronic device in which imaging assemblies are provided according to an example embodiment. Referring to  FIG. 10 , an electronic device  1000  may include an imaging device  1010  that includes imaging assemblies  1011 ,  1012 , and  1013 . For example, one of the imaging assemblies  1011 ,  1012 , and  1013  may perform wide-angle capturing, and another one may perform telephoto capturing. The imaging assembly that performs telephoto capturing may include the lens assembly  100  described above with reference to  FIG. 1 . Although the imaging device  1010  is illustrated as a rear camera of a smartphone in  FIG. 10 , the imaging device  1010  may also be a front camera of the smartphone. In addition, although the electronic device  1000  is illustrated as a smartphone, the electronic device  1000  may also be a mobile device such as a personal digital assistant (PDA), a netbook, a tablet computer, and a laptop computer, a wearable device such as a smartwatch, a smart band, and smart eyeglasses, a computing device such as a desktop and a server, a home appliance such as a television (TV), a smart TV, and a refrigerator, a security device such as a door lock and a close-circuit TV (CCTV), a vehicle such as an autonomous driving vehicle and a smart vehicle, a camera such as a virtual reality (VR)/augmented reality (AR) camera and a 360° camera, and other devices such as a drone. 
       FIG. 11  is a diagram illustrating an example of a configuration of an electronic device according to an example embodiment. Referring to  FIG. 11 , an electronic device  1100  may include a processor  1110 , a memory  1120 , a camera  1130 , a storage device  1140 , an input device  1150 , an output device  1160 , and a network interface  1170 , which may communicate with one another through a communication bus  1180 . For example, the electronic device  1100  may be provided as at least a portion of a mobile device such as a mobile phone, a smartphone, a PDA, a netbook, a tablet computer, and a laptop computer, a wearable device such as a smartwatch, a smart band, and smart eyeglasses, a computing device such as a desktop and a server, a home appliance such as a TV, a smart TV, and a refrigerator, a security device such as a door lock, a vehicle such as an autonomous driving vehicle and a smart vehicle, a camera such as a VR/AR camera and a 360° camera, and other devices such as a drone. 
     The processor  1110  may execute functions and instructions to be executed in the electronic device  1100 . For example, the processor  1110  may process instructions stored in the memory  1120  or the storage device  1140 . The processor  1110  may perform the operations or processes described herein with reference to  FIGS. 1 through 10, and 12 . The memory  1120  may include a computer-readable storage medium or device. The memory  1120  may store instructions to be executed by the processor  1110  and store related information while software or program is being executed in the electronic device  1100 . 
     The camera  1130  may capture a still image and/or a moving image (or a video). The storage device  1140  may include a computer-readable storage medium or device. The storage device  1140  may store a greater amount of information than the memory  1120  for a long period of time. The storage device  1140  may include, for example, a magnetic hard disk, an optical disc, a flash memory, a floppy disc, or other types of nonvolatile memory that are well-known in related technical fields. 
     The input device  1150  may receive an input from a user through an input means such as a keyboard and a mouse, or through an input means that is based on a touch input, a voice input, and an image input. The input device  1150  may include, as non-limiting examples, a keyboard, a mouse, a touchscreen, a microphone, and other devices configured to detect the input from the user and transfer the detected input to the electronic device  1100 . The output device  1160  may provide the user with an output of the electronic device  1100  through a visual, audio, or tactile channel. The output device  1160  may include, as non-limiting examples, a display, a touchscreen, a speaker, a vibration generator, and other devices configured to provide the user with the output. The network interface  1170  may communicate with an external device through a wired or wireless network. 
       FIG. 12  is a flowchart illustrating an example of a capturing method according to an example embodiment. Referring to  FIG. 12 , in operation  1210 , an electronic device may generate a plurality of partially captured images having different capturing views while adjusting a capturing view by rotating at least one of a first reflector configured to rotate on a first rotation axis or a second reflector configured to rotate on a second rotation axis. In operation  1220 , the electronic device may generate a single synthesized image based on the partially captured images. Each of the partially captured images may correspond to a high-resolution telephoto image, and the synthesized image may correspond to a high-resolution wide-angle image. The partially captured images may form different regions corresponding to different capturing views in the synthesized image. For a more detailed description of the capturing method, reference may be made to what has been described above with reference to  FIGS. 1 through 11 . 
     The units described herein may be implemented using hardware components and software components. For example, the hardware components may include microphones, amplifiers, band-pass filters, audio to digital convertors, non-transitory computer memory and processing devices. A processing device may be implemented using one or more general-purpose or special purpose computers, such as, for example, a processor, a controller and an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable gate array (FPGA), a programmable logic unit (PLU), a microprocessor or any other device capable of responding to and executing instructions in a defined manner. The processing device may run an operating system (OS) and one or more software applications that run on the OS. The processing device also may access, store, manipulate, process, and create data in response to execution of the software. For purpose of simplicity, the description of a processing device is used as singular; however, one skilled in the art will appreciated that a processing device may include multiple processing elements and multiple types of processing elements. For example, a processing device may include multiple processors or a processor and a controller. In addition, different processing configurations are possible, such as parallel processors. 
     The software may include a computer program, a piece of code, an instruction, or some combination thereof, to independently or collectively instruct or configure the processing device to operate as desired. Software and data may be embodied permanently or temporarily in any type of machine, component, physical or virtual equipment, computer storage medium or device, or in a propagated signal wave capable of providing instructions or data to or being interpreted by the processing device. The software also may be distributed over network coupled computer systems so that the software is stored and executed in a distributed fashion. The software and data may be stored by one or more non-transitory computer readable recording mediums. The non-transitory computer readable recording medium may include any data storage device that can store data which can be thereafter read by a computer system or processing device. 
     Example embodiments include non-transitory computer-readable media including program instructions to implement various operations embodied by a computer. The media may also include, alone or in combination with the program instructions, data files, data structures, tables, and the like. The media and program instructions may be those specially designed and constructed for the purposes of example embodiments, or they may be of the kind well known and available to those having skill in the computer software arts. Examples of non-transitory computer-readable media include magnetic media such as hard disks, floppy disks, and magnetic tape, optical media such as CD ROM disks, magneto-optical media such as floptical disks, and hardware devices that are specially configured to store and perform program instructions, such as read-only memory devices (ROM) and random-access memory (RAM). Examples of program instructions include both machine code, such as produced by a compiler, and files containing higher level code that may be executed by the computer using an interpreter. The described hardware devices may be configured to act as one or more software modules in order to perform the operations of the above-described example embodiments, or vice versa. 
     The foregoing example embodiments are merely exemplary and are not to be construed as limiting. The present disclosure can be readily applied to other types of apparatuses. Also, the description of the example embodiments is intended to be illustrative, and not to limit the scope of the claims, and many alternatives, modifications, and variations will be apparent to those skilled in the art. 
     While example embodiments have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope as defined by the following claims and their equivalents.