Patent Publication Number: US-2016241783-A1

Title: Portable terminal

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application claims priority under 35 U.S.C. §119 to Japanese Patent Application No. 2015-013962, filed on Jan. 28, 2015, entitled “Portable Terminal”. The content of which is incorporated by reference herein in its entirety. 
     FIELD 
     Embodiments of the present disclosure relate to a portable terminal. 
     BACKGROUND 
     A portable terminal including two cameras of a main camera and a sub camera has conventionally been known. 
     SUMMARY 
     A portable terminal according to one embodiment includes a display unit configured to be located on a front surface of the portable terminal, a front camera configured to be located on the front surface of the portable terminal, a rear camera configured to be located on a back surface of the portable terminal, a storage unit configured to store a control program, and a processor configured to control the portable terminal by executing the control program. The processor is configured to set any camera of the front camera and the rear camera to on and to have the display unit display an image input from the camera set to ON. The processor is configured to switch the camera to be set to ON when change in condition around the camera set to ON is detected. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram showing a configuration of a portable terminal in an embodiment. 
         FIG. 2  is a diagram showing appearance of the portable terminal in  FIG. 1  from a front (front surface) side. 
         FIG. 3  is a diagram showing appearance of a portable terminal  1  in  FIG. 1  from a rear (back surface) side. 
         FIG. 4  is a flowchart showing a procedure for shooting oneself in a first embodiment. 
         FIG. 5  is a diagram showing an operation by a user. 
         FIG. 6  is a diagram showing an example of a shot still image. 
         FIG. 7  is a diagram showing an operation by a user. 
         FIG. 8  is a flowchart showing a procedure for shooting oneself in a second embodiment. 
         FIGS. 9 and 10  are each a diagram showing an operation by a user. 
         FIGS. 11 and 12  are flowcharts showing a procedure for shooting oneself in a third embodiment. 
         FIGS. 13 and 14  are each a diagram showing an operation by a user. 
         FIGS. 15 and 16  are flowcharts showing a procedure for shooting oneself in a fourth embodiment. 
         FIG. 17  is a diagram showing an operation by a user. 
         FIGS. 18 and 19  are flowcharts showing a procedure for shooting oneself and a background in a fifth embodiment. 
         FIGS. 20 and 21  are each a diagram showing an example of a shot still image. 
         FIG. 22  is a diagram showing appearance of a portable terminal from a front (front surface) side. 
         FIG. 23  is a diagram showing appearance of the portable terminal from a rear (back surface) side. 
     
    
    
     DETAILED DESCRIPTION 
     First Embodiment 
     Referring to  FIGS. 1, 2, and 3 , this portable terminal  1  includes an antenna  22 , a radio communication unit  21 , a proximity sensor  6 , a front camera  8 , a rear camera  18 , a receiver  7 , a microphone  12 , a button group  9 , a touch screen  15 , a control unit  20 , and a storage unit  23 . Touch screen  15  is constituted of a display  16  and a touch panel  17 . 
     Button group  9  can function as an operation acceptance unit which can accept an instruction operation from a user for various types of processing. Examples of the operation acceptance unit include a button implemented as a physical mechanism (a hardware key) such as button group  9  and a key reproduced as software (a soft key). 
     Radio communication unit  21  can communicate with a radio base station through antenna  22 . Radio communication unit  21  includes an A/D converter, a D/A converter, a modulation unit, a demodulation unit, a frequency converter, and an amplification unit. 
     Display  16  can display a screen output from control unit  20 . Examples of display  16  include a liquid crystal display and an organic electro-luminescence (EL) display. 
     Touch panel  17  can function as an input acceptance unit which can accept input from a user. Though touch panel  17  detects contact or proximity of an object (a finger of a user or a pen) based on a capacitance, the touch panel is not limited as such. For example, input by a user may be detected based on an infrared technique or an electromagnetic induction technique. Other than the touch panel, for example, a component which accepts input without contact may be acceptable as the input acceptance unit, and a proximity sensor represents such an example. A hardware key may also be acceptable as the input acceptance unit. 
     Receiver  7  can output voice of a communication counterpart or sound of music data output from control unit  20 . Receiver  7  is implemented, for example, by an electromagnetic speaker. Alternatively, receiver  7  may be implemented by a piezoelectric oscillation element and may transmit voice and sound to a user by oscillating a panel on a surface. 
     Microphone  12  can receive voice of a communication counterpart and sound in the surroundings and output the voice and sound to control unit  20 . 
     Proximity sensor  6  can detect presence of a nearby object in a non-contact manner. Proximity sensor  6  can detect, for example, display  16  being brought closer to a face. 
     Rear camera  18  and front camera  8  can shoot a subject. 
     Storage unit  23  can store a control program. Control unit  20  can include a CPU (Central Processing Unit). The CPU can control the portable terminal  1  by executing the control program. 
     Storage unit  23  can store setting information of rear camera  18  and front camera  8  and can store a still image and moving images generated through shooting. The setting information can include on camera information representing which of front camera  8  and rear camera  18  is set to ON and information representing to which of a still image shooting mode and a moving image shooting mode a current shooting mode has been set. Front camera  8  is set to ON by default (hereinafter, an on camera). When the on camera is switched, control unit  20  can update the on camera information. Even when power of portable terminal  1  is turned off, the on camera information is maintained. The shooting mode is set to the still image shooting mode by default. After the moving image shooting mode is set and moving images are shot, control unit  20  can return the shooting mode to the still image shooting mode. 
     As shown in  FIG. 2 , receiver  7 , front camera  8 , and proximity sensor  6  can be arranged in an upper portion of a front surface of a housing  2  of portable terminal  1 . Display  16  and touch panel  17  can be arranged in the center of the front surface of housing  2  of portable terminal  1 . Touch panel  17  can be arranged on display  16 . 
     Buttons  9 D,  9 E, and  9 F can be arranged in a lower portion of the front surface of housing  2  of portable terminal  1 . A button  9 A can be arranged on an upper side of a side surface of housing  2  of portable terminal  1 . Buttons  9 B and  9 C can be arranged on a lateral side of a side surface of housing  2  of portable terminal  1 . 
