Patent Publication Number: US-11397513-B2

Title: Content transmission device and mobile terminal for performing transmission of content

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a Continuation of copending application Ser. No. 15/490,637, filed on Apr. 18, 2017, which claims priority under 35 U.S.C. § 119(a) to Application No. 10-2016-0047789, filed in Republic of Korea on Apr. 19, 2016, all of which are hereby expressly incorporated by reference into the present application. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a content transmission device and a mobile terminal, and more particularly to a content transmission device and a mobile terminal that is capable of easily performing the transmission of content from the content transmission device. 
     2. Description of the Related Art 
     A mobile terminal is a portable device having one or more functions, such as a function of performing voice and video communications, a function of inputting and outputting information, and a function of storing data. As the result of diversification of the functions of the mobile terminal, the mobile terminal has come to have complex functions, such as a function of taking still pictures or motion pictures, a function of playing music files or video files, a function of playing games, a function of receiving broadcasts, a function of providing wireless Internet access, and a function of transmitting and receiving messages. Owing to the diversified functions, the mobile terminal has been realized in the form of a total multimedia player. Various attempts based on hardware or software have been made in order for the mobile terminal realized in the form of the multimedia player to have increasingly complex functions. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a content transmission device and a mobile terminal that is capable of easily performing the transmission of content from the content transmission device. 
     In accordance with an aspect of the present invention, the above and other objects can be accomplished by the provision of a mobile terminal including a display unit, a communication unit to transmit a control signal to a content transmission device, and a controller to display a content playback setting screen, including an item related to at least one content reception device, an item related to at least one input terminal through which the at least one content reception device is connected to the content transmission device, and a thumbnail image corresponding to the item related to the at least one input terminal, in response to an input for the execution of a content playback application, wherein the controller performs a control operation to transmit content data received through a first input terminal of the content transmission device to a first content reception device based on the selection of the first content reception device from among the at least one content reception device and the selection of the first input terminal from among the at least one input terminal. 
     In accordance with another aspect of the present invention, there is provided a mobile terminal including a display unit, a communication unit to transmit a control signal to a content transmission device, and a controller to display a content playback setting screen, including a power on item, a power off item, an input item, and a thumbnail image corresponding to the input item, in response to an input for the execution of a content playback application, wherein the controller performs a control operation to transmit content data received through a first input terminal of the content transmission device to a content reception device based on the selection of the first input terminal as the input item. 
     In accordance with a further aspect of the present invention, there is provided a content transmission device including a communication unit to exchange data with a mobile terminal, an interface unit having a plurality of input terminals to receive content data from a plurality of external devices, and a controller to perform a control operation to, when receiving, from the mobile terminal, transmit a remote control signal in response to the selection of a first content reception device from among at least one content reception device and the selection of a first input terminal from among the input terminals, content data received through the first input terminal of the content transmission device to the first content reception device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a view showing a video display system based on the wireless transmission of content data according to an embodiment of the present invention; 
         FIG. 2A  is an internal block diagram of an example of a content transmission device shown in  FIG. 1 ; 
         FIG. 2B  is an internal block diagram of an example of a content reception device shown in  FIG. 1 ; 
         FIG. 3  is an internal block diagram of an example of a controller shown in  FIG. 2A ; 
         FIG. 4A  is a view showing a control method of a remote controller shown in  FIG. 2A ; 
         FIG. 4B  is an internal block diagram of the remote controller shown in  FIG. 2A ; 
         FIG. 5  is an internal block diagram of a mobile terminal shown in  FIG. 1 ; 
         FIG. 6  is a flowchart showing an example of a method of operating a mobile terminal according to an embodiment of the present invention; and 
         FIGS. 7 to 12G  are reference views illustrating the operation method of  FIG. 6 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Exemplary embodiments of the present invention will be described with reference to the attached drawings. The terms “module” and “unit,” when attached to the names of components, are used herein to help the understanding of the components and thus they should not be considered as having specific meanings or roles. Accordingly, the terms “module” and “unit” may be used interchangeably. 
       FIG. 1  is a view showing a video display system based on the wireless transmission of content data according to an embodiment of the present invention. Referring to this figure, the video display system based on the wireless transmission of content data, denoted by reference numeral  10 , may include a content transmission device  100   a , at least one content reception device  100   ba ,  100   bb , . . . (which may also be denoted by  100   b ), at least one display device  180   a ,  180   b , . . . , a remote controller  200 , and a mobile terminal  600 . 
     The content transmission device  100   a  may have a plurality of input terminals to receive content data from a plurality of external devices. The content transmission device  100   a  can transmit content data, input from one of the external devices through a corresponding one of the input terminals, to one of the at least one content reception device  100   ba ,  100   bb , . . . in a wireless fashion. 
     The external devices that are connected to the content transmission device  100   a  may be a camera device  101 , an optical disk player  213 , a game console  214 , a laptop computer  215 , a set-top box, etc., as shown in this figure. In addition, the input terminals of the content transmission device  100   a  may be an antenna terminal, a universal serial bus (USB) terminal, a high definition multimedia interface (HDMI) terminal, a wired local area network (LAN) terminal, an RGB terminal, an audio/video (AV) terminal, an S-video terminal, a Sony and Philips digital interconnect format (SPDIF) terminal, a secure digital (SD) terminal, a micro-SD terminal, a compact flash (CF) terminal, etc. 
