Patent Publication Number: US-2017357473-A1

Title: Mobile device with touch screens and method of controlling the same

Description:
PRIORITY 
     This application claims priority under 35 U.S.C. §119(a) to Korean Patent Application No. 10-2016-0071267, which was filed in the Korean Intellectual Property Office on Jun. 8, 2016, the entire disclosure of which is incorporated herein by reference. 
     BACKGROUND 
     1. Field of the Disclosure 
     The present disclosure relates generally to a mobile device including multiple touch screens, and more particularly, to a mobile device including multiple touch screens, which is capable of detecting, when the touch screens are opened with respect to each other, a touch applied to a rear touch screen whose image-display area is turned off. 
     2. Description of Related Art 
     In recent years, mobile devices have been developed to include multiple touch screens. 
     However, mobile devices including multiple touch screens consume more power than a single screen mobile device. 
     SUMMARY 
     Accordingly, the present disclosure is designed to address at least the problems and/or disadvantages described above and to provide at least the advantages described below. 
     Accordingly, an aspect of the present disclosure is to provide a mobile device including multiple touch screens, which detects, when the touch screens are opened with respect to each other, a touch applied to a rear touch screen whose image-display area is turned off, and a control method thereof. 
     In accordance with an aspect of the present disclosure, a method is provided for controlling a mobile device including multiple touch screens. The method includes calculating an angle between a first housing including a first touch screen and a second housing including a second touch screen, the second housing being rotatably connected to the first housing; and if the calculated angle is greater than a threshold, turning off an image-display area of the second touch screen, executing an application in response to a first touch applied to an icon displayed on the first touch screen, detecting a second touch in a touch detectable area of the turned-off image-display area of the second touch screen, and controlling the application in response to the detected second touch. 
     In accordance with another aspect of the present disclosure, a mobile device including multiple touch screens is provided. The mobile device includes a first housing including a first touch screen; a second housing, rotatably connected to the first housing, including a second touch screen; a sensor for detecting an angle between the first housing and the second housing; and a controller configured to calculate the angle between the first and second housings rotating with respect to each other, using the sensor, and if the calculated angle is greater than a threshold, turn off an image-display area of the second touch screen, execute an application in response to a first touch applied to an icon displayed on the first touch screen, detect a second touch in a touch detectable area of the turned-off image-display area of the second touch screen, and control the application in response to the detected second touch. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects, features, and advantages of certain embodiments of the disclosure will be more apparent from the following detailed description, taken in conjunction with the accompanying drawings, in which: 
         FIGS. 1A to 1D  are views illustrating a mobile device according to an embodiment of the present disclosure; 
         FIGS. 2A and 2B  are schematic block diagrams of mobile devices according to embodiments of the present disclosure; 
         FIG. 3  is a flowchart illustrating a method of controlling a mobile device according to an embodiment of the present disclosure; 
         FIGS. 4A to 4E  illustrate a method of controlling a mobile device according to an embodiment of the present disclosure; 
         FIGS. 5A and 5B  illustrate a method of controlling a mobile device according to an embodiment of the present disclosure; 
         FIGS. 6A and 6B  illustrate a method of controlling a mobile device according to an embodiment of the present disclosure; 
         FIGS. 7A and 7B  are illustrate a method of controlling a mobile device according to an embodiment of the present disclosure; and 
         FIGS. 8A and 8B  illustrate a method of controlling a mobile device according to an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS OF THE DISCLOSURE 
     The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the present disclosure as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the various embodiments described herein can be made without departing from the scope and spirit of the present disclosure. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness. 
     The same reference numbers are used throughout the drawings to refer to the same or similar parts. 
     The terms and words used in the following description and claims are not limited to the bibliographical meanings, but are used by the inventor to provide a clear and consistent understanding of the present disclosure. Accordingly, those skilled in the art will understand that the following description of various embodiments of the present disclosure is provided for illustration purpose only and not for the purpose of limiting the present disclosure as defined by the appended claims and their equivalents. 
     Singular forms are intended to include plural forms unless the context clearly indicates otherwise. 
     The expressions, such as “include”, “have”, and “may include”, denote the presence of the disclosed characteristics, numbers, components, functions, operations, constituent elements, or a combination thereof, but do not exclude the existence of or a possibility of addition of one or more other characteristics, numbers, components, functions, operations, and constituent elements. 
     Furthermore, the expression “and/or” includes any and all combinations of the associated listed words. For example, the expression “A and/or B” may include A, may include B, or may include both A and B. 
     The term “application” refers to an application program, app, or application software, which runs on Operating Systems (OS) for computers or mobile devices and are used by users. Examples of an application include a web browser, a camera application, a mobile payment application (or electronic payment application, payment application, etc.), a photo album application, a word processor, a spreadsheet, a contacts application, a calendar application, a memo application, an alarm application, a Social Network System (SNS) application, a call application, a game store, a game application, a chat application, a map application, a music player, a video player, etc. 
     The term “application also refers to an application program, app, or application software that runs on a mobile device or an external device (e.g., a wearable device, a server, etc.) connected to mobile devices in wireless or wired mode. 
     The term “content” refers to data, information, etc., which is executed or displayed on the screen as a corresponding application runs. Examples of content include a video file or an audio file that is played back by a video player as an application, a game file that is executed by a game application, a music file played back by a music player, a photo file displayed by a photo album application, a web file displayed by a web browser, payment information (e.g., a mobile card number, loan payment, a brand name, a service name, a store name, etc.) displayed by an electronic payment application, a call screen displayed by a call application, etc. For example, a call screen may be configured to include a caller phone number or caller identifier (ID), a caller name, a call start time, a caller video (or caller image) by a video call, etc. 
     Content may also include an executed application screen and a user interface configuring an application screen. Content may also include one or more pieces of content. 
     The term “widget” refers to a mini application or as a Graphic User Interface (GUI), which is capable of supporting the interaction between a user and an application/OS. Examples of a widget include a weather widget, a calculator widget, a clock widget, etc. 
     The expression “user input” refers to a user button (or key) selection, a user button (or key) press, a user button (or key) touch, a user touch or touch gesture applied to (detected via a touch screen), etc. Examples of a user touch or touch gesture are a non-contact gesture such as a hovering action, a voice command, a user&#39;s presence, a user&#39;s motion. A user&#39;s presence refers to the presence of a user within a range of camera recognition. 
       FIGS. 1A to 1D  are views illustrating a mobile device according to an embodiment of the present disclosure. 
     Referring to  FIG. 1A , the mobile device  100  includes a first housing  100   a  and a second housing  100   b , which are connected to each other, side-by-side, by hinges  100   c   1  and  100   c   2  or a flexible plastic (e.g., a flexible printed circuit board (PCB)). The first housing  100   a  and the second housing  100   b  may change locations with each other. A structure or a support for connecting the first housing  100   a  and the second housing  100   b  is not limited to the hinges  100   c   1  and  100   c   2 , and may include various types of structures or supports for connecting the first housing  100   a  and the second housing  100   b.    
     The first housing  100   a  and the second housing  100   b  include a first touch screen  190   a  and a second touch screen  190   b , at the center part, on the front side, respectively. The first touch screen  190   a  and the second touch screen  190   b  are spaced apart from each other, at a distance (e.g., less than the thickness of the first housing  100   a ), by the hinges  100   c   1  and  100   c   2 . 
     The first touch screen  190   a  and the second touch screen  190   b  are designed in such a way that the surface is flat and the edges and corners are curved. The curved edges of the first touch screen  190   a  and the second touch screen  190   b  may make the user view the interval between the first touch screen  190   a  and the second touch screen  190   b  as if the interval is narrow. 
     The first touch screen  190   a  and the second touch screen  190   b  may change locations with each other. 
     Alternatively, the mobile device  100  may include one housing which is flexible, e.g., foldable. 
     The first housing  100   a  includes, at the top, on the front side, a first camera  151  for taking a still image or a video, a proximity sensor  171  for detecting an approach of a user or an object, an illuminance sensor  172  for detecting ambient illuminance, and a first speaker  163   a  for outputting a voice and/or sound outside the mobile device  100 . 
     The first housing  100   a  also includes a second speaker (not shown) at the bottom on the front side for outputting a voice and/or sound outside the mobile device  100 . 
     The first housing  100   a  may include one button or a number of buttons at the bottom on the front side. The buttons may be physical buttons or may be implemented with touch buttons located inside or outside the first touch screen  190   a.    