     Button  9 D serves as a home button. Button  9 E serves as a back button. Button  9 F serves as a menu button. Button  9 A serves as a power on/off button. Button  9 B serves as a volume turn-up button. Button  9 C serves as a volume turn-down button. 
     Microphone  12  can be arranged in the lower portion of the front surface of housing  2  of portable terminal  1 . 
     As shown in  FIG. 3 , rear camera  18  can be arranged in an upper portion of a rear surface of housing  2  of portable terminal  1 . 
     When a user shoots the user himself/herself with front camera  8  of portable terminal  1 , the user has had to switch the camera to be set to ON from rear camera  18  to front camera  8  by touching an icon on touch screen  15 . The user has had to further touch another icon on touch screen  15  in order to click a shutter of front camera  8 . 
     Control unit  20  can set any of front camera  8  and rear camera  18  to ON based on the setting information (on camera information) and have display  16  display an image input from the camera set to ON. 
     Control unit  20  can switch the camera to be set to ON when the camera or a sensor located around the camera detects change in condition around the camera, for example, in response to covering of the camera set to ON by the user. An operation to cover the camera by the user includes an operation by the user to move a hand, a finger, or another body part of the user or an object other than the body of the user toward the camera set to ON. There are various methods for detecting an operation by the user to cover the camera set to ON. 
     In a first embodiment, control unit  20  can switch the camera to be set to ON based on an image input from the camera set to ON. Specifically, control unit  20  can switch the camera to be set to ON based on whether or not a quantity of light in all areas in the input image indicates a value not greater than a certain value. After control unit  20  switches the camera to be set to ON, it can automatically control face recognition autofocus (AF) and control self-timer shooting. 
       FIG. 4  is a flowchart showing a procedure for shooting oneself in the first embodiment. 
     Referring to  FIG. 4 , in step S 501 , when the user indicates launch of a camera application by touching a camera icon displayed on touch screen  15 , the process proceeds to step S 502 . 
     When the setting information of the camera stored in storage unit  23  indicates on of rear camera  18  in step S 502 , control unit  20  allows the process to proceed to step S 503 . When the setting information of the camera stored in storage unit  23  indicates on of front camera  8 , control unit  20  allows the process to proceed to step S 508 . 
     In step S 503 , control unit  20  can start input of an image from rear camera  18  and have the input image displayed on touch screen  15 . 
     In step S 504 , when a condition that a quantity of light in all areas in the image input from rear camera  18  is not greater than a certain value (that is, a pixel value is not greater than a certain value) continues for a prescribed time period or longer (S 504 : YES), control unit  20  allows the process to proceed to step S 505 . 
     An operation by the user for determination as YES in S 504  will be described with reference to  FIG. 5 . 
     As shown in  FIG. 5 , as the user orients front camera  8  to the user himself/herself and covers rear camera  18  with his/her hand for a prescribed time period or longer, a condition that the quantity of light in all areas in the image input from rear camera  18  is not greater than the certain value continues for a prescribed time period or longer, and the process proceeds to step S 505 . The reason why the quantity of light in all areas being not greater than the certain value has been set as a condition is for distinction from shooting of a night scene. 
     In step S 505 , control unit  20  can start input of an image from front camera  8  instead of rear camera  18 , and have the input image displayed on touch screen  15 . Control unit  20  can update setting information (on camera information) such that front camera  8  is on. 
     In step S 506 , control unit  20  can have front camera  8  control face recognition autofocus (AF). Specifically, control unit  20  can detect a position of a face in the image input from front camera  8  and adjust focus of an optical system of front camera  8  such that the detected face is focused on. 
     In step S 507 , control unit  20  can have a still image as shown in  FIG. 6  shot with a self-timer function. Specifically, control unit  20  can have storage unit  23  store an image input from front camera  8  after lapse of 10 seconds. 
     In step S 508 , control unit  20  can start input of an image from front camera  8  and have the input image displayed on touch screen  15 . 
     In step S 509 , when the condition that the quantity of light in all areas in the image input from front camera  8  is not greater than the certain value (that is, a pixel value is not greater than the certain value) has continued for the prescribed time period or longer (S 509 : YES), control unit  20  allows the process to proceed to step S 510 . 
     An operation by the user for determination as YES in S 509  will be described with reference to  FIG. 7 . 
     As shown in  FIG. 7 , as the user orients front camera  8  toward the user himself/herself and covers front camera  8  with his/her hand for a prescribed time period or longer, a condition that the quantity of light in all areas in the image input from front camera  8  is not greater than the certain value continues for the prescribed time period or longer and the process proceeds to step S 510 . 
     In step S 510 , control unit  20  can maintain input of an image from front camera  8  and have the input image displayed on touch screen  15 . 
     In step S 511 , control unit  20  can have front camera  8  execute face recognition autofocus (AF). Specifically, control unit  20  can detect a position of a face in the image input from front camera  8  and adjust focus of the optical system of front camera  8  such that the detected face is focused on. 
     In step S 512 , control unit  20  can have a still image as shown in  FIG. 6  shot with a self-timer function. Specifically, control unit  20  can have storage unit  23  store an image input from front camera  8  after lapse of 10 seconds. 
     As set forth above, according to the first embodiment, with a simple operation by the user to cover the camera set to ON with his/her hand, the camera to be set to ON can be switched from the rear camera to the front camera. 
     Second Embodiment 
     A second embodiment solves the problem the same as in the first embodiment with a different method. 
     In the second embodiment, control unit  20  can set any of front camera  8  and rear camera  18  to ON based on setting information (on camera information) and have display  16  display an image input from the camera set to ON. Control unit  20  can switch the camera to be set to ON based on the image input from the camera set to ON. Specifically, control unit  20  can switch the camera to be set to ON based on whether or not a prescribed gesture has been detected in the input image. After control unit  20  switches the camera to be set to ON, it can automatically control face recognition autofocus (AF) and control self-timer shooting. 
       FIG. 8  is a flowchart showing a procedure for shooting oneself in the second embodiment. 
     The flowchart in  FIG. 8  is different from the flowchart in  FIG. 4  as follows. 