     The at least one content reception device  100   ba ,  100   bb , . . . can receive predetermined content data from the content transmission device  100   a  in a wireless fashion, and can transmit the received content data to the at least one display device  180   a ,  180   b , . . . in a wireless fashion. Further, the at least one display device  180   a ,  180   b , . . . can display a video that corresponds to the wirelessly received content data. 
     Examples of the at least one display device  180   a ,  180   b , . . . include a monitor, a TV receiver, etc. Meanwhile, a content reception device and a display device may be integrated into a single device. An example of such an integrated device may be a tablet device. 
     The remote controller  200  and the mobile terminal  600  can each remotely control at least one selected from among the content transmission device  100   a , the at least one content reception device  100   ba ,  100   bb , . . . , and the at least one display device  180   a ,  180   b , For example, the remote controller  200  can transmit a power on signal, a power off signal, a channel control signal, or a volume control signal to the content transmission device  100   a , the at least one content reception device  100   ba ,  100   bb , . . . , and the at least one display device  180   a ,  180   b , . . . in a wireless fashion. 
     The power on signal, the power off signal, the channel control signal, or the volume control signal may be transmitted as an infrared (IR) signal. Further, the remote controller  200  can transmit a pointing signal for remote control pointing to at least one selected from among the content transmission device  100   a , the at least one content reception device  100   ba ,  100   bb , . . . , and the at least one display device  180   a ,  180   b, . . . .    
     The pointing signal may be a radio frequency (RF) signal, rather than an IR signal. The mobile terminal  600  can transmit a power on signal, a power off signal, a channel control signal, or a volume control signal to the content transmission device  100   a , the at least one content reception device  100   ba ,  100   bb , . . . , and the at least one display device  180   a ,  180   b , . . . in a wireless fashion. 
     The power on signal, the power off signal, the channel control signal, or the volume control signal may be transmitted as an IR signal. Further, the mobile terminal  600  can transmit a pointing signal for remote control pointing to at least one selected from among the content transmission device  100   a , the at least one content reception device  100   ba ,  100   bb , . . . , and the at least one display device  180   a ,  180   b , . . . . The pointing signal may also be an RF signal, rather than an IR signal. 
     The mobile terminal  600  can transmit a selection signal for selecting one of the at least one content reception device  100   ba ,  100   bb , . . . to the content transmission device  100   a , and can transmit a selection signal for selecting one of the input terminals of the content transmission device  100   a  or selecting one of content data from the external devices to the content transmission device  100   a.    
     Particularly, in an embodiment of the present invention, the mobile terminal  600  can transmit content data received through a first input terminal of the content transmission device  100   a  to a first content reception device  100   ba  based on the selection of the first content reception device  100   ba  from among the at least one content reception device  100   b  and the selection of the first input terminal from among the input terminals of the content transmission device  100   a  when a content playback setting screen including an item related to the at least one content reception device  100   b , an item related to at least one of the input terminals through which the at least one content reception device  100   b  is connected to the content transmission device  100   a , and a thumbnail image corresponding to the item related to the at least one of the input terminals, is displayed in response to an input for the execution of a content playback application. Consequently, it is possible to easily perform the transmission of content from the content transmission device  100   a  through the mobile terminal  600 . 
     Further, the mobile terminal  600  can display a screen for wireless pairing between the content transmission device  100   a  and the first content reception device  100   ba  in response to the selection of the first content reception device  100   ba  from among the at least one content reception device  100   b  and the selection of the first input terminal from among the input terminals of the content transmission device  100   a  such that pairing between the content transmission device  100   a  and the first content reception device  100   ba  is performed before the transmission of content, whereby the transmission of content is easily performed. 
     Meanwhile, when the content transmission device  100   a  transmits content data to the first content reception device  100   ba  in a first frequency band, the mobile terminal  600  can display a first object indicating that content data are being transmitted in the first frequency band. When the content transmission device  100   a  transmits content data to the first content reception device  100   ba  in a second frequency band, the mobile terminal  600  can display a second object indicating that content data are being transmitted in the second frequency band. When the content transmission device  100   a  transmits content data to the first content reception device  100   ba  in a third frequency band, the mobile terminal  600  can display a third object indicating that content data are being transmitted in the third frequency band. Consequently, it is possible to easily recognize the frequency band in which the content transmission device  100   a  is transmitting content data to the first content reception device  100   ba.    
     Further, the mobile terminal  600  can variably display the number of thumbnail images corresponding to the input terminals according to the item related to the at least one content reception device  100   b  that is selected in the content playback setting screen. Consequently, it is possible to easily recognize viewable content received through each input terminal. 
     The mobile terminal  600  can receive content data and display the received content data in a portion of the screen. In addition, the mobile terminal  600  can transmit information set based on a setting input of at least one selected from among the image size, playback time, fast-forward, and volume of a video based on the displayed content data to the content transmission device  100   a . Consequently, it is possible to improve user convenience. 
     When a second content reception device  100   bb  is further selected from among the at least one content reception device  100   b  and a second input terminal is further selected from among the input terminals of the content transmission device  100   a , the mobile terminal  600  can perform a control operation to further transmit second content data received through the second input terminal of the content transmission device  100   a  to the second content reception device  100   bb . Consequently, it is possible to transmit a plurality of pieces of content data. 
