Patent Publication Number: US-8531580-B2

Title: Imaging device including a plurality of imaging units

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority from Korean Patent Application No. 10-2010-0064520, filed in the Korean Intellectual Property Office on Jul. 5, 2010, the entire disclosure of which is incorporated herein by reference for all purposes. 
     BACKGROUND 
     1. Field 
     Apparatuses and methods consistent with embodiments relate generally to an imaging device, and more particularly, to an imaging device including a plurality of imaging units. 
     2. Description of the Related Art 
     Imaging devices for forming still images or moving images have been applied in various fields. Recently, imaging devices became essential components of portable electronics, such as a mobile phone and a Personal Digital Assistant (PDA), and their applications are now extending to medical cameras, security/monitoring cameras, on-vehicle cameras, cameras for robots, etc. With this trend, required functions or performances of imaging devices are also differentiated according to applications. 
     For example, a portable digital camera, a camcorder, a camera for mobile phone, etc. have primarily requirements for miniaturization, minimal thickness, light weight and high-resolution, but generally do not require a wide Field of View (FOV). These cameras generally have a maximum FOV of 60 to 65 degrees; and in the case of a wide-angle lens, a maximum FOV of 80 degrees. Accordingly, these cameras are not generally capable of photographing at a wide FOV reaching 120 degrees or more. Meanwhile, security/monitoring cameras, on-vehicle cameras for side view, cameras for robots, medical cameras, etc. may need a wide FOV reaching 120 degrees or more in order to minimize blind spots. 
     For this reason, various methods have been proposed to implement a wide FOV in an imaging device. One method is to use a special lens, such as a wide-angle lens or a fisheye lens, as a lens for an imaging device. However, in this case, the special lenses may cause distortion in acquired images, and the thickness of such a special lens also increases the entire thickness of the imaging device. Korea Laid-open Patent Application No. 2005-0044453, entitled “A Wide-Angle Imaging Optical System and Wide-Angle Imaging Device, Monitoring Imaging Device, On-Vehicle Imaging Device and Projection Device with Wide-Angle Imaging Optical System,” discloses an imaging device capable of forming panoramic images over a super-wide range by using a combination of reflective planes and a combination of lenses. Also, Korean Laid-open Patent application No. 2010-0006867, entitled “Flexible Image Photographing Apparatus with a Plurality of Image Forming Units and Method for Manufacturing the Same,” discloses an imaging device that can be bent forward and backward by arranging a plurality of image forming units in the form of an array and manufacturing all members including the main body with a flexible substance. 
     SUMMARY OF THE INVENTION 
     One or more exemplary embodiments provide an imaging device including a plurality of imaging units in a thin, compact structure that can achieve a wide, adjustable Field of View (FOV) without image distortion. 
     One or more exemplary embodiments also provide an imaging device including a plurality of imaging units capable of acquiring normal images and panoramic images by obtaining a wide FOV of 180 degrees or more with a small number of imaging units. 
     According to an aspect of an exemplary embodiment, there is provided an imaging device including a supporting substrate unit, a flexible substrate unit and a movable unit. The supporting substrate unit includes a supporting substrate formed with a hard material, and the flexible substrate unit includes a flexible substrate in which a plurality of imaging units are arranged at least in a width direction. The flexible substrate is fixed with the supporting substrate at a first edge portion of the flexible substrate, and an opposite second edge portion of the flexible substrate is coupled with the movable unit. The movable unit moves the opposite second edge portion of the plurality of imaging units in the width direction to bend the flexible substrate or flatten an already bent flexible substrate. A degree of curvature at which the flexible substrate is bent may vary based on a distance by which the movable unit moves in the width direction, so that a field of view (FOV) of the plurality of imaging units may be adjusted. 
     In another exemplary embodiment, an imaging device includes a flexible substrate, a plurality of imaging units and a movable unit configured to move the flexible substrate between a flat position and a curved position. 
     The above and/or other aspects will be more apparent from the following detailed description of exemplary embodiments taken in conjunction with the accompanying drawings and the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a sectional view illustrating an example of an imaging device, according to an exemplary embodiment. 
         FIG. 1B  is a sectional view illustrating a state where a flexible substrate of the imaging device illustrated in  FIG. 1A  is bent at a predetermined curvature, according to an exemplary embodiment. 
         FIG. 1C  is a plan view illustrating a part of the imaging device illustrated in  FIG. 1A , according to an exemplary embodiment. 