     Instead of steps S 504  and S 509  in  FIG. 4 ,  FIG. 8  has steps S 604  and S 609 . 
     In step S 604 , when a gesture operation to vertically wave a user&#39;s hand is detected in the image input from rear camera  18  (S 604 : YES), control unit  20  allows the process to proceed to step S 505 . 
       FIG. 9  is a diagram showing an operation by a user.  FIG. 9  shows an operation by the user for determination as YES in S 604 . 
     As shown in  FIG. 9 , as the user performs an operation to vertically wave his/her hand in front of rear camera  18 , the gesture is detected and the process proceeds to step S 505 . 
     In step S 609 , when a gesture operation to vertically wave a user&#39;s thumb is detected in the image input from front camera  8  (S 609 : YES), control unit  20  allows the process to proceed to step S 510 . 
       FIG. 10  is a diagram showing an operation by a user.  FIG. 10  shows an operation by the user for determination as YES in S 609 . 
     As shown in  FIG. 10 , as the user performs an operation to vertically wave his/her thumb in front of front camera  8 , the gesture is detected and the process proceeds to step S 510 . 
     As set forth above, according to the second embodiment, with a simple gesture operation by the user to wave his/her hand or finger in front of the camera set to ON, the camera set to ON can be switched from the rear camera to the front camera. 
     Third Embodiment 
     When rear camera  18  is higher in resolution than front camera  8 , some users shoot the users themselves with rear camera  18 . Some users shoot moving images of the users themselves. 
     A third embodiment relates to a portable terminal which allows shooting of oneself not only with front camera  8  but also with rear camera  18  and allows shooting of not only still images but also moving images of oneself. 
     In the third embodiment, when a duration of a condition that a quantity of light in all areas in an image input from rear camera  18  is not greater than a certain value is within a first prescribed range while rear camera  18  is set to ON, control unit  20  can switch the camera to be set to ON from rear camera  18  to front camera  8 , and when the duration of the condition that the quantity of light is not greater than the certain value is within a second prescribed range, control unit  20  can maintain rear camera  18  as the camera to be set to ON. 
     When an event that the quantity of light in all areas in the image input from rear camera  18  varies to a value not greater than the certain value and thereafter exceeds the certain value occurs N or more times (N being a natural number not smaller than 2) within a certain time period while rear camera  18  is set to ON, control unit  20  can switch the camera to be set to ON from rear camera  18  to front camera  8  and switch the shooting mode from the still image shooting mode to the moving image shooting mode. 
     When the duration of the condition that the quantity of light in all areas in the image input from front camera  8  is not greater than the certain value is within the first prescribed range while front camera  8  is set to ON, control unit  20  can maintain front camera  8  as the camera to be set to ON, and when the duration of the condition that the quantity of light is not greater than the certain value is within the second prescribed range, control unit  20  can switch the camera to be set to ON from front camera  8  to rear camera  18 . 
     When an event that the quantity of light in all areas in the image input from front camera  8  varies to a value not greater than the certain value and thereafter exceeds the certain value occurs N or more times (N being a natural number not smaller than 2) within the certain time period while front camera  8  is set to ON, control unit  20  can maintain front camera  8  as the camera to be set to ON and switch the shooting mode from the still image shooting mode to the moving image shooting mode. 
       FIGS. 11 and 12  are flowcharts showing a procedure for shooting oneself in the third embodiment. 
     Referring to  FIGS. 11 and 12 , when the user indicates launch of a camera application in step S 101  by touching a camera icon displayed on touch screen  15 , the process proceeds to step S 102 . 
     When the setting information of the camera stored in storage unit  23  indicates on of rear camera  18  in step S 102 , control unit  20  allows the process to proceed to step S 103 . When the setting information of the camera stored in storage unit  23  indicates on of front camera  8 , control unit  20  allows the process to proceed to step S 116 . 
     In step S 103 , control unit  20  can start input of an image from rear camera  18  and have the input image displayed on touch screen  15 . 
     In S 104 , when a duration of the condition that the quantity of light in all areas in the image input from rear camera  18  is not greater than the certain value (that is, a pixel value is not greater than the certain value) is within a first prescribed range (a period not shorter than 3 seconds and shorter than 5 seconds) (S 104 : YES), control unit  20  allows the process to proceed to step S 105 . 
     An operation by the user for determination as YES in S 104  will be described with reference to  FIG. 5 . 
     As shown in  FIG. 5 , as the user orients front camera  8  toward the user himself/herself and covers rear camera  18  with his/her hand for a period not shorter than 3 seconds and shorter than 5 seconds, the duration of the condition that the quantity of light in all areas in the image input from rear camera  18  is not greater than the certain value is within the first prescribed range (not shorter than 3 seconds and shorter than 5 seconds) and the process proceeds to step S 105 . 
     In step S 105 , control unit  20  can start input of an image from front camera  8  instead of rear camera  18  and have the input image displayed on touch screen  15 . Control unit  20  can update the setting information (on camera information) such that front camera  8  is on. 
     In step S 106 , control unit  20  can have front camera  8  execute face recognition autofocus (AF). Specifically, control unit  20  can detect a position of a face in the image input from front camera  8  and adjust focus of an optical system of front camera  8  such that the detected face is focused on. 
     In step S 107 , control unit  20  can have a still image as shown in  FIG. 6  shot with a self-timer function. Specifically, control unit  20  can have storage unit  23  store an image input from front camera  8  after lapse of 10 seconds. 
     When the duration of the condition that the quantity of light in all areas in the image input from rear camera  18  is not greater than the certain value (that is, a pixel value is not greater than the certain value) is within the second prescribed range (not shorter than 5 seconds and shorter than 8 seconds) (S 104 : NO, S 108 : YES), control unit  20  allows the process to proceed to step S 109 . 
     An operation by the user for determination as YES in S 108  will be described with reference to  FIG. 13 . 
     As shown in  FIG. 13 , as the user orients rear camera  18  toward the user himself/herself and covers rear camera  18  with his/her hand for a period not shorter than 5 seconds and shorter than 8 seconds, the duration of the condition that the quantity of light in all areas in the image input from rear camera  18  is not greater than the certain value is within the second prescribed range (not shorter than 5 seconds and shorter than 8 seconds) and the process proceeds to step S 109 . 