     The first housing  100   a  includes a power/lock button  161   d  and a volume button  161   e  on the side thereof. 
     The first housing  100   a  includes a microphone (not shown) and a connector (not shown), e.g., a universal serial bus (USB) connector, at the bottom on the side. 
     The second housing  100   b  may include, at the top, on the front side, a second camera for taking a still image or a video, and a third speaker for outputting a voice and/or sound outside the mobile device  100 . The second housing  100   b  may also include, at the bottom, a fourth speaker for outputting a voice and/or sound outside the mobile device  100 . 
     The second housing  100   b  may also include one button or a number of buttons at the bottom. The buttons may be physical buttons or may be implemented with touch buttons located inside or outside the second touch screen  190   b.    
     Referring to  FIG. 1B , the mobile device  100  may include a separate speaker for outputting a voice and/or sound, on a rear side of the first housing  100   a  and/or a rear side of the second housing  100   b . The mobile device  100  may also include a separate camera for taking a still image or a video, on a rear side of the first housing  100   a  and/or a rear side of the second housing  100   b.    
     The mobile device  100  may include a slot for an input pen (stylus pen) at the bottom of the rear side of the first housing  100   a  and/or at the bottom of the rear side of the second housing  100   b.    
     The mobile device  100  may be modified by replacement, addition, and removal with respect to at least one of the components, according to the performance and structure of the mobile device  100 . The components of the mobile device  100  may also vary in location according to the performance or structure of the mobile device  100 . 
     Referring to  FIG. 1C , in diagram (b), the first housing  100   a  and the second housing  100   b  of the mobile device  100  are in an open state where an angle between the first housing  100   a  and the second housing  100   b  is 360°. Referring again to  FIG. 1A , the first housing  100   a  and the second housing  100   b  of the mobile device  100  are in a spread state where an angle between the first housing  100   a  and the second housing  100   b  is 180°. 
     Herein, if one of the first housing  100   a  and the second housing  100   b  in a spread state is rotated with respect to the other, e.g., as illustrated in  FIG. 1C , they are referred to as being in an open state. 
     The first housing  100   a  and the second housing  100   b  may be rotated with respect to each other (for example, opened from or closed to) by hinges  100   c   1  and  100   c   2  or a flexible PCB within a range of 0° to 360°. 
     Referring again to diagram (b) of  FIG. 1C , when the first housing  100   a  and the second housing  100   b  are in an open state, the rear sides of the first housing  100   a  and the second housing  100   b  are in parallel or face each other (e.g., the angle between the rear sides of the first housing  100   a  and the second housing  100   b  is less than or equal to 4°). The rear sides of the first housing  100   a  and the second housing  100   b  may contact each other or may be spaced apart from each other at a preset interval (e.g., 3 mm or less than 3 mm). 
     The hinges  100   c   1  and  100   c   2  are located at both ends of the first housing  100   a  and the second housing  100   b , spaced apart from each other at an interval d 1 . The interval d 1  between the hinge  100   c   1  and  100   c   2  may be greater than the height (length) h of the first touch screen  190   a . The interval d 1  between the hinge  100   c   1  and  100   c   2  may be greater than the width w of the first touch screen  190   a.    
     Although the heights of the first touch screen  190   a  and the height of the second touch screen  190   b  are less than the interval d 1  in  FIG. 1C , the present disclosure is not limited thereto. Alternatively, the heights of the first touch screen  190   a  and the height of the second touch screen  190   b  may be greater than the interval d 1 . 
     Referring to  FIG. 1D , the first housing  100   a  and the second housing  100   b  of the mobile device  100  are folded into a closed state, where the angle between the first housing  100   a  and the second housing  100   b  is 0°, 0°±3° or less than ±3°). 
     In diagram (a) of  FIG. 1D , at least one of the first housing  100   a  and the second housing  100   b  in a spread state is rotated with respect to the other housing into a closed state, as illustrated in diagram (b) of  FIG. 1D . 
     The first housing  100   a  and/or the second housing  100   b  may be closed with respect to each other by the hinges  100   c   1  and  100   c   2  or a flexible PCB located between the first housing  100   a  and the second housing  100   b.    
     When the first housing  100   a  and the second housing  100   b  are in a closed state, the front sides of the first housing  100   a  and the second housing  100   b  are in parallel or face each other (e.g., the angle between the rear sides of the first housing  100   a  and the second housing  100   b  is less than or equal to 4°). The front sides of the first housing  100   a  and the second housing  100   b  may contact each other or may be spaced apart from each other at a preset interval (e.g., 3 mm or less than 3 mm). 
     Although the embodiments of the present disclosure are illustrated such that the touch screens are shaped as rectangles, the present disclosure is not limited thereto. For example, the touch screens may vary in shape and/or arrangement. 
     Alternatively, unlike the embodiment illustrated in  FIG. 1A , the first housing  100   a  and the second housing  100   b  may be connected by one hinge. For example, the one hinge may be located between a side edge of the first touch screen  190   a  of the first housing  100   a  and a side edge of the second touch screen  190   b  of the second housing  100   b.    
     As yet another alternative, the first housing  100   a  and the second housing  100   b  may be connected by three or more hinges. 
       FIG. 2A  illustrates a mobile device according to an embodiment of the present disclosure. 
     Referring to  FIG. 2A , the mobile device  100  includes a controller  110 , the mobile communication unit  120 , the sub-communication unit  130 , a multimedia unit  140 , a camera  150 , a positioning information receiver  155 , an input/output unit  160 , a connector  165 , a sensor unit  170 , a storage unit  175 , a power supply  180 , a first touch screen  190   a , a second touch screen  190   b , and a touch screen controller  195 . 
     The mobile device  100  is capable of functionally connecting to another device (e.g., another mobile device, a server, etc.) via at least one of the mobile communication unit  120 , the sub-communication unit  130 , and the connector  165 . 
     The mobile device  100  is capable of transmitting/receiving data to/from outside, using the first touch screen  190   a  and the second touch screen  190   b , via the communication unit  120  or the sub-communication unit  130 . The mobile device  100  is capable of transmitting/receiving data to/from outside, using a stylus pen  167 , the first touch screen  190   a  and the second touch screen  190   b , via the communication unit  120  or the sub-communication unit  130 . 
     The mobile device  100  is capable of transmitting/receiving data to/from outside, according to a user input (e.g., touch, etc.) applied to the first touch screen  190   a  and the second touch screen  190   b , via the communication unit  120  or the sub-communication unit  130 . 
     The controller  110  includes a processor  111 , a read only memory (ROM)  112 , and a random access memory (RAM)  113 . The ROM  112  stores a control program for controlling the mobile device  100 , and the RAM  113  stores data or signals received from the outside of the mobile device  100  or for serving as a space for storing tasks/jobs executed in the mobile device  100 . 
     The controller  110  controls all the operations of the mobile device  100  and the signals flowing among components  120  to  195  in the mobile device  100 , and processes data. The controller  110  controls the power supply  180  to supply power to the components  120  to  195 . 
     The controller  110  is capable of controlling the mobile communication unit  120 , the sub-communication unit  130 , the multimedia unit  140 , the camera  150 , the positioning information receiver  155 , the input/output unit  160 , the sensor unit  170 , the storage unit  175 , the power supply  180 , the first touch screen  190   a , the second touch screen  190   b  and the touch screen controller  195 . 
     The processor  111  may also include a graphic processing unit (GPU) for processing graphic data, a sensor processor for controlling sensors, and/or a communication processor for controlling communication. 
     The processor  111  may be implemented as a system on chip (SoC) including a core (and a GPU. The processor  111  may include a single core, a dual core, a triple core, a quad core, or a multi-core. 
     The processor  111 , the ROM  112 , and the RAM  113  are connected to each other via bus. The mobile communication unit  120  connects the mobile device  100  to other devices (e.g., another mobile device, a server, etc.), via a mobile communication network, using one or more antennas, under the control of the controller  110 . 
     The sub-communication unit  130  is connects the mobile device  100  to other devices (e.g., another mobile device, a server, etc.), via a wireless local area network (WLAN) communication unit  131  and/or a short-range communication unit  132 , using one or more antennas, under the control of the controller  110 . The sub-communication unit  130  may include an antenna for WLAN, an antenna for magnetic secure transmission (MST) for electronic payment, and/or an antenna for near field communication (NFC). 
     A WLAN communication unit  131  wirelessly connects the mobile device  100  to an access point (AP) under the control of the controller  110 . The WLAN communication unit  131  may support Wi-Fi communication. 