         FIG. 2  is a graph plotting the relationship of the radius of curvature R and the angle at the circumference with respect to a movement distance X when L=60 millimeters (mm), according to an exemplary embodiment. 
         FIG. 3  is a sectional view illustrating an imaging unit, according to an exemplary embodiment. 
         FIG. 4  is a sectional view illustrating another imaging device, according to an exemplary embodiment. 
         FIG. 5  is a sectional view illustrating another imaging device, according to an exemplary embodiment. 
         FIG. 6  is a sectional view illustrating another imaging device, according to an exemplary embodiment. 
         FIG. 7A  is a view illustrating a motor driven type of driving unit, according to an exemplary embodiment. 
         FIG. 7B  is a view illustrating a manual driven type of driving unit, according to an exemplary embodiment. 
         FIGS. 8A ,  8 B,  9 A and  9 B are front and side views illustrating an exemplary embodiment of a pantoscopic camera, wherein  FIGS. 8A and 8B  show a state when photographing is performed with a single imaging unit, and wherein  FIGS. 9A and 9B  show a state when photographing is performed with a plurality of imaging units. 
         FIGS. 10A ,  10 B,  11 A and  11 B are front and side views illustrating another exemplary embodiment of a pantoscopic camera, wherein  FIGS. 10A and 10B  show a state when photographing is performed with a single imaging unit, wherein and  FIGS. 11A and 11B  show a state when photographing is performed with a plurality of imaging units. 
     
    
    
     Throughout the drawings and the detailed description, unless otherwise described, the same drawing reference numerals will be understood to refer to the same elements, features, and structures. The relative size and depiction of these elements may be exaggerated for clarity, illustration, and convenience. 
     DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS 
     The following description is provided to assist the reader in gaining a comprehensive understanding of the methods, apparatuses, and/or systems described herein. Accordingly, various changes, modifications, and equivalents of the methods, apparatuses, and/or systems described herein will be suggested to those of ordinary skill in the art. Also, descriptions of well-known functions and constructions may be omitted for increased clarity and conciseness. 
       FIGS. 1A and 1B  are sectional views illustrating an exemplary embodiment of an imaging device  100  with a plurality of imaging units, wherein  FIG. 1A  shows a state where a flexible substrate  121  of the imaging device  100  is flattened, and  FIG. 1B  shows a state where the flexible substrate unit  121  is bent at a predetermined curvature. Referring to  FIGS. 1A and 1B , the imaging device  100  includes a supporting substrate unit  110 , a flexible substrate  120  and a movable unit  130 . 
     The supporting substrate unit  110  includes a supporting substrate  111  made of a hard material, and the flexible substrate unit  120  includes a flexible substrate  121  made of a flexible material. The supporting substrate  111  may be formed with a material such as epoxy resin generally used for a hard Printed Circuit Board (PCB), or with a material such as ceramic, plastic, glass or the like. Meanwhile, the flexible substrate  121  may be formed with a flexible material such as polyester, polyimide or the like. 
     The supporting substrate  111  acts to structurally support the imaging device  100 . The supporting substrate  111  affixes a part of the flexible substrate  121 ; that is, a fixing portion  121   a  of the flexible substrate  121  is affixed with the supporting substrate  111  to prevent the flexible substrate  121  from moving in a width direction. Here, the fixing portion  121   a  is a part of the flexible substrate  121  that is fixed with the supporting substrate  111 . 
     The fixing portion  121   a  of the flexible substrate  121  may be directly fixed with the supporting substrate  111  or indirectly fixed with the supporting substrate  111  using another component fixed with the supporting substrate  111  as a medium. For example, as illustrated in  FIG. 1C , the fixing portion  121   a  of the flexible substrate  121  may be indirectly fixed with the supporting substrate  111  using a connecting member  118  fixed with the supporting substrate  111  as a medium. The connecting member  118  may include a fixing member  118   a  fixed with the supporting substrate  111  and a pair of fixing plates  118   b  that are coupled with the fixing member  118   a  in such a manner to have mobility at least in a up-down direction with respect to the fixing member  118 . However, this structure is only exemplary ( FIG. 1C  shows a structure where the fixing plate  118   b  is coupled with the fixing member  118   a  in such a manner to be movable in a up-down direction with respect to the fixing member  118   a ). 