     In step S 109 , control unit  20  can maintain input of the image from rear camera  18  and have the input image displayed on touch screen  15 . 
     In step S 110 , control unit  20  can have rear camera  18  execute face recognition autofocus (AF). Specifically, control unit  20  can detect a position of a face in the image input from rear camera  18  and adjust focus of an optical system of rear camera  18  such that the detected face is focused on. 
     In step S 111 , control unit  20  can have a still image as shown in  FIG. 6  shot with a self-timer function. Specifically, control unit  20  can have storage unit  23  store an image input from rear camera  18  after lapse of 10 seconds. 
     When an event that the quantity of light in all areas in the image input from rear camera  18  varies to a value not greater than the certain value and thereafter exceeds the certain value occurs two or more times within the certain time period (for example, 10 seconds) (S 104 : NO, S 108 : NO, S 112 : YES), control unit  20  allows the process to proceed to step S 113 . 
     An operation by the user for determination as YES in S 112  will be described with reference to  FIG. 5 . 
     As shown in  FIG. 5 , as the user orients front camera  8  toward the user himself/herself and performs an operation to cover rear camera  18  with his/her hand twice or more within the certain time period, an event that the quantity of light in all areas in the image input from rear camera  18  varies to a value not greater than the certain value and thereafter exceeds the certain value occurs twice or more within the certain time period, and the process proceeds to step S 113 . 
     In step S 113 , control unit  20  can start input of an image from front camera  8  instead of rear camera  18  and have the input image displayed on touch screen  15 . Control unit  20  can update the setting information (on camera information) such that front camera  8  is on and switch the shooting mode to the moving image shooting mode. 
     In step S 114 , control unit  20  can have front camera  8  execute face recognition autofocus (AF). Specifically, control unit  20  can detect a position of a face in the image input from front camera  8  and adjust focus of an optical system of front camera  8  such that the detected face is focused on. 
     In step S 115 , control unit  20  can have moving images shot with a self-timer function. Specifically, control unit  20  can have storage unit  23  store video images (moving images) input from front camera  8  after lapse of 10 seconds. 
     In step S 116 , control unit  20  can start input of an image from front camera  8  and have the input image displayed on touch screen  15 . 
     When the duration of the condition that the quantity of light in all areas in the image input from front camera  8  is not greater than the certain value (that is, a pixel value is not greater than the certain value) is within the first prescribed range (a period not shorter than 3 seconds and shorter than 5 seconds) (S 117 : YES), control unit  20  allows the process to proceed to step S 118 . 
     An operation by the user for determination as YES in S 117  will be described with reference to  FIG. 7 . 
     As shown in  FIG. 7 , as the user orients front camera  8  toward the user himself/herself and covers front camera  8  with his/her hand for a period not shorter than 3 seconds and shorter than 5 seconds, the duration of the condition that the quantity of light in all areas in the image input from front camera  8  is not greater than the certain value is within the first prescribed range (not shorter than 3 seconds and shorter than 5 seconds) and the process proceeds to step S 118 . 
     In step S 118 , control unit  20  can have input of an image from front camera  8  maintained and have the input image displayed on touch screen  15 . 
     In step S 119 , control unit  20  can have front camera  8  execute face recognition autofocus (AF). Specifically, control unit  20  can detect a position of a face in the image input from front camera  8  and adjust focus of an optical system of front camera  8  such that the detected face is focused on. 
     In step S 120 , control unit  20  can have a still image as shown in  FIG. 6  shot with a self-timer function. Specifically, control unit  20  can have storage unit  23  store an image input from front camera  8  after lapse of 10 seconds. 
     When the duration of the condition that the quantity of light in all areas in the image input from front camera  8  is not greater than the certain value (that is, a pixel value is not greater than the certain value) is within the second prescribed range (not shorter than 5 seconds and shorter than 8 seconds) (S 117 : NO, S 121 : YES), control unit  20  allows the process to proceed to step S 122 . 
     An operation by the user for determination as YES in S 121  will be described with reference to  FIG. 14 . 
     As shown in  FIG. 14 , as the user orients rear camera  18  toward the user himself/herself and covers front camera  8  with his/her hand for a period not shorter than 5 seconds and shorter than 8 seconds, the duration of the condition that the quantity of light in all areas in the image input from front camera  8  is not greater than the certain value is within the second prescribed range (not shorter than 5 seconds and shorter than 8 seconds) and the process proceeds to step S 122 . 
     In step S 122 , control unit  20  can start input of an image from rear camera  18  instead of front camera  8  and have the input image displayed on touch screen  15 . Control unit  20  can update the setting information (on camera information) such that rear camera  18  is on. 
     In step S 123 , control unit  20  can have rear camera  18  execute face recognition autofocus (AF). Specifically, control unit  20  can detect a position of a face in the image input from rear camera  18  and adjust focus of an optical system of rear camera  18  such that the detected face is focused on. 
     In step S 124 , control unit  20  can have a still image as shown in  FIG. 6  shot with a self-timer function. Specifically, control unit  20  can have storage unit  23  store an image input from rear camera  18  after lapse of 10 seconds. 
     When an event that the quantity of light in all areas in the image input from front camera  8  varies to a value not greater than the certain value and thereafter exceeds the certain value occurs twice or more within the certain time period (for example, 10 seconds) (S 117 : NO, S 121 : NO, S 125 : YES), control unit  20  allows the process to proceed to step S 126 . 
     An operation by the user for determination as YES in S 125  will be described with reference to  FIG. 7 . 
     As shown in  FIG. 7 , as the user orients front camera  8  toward the user himself/herself and performs an operation to cover front camera  8  with his/her hand twice or more within a prescribed time period, an event that the quantity of light in all areas in the image input from front camera  8  varies to a value not greater than the certain value and thereafter exceeds the certain value occurs twice or more within the certain time period, and the process proceeds to step S 126 . 