     Examples of the short-range communication provided by the short-range communication unit  132  may include Bluetooth communication, Bluetooth low energy (BLE) communication, infrared data association (IrDA) communication, ultra-wideband (UWB) communication, MST communication, NFC communication, etc. 
     The multimedia unit  140  performs audio playback, video playback, and/or broadcast playback, under the control of the controller  110 . 
     The audio playback unit  141  may play back an audio source (e.g., audio files whose file extensions have mp3, wma, ogg or way), stored in the storage unit  175  or received from outside, using an audio codec, under the control of the controller  110 . 
     The audio playback unit  141  may play back auditory feedback, in response to commands and/or inputs received in the mobile device  100 . 
     The video playback unit  142  may play back a digital video source (e.g., video files whose file extensions have mpeg, mpg, mp4, avi, mov, or mkv), stored in the storage unit  175  or received from outside, using a video codec, under the control of the controller  110 . 
     The video playback unit  142  may play back visual feedback, in response to commands and/or inputs received in the mobile device  100 . 
     The broadcast communication unit  143  receives a broadcast signal (e.g., a television (TV) broadcast signal, a radio broadcast signal, or a data broadcast signal), and broadcast additional information (e.g., electronic program guide (EPG) or electronic service guide (ESG), broadcast from a broadcasting station, via an antenna, under the control of the controller  110 . 
     Alternatively, the multimedia unit  140  may omit certain units, e.g., the broadcast communication unit  143 , according to the performance or the structure of the mobile device  100 . Additionally, the controller  110  may include the audio playback unit  141  and/or the video playback unit  142  of the multimedia unit  140 . 
     The camera  150  takes still images and/or videos, under the control of the controller  110 . The camera  150  includes a first camera  151  located on the front side of the first housing  190   a . The camera  150  may also include a second camera on the second housing  190   b . The first camera  151  and/or the second camera may include an auxiliary light source (e.g. a flashlight  153 ) for providing an amount of light corresponding to the illumination of scenes to be photographed. 
     The camera  150  may also include an additional camera (e.g., a third camera) adjacent to the first camera  151  (e.g., where the interval between the two optical axes is greater than 5 mm and less than 80 mm). The camera  150  may also include the first camera  151  and a third camera integrally formed into a single unit. The controller  110  may take 3-dimensional (3D) still images and/or videos, using the first camera  151  and the third camera. 
     The camera  150  may also include a second camera located on the front side of the first housing  190   a  and a fourth camera adjacent to the second camera (e.g., where the interval between the two optical axes is greater than 5 mm and less than 80 mm). The second camera and the fourth camera may be integrally formed into a single unit. The controller  110  may take 3D still images and/or videos using the second and the fourth cameras. 
     The camera  150  may perform wide-angle photography, telephotography, and/or macrophotography, using an additional lens that is detachably coupled to the mobile device  100 , e.g., using a separate adaptor. 
     The positioning information receiver  155  periodically receives signals (e.g., global positioning system (GPS) satellite orbital information, GPS satellite time information, a navigation message, etc.). 
     In an indoor environment, the mobile device  100  may obtain its location or moving velocity using a wireless AP, e.g., using a cell-ID method, an enhanced cell-ID method, or an angle of arrival (AoA) method. In an indoor environment, the mobile device  100  is also capable of obtaining its location or moving velocity, using a wireless beacon. 
     The input/output unit  160  includes a button  161 , a microphone  162 , a speaker  163 , a vibration motor  164 , a connector  165 , a keypad  166 , and a stylus pen  167 . 
     The button  161  may include the power/lock button  161   e  and the volume buttons  161   d  located on the side of the mobile device  100  illustrated in  FIG. 1A . The button  161  may include physical buttons located at the bottom on the front side of the mobile device  100  (or touch buttons displayed on the touch screens  190   a  and/or  190   b , in a form of text, image, and/or icon), such as a home button, a recently executed app button, and/or a return button. 
     The controller  110  receives an electrical signal from the button  161  according to a user input. The controller  110  detects a user input using the received signal (e.g., a signal created by pressing the button  161 , a signal by contacting the button  161 ). 
     The form, location, function, name, etc., of the buttons described herein are only examples for the description of the present disclosure, and the present disclosure is not limited thereto. 
     The microphone  162  receives a voice or sound from the outside, and creates electrical signals, under the control of the controller  110 . The audio codec converts the electrical signals of the microphone  162  to audio signals and stores/outputs the converted signals in the storage unit  175 /to the speaker  163 , under the control of the controller  110 . 
     The microphones  162  may be installed at the front side, lateral side, and/or rear side of the first housing  190   a  and/or the second housing  190   b  of the mobile device  100 . 
     The speaker  163  outputs sound corresponding to various signals (e.g., a wireless signal, a broadcast signal, audio source, video file, photographing, etc.) decoded by an audio codec, under the control of the controller  110 . 
     A number of speakers  163  may be installed at the front side, lateral side, and/or rear side of the mobile device  100 . 
     The speaker  163  may play back auditory feedback, in response to the reception of commands and/or user inputs in the mobile device  100 . 
     The vibration motor  164  converts an electrical signal to a mechanical vibration, under the control of the controller  110 . The vibration motor  164  may be implemented with a linear vibration motor, a bar type vibration motor, a coin type vibration motor, or a piezoelectric element vibration motor. 
     One or more vibration motors  164  may be installed in the first housing  100   a  or the second housing  100   b  of the mobile device  100 . 
     The vibration motor  164  may output tactile feedback, in response to the reception of commands and/or user inputs in the mobile device  100 . The vibration motor  164  is capable of providing various types of tactile feedback (e.g., the intensity of vibration intensity, the duration of vibration), which are stored in the storage unit or received from the outside, based on a control instruction of the controller  110 . 
     The connector  165  serves as an interface connecting the mobile device  100  and an external device or a power source, e.g., charger. The connector  165  may include a micro USB type connector or a USB-C type connector. 
     The mobile device  100  may also transmit data (e.g., content) stored in the storage unit  175  to the outside or receiving data from the outside, via a cable connected to the connector  165 , under the control of the controller  110 . The mobile device  100  may receive power from a power source and/or charge the battery  185  via a cable connected to the connector  165 , under the control of the controller  110 . 
     The keypad  166  receives user inputs for controlling the mobile device  100 . The keypad  166  may include a virtual keypad displayed on the first touch screen  190   a  and/or the second touch screen  190   b  or a physical keypad installed at the front side of the mobile device  100 . The keypad  166  may further include a separate keypad that is connected to the mobile device in wired mode or wireless mode (e.g., short-range communication). 
     The input pen (stylus pen)  167  is designed to be pushed into/pulled out of the first housing  100   a  or the second housing  100   b  of the mobile device  100 . The stylus pen  167  may be used by the user to select (or touch) an object and/or content configuring a screen of a handwriting/drawing application displayed on the touch screen  190   a  or  190   b  of the mobile device  100 ; or perform handwriting, drawing, painting and/or sketching, on the screen. Examples of a screen are a memo screen, notepad screen, calendar screen, etc. Examples of an object are a menu, text, image (or electronic card, etc.), video, diagram, icon and shortcut icon. Examples of content are a text file, image file, audio file, video file, payment information or web page. 
     The sensor unit  170  may detect states of the mobile device  100  and/or the ambient states of the mobile device  100 . The sensor unit  170  includes one or more sensors. The sensor unit  170  includes a proximity sensor  171  for detecting whether a user approaches the mobile device  100 ; an illuminance sensor  172  for detecting the intensity of the ambient light of the mobile device  100 ; a finger-print sensor  173  for scanning a user&#39;s fingerprint; and an angle sensor  174  for detecting an angle between the first housing  190   a  and the second housing  190   b.    
     The proximity sensor  171  and the illuminance sensor  172  may be installed to the front side of the first housing  190   a  and/or the front side of the second housing  190   b.    
     The fingerprint sensor  173  may be located at a physical button located on the front side of the first housing  190   a  or the second housing  190   b , or a separate physical button located at the rear side of the first housing  190   a  or the second housing  190   b . The fingerprint sensor  173  may also scan a user&#39;s fingerprint via part of the first touch screen  190   a  of the mobile device  100  (e.g., an area adjacent to a home button) and part of the second touch screen  190   b  (e.g., an area adjacent to a home button). 