     The fixing portion  121   a  of the flexible substrate  121  may correspond to an edge portion of the flexible substrate  121 ; however, this is only exemplary. Since the flexible substrate  121  is fixed with the supporting substrate  111  at an edge portion, when a width direction force is applied to move the opposite edge portion  121   b  of the fixing portion  121   a  toward the fixing portion  121   a , the flexible substrate  121  gets bent at a predetermined curvature (see  FIG. 1B ). If necessary, an extra device for bending the flexible substrate  121  in the outer direction (that is, in the direction away from the supporting substrate  111 ) may be provided. 
     The flexible substrate unit  120  includes a plurality of imaging units  122  that are installed in the flexible substrate  121 . That is, the flexible substrate  121  may be a FPCB (Flexible Printed Circuit Board) in which a plurality of imaging units  122  are installed. The plurality of imaging units  122  may be aligned in a horizontal or width direction between the fixing portion  121   a  and the opposite edge portion  121   b  (hereinafter, referred to as an “image unit region”). For example, the imaging units  122  may be aligned in a width direction or 2-dimensionally arranged in the form of an array. Alternatively, a portion of the imaging units  122  may be aligned in a width direction, and the remaining portion of the imaging units  122  may be arranged at a different location (see  FIGS. 10A and 11A ). 
     Each of the imaging units  122  receives incident light from outside of the device and converts the received light into electrical signals, thus generating image signals (in  FIGS. 1A and 1B , each imaging unit  122  is illustrated to have a lens shape, but each imaging unit  122  may have any other shape). The imaging units  122  may be arranged at least in a width direction on the imaging unit region. In this case, by applying a width direction force to the flexible substrate  121  to protrude the imaging unit region upward, a Field of View (FOV) of the imaging device  100  may be increased. Then, by adjusting a curvature at which the imaging unit region is bent, that is, a distance by which the movable unit  130  moves, the FOV of the imaging device  100  may be adjusted. 
     In more detail, as illustrated in  FIGS. 1A and 1B , it is assumed that when a movable column  132  moves by a distance X toward the fixing portion  121   a , the imaging unit region is bent with the radius of curvature R in a circular form. In this case, when a bending angle between imaging units  122   a  and  122   e  positioned at both ends of the imaging units  122  and spaced apart by a distance L, that is, the angle of circumference whose circular arc is the imaging unit region is Φ, Equations 1 and 2 are satisfied below. 
     
       
         
           
             
               
                 
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                       R 
                     
                   
                 
               
               
                 
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     By using Equations 1 and 2, the relationship between the radius of curvature R and the angle of circumference Φ of the flexible substrate  121  with respect to the movement distance X of the movable column  132  may be calculated. That is, the relationship between the radius of curvature R and the angle of circumference Φ of the flexible substrate  121  with respect to the movement distance X of the opposite edge portion  121   b  may be calculated. The FOV of the imaging device  100  may be calculated using the angle of circumference Φ of the imaging unit region and the FOV of each of the imaging units  122   a  to  122   e . Accordingly, the FOV of the imaging device  100  may be controlled by adjusting the movement distance X of the movable column  132 . That is, as the movement distance X increases, the angle of circumference Φ increases, resulting in an increase of the FOV of the imaging device  100 . 
       FIG. 2  is a graph plotting the relationship of the radius of curvature R and the angle at the circumference Φ with respect to a movement distance X when L=60 millimeters (mm) in the example of  FIG. 1B . It is seen from  FIG. 2  that as the movement distance X increases, the radius of curvature R decreases and the angle of circumference Φ of the imaging unit region increases. If the FOV of each of the imaging units  122   a  to  122   e  positioned at the edge portions of the flexible substrate  121  is 50 degrees, the angle of circumference Φ of the imaging unit region has to be 130 degrees in order to make the FOV of the imaging device  100  180 degrees. According to the graph illustrated in  FIG. 2 , it is seen that by moving the movable column  132  by about 12 mm, the angle of circumference Φ of the imaging unit region becomes 130 degrees. 
     As described above, the imaging units  122  may be arbitrary kinds of imaging devices. One exemplary embodiment of such an imaging unit  122  is illustrated in  FIG. 3 .  FIG. 3  is a sectional view illustrating an exemplary embodiment of the imaging unit  122 . Referring to  FIG. 3 , the imaging unit  122  includes an image sensor  1221  and a lens unit  1224 . 