     In step S 126 , control unit  20  can have input of an image from front camera  8  maintained and have the input image displayed on touch screen  15 . Control unit  20  can switch the shooting mode to the moving image shooting mode. 
     In step S 127 , control unit  20  can have front camera  8  execute face recognition autofocus (AF). Specifically, control unit  20  can detect a position of a face in the image input from front camera  8  and adjust focus of an optical system of front camera  8  such that the detected face is focused on. 
     In step S 128 , control unit  20  can have moving images shot with a self-timer function. Specifically, control unit  20  can have storage unit  23  store video images (moving images) input from front camera  8  after lapse of 10 seconds. 
     As set forth above, according to the third embodiment, as the user changes how to wave his/her hand or finger in front of the camera set to ON, the camera to be set to ON can be maintained, the camera to be set to ON can be switched, or the shooting mode can be switched to an operation shooting mode. 
     Fourth Embodiment 
     A fourth embodiment solves the problem the same as in the third embodiment with a different method. 
     In the fourth embodiment, when the duration of the condition that the quantity of light in all areas in the image input from rear camera  18  is not greater than the certain value is within a prescribed range while rear camera  18  is set to ON, control unit  20  can switch the camera to be set to ON from rear camera  18  to front camera  8  or can maintain rear camera  18  as the camera to be set to ON based on whether or not proximity sensor  6  detects proximity of an object. 
     When the duration of the condition that the quantity of light in all areas in the image input from front camera  8  is not greater than the certain value is within the prescribed range while front camera  8  is set to ON, control unit  20  can switch the camera to be set to ON from front camera  8  to rear camera  18  or can maintain front camera  8  as the camera to be set to ON based on whether or not proximity sensor  6  detects proximity of an object. 
       FIGS. 15 and 16  are flowcharts showing a procedure for shooting oneself in the fourth embodiment. 
     The flowcharts in  FIGS. 15 and 16  are different from the flowcharts in  FIGS. 11 and 12  as follows. 
     Instead of steps S 104 , S 108 , S 117 , and S 121  in  FIG. 11 ,  FIG. 14  has steps S 204 , S 208 , S 217 , and S 221 . 
     In step S 204 , when the duration of the condition that the quantity of light in all areas in the image input from rear camera  18  is not greater than the certain value (that is, a pixel value is not greater than the certain value) is within the first prescribed range (a period not shorter than 3 seconds and shorter than 5 seconds) and when detection of an object by proximity sensor  6  is absent (S 204 : YES), control unit  20  allows the process to proceed to step S 105 . 
     An operation by the user for determination as YES in S 204  will be described with reference to  FIG. 5 . 
     As shown in  FIG. 5 , though the user orients front camera  8  toward the user himself/herself and covers rear camera  18  with his/her hand for a period not shorter than 3 seconds and shorter than 5 seconds, the user&#39;s hand is not proximate to sensor  6 . Thus, the duration of the condition that the quantity of light in all areas in the image input from rear camera  18  is not greater than the certain value is within the first prescribed range (not shorter than 3 seconds and shorter than 5 seconds) and approach of an object (the user&#39;s hand) is not detected by proximity sensor  6 . Therefore, the process proceeds to step S 105 . 
     In step S 208 , when the duration of the condition that the quantity of light in all areas in the image input from rear camera  18  is not greater than the certain value (that is, a pixel value is not greater than the certain value) is within the first prescribed range (a period not shorter than 3 seconds and shorter than 5 seconds) and when detection of an object by proximity sensor  6  is present (S 208 : YES), control unit  20  allows the process to proceed to step S 109 . 
     An operation by the user for determination as YES in S 208  will be described with reference to  FIG. 17 . 
     As shown in  FIG. 17 , the user orients rear camera  18  toward the user himself/herself and covers rear camera  18  with his/her hand for a period not shorter than 3 seconds and shorter than 5 seconds, and the user&#39;s hand is proximate to proximity sensor  6 . Thus, the duration of the condition that the quantity of light in all areas in the image input from rear camera  18  is not greater than the certain value is within the first prescribed range (not shorter than 3 seconds and shorter than 5 seconds) and approach of an object (the user&#39;s hand) is detected by proximity sensor  6 . Therefore, the process proceeds to step S 109 . 
     In step S 217 , when the duration of the condition that the quantity of light in all areas in the image input from front camera  8  is not greater than the certain value (that is, a pixel value is not greater than the certain value) is within the first prescribed range (a period not shorter than 3 seconds and shorter than 5 seconds) and when detection of an object by proximity sensor  6  is absent (S 217 : YES), control unit  20  allows the process to proceed to step S 118 . 
     An operation by the user for determination as YES in S 217  will be described with reference to  FIG. 7 . 
     As shown in  FIG. 7 , though the user orients front camera  8  toward the user himself/herself and covers front camera  8  with his/her hand for a period not shorter than 3 seconds and shorter than 5 seconds, the user&#39;s hand is not proximate to proximity sensor  6 . Thus, the duration of the condition that the quantity of light in all areas in the image input from front camera  8  is not greater than the certain value is within the first prescribed range (not shorter than 3 seconds and shorter than 5 seconds) and approach of an object (the user&#39;s hand) is not detected by proximity sensor  6 . Therefore, the process proceeds to step S 118 . 
     In S 221 , when the duration of the condition that the quantity of light in all areas in the image input from front camera  8  is not greater than the certain value (that is, a pixel value is not greater than the certain value) is within the first prescribed range (a period not shorter than 3 seconds and shorter than 5 seconds) and when detection of an object by proximity sensor  6  is present (S 221 : YES), control unit  20  allows the process to proceed to step S 122 . 
     An operation by the user for determination as YES in S 221  will be described with reference to  FIG. 14 . 
     As shown in  FIG. 14 , the user orients rear camera  18  toward the user himself/herself and covers front camera  8  with his/her hand for a period not shorter than 5 seconds and shorter than 8 seconds, and the user&#39;s hand is proximate to proximity sensor  6 . Thus, the duration of the condition that the quantity of light in all areas in the image input from front camera  8  is not greater than the certain value is within the first prescribed range (not shorter than 3 seconds and shorter than 5 seconds) and approach of an object (the user&#39;s hand) is detected by proximity sensor  6 . Therefore, the process proceeds to step S 122 . 