     The angle sensor  174  (or a tilt sensor, etc.) is located at the hinges  100   c   1  and  100   c   2  of the mobile device  100  and detects a signal (e.g., current, voltage, resistance, etc.) corresponding to an angle between the first housing  100   a  and the second housing  100   b . Alternatively, the angle sensor  174  is located at the first housing  100   a  or the second housing  100   b  of the mobile device  100  and detects a signal corresponding to an angle between the first housing  100   a  and the second housing  100   b . Alternatively, the angle sensor  174  is located at the flexible PCB of the mobile device  100  and detects a signal corresponding to an angle between the first housing  100   a  and the second housing  100   b . The angle sensor  174  converts the detected signal into an electrical signal and transfers the converted signal to the controller  110 . The controller  110  calculates an angle of 0° to 360°, based on the converted signal from the angle sensor  174 . 
     The angle sensor  174  may be implemented with a terrestrial magnetism sensor or a gyro sensor. The angle sensor  174  may include a hinge type angle sensor rotating by an angle between the first housing  100   a  and the second housing  100   b.    
     If the first touch screen  190   a  and the second touch screen  190   b  are installed in one flexible housing, the controller  110  may calculate an angle between the first touch screen  190   a  and the second touch screen  190   b , using the angle sensor  174 . If the mobile device is implemented with multiple flexible housings, the controller  110  may calculate an angle between the flexible housings, using a bending sensor or a pressure sensor. 
     The sensor unit  170  may further include an acceleration sensor, a gyro sensor, a gravity sensor, an altimeter, a biometric signal sensor (e.g., a heart-rate sensor), etc. 
     The sensors included in the sensor unit  170  detect states of the mobile device  100  and the user, create electrical signals corresponding to the detected results, and transfer the created signals to the controller  110 . The sensor unit  170  may be modified through addition, alteration, replacement, or removal of sensors, according to the performance of the mobile device  100 . 
     The storage unit  175  may store signals or data corresponding to operations of the communication unit  120 , the sub-communication unit  130 , the multimedia unit  140 , the camera  150 , the positioning information receiver  155 , the input/output unit  160 , the sensor unit  170 , and the touch screens  190   a  and  190   b , under the control of the controller  110 . The storage unit  175  is also capable of storing control programs related to the control of the mobile device  100  or the controller  110 , GUIs related to applications provided by mobile device manufactures or downloaded from the outside, images corresponding to the GUIs, user information, documents, databases, data related thereto, etc. 
     The storage unit  175  may store visual feedback (e.g., a video source, etc.), output in response to received commands and/or inputs, so that the user can recognize the visual feedback; auditory feedback (e.g., a sound source, etc.) output via the speaker  163  so that the user can recognize the auditory feedback; and tactile feedback (e.g., a haptic pattern, etc.), output via a vibration motor  164  so that the user can recognize the tactile feedback. 
     The storage unit  175  may store a duration for providing the feedback to a user (e.g., 500 ms). 
     The storage unit  175  may include a memory card (e.g., a micro SD card, memory stick, etc.), a non-volatile memory, a volatile memory, a hard disk drive (HDD), a solid state drive (SSD), etc. 
     The power supply  180  supplies power to the components  110  to  195  of the mobile device  100 , under the control of the controller  110 . The power supply  180  may receive power from an external power source via a cable connected to the connector  165 , and supply power to components of the mobile device  100 , under the control of the controller  110 . 
     The power supply  180  may charge one or more batteries  185 , under the control of the controller  110 . 
     The power supply  180  may supply power from the battery  185  to an accessory via a cable. Alternatively, the power supply  180  may wirelessly charge other devices (e.g., another mobile device or an accessory), via a transmission coil connected to the battery  185 , under the control of the controller  110 . Examples of the wireless charging are magnetic resonance charging, electromagnetic charging, and magnetic induction charging. 
     The first and second touch screens  190   a  and  190   b  are capable of providing a user with GUIs corresponding to various services (e.g., voice call, video call, data transmission, broadcast reception, photographing, video viewing, electronic payment, mobile payment, etc.). The first and second touch screens  190   a  and  190   b  each include a display panel for showing screens and a touch panel receiving user inputs (e.g., touches, etc.). Alternatively, the first and second touch screens  190   a  and  190   b  each include an edge display panel for showing screens and an edge touch panel receiving user inputs (e.g., touches, etc.). 
     The first and second touch screens  190   a  and  190   b  may transfer analog signals corresponding to a single touch or multi-touches, received via GUIs or a home screen, to the touch screen controller  195 . The first and second touch screens  190   a  and  190   b  may receive a single touch or multi-touches, via part of a user&#39;s body (e.g., fingers) or the stylus pen  167 . 
     The first touch screen  190   a  may output visual feedback in response to reception on a command and/or input via the second touch screen  190   b.    
     The touch screen controller  195  converts analog signals, corresponding to a single touch or multi-touches applied to the first and second touch screens  190   a  and  190   b , into digital signals, and transfers the converted signals to the controller  110 . The controller  110  calculates X- and Y-coordinates of each of the touch locations on the first and second touch screens  190   a  and  190   b , using the digital signals output from the touch screen controller  195 . 
     The controller  110  may control the first and second touch screens  190   a  and  190   b , using the digital signals output from the touch screen controller  195 . For example, the controller  110  may distinguished a touched a shortcut icon displayed on the first and second touch screens  190   a  and  190   b , from another displayed shortcut icon, or may execute an application (e.g., a game application) corresponding to a selected shortcut icon and display the application screen (i.e., the game application screen) on the first and second touch screens  190   a  and  190   b.    
     The mobile device  100  illustrated in  FIGS. 1A to 1D  and  FIG. 2A  may be modified through addition, alteration, replacement, or removal of components, according to the performance of the mobile device  100 . 
       FIG. 2B  illustrates a mobile device according to an embodiment of the present disclosure. Specifically, the mobile device illustrated in  FIG. 2B  is configured in the same way as the mobile device illustrated in  FIG. 2A , except that each touch screen includes its own touch screen controller and controller. Accordingly, instead of a controller  110  and a touch screen controller  195 , the mobile device illustrated in  FIG. 2B  includes a first controller  110   a , a second controller  110   b , a first touch screen controller  195   a , and a second touch screen controller  195   b . A detailed description regarding the same components illustrated in  FIG. 2A  will be omitted below. 
     Referring to  FIG. 2B , the first controller  110   a  includes a first processor  111   a , a first ROM  112   a  for storing a control program for controlling the mobile device  100 , and a first RAM  113   a  for storing data or signals received from the outside of the mobile device  100  or serving as a space for storing jobs/tasks executed in the mobile device  100 . 
     The first controller  110   a  may control the mobile communication unit  120 , the sub-communication unit  130 , the multimedia unit  140 , the camera  150 , the positioning information receiver  155 , the input/output unit  160 , the sensor unit  170 , the storage unit  175 , the power supply  180 , the first touch screen  190   a , and the first touch screen controller  195   a.    
     The first touch screen controller  195   a  converts analog signals corresponding to one or more touches applied to the first touch screen  190   a  into digital signals (e.g., X- and Y-coordinates) and transfers the digital signals to the first controller  110   a . The first controller  110   a  may control the first touch screen  190   a , using the digital signals received from the first touch screen controller  195   a . Alternatively, the first touch screen controller  195   a  may be included in the first controller  110   a.    
     The second controller  110   b  includes a second processor  111   b , a second ROM  112   b  for storing a control program for controlling the mobile device  100 , and a second RAM  113   b  for storing data or signals received from the outside of the mobile device  100  or serving as a space for storing jobs/tasks executed in the mobile device  100 . 
     The second controller  110   b  may control the mobile communication unit  120 , the sub-communication unit  130 , the multimedia unit  140 , the camera  150 , the positioning information receiver  155 , the input/output unit  160 , the sensor unit  170 , the storage unit  175 , the power supply  180 , the second touch screen  190   b , and the second touch screen controller  195   b.    
     The second touch screen controller  195   b  converts analog signals corresponding to one or more touches applied to the second touch screen  190   b  into digital signals (e.g., X- and Y-coordinates) and transfers the digital signals to the second controller  110   b . The second controller  110   b  may control the second touch screen  190   b , using the digital signals received from the second touch screen controller  195   b . Alternatively, the second touch screen controller  195   b  may be included in the second controller  110   b.    
     The first controller  110   a  may control at least one component that can be installed at the first housing  100   a , such as the first touch screen  190   a , the first touch screen controller  195   a , the mobile communication unit  120 , the sub-communication unit  130 , the multimedia unit  140 , the first camera  151 , the positioning information receiver  155 , the button  161 , the sensor unit  170 , the storage unit  175 , and the power supply  180 . 