     The image sensor  1221  is an electronic device that receives light incident through the lens unit  1224  and converts the received light into an electrical signal. The image sensor  1221  may be a Complementary Metal-Oxide Semiconductor (CMOS) image sensor or a Charged Coupled Device (CCD) image sensor. Also, the image sensor  1221  may be a low resolution image sensor with a 1 megapixel or less resolution, or a high resolution image sensor with a 3 megapixel or more resolution. The imaging units  122  illustrated in  FIG. 1A  or  1 B do not need to have the same resolution and may be a group of imaging units that are combined in various manners according to applications. For example, only an imaging unit  122   c  positioned in the center may have a relatively higher resolution than the other imaging units  122   a ,  122   b ,  122   d  and  122   d . Or, as illustrated in an example of  FIG. 10A  or  11 A, it is possible that imaging units  42  aligned in a width direction have the same or different resolutions and at least one imaging unit  43  spaced apart from the imaging units  42  has a relatively higher or lower resolution than the imaging units  42 . 
     Below the image sensor  1221 , a terminal for electrical connection to an external device is formed; for example a contact pad  1222 . For example, image signals acquired by the image sensor  1221  may be transferred to an image signal processor, etc. via the contact pad  1222 . In  FIG. 3 , a solder ball is illustrated as the contact pad  1222 ; however, the kind of the contact pad  1222  may depend on a method in which the imaging unit  122  is packaged in the flexible substrate  121 . A cover glass  1223  is disposed over the image sensor  1221  in order to protect the image sensor  1221  and prevent the image sensor  1221  from being contaminated. Also, an optical coating layer, such as an optical low-pass filter, a chrominance filter, an Infra-Red (IR) filter, etc. may be disposed above and/or below the cover glass  1223 , which is not shown in  FIG. 3 . 
     The lens unit  1224  is provided above the cover glass  1223 , that is, in front of the image sensor  1221  on an optical path, to form light reflected from a subject as an image on a light-receiving area of the image sensor  1221 . For this, the lens unit  1224  includes one or more lens elements L 1  through L 6 ; the kind, material, number, etc. of which may vary.  FIG. 3  shows an exemplary embodiment where the lens unit  1224  includes 3 wafer-scale lenses spaced apart by spacers having a predetermined height. Each wafer-scale lens includes a transparent substrate and at least one lens element attached on one or both sides of the transparent substrate. 
     The imaging unit  122  may further include a fluidic lens, a mechanical shutter, etc., which are not illustrated in  FIG. 3 . The fluidic lens is used to adjust a focus distance to provide the imaging unit  122  with a macro function, an auto-focusing function, a zoom function, etc. The mechanical shutter is used to adjust the amount of light incident to the lens unit  1224 ; for example, an opened range of the lens unit  1224 , a time for which the lens unit is opened, etc. 
     Hereinafter, the structure of the imaging device  100  will be described with reference to  FIGS. 1A and 1B . In the following description, the flexible substrate  121  is divided into a first region I and a second region II in a width direction, but the division between the first region I and second region II does not mean that the flexible substrate  121  is physically divided into two portions. The division between the first region I and second region II are intended to more clearly describe the technical features of the current example. 
     The first region I of the flexible substrate  121  includes the imaging unit region and is located above the supporting substrate  111 . Meanwhile, the second portion II of the flexible substrate  121  may be located above the supporting substrate  111  (see  FIG. 4 ) or bent to penetrate the supporting substrate  111  such that an end  121   c  is located below the supporting substrate  111  (see  FIGS. 1A and 1B ). In the latter case, a through slit  116  may be formed in the supporting substrate  111  through which the flexible substrate  121  can pass. When the supporting substrate  111  has a predetermined thickness, a part of the flexible substrate  121  passing through the through slit  116  may be positioned structurally in a substantially vertical direction. The fixing portion  121   a  of the flexible substrate  121  may be directly or indirectly fixed at the through slit  116  or on the supporting substrate  111  around the through slit  116 . As such, when the flexible substrate  121  is positioned in a substantially vertical direction around the fixing portion  121   a , applying a force to the flexible substrate  121  in a width direction by moving the edge portion  121   b  of the first region I toward the fixing portion  121   a  makes the imaging unit region bent to a more circular shape. This will be described in more detail below. 
       FIG. 4  is a sectional view illustrating another exemplary embodiment of an imaging device  200 . Referring to  FIG. 4 , the imaging device  200  includes, like the imaging device  100  illustrated in  FIG. 1B , a supporting substrate unit  210 , a flexible substrate unit  220  and a movable unit  230 . Also, a plurality of imaging units  222  are arranged in a width direction in an imaging unit region of the flexible substrate  221 . However, unlike the imaging device  100  illustrated in  FIG. 1B , the entire flexible substrate  221  is located above the supporting substrate  211 . Also, the fixing portion  221   a  is affixed with the supporting substrate  211  without any mobility, and the opposite edge portion  221   b  of the fixing portion  221   a  is not coupled with the movable column  232 . However, this structure is only exemplary. 