     In another embodiment of the present invention, the mobile terminal  600  can include a display unit  680 , a communication unit  610  for transmitting a control signal to the content transmission device  100   a , and a controller  670  for performing control such that a content playback setting screen, including a power on item, a power off item, an input item, and a thumbnail image corresponding to the input item, is displayed in response to an input for the execution of a content playback application. The controller  670  can transmit content data received through the first input terminal of the content transmission device  100   a  to the at least one content reception device  100   b  based on the selection of the first input terminal as the input item. Consequently, it is possible to easily perform the transmission of content from the content transmission device  100   a.    
     Further, the mobile terminal  600  can perform a control operation to power on the content transmission device  100   a  and the at least one content reception device  100   b  by transmitting power on signals to the content transmission device  100   a  and the at least one content reception device  100   b  when the power on item in the content playback setting screen is selected. 
     The mobile terminal  600  can transmit a pairing signal to the content transmission device  100   a  after the content transmission device  100   a  is powered on in response to the power on signal, and may be connected to the content transmission device  100   a  based on a pairing response signal received from the content transmission device  100   a . Consequently, it is possible to easily perform pairing. 
     Further, in an embodiment of the present invention, the content transmission device  100   a  may include a communication unit  135  for exchanging data with the mobile terminal  600 , an interface unit  130  having a plurality of input terminals to receive content data from a plurality of external devices, and a controller  170  for performing control such that content data received through the first input terminal of the content transmission device  100   a  are transmitted to the first content reception device  100   ba  when receiving, from the mobile terminal  600 , a remote control signal in response to the selection of the first content reception device  100   ba  from among the at least one content reception device  100   b  and the selection of the first input terminal from among the input terminals of the content transmission device  100   a . Consequently, it is possible to easily perform the transmission of content from the content transmission device  100   a.    
     The content transmission device  100   a  can transmit a pairing signal to the first content reception device  100   ba  when receiving, from the mobile terminal  600 , a remote control signal in response to the selection of the first content reception device  100   ba  from among the at least one content reception device  100   b  and the selection of the first input terminal from among the input terminals of the content transmission device  100   a , and can perform pairing based on a pairing response signal received from the first content reception device  100   ba . Consequently, it is possible to easily perform the transmission of content from the content transmission device  100   a.    
     The content transmission device  100   a  can transmit content data received through the first input terminal of the content transmission device  100   a  to the first content reception device  100   ba  in any one selected from among the first frequency band to the third frequency band depending on the state of the wireless connection between the content transmission device  100   a  and the first content reception device  100   ba . Consequently, it is possible to transmit content data without loss or delay. 
     The operation of the content transmission device  100   a , the mobile terminal  600 , etc. will be described in more detail with reference to  FIG. 6  and subsequent figures. In particular,  FIG. 2A  is an internal block diagram of an example of the content transmission device shown in  FIG. 1 . 
     Referring to  FIG. 2A , in an embodiment of the present invention, the content transmission device  100   a  may include a broadcast reception unit  105 , a memory  140 , a user input interface unit  150 , a sensor unit, a controller  170 , and a power supply unit  190 . The broadcast reception unit  105  may include a tuner unit  110 , a demodulator  120 , a communication unit  135 , and an external device interface unit  130 . 
     Unlike what is shown in this figure, the broadcast reception unit  105  may include only the tuner unit  110  and the demodulator  120 . That is, the broadcast reception unit  105  may not include the communication unit  135  or the external device interface unit  130 . The tuner unit  110  tunes to a radio frequency (RF) broadcast signal corresponding to a channel selected by a user or all pre-stored channels from among RF broadcast signals received through an antenna terminal. In addition, the tuner unit  110  converts the tuned RF broadcast signal into an intermediate frequency (IF) signal or a baseband video or audio signal. 
     For example, when the selected RF broadcast signal is a digital broadcast signal, the tuner unit  110  converts the selected RF broadcast signal into a digital IF (DIF) signal. When the selected RF broadcast signal is an analog broadcast signal, the tuner unit  110  converts the selected RF broadcast signal into an analog baseband video or audio signal (CVBS/SIF). That is, the tuner unit  110  can process the digital broadcast signal or the analog broadcast signal. The analog baseband video or audio signal (CVBS/SIF) output from the tuner unit  110  may be directly input to the controller  170 . 
     Also, in the present invention, the tuner unit  110  may sequentially tune to RF broadcast signals of all broadcast channels stored using a channel memory function, among RF broadcast signals received through the antenna, and may convert the tuned RF broadcast signals into intermediate frequency signals or baseband video or audio signals. 
     The tuner unit  110  may include a plurality of tuners in order to receive broadcast signals of a plurality of channels. Alternatively, the tuner unit  110  may include a single tuner that is capable of simultaneously receiving broadcast signals of a plurality of channels. 
     The demodulator  120  can receive the digital IF (DIF) signal converted by the tuner unit  110 , and can perform demodulation. After performing demodulation and channel decoding, the demodulator  120  may output a stream signal (TS). In this instance, the stream signal may be a multiplexed video signal, a multiplexed audio signal, or a multiplexed data signal. 