     Similarly, the second controller  110   b  may control at least one component that can be installed to the second housing  100   b  where the second controller  110   b  is located, such as the second touch screen  190   b , the second touch screen controller  195   b , a second camera, the storage unit  175 , and the power supply  180 . 
     Alternatively, the first controller  110   a  and the second controller  110   b  may control the mobile device  100  based on units of components. For example, the first controller  110   a  controls the mobile communication unit  120 , the sub-communication unit  130 , and the input/output unit  160 , while the second controller  110   b  controls the multimedia unit  140 , the camera  150 , the positioning information receiver  155 , and the sensor unit  170 . 
     The first controller  110   a  and the second controller  110   b  may control components based on priority. For example, the first controller  110   a  preferentially controls the mobile communication unit  120  and the second controller  110   b  preferentially controls the multimedia unit  140 . 
     While the embodiment of  FIG. 2B  is implemented in such a way that the first controller  110   a  and the second controller  110   b  are installed to the first housing  100   a  and the second housing  100   b , respectively, as an alternative, the first controller  110   a  and the second controller  110   b  may be installed in one housing, e.g., the first housing  100   a.    
     Alternatively, the first controller  110   a  and the second controller  110   b  may be integrated into a single processor with a number of cores (e.g., dual core, quad core, etc.). 
     Alternatively, the first touch screen  190   a  and the second touch screen  190   b  may be installed to one flexible housing, where the first touch screen  190   a  and the second touch screen  190   b  are spaced apart from each other by an interval sufficient for an angle between the first touch screen  190   a  and the second touch screen  190   b  to be detected. 
     The flexible housing may include a flexible display. The flexible housing or the flexible display may include part or all of the components  110  to  195  shown in  FIGS. 1A to 1D  and  FIGS. 2A and 2B . Since the flexible housing and the flexible display have the same components as the mobile device  100 , a detailed description is omitted. 
       FIG. 3  is a flowchart illustrating a method of controlling a mobile device according to an embodiment of the present disclosure. 
       FIGS. 4A to 4E  illustrate a method of controlling a mobile device according to an embodiment of the present disclosure. 
     Referring to  FIG. 3 , in step S 310 , the mobile device displays a home screen on a first touch screen of a first housing and a second touch screen of a second housing. 
     Referring to  FIG. 4A , the mobile device  100  displays a home screen  400  on the first touch screen  190   a  and the second touch screen  190   b . The home screen  400  includes a first home screen  400   a  that is displayed on the first touch screen  190   a , and a second home screen  400   b , which is connected to the first home screen  400   a , displayed on the second touch screen  190   b.    
     The home screen  400  may include a status bar, shortcut icons  401 , a widget  402 , etc. 
     Although the home screen  400  is displayed on the first touch screen  190   a  and the second touch screen  190   b , the present disclosure is not limited thereto. The mobile device  100  may also display an executed application screen on the first touch screen  190   a  and the second touch screen  190   b . For example, the mobile device  100  may extend and display a single window according to the execution of a single application across the first touch screen  190   a  and the second touch screen  190   b . Alternatively, the mobile device  100  may display application screens (windows) according to the execution of applications on the first touch screen  190   a  and the second touch screen  190   b , respectively. Alternatively, the mobile device  100  may display a home screen and an application screen (window) on the first touch screen  190   a  and the second touch screen  190   b , respectively. 
     Referring again to  FIG. 3 , in step S 320 , the mobile device calculates an angle between the first housing and the second housing. 
     Referring to  FIG. 46 , one of the first housing  100   a  and the second housing  100   b  of the mobile device  100  is rotated with respect to the other. The user of the mobile device  100  rotates one of the first housing  100   a  and the second housing  100   b  with respect to the other, so that the rear sides of the first housing  100   a  and the second housing  100   b  come closer to each other. For example, when the second housing  190   b  and the first housing  190   a  are in a spread state, as illustrated in  FIG. 4A , the user can rotate the second housing  190   b  with respect to the first housing  190   a  in the counter-clockwise direction. Alternatively, the user can rotate the first housing  190   a  with respect to the second housing  190   b  in the clockwise direction. 
     The controller  110  may calculate an angle between the first housing  100   a  and the second housing  100   b , using the angle sensor  174 . The angle sensor  174  may output a signal corresponding to an angle of 0° to 360°. 
     The controller  110  may automatically or according to a user input calculate an angle between the first housing  100   a  and the second housing  100   b  using the sensor unit  170 . 
     A user of the mobile device  100  can input an angle formed by the touch screens  190   a  and  190   b  by selecting an object (e.g., icon or text, etc.) displayed on the touch screens  190   a  and  190   b , corresponding to various angles of the mobile device  100 . For example, an object corresponding to a mobile device in a closed state, e.g., as illustrated in diagram (b) of  FIG. 1D , may indicate that the angle between the first housing  100   a  and the second housing  100   b  is 0°. An object corresponding to a mobile device in a spread state, e.g., as illustrated in  FIG. 1A , may indicate that the angle between the first housing  100   a  and the second housing  100   b  is 180°. An object corresponding to a mobile device in an open state, as illustrated in diagram (b) of  FIG. 1C , may indicate that the angle between the first housing  100   a  and the second housing  100   b  is 360°. An object corresponding to a mobile device shaped as a triangle, such as a desktop calendar, may indicate that the angle between the first housing  100   a  and the second housing  100   b  is 60°. An object corresponding to a mobile device in a random state may indicate that the angle between the first housing  100   a  and the second housing  100   b  is one of 0° to 360°. 
     The controller  110  may calculate an angle between the first housing  100   a  and the second housing  100   b  using an acceleration sensor. An angle value may be input via a sensor (e.g., an angle sensor, an acceleration sensor, etc.) or by a user. 
     Referring again to  FIG. 3 , in step S 330 , if the angle between the first housing and the second housing is greater than a threshold, the mobile device operated according to a first touch mode. 
     Referring again to  FIG. 4B , the controller  110  calculates an angle α between the first housing  100   a  and the second housing  100   b  which are rotated, using the angle sensor  174 . If the angle α is greater than a threshold (which may be set to a value according to the settings), the controller  110  triggers the second touch screen  190   b  of the second housing  100   b  to operate in a first touch mode. 
     For example, a threshold for the angle α may be 310°, 275° to 330°, or 300° to 355°. The threshold may also be set to any other value. 
     When the angle α is greater than the threshold, the rear side of the first housing  100   a  and the rear side of the second housing  100   b  are closer to each other, such that the controller  110  may turn off a screen displayed on the second touch screen  190   b  of the second housing  100   b , in the first touch mode. 
     Turning off a touch screen reduces or stops power supplied to a display panel of the touch screen that is turned off, such that the screen background of the touch screen is displayed in black color (or achromatic color). 
     If the screen of the second touch screen  190   b  is turned off, the controller  110  may restrict or cut off power supplied to a display panel of the second touch screen  190   b , e.g., by controlling the power supply  180  to restrict or cut off power supplied to a display panel of the second touch screen  190   b.    
     Herein, turning off a touch screen means that power is still supplied to a touch panel of the touch screen, which can receive a user input (e.g., a touch, a touch gesture, etc.). 
     If a screen of the second touch screen  190   b  is turned off, the controller  110  still supplies power to a touch panel of the second touch screen  190   b , e.g., by controlling the power supply  180  to supply power to a touch panel of the second touch screen  190   b . If a screen of the second touch screen  190   b  is turned off, the controller  110  may control the power supply  180  to supply power to a specific area of a touch panel of the second touch screen  190   b.    
     The controller  110  may switch a second touch screen  190   b  of the second housing  100   b  to a first touch mode, according to a trigger. The controller  110  is capable of turning off a screen displayed on the second touch screen  190   b , according to the operation of switching the second touch screen  190   b  to the first touch mode. 
     Referring to  FIG. 4D , in the first touch mode, an area  420  of the second touch screen  190   b  may be switched to a touch reception area. Consequently, in the first touch mode, a touch may still be detected the second touch screen  190   b , but only in the touch reception area  420 . Referring again to  FIG. 3 , in step S 340 , the mobile device detects a touch applied to a shortcut icon displayed on the first touch screen. 
     Referring to  FIG. 4C , a first user input  409  (e.g., a touch, hovering gesture, etc.) is applied to a shortcut icon  401   a  displayed on the home screen  400   a  of the first touch screen  190   a  when the mobile device  100  is in an open state. 