     As illustrated in  FIG. 4 , applying a force in a width direction to the flexible substrate  221  by moving the movable column  232  in the width direction makes the imaging unit region of the flexible substrate  221  bent and protruded. However, in this case, the bent shape may be not circular but rather asymmetrical, wherein the edge portion of the imaging unit region has a nearly infinite curvature such that the bent shape becomes a bell shape. As a result, images acquired by two imaging units  222   a  and  222   b  adjacent to the fixing portion  221   a  are the same or nearly same, so that the FOVs of the imaging units  222   a  and  222   b  overlap each other. Accordingly, it is difficult for the imaging device  200  illustrated in  FIG. 4  to acquire a maximum FOV with the imaging units  222  installed in the flexible substrate  221 . 
     There are several reasons why the imaging unit region of the flexible substrate  221  may be bent to be asymmetrical. The first reason is because the flexible substrate  221  positioned above the supporting substrate  211  is fixed with the fixing portion  221  on the supporting substrate  211  in a width direction. Unlike the structure of  FIG. 4 , in the structure illustrated in  FIGS. 1A and 1B , the flexible substrate  121  may be disposed to penetrate the through slit  116  of the supporting substrate  111  such that a part of the flexible substrate  121  passing through the through slit  116  is positioned in a substantially vertical direction. As a result, the imaging unit region of the imaging device  100  extends from the vertically disposed part of the flexible substrate  121  so that the imaging unit region is bent to be a more circular shape. If necessary, a roller bar having a predetermined curvature may be disposed on the supporting substrate near the through slit  116 , and the flexible substrate  121  may be affixed at the roller bar, such that the part of the flexible substrate  121  passing through the through slit  116  (that is, the edge portion of the imaging unit region) may be easily bent to form the circular shape. 
     Another reason why the imaging unit region of the flexible substrate  221  illustrated in  FIG. 4  is bent to be asymmetrical is because the fixing portion  221   a  of the flexible substrate  221  and the opposite edge portion  221   b  are fixed without mobility. The fixing portion  221   a  and the opposite edge portion  221   b  are fixed without mobility to prevent both edge portions of the imaging unit region from being bent to a circular shape. On the contrary, in the exemplary embodiments illustrated in  FIGS. 1A ,  1 B and  1 C, the fixing portion  121   a  and the opposite edge portion  121   b  of the flexible substrate  121  are fixed using connecting members  118  and  134  to permit mobility at least in an up-down direction, the imaging unit region may be bent to be a nearly circular shape. The circular shape results because the connecting members  118  and  134  are rotated at a predetermined angle in an up direction when a force is applied to the flexible substrate  121  in a width direction. 
     Also, when the connecting members  118  and  134  include fixing plates  118   b  having a predetermined width that are coupled with the connecting members  118  and  134  in such a manner as to have up-down directional mobility, and the fixing part  121   a  penetrating the through slit  116  has an inclination (that is, a predetermined magnitude of virtual component) corresponding to upward rotation of the fixing plate  118   b . Accordingly, the imaging unit region of the flexible substrate  121  becomes a nearly circular shape. 
     Referring again to  FIGS. 1A and 1B , the supporting substrate  111  may be a main printed circuit board (PCB) on which various circuits and electronic devices for driving the imaging device  100  are mounted and/or packaged. In this exemplary embodiment, various electrical devices required to operate the imaging device  100  may be mounted and/or packaged on one or both sides of the supporting substrate  111 . These electrical devices may be electronic circuits, memories, etc., including an image signal processor (ISP)  112 . Also, a conductor that is electrically connected with the image signal processor  112 , etc. may be formed on the supporting substrate  111 ; for example, a contact member  114  such as an electrode pad. The contact member  114  formed on the supporting substrate  111  may be electrically connected with a contact member  124  formed on the flexible substrate  121  so that image signals generated by the imaging units  122  are transferred to the image signal processor  112  and processed. 
     In an exemplary embodiment where the flexible substrate is disposed above the supporting substrate  211 , as illustrated in  FIG. 4 , two contact members  214  and  224  are connected above the supporting substrate  211 . In this embodiment, since a connector (not shown) connecting the contact members  214  and  224  is positioned outside of the fixing portion  221   a , electrical leads may be formed between the image signal processor  212  and the contact member  214 ; such as, for example, signal line paths formed on the upper surface of the supporting substrate  211 . 