     The stream signal output from the demodulator  120  may be input to the controller  170 . The controller  170  can perform demultiplexing, video/audio signal processing, etc. Subsequently, the controller  170  can transmit the processed signal to the at least one content reception device  100   ba ,  100   bb , . . . in a wireless fashion. The external device interface unit  130  may include an antenna terminal, a USB terminal, an HDMI terminal, a wired LAN terminal, an RGB terminal, an AV terminal, an S-video terminal, an SPDIF terminal, an SD terminal, a micro-SD terminal, and a CF terminal. 
     The external device interface unit  130  can transmit or receive data to or from an external device, such as a set-top box, connected through one of the input terminals. Thus, the external device interface unit  130  may include an A/V input and output unit. 
     The external device interface unit  130  may be connected to an external device, such as a digital versatile disk (DVD) player, a Blu-ray player, a game console, a camera, a camcorder, a computer (a laptop computer), or a set-top box, in a wired or wireless fashion. In addition, the external device interface unit  130  can perform an input operation to or an output operation from the external device. The A/V input and output unit can receive a video signal and an audio signal from the external device. 
     The communication unit  135  may provide an interface for connecting the content transmission device  100   a  to a wired or wireless network, including the Internet. For example, the communication unit  135  can receive content or data provided by a content provider or a network operator over a network, such as the Internet. 
     The communication unit  135  may include a wired communication unit  135   a  and a wireless communication unit  135   b . The communication unit  135  may also exchange data with the mobile terminal  600  or the remote controller  200  through the wireless communication unit  135   b.    
     The memory  140  may store a program for processing and controlling signals in the controller  170 . Alternatively, the first storage unit  140  may store a processed video, audio, or data signal. In addition, the memory  140  may temporarily store a video, audio, or data signal input to the external device interface unit  130 . Furthermore, the memory  140  may store information about a specific broadcast channel using a channel memory function, such as a channel map. 
     In  FIG. 2A , the memory  140  is provided separately from the controller  170 . However, the present invention is not limited thereto. For example, the memory  140  may be included in the controller  170 . The user input interface unit  150  may transfer a signal input by a user to the controller  170 , or may transfer a signal from the controller  170  to the user. 
     For example, the user input interface unit  150  can transmit/receive a user input signal, such as power on/off, channel selection, or screen setting, to/from the remote controller  200  or the mobile terminal  600 , can transfer a user input signal input from a local key, such as a power key, a channel key, a volume key, or a setting key, to the controller  170 , can transfer a user input signal input from a sensor unit for sensing a gesture of a user to the controller  170 , or can transmit a signal from the controller  170  to the sensor unit. 
     The controller  170  can demultiplex streams input through the tuner unit  110 , the demodulator  120 , the communication unit  135 , or the external device interface unit  130 , or can process the demultiplexed signals to generate and output a video or audio output signal. The video signal processed by the controller  170  may be transmitted to the at least one content reception device  100   ba ,  100   bb , . . . in a wireless fashion. 
     The audio signal processed by the controller  170  may be transmitted to the at least one content reception device  100   ba ,  100   bb , . . . in a wireless fashion. Further, the controller  170  may include a demultiplexer and a video processing unit, which will hereinafter be described with reference to  FIG. 3 . 
     In addition, the controller  170  can control the operations of the respective units in the content transmission device  100   a . The power supply unit  190  may supply power to the content transmission device  100   a . In particular, the power supply unit  190  may supply power to the controller  170 , which may be embodied in the form of a system on chip (SOC). Specifically, the power supply unit  190  may include an AC/DC converter for converting AC power into DC power and a DC/DC converter for changing the level of the DC power. 
     The remote controller  200  can transmit a user input to the user input interface unit  150 . Thus, the remote controller  200  may use Bluetooth communication, radio frequency (RF) communication, infrared (IR) communication, ultra wideband (UWB) communication, or ZigBee communication. In addition, the remote controller  200  can receive a video, audio, or data signal output from the user input interface unit  150  such that the remote controller  200  displays the received signal or outputs the received signal in the form of audible sound. 
     The content transmission device  100   a  may be a fixed or mobile digital broadcast receiver that is capable of receiving a digital broadcast. The block diagram of the content transmission device  100   a  shown in  FIG. 2A  is a view illustrating an embodiment of the present invention. The respective components of the block diagram may be combined, added, or omitted depending on the specifications of the content transmission device  100   a  that is actually embodied. That is, two or more components may be combined into a single component or one component may be divided into two or more components as needed. In addition, the function performed by each block is intended for description of the embodiment of the invention, and its detailed action or device does not limit the scope of the invention. 
     Next,  FIG. 2B  is an internal block diagram of an example of a content reception device shown in  FIG. 1 . Referring to  FIG. 2B , in an embodiment of the present invention, the content reception device  100   b  may include a communication unit  136 , an external device interface unit  131 , a memory  141 , a user input interface unit  151 , a controller  171 , and a power supply unit  191 . 
     The operation of the external device interface unit  131 , the memory  141 , the user input interface unit  151 , the controller  171 , and the power supply unit  191  may be similar to the operation of the external device interface unit  130 , the memory  140 , the user input interface unit  150 , the controller  170 , and the power supply unit  190  of the content transmission device  100   a  shown in  FIG. 2A . 