     As set forth above, according to the fourth embodiment, as the user changes how to wave his/her hand or finger in front of the camera set to ON or changes approach of his/her hand or finger to the proximity sensor, the camera to be set to ON can be maintained, the camera to be set to ON can be switched, or the shooting mode can be switched to the operation shooting mode. 
     Fifth Embodiment 
     Some portable terminals can generate a photograph synthesized from images input from not only one camera but also from two cameras. 
     A fifth embodiment relates to a portable terminal which can switch any of front camera  8  and rear camera  18  between a main camera and a sub camera. 
     In the fifth embodiment, control unit  20  can set one of front camera  8  and rear camera  18  as the main camera and set the other camera as the sub camera, and can have an image input from the main camera displayed in a first region (a main image area large in display region) of display  16  and have an image input from the sub camera displayed in a second region (a sub image area small in display region) of display  16 . 
     Control unit  20  can switch a camera to be set as the main camera based on an image input from the camera set as the main camera. 
       FIGS. 18 and 19  are flowcharts showing a procedure for shooting oneself and a background in the fifth embodiment. 
     Referring to  FIGS. 18 and 19 , when the user indicates in step S 301  launch of a camera application by touching a camera icon displayed on touch screen  15 , the process proceeds to step S 302 . 
     When the setting information of the camera stored in storage unit  23  indicates setting of rear camera  18  as the main camera in step S 302 , control unit  20  allows the process to proceed to step S 303 . When the setting information of the camera stored in storage unit  23  indicates setting of front camera  8  as the main camera, control unit  20  allows the process to proceed to step S 316 . 
     In step S 303 , control unit  20  can start input of an image with rear camera  18  being set as the main camera and have the input image displayed in the main image area of touch screen  15 . Control unit  20  can start input of an image with front camera  8  being set as the sub camera and have the input image displayed in the sub image area of touch screen  15 . 
     When the duration of the condition that the quantity of light in all areas in the image input from rear camera  18  is not greater than the certain value (that is, a pixel value is not greater than the certain value) is within the first prescribed range (a period not shorter than 3 seconds and shorter than 5 seconds) (S 304 : YES), control unit  20  allows the process to proceed to step S 305 . 
     An operation by the user for determination as YES in S 304  will be described with reference to  FIG. 5 . 
     As shown in  FIG. 5 , as the user orients front camera  8  toward the user himself/herself and covers rear camera  18  with his/her hand for a period not shorter than 3 seconds and shorter than 5 seconds, the duration of the condition that the quantity of light in all areas in the image input from rear camera  18  is not greater than the certain value is within the first prescribed range (not shorter than 3 seconds and shorter than 5 seconds) and the process proceeds to step S 305 . 
     In step S 305 , control unit  20  can switch the main camera from rear camera  18  to front camera  8 . Specifically, input of an image can be started with front camera  8  being set as the main camera and the input image can be displayed in the main image area of touch screen  15 . Control unit  20  can start input of the image with rear camera  18  being set as the sub camera and have the input image displayed in the sub image area of touch screen  15 . Control unit  20  can update the setting information (on camera information) such that front camera  8  is set as the main camera. 
     In step S 306 , control unit  20  can have front camera  8  execute face recognition autofocus (AF). Specifically, control unit  20  can detect a position of a face in the image input from front camera  8  and adjust focus of an optical system of front camera  8  such that the detected face is focused on. 
     In step S 307 , control unit  20  can have a still image as shown in  FIG. 6  shot with a self-timer function. Specifically, control unit  20  can have storage unit  23  store an image including an image input from rear camera  18  in a sub image area  350  and including an image input from front camera  8  in a main image area  351  after lapse of 10 seconds. 
     In step S 308 , when the duration of the condition that the quantity of light in all areas in the image input from rear camera  18  is not greater than the certain value (that is, a pixel value is not greater than the certain value) is within the second prescribed range (not shorter than 5 seconds and shorter than 8 seconds) (S 304 : NO, S 308 : YES), control unit  20  allows the process to proceed to step S 309 . 
     An operation by the user for determination as YES in S 308  will be described with reference to  FIG. 13 . 
     As shown in  FIG. 13 , as the user orients rear camera  18  toward the user himself/herself and covers rear camera  18  with his/her hand for a period not shorter than 5 seconds and shorter than 8 seconds, the duration of the condition that the quantity of light in all areas in the image input from rear camera  18  is not greater than the certain value is within the second prescribed range (not shorter than 5 seconds and shorter than 8 seconds) and the process proceeds to step S 309 . 
     In step S 309 , control unit  20  can maintain rear camera  18  as the main camera and maintain front camera  8  as the sub camera. 
     In step S 310 , control unit  20  can have rear camera  18  execute face recognition autofocus (AF). Specifically, control unit  20  can detect a position of a face in the image input from rear camera  18  and adjust focus of an optical system of rear camera  18  such that the detected face is focused on. 
     In step S 311 , control unit  20  can have a still image as shown in  FIG. 20  shot with a self-timer function. Specifically, control unit  20  can have storage unit  23  store an image including an image input from front camera  8  in sub image area  350  and including an image input from rear camera  18  in main image area  351  after lapse of 10 seconds. 
     In step S 312 , when an event that the quantity of light in all areas in the image input from rear camera  18  varies to a value not greater than the certain value and thereafter exceeds the certain value occurs twice or more within the certain time period (for example, 10 seconds) (S 304 : NO, S 308 : NO, S 312 : YES), control unit  20  allows the process to proceed to step S 313 . 
     An operation by the user for determination as YES in S 312  will be described with reference to  FIG. 5 . 
     As shown in  FIG. 5 , as the user orients front camera  8  toward the user himself/herself and performs an operation to cover rear camera  18  with his/her hand twice or more within a certain time period, an event that the quantity of light in all areas in the image input from rear camera  18  varies to a value not greater than the certain value and thereafter exceeds the certain value occurs twice or more within a certain time period, and the process proceeds to step S 313 . 