     Meanwhile, when the flexible substrate  121  is bent to penetrate the through slit  116 , the contact members  114  and  124  may be connected below the supporting substrate  111 . For example, as illustrated in  FIGS. 1A  and  1 B, both edge portions  121   b  and  121   c  of the flexible substrate  121  are positioned on different sides of the supporting substrates with respect to the through slit  116 , so that a connector (not shown) between the contact members  114  and  124  may be positioned at the opposite side of the through slit  116  from the image signal processor  112 . In this exemplary embodiment, a signal line path that connects the image signal processor  112  with the contact member  114  may be formed by making a detour around the through slit  116 . 
     When a supporting substrate functions as a main PCB, an exemplary method of ensuring that a signal line path connects an image signal processor with a contact member when a through slot is formed in a supporting substrate is to bend a flexible substrate to a “ ” shape, such that both edge portions of the flexible substrate are positioned on the same side with respect to the through slot.  FIG. 5  is a sectional view illustrating an exemplary embodiment of an imaging device  300  having such a structure. Referring to  FIG. 5 , a flexible substrate  321  of the imaging device  300  is bent to penetrate a through slit  316 , in such a manner that both edge portions of the flexible substrate  321  are positioned at the same side of a supporting substrate  311  with respect to the through slit  316 . In this exemplary embodiment, two contact members  314  and  324  are connected below the supporting substrate  311 , and a connector (not shown) between the contact members  314  and  324  is positioned on the same side of the supporting substrate  311  as an image signal processor  312  with respect to the through slit  316 . Accordingly, a wire (not shown) that connects the image signal processor  312  with the contact member  314  does not need to pass across the through slit  316 , which ensures a sufficient signal line path. 
     Another exemplary embodiment of a method of ensuring a sufficient signal line path when a through slit is formed in a supporting substrate is for a supporting substrate to perform only a function of supporting and affixing the flexible substrate. In this case, the imaging device further includes a third substrate, such as a main PCB, which includes an image signal processor, etc. disposed thereon.  FIG. 6  is a sectional view illustrating an example of an imaging device  400  that includes a main PCB  441 . Referring to  FIG. 6 , the imaging device  400  further includes a supporting substrate  411 , a flexible substrate  420  and the third substrate, or main PCB  441  disposed below the supporting substrate  411 . An image signal processor  412  and a contact member  444  electrically connected with the image signal processor  412  are packaged or formed on the main PCB  441 . In this exemplary embodiment, a connector (not shown) that connects two contact pads  424  and  444  with each other is disposed on the main PCB  441 , which lacks a through slit. Accordingly, a sufficient signal line path is ensured on the main PCB  441 . 
     Referring to  FIGS. 1A and 1B , the movable unit  130  is used to move the opposite edge portion  121   b  of the flexible substrate  121  with respect to the fixing portion  121   a  in a width direction. For example, the movable unit  130  bends the imaging unit region to a circular shape by moving the edge portion of the first region I of the flexible substrate  121 , that is, the opposite edge portion  121   b  of the flexible substrate  121  with respect to the fixing portion  121   a , toward the fixing portion  121   a . The movable unit  130  may also flatten the circular-shaped imaging unit region by moving the opposite edge portion  121   b  of the first region I of the flexible substrate  121  away from an end  121   c . For this movement, the movable unit  130  may include a movable column  132  that is movable in a width direction, and a connecting member  134  that connects the edge portion  121   b  of the first portion I of the flexible substrate  121  with the movable column  132 . Also, the movable unit  130  may further include a guiding member  136  (see  FIG. 7A ) for guiding the movable column  132  to move in a width direction, and a driving unit (not shown) for moving the movable column  132  in the width direction. 
     If the guiding member  136  is disposed below the supporting substrate  111 , the movable column  132  may be positioned to penetrate the supporting substrate  111  or positioned to avoid coming in contact with the supporting substrate  111 . In this exemplary embodiment, a guide channel (not shown) may be formed in the supporting substrate  111  through which the movable column  132  can move in a width direction. The guide channel is a passage formed in the supporting substrate  111  such that the movable column  132  penetrates the supporting substrate  111  and can move in the width direction. In the exemplary embodiment where the movable column  132  is positioned to avoid coming in contact with the supporting substrate  111 , s guide channel need not be formed in the supporting substrate  111 . In another exemplary embodiment, the guiding member  136  may be disposed above the supporting substrate  111 . In this exemplary embodiment, the movable column  132  needs neither to penetrate the supporting substrate  111  nor be positioned to avoid contacting the supporting substrate  111 . 