     The communication unit  136  can receive content data from the content transmission device  100   a  in a wireless fashion, and may directly transmit the received content data to a display device  180  in a wireless fashion without additional signal processing. Alternatively, the communication unit  136  can receive content data from the content transmission device  100   a  in a wireless fashion, and can transmit the content data to a display device  180  in a wireless fashion after the content data is processed by the controller  171 . 
     Thus, the communication unit  136  may include a first communication unit  136   a  and a second communication unit  136   b . The first communication unit  136   a  can receive content data from the content transmission device  100   a , and the second communication unit  136   b  can transmit the content data to the display device  180  in a wireless fashion. 
     The display device  180  may include a display module  181 , a controller  183 , an audio output unit  185 , and a communication unit. In addition, the communication unit can receive content data from the content reception device  100   b  in a wireless fashion. 
     The controller  183  can process the received content data. The video signal processed by the controller  171  may be input to the display module  181  such that a video based on the video signal is displayed on the display module  181 . The controller  183  can process the received content data. The audio signal processed by the controller  171  may be output through the audio output unit  185  in the form of audible sound. 
     Next,  FIG. 3  is an internal block diagram of an example of the controller shown in  FIG. 2A . Referring to this figure, in an embodiment of the present invention, the controller  170  may include a demultiplexer  310 , a video processing unit  320 , a processor  330 , an on-screen display (OSD) generator  340 , a mixer  345 , a frame rate converter (FRC)  350 , and a formatter  360 . In addition, the controller  170  may further include an audio processing unit and a data processing unit. 
     The demultiplexer  310  can demultiplex an input stream. For example, when an MPEG-2 TS is input, the demultiplexer  310  can demultiplex the MPEG-2 TS into video, audio, and data signals. The stream signal that is input to the demultiplexer  310  may be a stream signal output from the tuner unit  110 , the demodulator  120 , or the external device interface unit  130 . 
     The video processing unit  320  can process a demultiplexed video signal. Thus, the video processing unit  320  may include a video decoder  325  and a scaler  335 . The video decoder  325  can decode the demultiplexed video signal, and the scaler  335  can scale the resolution of the decoded video signal such that the video signal can be output to the at least one display device  180   a ,  180   b, . . . .    
     Decoders based on various standards may be used as the video decoder  325 . For example, an MPEG-2 decoder, an H264 decoder, a 3D image decoder, such as a color image decoder or a depth image decoder, or a multi-viewpoint image decoder may be used as the video decoder  325 . 
     The processor  330  controls the overall operation of the content transmission device  100   a  or the controller  170 . For example, the processor  330  can control the tuner unit  110  to tune to an RF broadcast corresponding to a channel selected by a user or a pre-stored channel. In addition, the processor  330  can control the content transmission device  100   a  based on a user command input through the user input interface unit  150  or an internal program. 
     Furthermore, the processor  330  can control data transmission to the communication unit  135  or the external device interface unit  130 . In addition, the processor  330  can control the operation of the demultiplexer  310 , the video processing unit  320 , and the OSD generator  340  of the first processor  170 . 
     The OSD generator  340  can generate an OSD signal, either in response to a user input or autonomously. For example, the OSD generator  340  can generate a signal for displaying various kinds of information on the screen of the at least one display device  180   a ,  180   b , . . . in the form of graphics or text based on a user input signal. The generated OSD signal may include various data from the content transmission device  100   a , such as user interface screens, various menu screens, widgets, and icons. In addition, the generated OSD signal may include a 2D object or a 3D object. 
     In addition, the OSD generator  340  can generate a pointer that can be displayed on the display unit based on a pointing signal input from the remote controller  200 . In particular, the pointer may be generated by a pointing signal processing unit. The OSD generator  340  may include such a pointing signal processing unit. Of course, the pointing signal processing unit may not be provided in the OSD generator  340  but may be provided separately. 
     The mixer  345  can mix the OSD signal, generated by the OSD generator  340 , with the decoded video signal processed by the video processing unit  320 . The mixed video signal may be provided to the frame rate converter  350 . The frame rate converter  350  can convert the frame rate of an input video. Alternatively, the frame rate converter  350  may directly output an input video without converting the frame rate of the input video. 
     The formatter  360  can arrange left-eye video frames and right-eye video frames of a 3D video, the frame rate of which has been converted. In addition, the formatter  360  can output a synchronizing signal Vsync for opening a left-eye glass and a right-eye glass of a 3D viewing device. 
     The formatter  360  can change the format of the input video signal into the format of a video signal that is to be displayed on the display device, and may output the changed video signal. In addition, the formatter  360  can change the format of a 3D video signal. For example, the formatter  360  may change the format of the 3D video signal into any one selected from among various 3D formats, such as a side-by-side format, an up-and-down format, a sequential frame format, an interlaced format, and a checker box format. 
     The formatter  360  can convert a 2D video signal into a 3D video signal. For example, the formatter  360  can detect an edge or a selectable object in a 2D video signal, and separate an object based on the detected edge or the selectable object from the 2D video signal to generate a 3D video signal according to a 3D video generation algorithm. As described above, the generated 3D video signal may be divided into a left-eye video signal L and a right-eye video signal R, which may be arranged appropriately. 