     Specifically, the controller  110  detects the first user input  409 , using the first touch screen  190   a  and the touch screen controller  195 . The controller  110  calculates a first user input location  409   a  (e.g., X1- and Y1-coordinates) corresponding to the first user input  409 , using an electrical signal received from the touch screen controller  195 . 
     The controller  110  stores the touch location  409   a , a touch detection time (e.g., 10:05 AM), and the information regarding the detected touch in the storage unit  175 . The first touch  409  may be applied to the first touch screen  190   a  by a user&#39;s finger, a stylus pen  167 , etc. 
     The controller  110  executes an application (e.g., a camera application, etc.) corresponding to the first user input  409 . 
     Referring again to  FIG. 3 , in step S 350 , the mobile device displays an application corresponding to the touched shortcut icon on the first touch screen. 
     Referring again to  FIG. 4D , the controller  110  executes an application (e.g., a camera application) corresponding to the touch  409  of the touched shortcut icon  401   a  and displays the executed camera application screen  410  on the first touch screen  190   a.    
     The camera application screen  410  may display a preview of a subject through a first camera  151  capable of supporting a selfie function. The camera application screen  410  may include a photographing mode  410  and a preview  410   a  of a pre-shot image, overlapping a subject to be photographed. The camera application screen  410  may further include a photographing button for receiving a user input corresponding to an instruction for photographing a subject. 
     The controller  110  may execute the second touch screen  190   b  in the first touch mode when the mobile device  100  is in an open state. In the first touch mode, the second touch screen  190   b  powers the touch panel, but disables the display panel. 
     In the first touch mode, the second touch screen  190   b  powers part of the touch panel, e.g., the area  420 , but disables the display panel. Alternatively, in the first touch mode, the second touch screen  190   b  powers part of the touch panel, and part of the display panel corresponding to the part of the touch panel (e.g., a line, a diagram, an image, etc. to distinguish an invisible area from the remaining area). 
     The controller  110  may control the power supply  180  to supply power to the touch panel of the second touch screen  190   b  or to supply power to a specific area of the touch panel of the second touch screen  190   b , e.g., the area  420 . 
     The controller  110  may set a touch reception area  420  to receive a user input applied to the second touch screen  190   b . The touch reception area  420  may be an invisible area that is capable of detecting a user input (e.g., a touch, etc.). Alternatively, the second touch screen  190   b  may display a boundary with a line (e.g., straight line, dot line, etc.), a diagram (e.g., a circle, a polygon, etc.), an image, etc., in order to distinguish the touch reception area  420  from the remaining area.’ 
     The touch reception area  420  may have an area and a location in the second touch screen  190   b , corresponding to an attribute of an application displayed on the first touch screen  190   a . Alternatively, the touch reception area  420  may have a form (e.g., a circle, an ellipse, a polygon, etc.) in the second touch screen  190   b , corresponding to an attribute of an application displayed on the first touch screen  190   a.    
     If the mobile device  100  is an Android® OS based device, the controller  110  may detect an attribute of an executed application, using information included in “androidmanifest.xml” stored in the storage unit  175 . For example, attributes of an application may include an application name, libraries used in an application, an OS version, application permission, resolutions supported by an application, application components (e.g., activity, services), etc. 
     Files storing attributes of an application may vary according to types of a mobile device OS. 
     The touch reception area  420  corresponding to an executed camera application may be located at the top of the second touch screen  190   b  (e.g., higher than the center of the second touch screen  190   b ), considering the finger length of a user&#39;s hand (e.g., the right hand) holding the mobile device  100 . If the finger length of a user&#39;s hand (e.g., the right hand) holding the mobile device  100  is relatively short, the touch reception area  420  may be located at the top and the middle of the second touch screen  190   b  (e.g., including the central area of the second touch screen  190   b , except for the bottom of the second touch screen  190   b  corresponding to the user&#39;s palm). 
     For example, the area of the touch reception area  420  may be less than or equal to 30% of the area of the second touch screen  190   b . Alternatively, the area of the touch reception area  420  may be less than or equal to 55% of the area of the second touch screen  190   b.    
     The touch reception area  420  corresponding to an attribute of an executed application (e.g., camera application, etc.) may be located at the top of the second touch screen  190   b  (e.g., higher than the center of the second touch screen  190   b ). The number of touch reception areas corresponding to an attribute of an executed camera application may be set to one touch reception area on the second touch screen  190   b . Alternatively, the area size of the touch reception area  420  corresponding to an attribute of an executed camera application may be set via the second touch screen  190   b.    
     Referring again to  FIG. 3 , in step S 360 , the mobile device detects a touch (or touch gesture) in a touch reception area on the second touch screen. 
     Referring to  FIG. 4E , the mobile device  100 , in an open state, receives a second user input  429  (e.g., a touch, a touch gesture, etc.) in touch reception area  420  on the second touch screen  190   b . The controller  110  detects a second user input  429 , using the second touch screen  190   b  and the touch screen controller  195 . The controller  110  calculates a second user input location  429   a  (e.g., X2- and Y2-coordinates) corresponding to the second user input  429 , using an electrical signal received from the touch screen controller  195 . 
     The controller  110  stores the touch location  429   a , a touch detection time (e.g., 10:06 AM) and the information regarding the detected touch in the storage unit  175 . The second touch  429  may be applied to the second touch screen  190   b  by a user&#39;s finger, a stylus pen  167 , etc. 
     The second user input  429  detected in the touch reception area  420  on the second touch screen  190   b  may be a pre-set (stored) touch (e.g., tap, etc.) or a pre-set (stored) touch gesture (e.g., a drag gesture, etc.). 
     The controller  110  may control the camera application in response to the second user input  429 . 
     Alternatively, the second controller  110   b  may detect the second user input  429 , using the second touch screen  190   b  and the second touch screen controller  195   b . The second controller  110   b  calculates a second user input location  429   a  (e.g., X2- and Y2-coordinates) corresponding to the second user input  429 , using an electrical signal received from the second touch screen controller  195   b.    
     The second controller  110   b  stores the touch location  429   a , a touch detection time (e.g., 10:06 AM) and the information regarding the detected touch in the storage unit  175 . The second touch  429  may be applied to the second touch screen  190   b  by a user&#39;s finger, a stylus pen  167 , etc. 
     The first controller  110   a  may control the camera application in response to the second user input  429 . 
     Referring again to  FIG. 3 , in step S 370 , the mobile device controls operations of the application according to the touch (or touch gesture) detected in the touch reception area. 
     Referring again to  FIG. 4E , the controller  110  may control the operations of the camera application in response to the second user input  429 . For example, the controller  110  captures a subject via a first camera  151 , in response to the second user input  429 . The controller  110  may display an image corresponding to the captured subject via a preview icon  410   a  located at the bottom of the application screen  410 . 
     The controller  110  may display an image of a subject  411  in a different pose on the camera application screen. 
     Alternatively, if the second user input  429  is a touch gesture (e.g., a rotation gesture), the controller  110  may shoot a video of a subject via the first camera  151 . 
       FIGS. 5A and 5B  illustrate a method of controlling a mobile device according to an embodiment of the present disclosure. Referring to  FIG. 5A , the controller  110  executes an application (e.g., a video call application) corresponding to a touch  409  of a touched shortcut icon. The controller  110  displays the executed video call application screen  510  on the first touch screen  190   a.    
     The video call application screen  510  displays the other party as a video calling correspondent and a video calling user captured by a first camera  151 . The mobile device  100  displays a video calling user on a small window  510   a  at the bottom of the video call application screen  510 . 
     Because the first touch mode of  FIG. 5A  is the same as the embodiment illustrated in  FIG. 4D , a detailed description is omitted below. 
     The touch reception area  520  corresponding to an executed video call application may be located at the top and the middle of the second touch screen  190   b  (e.g., including the central area of the second touch screen  190   b , except for the bottom of the second touch screen  190   b  corresponding to the user&#39;s palm), considering the finger length of a user&#39;s hand (e.g., the right hand) holding the mobile device  100 . 
     For example, the area of the touch reception area  520  may be less than or equal to 50% of the area of the second touch screen  190   b , or less than or equal to 65% of the area of the second touch screen  190   b.    
     Referring to  FIG. 5B , the mobile device  100 , in an open state, receives a second user input  529  (e.g., a touch, a touch gesture, etc.) in touch reception area  520  on the second touch screen  190   b.    