     The connecting member  134  connects the edge portion  121   b  of the first region I of the flexible substrate  121  with the movable column  132 , thus transferring width-directional movement of the movable column  132  to the edge portion  121   b  of the first region I of the flexible substrate  121 . As a result, when the movable column  132  moves toward the fixing portion  121   a , the imaging unit region of the flexible substrate  121  is bent. At this time, if the connecting member  134  has up-down directional mobility, the imaging unit region can be bent to a more circular shape. For example, the connecting member  134  may include a universal joint. 
     The guiding member  136  guides the movable column  132  to move in the width direction and may be one of various kinds of guide devices. For example, the guiding member  136  may be a pair of linear motion (LM) guides (see  136  of  FIGS. 7A and 7B ) that are connected with the movable column  132 . If the movable column  132  can perform width-directional movement without any guiding member, no guiding member may be included in the movable unit  130 . 
     A driving unit for driving the movable column  132  may be a motor-driven type or a manual-driven type.  FIG. 7A  is a view illustrating an exemplary embodiment of a motor-driven type of driving unit, and  FIG. 7B  is a view illustrating an example of a manual-driven type of driving unit. Referring to  FIG. 7A , the driving unit may include a small motor  137 , such as a step motor or a servo motor, and a power transfer unit  138  such as a rack and pinion to convert rotation movement of a motor (a rotation motor) into linear movement. If a linear motor for generating linear movement is used, no power transfer unit for converting rotation movement into linear movement is needed. The power transfer unit  138  converts rotation movement of the motor  137  into linear movement and transfer the linear movement to the movable column  132 . The movable column  132  moves in the width direction along the guiding member  136 . 
     In another exemplary embodiment where the driving unit is a manual-driven type, as illustrated in  FIG. 7B , the power transfer unit  138  may be included in the driving unit, and may further include a manipulation unit  139  that is manually operated, instead of a motor. The manipulation unit  139  may be a bar type, a wheel type or a button type. The power transfer unit  138  converts movement of the manipulation unit  139  or rotation movement into linear movement and transfers it to the movable column  132 . The movable column  132  moves in the width direction along the guiding member  136 . The manipulation unit  139  may be exposed outside the housing of the imaging device  100 . 
     Hereinafter, a pantoscopic camera including the imaging device with the plurality of imaging units as described above will be schematically described. 
       FIGS. 8A ,  8 B,  9 A and  9 B are front and side views illustrating an exemplary embodiment of a pantoscopic camera, wherein  FIGS. 8A and 8B  show a pantoscopic camera with a single imaging unit.  FIGS. 9A and 9B  show a pantoscopic camera with a plurality of imaging units. In  FIGS. 8A ,  8 B,  9 A and  9 C, the entire structure of the imaging device with the plurality of imaging units is not definitely shown, but the imaging device is disposed in a housing  10 , a portion of whose front side (not shown) is opened. 
     Referring to  FIGS. 8A and 8B , in a configuration where photographing is performed with only one imaging unit, the flexible substrate  21  (and specifically the imaging unit region of the flexible substrate  21 ) is flattened. The pantoscopic camera may be also flattened when being carried or held. When the flexible substrate  21  is flattened, the thickness of the pantoscopic camera will be relatively thin. In the flattened state, a window  12  for multiple lens units mounted in the opened portion of the front side of the housing  10  is closed, but an imaging unit  22   c  of the imaging units  22  is exposed to the outside. Images taken at an FOV of 60 degrees are acquired through the exposed imaging unit  22   c  and may be displayed on a display  14  mounted in the housing  10 . When a user presses a shutter button  16  while viewing an image displayed on the display  14 , the pantoscopic camera photographs at a more widely-used FOV. 
     Referring to  FIGS. 9A and 9B , in the configuration where photographing is performed using a plurality of imaging units, the flexible substrate  21  (more specifically the imaging unit region of the flexible substrate  21 ) is bent at a predetermined curvature. A degree at which the flexible substrate  21  is bent may be adjusted by a user, and this degree corresponds to a degree of FOV at which a plurality of imaging units photograph. For example, a user may drive a movable unit (not shown) of the imaging device using a button  18  for FOV adjustment to adjust a degree at which the flexible substrate  21  is bent, which correspondingly changes the degree of FOV at which the device photographs an image. At this time, the window  12  for multiple lens units is opened to expose all or part of the imaging units  22  to an outside of the housing  10 , and the flexible substrate  21  is also bent to be exposed to the outside. Images, such as a panoramic image with 180 or more degrees of FOV, acquired through the exposed imaging units  22  may be displayed on the display  14  mounted on the housing  10 . When the user presses the shutter button  16  while viewing an image displayed on the display  14 , the pantoscopic camera performs photographing at a wide angle. 