     In addition, a 3D processor for processing 3D effects may be further provided after the formatter  360 . The 3D processor can control the brightness, tint, and color of a video signal in order to improve the 3D effects. For example, the 3D processor can perform signal processing in order to sharpen nearby items and to blur distant items. The function of the 3D processor may be incorporated into the formatter  360  or the video processing unit  320 . 
     The audio processing unit in the controller  170  can process a demultiplexed audio signal. Thus, the audio processing unit may include various decoders. In addition, the audio processing unit in the controller  170  can control the bass, treble, and volume of an audio signal. 
     The data processing unit in the controller  170  can process a demultiplexed data signal. For example, when the demultiplexed data signal is an encoded data signal, the data processing unit can decode the demultiplexed data signal. The encoded data signal may be electronic program guide (EPG) information containing broadcast information, such as a start time and an end time, of a broadcast program provided by each channel. 
     The block diagram of the controller  170  shown in  FIG. 3  is a view illustrating an embodiment of the present invention. The respective components of the block diagram may be combined, added, or omitted depending on the specifications of the controller  170  that is actually embodied. In particular, the frame rate converter  350  and the formatter  360  may not be provided in the controller  170  but may be separately provided. 
       FIG. 4A  is a view showing a control method of the remote controller shown in  FIG. 2A . As shown in  FIG. 4A (a), a pointer  205  corresponding to the remote controller  200  is displayed on the display device  180 . A user can move or rotate the remote controller  200  up and down, side to side ( FIG. 4A (b)), or back and forth ( FIG. 4A (c)). The pointer  205  displayed on the display device  180  corresponds to the motion of the remote controller  200 . Since the pointer  205  corresponding to the remote controller  200  is moved and displayed in response to the motion of the remote controller  200  in a 3D space, as shown in these figures, the remote controller  200  can be named a spatial remote controller or a 3D pointing device. 
       FIG. 4A (b) illustrates that, when the user moves the remote controller  200  to the left, the pointer  205  moves to the left on the display device  180  in response to the motion of the remote controller  200 . Information about the motion of the remote controller  200 , sensed by a sensor of the remote controller  200 , is transmitted to the content transmission device. The content transmission device may calculate the coordinates of the pointer  205  from information about the motion of the remote controller  200 . The content transmission device may display the pointer  205  such that the pointer  205  corresponds to the calculated coordinates. 
       FIG. 4A (c) illustrates when the user moves the remote controller  200  away from the display device  180  while pressing a specific button on the remote controller  200 . As a result, the selected area in the display device  180  corresponding to the pointer  205  can be zoomed in, and thus enlarged, on the display device  180 . When the user moves the remote controller  200  toward the display device  180 , the selected area in the display device  180  corresponding to the pointer  205  can be zoomed out, and thus contracted, on the display device  180 . Alternatively, the selected area may be zoomed out when the remote controller  200  moves away from the display device  180 , and the selected area may be zoomed in when the remote controller  200  moves toward the display device  180 . 
     The upward, downward, leftward, and rightward movement of the remote controller  200  may not be recognized in the state in which a specific button of the remote controller  200  is pressed. That is, when the remote controller  200  moves away from or toward the display device  180 , the upward, downward, leftward, and rightward movement of the remote controller  200  may not be recognized, but only the forward and rearward movement of the remote controller  200  may be recognized. In the state in which a specific button of the remote controller  200  is not pressed, only the pointer  205  moves in response to the upward, downward, leftward, and rightward movement of the remote controller  200 . The movement speed or direction of the pointer  205  may correspond to the movement speed or direction of the remote controller  200 . 
     Next,  FIG. 4B  is an internal block diagram of the remote controller shown in  FIG. 2A . Referring to this figure, the remote controller  200  may include a wireless communication unit  420 , a user input unit  430 , a sensor unit  440 , an output unit  450 , a power supply unit  460 , a memory  470 , and a controller  480 . 
     The wireless communication unit  420  can transmit and receive signals to and from any one of the content transmission devices according to the embodiments of the present invention described above. In the following, the content transmission device  100   a , which is one of the content transmission devices according to the embodiments of the present invention, will be described by way of example. 
     In this embodiment, the wireless communication unit  420  may include an RF module  421  for transmitting and receiving signals to and from the content transmission device  100   a  in accordance with an RF communication standard. In addition, the wireless communication unit  420  may further include an IR module  423  for transmitting and receiving signals to and from the content transmission device  100   a  in accordance with an IR communication standard. 
     In this embodiment, the remote controller  200  can transmit a signal containing information about the motion of the remote controller  200  to the content transmission device  100   a  through the RF module  421 . In addition, the remote controller  200  can receive a signal from the content transmission device  100   a  through the RF module  421 . As needed, the remote controller  200  can transmit a command, such as a power on/off command, a channel change command, or a volume change command, to the content transmission device  100   a  through the IR module  423 . 
     The user input unit  430  may include a keypad, a button, a touchpad, or a touchscreen. The user can input a command related to the content transmission device  100   a  to the remote controller  200  by manipulating the user input unit  430 . When the user input unit  430  includes a hard key button, the user can input a command related to the content transmission device  100   a  to the remote controller  200  by pushing the hard key button. When the user input unit  430  includes a touchscreen, the user can input a command related to the content transmission device  100   a  to the remote controller  200  by touching a soft key on the touchscreen. In addition, the user input unit  430  may include various kinds of input tools, such as a scroll key and a jog wheel, which do not limit the scope of the present invention. 