     The controller  110  detects a second user input  529 , using the second touch screen  190   b  and the touch screen controller  195 . The controller  110  calculates a second user input location  529   a  (e.g., X21- and Y21-coordinates) corresponding to the second user input  529 , using an electrical signal received from the touch screen controller  195 . 
     The controller  110  stores the touch location  529   a , a touch detection time (e.g., 10:06 AM) and the information regarding the detected touch in the storage unit  175 . The second touch  529  may be applied to the second touch screen  190   b  by a user&#39;s finger, a stylus pen  167 , etc. 
     The controller  110  controls the volume of the video call application in response to the second user input  529 . 
     Alternatively, the second controller  110   b  detects the second user input  529 , using the second touch screen  190   b  and the second touch screen controller  195   b . The second controller  110   b  calculates a second user input location  529   a  (e.g., X22- and Y22-coordinates) corresponding to the second user input  529 , using an electrical signal received from the second touch screen controller  195   b.    
     The second controller  110   b  stores the touch location  529   a , a touch detection time (e.g., 10:06 AM) and the information regarding the detected touch in the storage unit  175 . The second touch  529  may be applied to the second touch screen  190   b  by a user&#39;s finger, a stylus pen  167 , etc. 
     The first controller  110   a  controls the volume of the video call application in response to the second user input  529 . 
     The controller  110  may control the operations of the video call application in response to the second user input  529 . For example, the controller  110  may display a volume control pop-up  511  on the video call application screen  510  in response to the second user input  529 . 
     If a continuous movement (e.g., from  529   a   1  to  529   a   4 ) of a second user input  529  is applied to the second touch screen  190   b , the controller  110  moves the indicator  511   a  of the volume control pop-up  511  in the right or left direction on the video call application screen  510 . For example, if a continuous movement (e.g.,  529   a   1 ,  529   a   4 ) of a second user input  529  is applied to the second touch screen  190   b , the controller  110  moves the indicator  511   a  of the volume control pop-up  511  in the right direction on the video call application screen  510 . If a continuous movement (e.g.,  529   a   2 ,  529   a   3 ) of a second user input  529  is applied to the second touch screen  190   b , the controller  110  moves the indicator  511   a  of the volume control pop-up  511  in the left direction on the video call application screen  510 . 
     Alternatively, if the second user input  529  is a touch gesture (e.g., a rotation gesture), the controller  110  changes the screen locations of a video call correspondent and a video call user with each other (e.g., screen switching, i.e., displaying the video call correspondent on a small window  510   a ). 
     As another alternative, if the second user input  529  is a touch (e.g., a long press), the controller  110  displays a screen brightness control pop-up (not shown) for controlling the brightness of the video call application screen  520 . If a continuous movement (e.g., from  529   a   1  to  529   a   4 ) of a second user input  529  is applied to the second touch screen  190   b , the controller  110  moves the indicator of the screen brightness control pop-up (not shown) in the right or left direction on the video call application screen  510 . 
       FIGS. 6A and 6B  illustrate a method of controlling a mobile device according to an embodiment of the present disclosure. Referring to  FIG. 6A , the controller  110  may execute an application (e.g., a web browser, an SNS application, etc.) corresponding to a touch  409  of a touched shortcut icon. The controller  110  displays the executed web browser screen  610  including web pages on the first touch screen  190   a.    
     Since the first touch mode of  FIG. 6A  is the same as the embodiment of  FIG. 4D , a detailed description is omitted below. The touch reception area  620  corresponding to an executed web browser may be located at the middle of the second touch screen  190   b  (e.g., including the central area of the second touch screen  190   b ), considering the finger length of a user&#39;s hand (e.g., the right hand) holding the mobile device  100 . 
     For example, the area of the touch reception area  620  may be less than or equal to 70% of the area of the second touch screen  190   b , or less than or equal to 85% of the area of the second touch screen  190   b.    
     Referring to  FIG. 6B , the mobile device  100 , in an open state, receives a second user input  629  (e.g., a touch, a touch gesture, etc.) in touch reception area  620  on the second touch screen  190   b.    
     The controller  110  detects a second user input  629 , using the second touch screen  190   b  and the touch screen controller  195 . The controller  110  calculates a second user input location  629   a  (e.g., X23- and Y23-coordinates) corresponding to the second user input  629 , using an electrical signal received from the touch screen controller  195 . 
     The controller  110  stores the touch location  629   a , a touch detection time (e.g., 10:06 AM) and the information regarding the detected touch in the storage unit  175 . The second touch  629  may be applied to the second touch screen  190   b  by a user&#39;s finger, a stylus pen  167 , etc. 
     The controller  110  controls the movement (e.g., scrolling) of web pages in response to the second user input  629 . 
     Since the process where the second controller  110   b  detects the second user input  629 , using the second touch screen  190   b  and the second touch screen controller  195   b , as illustrated in  FIG. 6B , is similar to the process in which the second controller  110   b  detects the second user input  529 , using the second touch screen  190   b  and the second touch screen controller  195   b , as illustrated in  FIG. 5B , a detailed description is omitted below. 
     The controller  110  may control the movement of web pages in response to the second user input  629 . For example, the controller  110  may prepare for the movement of web pages in response to the second user input  629 . 
     If continuous movements (e.g.,  629   a  to  629   b ) of a second user input  629  are applied to the second touch screen  190   b , the controller  110  moves (scrolling) a web page down. 
     Alternatively, if the second user input  629  is a touch gesture (e.g., a rotation gesture), the controller  110  returns from the current web page to the previous web page. 
       FIGS. 7A and 7B  are illustrate a method of controlling a mobile device according to an embodiment of the present disclosure. Referring to  FIG. 7A , the controller  110  may execute an application (e.g., a video player, etc.) corresponding to a touch of a touched shortcut icon. The controller  110  may display the executed video player screen  710  on the first touch screen  190   a.    
     The controller  110  displays video content (e.g., a video file) on the video player screen  710 . 
     Because the first touch mode of  FIG. 7A  is the same as the embodiment of  FIG. 4D , a detailed description is omitted below. 
     The touch reception areas  720  and  721  corresponding to the executed video player may be located at the left or right region in the second touch screen  190   b , considering the position (orientation) of the mobile device (e.g., a landscape). Alternatively, the touch reception areas  720  and  721  corresponding to the executed video player may be located at both regions (the left and right regions) in the second touch screen  190   b , respectively, considering the position (orientation) of the mobile device (e.g., a landscape). Alternatively, the touch reception area  720  or  721  corresponding to the executed video player may be located in the second touch screen  190   b , considering the position (orientation) of the mobile device (e.g., a landscape). 
     For example, the area of each of the touch reception areas  720  and  721  may be less than or equal to 30% of the area of the second touch screen  190   b , or less than or equal to 40% of the area of the second touch screen  190   b.    
     The touch reception areas  720  and  721  may differ in area from each other. In addition, the shape (e.g., a polygon, etc.) of the touch reception area  721  located at the left region may differ from that (e.g., an ellipse, etc.) of the touch reception area  720  located at the right region on the screen. 
     Referring to  FIG. 7B , the mobile device  100 , in an open state, receives a second user input  728  (e.g., a touch, a touch gesture, etc.) in the touch reception area  721  located at the left region in the second touch screen  190   b.    
     The controller  110  detects a second user input  728 , using the second touch screen  190   b  and the touch screen controller  195 . The controller  110  calculates a second user input location  728   a  (e.g., X24- and Y24-coordinates) corresponding to the second user input  728 , using an electrical signal received from the touch screen controller  195 . 
     The controller  110  stores the touch location  728   a , a touch detection time (e.g., 10:06 AM) and the information regarding the detected touch in the storage unit  175 . The second touch  728  may be applied to the second touch screen  190   b  by a user&#39;s finger, a stylus pen  167 , etc. 
     The controller  110  controls the volume of the video player application in response to the second user input  728 . 
     The mobile device  100 , in an open state, receives a third user input  729  (e.g., a touch, a touch gesture, etc.) in touch reception area  620  located at the right region in the second touch screen  190   b.    
     The controller  110  detects the third user input  729 , using the second touch screen  190   b  and the touch screen controller  195 . The controller  110  calculates a third user input location  729   a  (e.g., X25- and Y25-coordinates) corresponding to the third user input  729 , using an electrical signal received from the touch screen controller  195 . 
     The controller  110  stores the touch location  728   a , a touch detection time (e.g., 10:06 AM) and the information regarding the detected touch in the storage unit  175 . The third touch  729  may be applied to the second touch screen  190   b  by a user&#39;s finger, a stylus pen  167 , etc. 