       FIGS. 10A ,  10 B,  11 A and  11 B are front and side views illustrating another exemplary embodiment of a pantoscopic camera, wherein  FIGS. 10A and 10B  show a configuration for photographing an image with a single imaging unit, and  FIGS. 11A and 11B  show a configuration for photographing an image with a plurality of imaging units. An imaging device having the plurality of imaging units is installed in a housing  30  whose front side is opened, which is not illustrated in the drawings. 
     The pantoscopic camera illustrated in  FIGS. 10A ,  10 B,  11 A and  11 B is different from the previously-described exemplary embodiment illustrated in  FIGS. 8A ,  8 B,  9 A and  9 B in that the pantoscopic camera of  FIGS. 10A ,  10 B,  11 A and  11 B further includes a separate imaging unit for normal photographing as well as a plurality of imaging units aligned in a width direction. That is, the pantoscopic camera illustrated in the example of  FIGS. 8A ,  8 B,  9 A and  9 B, in which an imaging device includes only a plurality of imaging units aligned in a width direction, performs normal photographing using one of plurality of imaging units, whereas the pantoscopic camera illustrated in the exemplary embodiment of  FIGS. 10A ,  10 B,  11 A and  11 B includes a plurality of imaging units  42  and a separate imaging unit  43  for normal photographing that is disposed at a different location from the imaging units  42 . The imaging unit  43  for normal photographing may have different features from the imaging units  42 , including a zoom function, an auto focusing function, resolution, etc.unitunit The imaging unit  43  may be a high performance imaging unit. 
     Referring to  FIGS. 10A and 10B , in the configuration where photographing is performed with a single imaging unit, a flexible substrate  41  (specifically the imaging unit region of the flexible substrate  41 ) is flattened. When the pantoscopic camera is carried or held and is not being used, the thickness of the pantoscopic camera is relatively thin. A multiple lens unit window  32  mounted in the opened portion of the front side of the housing  30  is closed to cover all the imaging units aligned in the width direction. In contrast, the imaging unit  43  for normal photographing is not covered by the multiple lens unit window  32 . Images acquired by the imaging unit  43  for photographing at 60 degrees of FOV may be displayed on a display  34  mounted on the housing  30 . When a user presses a shutter button  36  while viewing an image displayed on the display  34 , photographing of the image is performed through the imaging unit  43 . 
     Referring to  FIGS. 11A and 11B , in a configuration where photographing is performed using the plurality of imaging units  42 , the flexible substrate  41  (specifically the imaging unit region of the flexible substrate  41 ) is bent at a predetermined curvature. A degree at which the flexible substrate  41  is bent can be adjusted by a user, and this degree corresponds to a degree of FOV at which the plurality of imaging units photograph. For example, a user may drive a movable unit (not shown) of the imaging device using a button  38  for FOV adjustment to adjust a degree at which the flexible substrate  41  is bent, which correspondingly changes the degree of FOV at which the device photographs an image. At this time, the multiple lens unit window  32  is opened to expose all or part of the imaging units  42  to an outside of the housing  30 , and the flexible substrate  31  is also bent to be exposed to the outside. Meanwhile, the imaging unit  43  for normal photographing is controlled neither to be covered by any window nor to operate. Images such as a panoramic image with 180 or more degrees of FOV, acquired through the exposed imaging units  42  may be displayed on the display  34  mounted on the housing  30 . When the user presses the shutter button  36  while viewing the image displayed on the display  14 , photographing is performed at a wide angle through the imaging units  42 . 
     Therefore, a FOV reaching approximately 150 degrees or more may be obtained from a plurality of imaging units mounted upon a flexible substrate by adjusting a degree at which the flexible substrate is bent. The wide FOV may be achieved without utilizing a special lens, such as a fisheye lens, and therefore no image distortion occurs upon wide-angle photographing. In addition, since the flexible substrate may be flattened upon normal photographing or upon being held when not being used, the imaging device may be manufactured to be compact and slim. 
     A number of examples have been described above. Nevertheless, it will be understood that various modifications may be made. For example, 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. Accordingly, other implementations are within the scope of the following claims.