     The sensor unit  440  may include a gyro sensor  441  or an acceleration sensor  443 . The gyro sensor  441  can sense information about the motion of the remote controller  200 . For example, the gyro sensor  441  may sense information about the motion of the remote controller  200  in x, y, and z-axis directions. The acceleration sensor  443  may sense information about the speed of movement of the remote controller  200 . The sensor unit  440  may further include a distance sensor for sensing the distance between the remote controller  200  and the display device  180 . 
     The output unit  450  may output a video or audio signal corresponding to the manipulation of the user input unit  430  or to a signal received from the content transmission device  100   a . The user can recognize whether the user input unit  430  has been manipulated or whether the content transmission device  100   a  has been controlled, through the output unit  450 . 
     For example, the output unit  450  may include a light emitting diode (LED) module  451  configured to be turned on when the user input unit  430  is manipulated or when a signal is received from or transmitted to the content transmission device  100   a  through the wireless communication module  420 , a vibration module  453  for generating vibration, a sound output module  455  for outputting sound, or a display module  457  for outputting a video. 
     The power supply unit  460  may supply power to the remote controller  200 . When the remote controller  200  remains stationary for a predetermined time, the power supply unit  460  may interrupt the supply of power to the remote controller  200  in order to reduce power consumption. The power supply unit  460  may resume the supply of power to the remote controller  200  when a predetermined key of the remote controller  200  is manipulated. 
     The memory  470  may store various kinds of programs and application data necessary to control or drive the remote controller  200 . The remote controller  200  may wirelessly transmit and receive signals to and from the content transmission device  100   a  in a predetermined frequency band through the RF module  421 . The controller  480  of the remote controller  200  may store, in the memory  470 , information about the frequency band within which signals are transmitted to and received from the content transmission device  100   a , which is paired with the remote controller  200  in a wireless fashion, and may refer to the stored information. 
     The controller  480  can control the overall operation of the remote controller  200 . The controller  480  can transmit a signal corresponding to the manipulation of a predetermined key of the user input unit  430  or a signal corresponding to the motion of the remote controller  200  sensed by the sensor unit  440  to the content transmission device  100   a  through the wireless communication unit  420 . 
     The user input interface unit  150  of the content transmission device  100   a  may include a wireless communication unit  411  for wirelessly transmitting and receiving signals to and from the remote controller  200  and a coordinate value calculator  415  for calculating a coordinate value of a pointer corresponding to the motion of the remote controller  200 . 
     The user input interface unit  150  can wirelessly transmit and receive signals to and from the remote controller  200  through an RF module  412 . In addition, the user input interface unit  150  can receive a signal transmitted by the remote controller  200  in accordance with an IR communication standard through an IR module  413 . 
     The coordinate value calculator  415  can correct a hand tremor or an error in a signal corresponding to the motion of the remote controller  200 , received through the wireless communication unit  411 , in order to calculate coordinate values (x,y) of the pointer  205  that is to be displayed on the display device  180 . 
     A signal from the remote controller  200 , which is input to the content transmission device  100   a  through the user input interface unit  150 , is transmitted to the controller  170  of the content transmission device  100   a . The controller  170  may differentiate information about the motion and key manipulation of the remote controller  200  from the signal received from the remote controller  200 , and can control the content transmission device  100   a  in response thereto. 
     In another example, the remote controller  200  may calculate coordinate values of the pointer corresponding to the motion thereof, and may output the calculated coordinate values to the user input interface unit  150  of the content transmission device  100   a . In this instance, the user input interface unit  150  of the content transmission device  100   a  can transmit information about the received coordinate values of the pointer to the controller  170  without correcting a hand tremor or an error. In a further example, the coordinate value calculator  415  may be provided in the controller  170 , rather than in the user input interface unit  150 , unlike what is shown in this figure. 
     Next,  FIG. 5  is an internal block diagram of the mobile terminal shown in  FIG. 1 . Referring to this figure, the terminal  600  may include a wireless communication unit  610 , an audio/video (AN) input unit  620 , a user input unit  630 , a sensing unit  640 , an output unit  650 , a memory  660 , an interface unit  625 , a controller  670 , and a power supply unit  690 . The wireless communication unit  610  may include a broadcast reception module  611 , a mobile communication module  613 , a wireless Internet module  615 , a sound communication unit  617 , and a global positioning system (GPS) module  619 . 
     The broadcast reception module  611  can receive a broadcast signal and/or broadcast-related information from an external broadcast management server through a broadcast channel. The broadcast channel may include a satellite channel and a terrestrial channel. The broadcast signal and/or the broadcast-related information received through the broadcast reception module  611  may be stored in the memory  660 . 
     The mobile communication module  613  can transmit and receive a wireless signal to and from at least one selected from among a base station, an external terminal, and a server over a mobile communication network. The wireless signal may include a voice call signal, a video communication call signal, or various types of data based on text/multimedia message transmission and reception. 
     The wireless Internet module  615  is a module for wireless Internet access. The wireless Internet module  615  may be mounted inside or outside the mobile terminal  600 . For example, the wireless Internet module  615  can perform wireless communication based on Wi-Fi or wireless communication based on Wi-Fi Direct. 