     The controller  110  controls the brightness of the video player application in response to the third user input  729 . 
     Because the process where the second controller  110   b  detects the second user input  728  and the third user input  729 , using the second touch screen  190   b  and the second touch screen controller  195   b , as illustrated in  FIG. 7B , is similar to the process where the second controller  110   b  detects the second user input  529 , using the second touch screen  190   b  and the second touch screen controller  195   b , as illustrated in  FIG. 5B , a detailed description is omitted below. 
     The controller  110  may control the volume of the video player application in response to the second user input  728 . The controller  110  is displays a volume control pop-up  711  on the video player application screen  710  in response to the second user input  728 . 
     If a continuous movement (e.g., from  728   a  to  728   b ) of a second user input  728  is applied to the second touch screen  190   b , the controller  110  moves the indicator  711   a  of the volume control pop-up  711  in the left direction on the video player application screen  710 . 
     The controller  110  may control the screen brightness of the video player application in response to the third user input  729 . The controller  110  may display a screen brightness control pop-up on the video player screen  710  in response to the third user input  729 . 
     If a continuous movement (e.g., from  728   a  to  728   b ) of a second user input  728  is applied to the second touch screen  190   b , the controller  110  moves the indicator of the screen brightness control pop-up in the left direction (or downward). 
       FIGS. 8A and 8B  illustrate a method of controlling a mobile device according to an embodiment of the present disclosure Referring to  FIG. 8A , the controller  110  executes an application (e.g., a game application, etc.) corresponding to a touch of a touched shortcut icon. The controller  110  displays the executed game application screen  810  including game content (e.g., an airplane shooting game) on the first touch screen  190   a.    
     Because the first touch mode of  FIG. 8A  is the same as the embodiment of  FIG. 4D , a detailed description is omitted below. 
     The touch reception areas  820  and  821  corresponding to the executed game application are located at the left and/or right region in the second touch screen  190   b , considering the position (orientation) of the mobile device (e.g., a landscape). 
     Alternatively, the touch reception area  820  or  821  corresponding to the executed game application may be located in the second touch screen  190   b , considering the position (orientation) of the mobile device (e.g., a landscape). 
     For example, the total area of the touch reception areas  820  and  821  may be less than or equal to 80% of the area of the second touch screen  190   b , or the area of the touch reception area  821  may be less than or equal to 50% of the area of the second touch screen  190   b.    
     The touch reception areas  820  and  821  may differ in size from each other. For example, the touch reception area  821  for the direction control and/or movement of an airplane (a range of controllable angle of 360°) is greater in area size than one touch reception area  820  for the shooting motion. 
     The area of the touch reception area for receiving a touch gesture may vary according to the input directions of the touch gesture. For example, the area of the touch reception area  821 , which receives a touch gesture in the up and down directions, may be smaller than that of the touch reception area  821 , which receives a touch gesture in the up/down/side-to-side directions. 
     In addition, the areas of the touch reception areas may differ according to the type of application. 
     In addition, the shape (e.g., a polygon, etc.) of the touch reception area  821  located in the left region may differ from that (e.g., an ellipse, etc.) of the touch reception area  820  located in the right region. 
     Referring to  FIG. 8B , the mobile device  100 , in an open state, receives a second user input  828  (e.g., a touch, a touch gesture, etc.) in the touch reception area  821  located at the left region in the second touch screen  190   b.    
     The controller  110  detects a second user input  828 , using the second touch screen  190   b  and the touch screen controller  195 . The controller  110  calculates a second user input location  828   a  (e.g., X25- and Y25-coordinates) corresponding to the second user input  828 , using an electrical signal received from the touch screen controller  195 . 
     The controller  110  stores the touch location  828   a , a touch detection time (e.g., 10:06 AM) and the information regarding the detected touch in the storage unit  175 . The second touch  828  may be applied to the second touch screen  190   b  by a user&#39;s finger, a stylus pen  167 , etc. 
     The controller  110  controls the shooting motion of the game application (e.g., firing, etc.) in response to the second user input  828 . 
     The mobile device  100 , in an open state, receives a third user input  829  (e.g., a touch, a touch gesture, etc.) in touch reception area  820  located at the right region in the second touch screen  190   b.    
     The controller  110  detects the third user input  829 , using the second touch screen  190   b  and the touch screen controller  195 . The controller  110  calculates a third user input location  829   a  (e.g., X26- and Y26-coordinates) corresponding to the third user input  829 , using an electrical signal received from the touch screen controller  195 . 
     The controller  110  stores the touch location  828   a , a touch detection time (e.g., 10:06 AM) and the information regarding the detected touch in the storage unit  175 . The third touch  829  may be applied to the second touch screen  190   b  by a user&#39;s finger, a stylus pen  167 , etc. 
     The controller  110  controls the shooting motion to an airplane in response to the third user input  829 . 
     Because the process in which the second controller  110   b  detects the second user input  828  and the third user input  829 , using the second touch screen  190   b  and the second touch screen controller  195   b , as illustrated in  FIG. 8B , is similar to the process in which the second controller  110   b  detects the second user input  728  and the third user input  729 , using the second touch screen  190   b  and the second touch screen controller  195   b , as illustrated in  FIG. 7B , a detailed description is omitted below. 
     The controller  110  may control the direction and/or movement of an airplane in response to the second user input  828 . 
     If a continuous movement (e.g., from  828   a  to  828   b ) of a second user input  828  is applied to the second touch screen  190   b , the controller  110  controls the direction and/or movement of an airplane in response to the second user input  828 . The controller  110  is also capable of controlling the shooting motion to an airplane in response to the third user input  829 . 
     In accordance with the above-described embodiments of the present disclosure, a mobile device may be configured in such a way as to include a number of touch screens, connected to each other with a hinge or a flexible PCB, and is capable of detecting, when the touch screens are opened with respect to each other, a touch applied to a rear touch screen whose image-display area is turned off. 
     A mobile device is also configured in such a way as to include a number of touch screens, connected to each other with a hinge or a flexible PCB, and is capable of detecting, when the touch screens are opened with respect to each other, a touch applied to a rear touch screen whose image-display area is turned off, reducing power consumption. 
     A mobile device is also configured in such a way as to include a number of touch screens, connected to each other with a hinge or a flexible PCB, and is capable of detecting, when the touch screens are opened with respect to each other, a touch applied to a visible touch detectable area of a rear touch screen whose image-display area is turned off, reducing power consumption. 
     A mobile device is also configured in such a way as to include a number of touch screens, connected to each other with a hinge or a flexible PCB, and is capable of detecting, when the touch screens are opened with respect to each other, a touch applied to a touch detectable area (or part) of a rear touch screen whose image-display area is turned off, reducing power consumption. A mobile device is also configured in such a way as to include a number of touch screens, connected to each other with a hinge or a flexible PCB, and is capable of detecting, when the touch screens are opened with respect to each other, a preset touch applied to a touch detectable area (or part) of a rear touch screen whose image-display area is turned off, reducing power consumption. 
     The present disclosure is not limited to the embodiments described above. Mobile devices may also be configured in such a way as to include a number of touch screens, connected to each other with a hinge or a flexible PCB, and is capable of detecting, when the touch screens are opened with respect to each other, a preset touch applied to a rear touch screen whose image-display area is turned off, reducing power consumption. 
     The methods according to above-described embodiments of the present disclosure may also be performed through various computer means. 
     The various embodiments of the present disclosure as described above typically involve the processing of input data and the generation of output data to some extent. 
     This input data processing and output data generation may be implemented in hardware or software in combination with hardware. For example, specific electronic components may be employed in a mobile device or similar or related circuitry for implementing the functions associated with the various embodiments of the present disclosure as described above. 
     Alternatively, one or more processors operating in accordance with stored instructions may implement the functions associated with the various embodiments of the present disclosure as described above. If such is the case, it is within the scope of the present disclosure that such instructions may be stored on one or more non-transitory processor readable mediums. 
     Examples of the processor readable mediums include a ROM, a RAM, CD-ROMs, magnetic tapes, floppy disks, and optical data storage devices. The processor readable mediums can also be distributed over network coupled computer systems so that the instructions are stored and executed in a distributed fashion. In addition, functional computer programs, instructions, and instruction segments for accomplishing the present disclosure can be easily construed by programmers skilled in the art to which the present disclosure pertains. 
     While the present disclosure has been shown and described with reference to various embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present disclosure as defined by the appended claims and their equivalents.