     In step S 313 , control unit  20  can switch the main camera from rear camera  18  to front camera  8 . Specifically, input of an image can be started with front camera  8  being set as the main camera and the input image can be displayed in the main image area of touch screen  15 . Control unit  20  can start input of the image with rear camera  18  being set as the sub camera and have the input image displayed in the sub image area of touch screen  15 . Control unit  20  can update the setting information (on camera information) such that front camera  8  is set as the main camera and switch the shooting mode to the moving image shooting mode. 
     In step S 314 , control unit  20  can have front camera  8  execute face recognition autofocus (AF). Specifically, control unit  20  can detect a position of a face in the image input from front camera  8  and adjust focus of an optical system of front camera  8  such that the detected face is focused on. 
     In step S 315 , control unit  20  can have moving images shot with a self-timer function. Specifically, control unit  20  can have storage unit  23  store moving images including an image input from rear camera  18  in the sub image area and including an image input from front camera  8  in the main image area after lapse of 10 seconds. 
     In step S 316 , control unit  20  can start input of an image with front camera  8  being set as the main camera and have the input image displayed in the main image area of touch screen  15 . Control unit  20  can start input of an image with rear camera  18  being set as the sub camera and have the input image displayed in the sub image area of touch screen  15 . 
     In step S 317 , when the duration of the condition that the quantity of light in all areas in the image input from front camera  8  is not greater than the certain value (that is, a pixel value is not greater than the certain value) is within the first prescribed range (a period not shorter than 3 seconds and shorter than 5 seconds) (S 317 : YES), control unit  20  allows the process to proceed to step S 318 . 
     An operation by the user for determination as YES in S 317  will be described with reference to  FIG. 7 . 
     As shown in  FIG. 7 , as the user orients front camera  8  toward the user himself/herself and covers front camera  8  with his/her hand for a period not shorter than 3 seconds and shorter than 5 seconds, the duration of the condition that the quantity of light in all areas in the image input from front camera  8  is not greater than the certain value is within the first prescribed range (not shorter than 3 seconds and shorter than 5 seconds) and the process proceeds to step S 318 . 
     In step S 318 , control unit  20  can maintain front camera  8  as the main camera and maintain rear camera  18  as the sub camera. 
     In step S 319 , control unit  20  can have front camera  8  execute face recognition autofocus (AF). Specifically, control unit  20  can detect a position of a face in the image input from front camera  8  and adjust focus of an optical system of front camera  8  such that the detected face is focused on. 
     In step S 320 , control unit  20  can have a still image as shown in  FIG. 20  shot with a self-timer function. Specifically, control unit  20  can have storage unit  23  store an image including an image input from rear camera  18  in sub image area  350  and including an image input from front camera  8  in main image area  351  after lapse of 10 seconds. 
     In step S 321 , when the duration of the condition that the quantity of light in all areas in the image input from front camera  8  is not greater than the certain value (that is, a pixel value is not greater than the certain value) is within the second prescribed range (not shorter than 5 seconds and shorter than 8 seconds) (S 317 : NO, S 321 : YES), control unit  20  allows the process to proceed to step S 322 . 
     An operation by the user for determination as YES in S 321  will be described with reference to  FIG. 14 . 
     As shown in  FIG. 14 , as the user orients rear camera  18  toward the user himself/herself and covers front camera  8  with his/her hand for a period not shorter than 5 seconds and shorter than 8 seconds, the duration of the condition that the quantity of light in all areas in the image input from front camera  8  is not greater than the certain value is within the second prescribed range (not shorter than 5 seconds and shorter than 8 seconds) and the process proceeds to step S 322 . 
     In step S 322 , control unit  20  can switch the main camera from front camera  8  to rear camera  18 . Specifically, control unit  20  can start input of an image with rear camera  18  being set as the main camera and have the input image displayed in the main image area of touch screen  15 . Control unit  20  can start input of an image with front camera  8  being set as the sub camera and have the input image displayed in the sub image area of touch screen  15 . Control unit  20  can update the setting information (on camera information) such that rear camera  18  is set as the main camera. 
     In step S 323 , control unit  20  can have rear camera  18  execute face recognition autofocus (AF). Specifically, control unit  20  can detect a position of a face in the image input from rear camera  18  and adjust focus of an optical system of rear camera  18  such that the detected face is focused on. 
     In step S 324 , control unit  20  can have a still image as shown in  FIG. 20  shot with a self-timer function. Specifically, control unit  20  can have storage unit  23  store an image including an image input from front camera  8  in sub image area  350  and including an image input from rear camera  18  in main image area  351  after lapse of 10 seconds. 
     In step S 325 , when an event that the quantity of light in all areas in the image input from front camera  8  varies to a value not greater than the certain value and thereafter exceeds the certain value occurs twice or more within the certain time period (for example, 10 seconds) (S 317 : NO, S 321 : NO, S 325 : YES), control unit  20  allows the process to proceed to step S 326 . 
     An operation by the user for determination as YES in S 325  will be described with reference to  FIG. 7 . 
     As shown in  FIG. 7 , as the user orients front camera  8  toward the user himself/herself and performs an operation to cover front camera  8  with his/her hand twice or more within a prescribed time period, an event that the quantity of light in all areas in the image input from front camera  8  varies to a value not greater than the certain value and thereafter exceeds the certain value occurs twice or more within the certain time period, and the process proceeds to step S 326 . 
     In step S 326 , control unit  20  can maintain front camera  8  as the main camera and rear camera  18  as the sub camera and switch the shooting mode to the moving image shooting mode. 
     In step S 327 , control unit  20  can have front camera  8  execute face recognition autofocus (AF). Specifically, control unit  20  can detect a position of a face in the image input from front camera  8  and adjust focus of an optical system of front camera  8  such that the detected face is focused on. 
     In step S 328 , control unit  20  can have moving images shot with a self-timer function. Specifically, control unit  20  can have storage unit  23  store moving images including an image input from rear camera  18  in the sub image area and including an image input from front camera  8  in the main image area after lapse of 10 seconds. 
     As set forth above, according to the fifth embodiment, as the user changes how to wave his/her hand or finger in front of the camera set to ON, the camera to be set as the main camera can be maintained, the camera to be set as the main camera can be switched, or the shooting mode can be switched to the operation shooting mode. 
     (Modification) 
     The present disclosure is not limited to the embodiments above, and for example, a modification as below is also encompassed. 
     (1) Condition for Switching of Camera 
     In steps S 104  and S 117  in  FIGS. 11 and 12  in the third embodiment and steps S 304  and S 317  in  FIGS. 18 and 19  in the fifth embodiment, a condition is such that a duration of a condition that a quantity of light in all areas in an image is not greater than a certain value is not shorter than 3 seconds and shorter than 5 seconds, and in steps S 108 , S 121 , S 308 , and S 321 , a condition is such that a duration of a condition that a quantity of light in all areas in an image is not greater than a certain value is not shorter than 5 seconds and shorter than 8 seconds. Such a condition, however, may be reversed. Specifically, in steps S 104 , S 117 , S 304 , and S 317  in  FIGS. 11 and 12 , a condition may be such that a duration of a condition that a quantity of light in all areas in an image is not greater than a certain value is not shorter than 5 seconds and shorter than 8 seconds, and in steps S 108 , S 121 , S 308 , and S 321 , a condition may be such that a duration of a condition that a quantity of light in all areas in an image is not greater than a certain value is not shorter than 3 seconds and shorter than 5 seconds. 
     In steps S 204  and S 217  in  FIGS. 15 and 16  in the fourth embodiment, a condition is such that a duration of a condition that a quantity of light in all areas in an image is not greater than a certain value is not shorter than 3 seconds and shorter than 5 seconds and detection of proximity of an object by a proximity sensor is absent, and in steps S 208  and S 221 , a condition is such that a quantity of light in all areas in an image is not greater than a certain value is not shorter than 3 seconds and shorter than 5 seconds and detection of proximity of an object by a proximity sensor is present. Such a condition, however, may be reversed. Specifically, in steps S 204  and S 217  in  FIGS. 15 and 16 , a condition may be such that a duration of a condition that a quantity of light in all areas in an image is not greater than a certain value is not shorter than 3 seconds and shorter than 5 seconds and detection of proximity of an object by a proximity sensor is present, and in steps S 208  and S 221 , a condition may be such that a duration of a condition that a quantity of light in all areas in an image is not greater than a certain value is not shorter than 3 seconds and shorter than 5 seconds and detection of proximity of an object by a proximity sensor is absent. 
     (2) Moving Image Shooting Mode 
     In steps S 112  and  125  in  FIGS. 11 and 12  in the third embodiment and  FIGS. 15 and 16  and in steps S 312  and S 325  in  FIGS. 18 and 19 , a condition is such that an event that a quantity of light in all areas in an image input from a camera set to ON or as a main camera varies to a value not greater than a certain value and thereafter exceeds the certain value occurs twice or more within a certain time period (for example, 10 seconds), however, limitation thereto is not intended. Instead of twice, N times (N being a natural number not smaller than 3) may be set as the condition. 
     (3) Switching of Main Camera 
     In steps S 304  and S 317  in  FIGS. 18 and 19  in the fifth embodiment, a condition is such that a duration of a condition that a quantity of light in all areas in an image is not greater than a certain value is not shorter than 3 seconds and shorter than 5 seconds, and in steps S 308  and S 321 , a condition is such that a duration of a condition that a quantity of light in all areas in an image is not greater than a certain value is not shorter than 5 seconds and shorter than 8 seconds. Limitation thereto, however, is not intended. 
     In steps S 304  and S 317 , a condition may be such that a quantity of light in all areas in an image is not greater than a certain value is not shorter than 3 seconds and shorter than 5 seconds and proximity of an object by a proximity sensor is absent (or present), and in steps S 308  and S 321 , a condition may be such that a quantity of light in all areas in an image is not greater than a certain value is not shorter than 3 seconds and shorter than 5 seconds and proximity of an object by a proximity sensor is present (or absent). 
     (4) Gesture 
     In the third to fifth embodiment, the control unit switches a camera to be set to ON or a camera to be set as main or switches the shooting mode to the moving image shooting mode based on whether or not a condition that a quantity of light in all areas in an image is not greater than a certain value continues or based on the number of times of continuance of such a condition, however, limitation thereto is not intended. 
     In the third to fifth embodiments as well, the control unit may make switching described above based on a difference in gesture by a user. For example, difference in waving a hand among lateral waving, vertical waving, and diagonal waving may be employed as the difference in gesture, or difference among waving of a thumb, waving of three fingers, and waving of five fingers may be employed as the difference in gesture. 
     (5) Main Image and Sub Image 
     In the fifth embodiment, the user orients the main camera toward the user himself/herself, so that the user himself is shot by the main camera and an image of the user himself/herself is arranged in the main image area large in display region and a background is shot by the sub camera and an image of the background is arranged in the sub image area small in display region. Limitation thereto, however, is not intended. 
     For example, as shown in  FIG. 21 , an image from the sub camera may be arranged in the main image area and an image from the main camera may be arranged in the sub image area. 
     Alternatively, the sub camera may be oriented to the user himself/herself, so that the background is shot by the main camera and an image of the background is arranged in the main image area and the user himself/herself is shot by the sub camera and an image of the user himself/herself is arranged in the sub image area as shown in  FIG. 21 . 
     (6) Switching Only Based on Result of Detection by Proximity Sensor without Using Image 
     In the embodiments above, a camera to be set to ON or a camera to be set as the main camera is switched by detecting whether or not a user covers the camera set to ON or the camera set as the main camera by using an image from the camera or the image from the camera and a result of detection by the proximity sensor, however, limitation thereto is not intended. An image from the camera does not have to be used. 
     A portable terminal may include a proximity sensor  49  in the vicinity of front camera  8  and a proximity sensor  48  in the vicinity of rear camera  18  (see  FIGS. 22 and 23 ) and the control unit may switch a camera to be set to ON or a camera to be set as the main camera based on whether or not proximity sensor  49  or  48  detects covering by the user of the camera set to ON or the camera set as the main camera. 
     It should be understood that the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present disclosure is defined by the terms of the claims and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.