     The sound communication unit  617  can perform sound communication. In a sound communication mode, the sound communication unit  617  may add predetermined information data to audio data that are to be output in order to output sound. In addition, the sound communication unit  617  may extract predetermined information from an external sound in the sound communication mode. Bluetooth, radio frequency identification (RFID), infrared data association (IrDA), ultra wideband (UWB), or ZigBee may be used as short-range communication technology. 
     The GPS module  619  can receive position information from a plurality of artificial GPS satellites. The A/V input unit  620  may be provided for inputting an audio signal or video signal. The A/V input unit  620  may include a camera  621  and a microphone  623 . 
     The user input unit  630  can generate key input data that are input by the user to control the operation of the terminal. Thus, the user input unit  630  may include a keypad, a dome switch, and a touchpad (static pressure or electrostatic). Particularly, when the touchpad forms a layered structure together with a display unit  680 , an assembly consisting of the touchpad and the display unit  680  may be called a touchscreen. 
     The sensing unit  640  can sense the current state of the mobile terminal  600 , such as the activated or deactivated state of the mobile terminal  600 , the position of the mobile terminal  600 , and whether user contact with the mobile terminal  600  has occurred, to generate a sensing signal for controlling the operation of the mobile terminal  600 . 
     The sensing unit  640  may include a proximity sensor  641 , a pressure sensor  643 , and a motion sensor  645 . The motion sensor  645  may sense the motion or position of the mobile terminal  600  using an acceleration sensor, a gyro sensor, a gravity sensor, or the like. In particular, the gyro sensor is a sensor for measuring the angular velocity of the mobile terminal  600 . The gyro sensor may sense the angle at which the mobile terminal  600  is rotated relative to a reference direction. 
     The output unit  650  may include a display unit  680 , an audio output unit  653 , an alarm unit  655 , and a haptic module  657 . The display unit  680  may output information that is processed by the mobile terminal  600 . For example, the display unit  680  may display information that is processed by the mobile terminal  600 . 
     When the display unit  680  and the touchpad are disposed as a layered structure to form a touchscreen as described above, the display unit  680  may also be used as an input device that allows a user to input information via touch, in addition to an output device. The audio output unit  653  may output audio data, which are received from the wireless communication unit  610  or are stored in the memory  660 . The audio output unit  653  may include a speaker and a buzzer. 
     The alarm unit  655  can output a signal indicating the occurrence of an event of the mobile terminal  600 . For example, the alarm unit  655  can output a signal in the form of vibrations. The haptic module  657  may generate a variety of tactile effects that the user can feel. A typical example of the tactile effects generated by the haptic module  657  may be a vibration effect. 
     The memory  660  can store a program for processing or control of the controller  670 , or may temporarily store input or output data (e.g. phonebooks, messages, still pictures, and motion pictures). The interface unit  625  can provide an interface between the mobile terminal  600  and all external devices connected to the mobile terminal  600 . The interface unit  625  can receive data or power from the external devices, and transfer the received data or power to the respective components of the mobile terminal  600 . In addition, data may be transmitted from the mobile terminal  600  to the external devices via the interface unit  625 . 
     The controller  670  can control the operation of the respective components of the mobile terminal  600 , thereby controlling the overall operation of the mobile terminal  600 . For example, the controller  670  can perform control or processing for voice communication, data communication, and video communication. In addition, the controller  670  may further include a multimedia playback module  681  for playing back multimedia content. The multimedia playback module  681  may be incorporated into the controller  670  in the form of hardware. Alternatively, the multimedia playback module  681  may be configured separately from the controller  670  in the form of software. 
     The power supply unit  690  can supply external power or internal power to the respective components of the mobile terminal  600  under the control of the controller  670 . The block diagram of the mobile terminal  600  shown in  FIG. 5  is a view illustrating an embodiment of the present invention. Respective components of the block diagram may be combined, added, or omitted depending on the specifications of the mobile terminal  600  that is actually embodied. That is, two or more components may be combined into a single component or one component may be divided into two or more components as needed. In addition, the function performed by each block is given for description of the embodiment of the invention, and detailed actions or device pertaining thereto do not limit the scope of the invention. 
     Next,  FIG. 6  is a flowchart showing an example of a method of operating a mobile terminal according to an embodiment of the present invention, and  FIGS. 7 to 12G  are reference views illustrating the operation method of  FIG. 6 . Referring first to  FIG. 6 , the controller  670  of the mobile terminal  600  executes a content playback application in response to an input for the execution of the content playback application (S 610 ). 
     For example, when the execution of a content playback application is input and a content playback execution screen is displayed on the mobile terminal  600 , as shown in  FIG. 8B , the controller  670  of the mobile terminal  600  can execute the content playback application, and can display a content playback setting screen  820 , as shown in  FIG. 8B . 
     For example, when the execution of a content playback application is input and a content playback execution screen is displayed on the mobile terminal  600 , as shown in  FIG. 8B , the controller  670  of the mobile terminal  600  can transmit a pairing signal to the content transmission device  100   a  through the communication unit  610 . 
     Subsequently, the controller  670  of the mobile terminal  600  can receive a pairing response signal from the content transmission device  100   a  through the communication unit  610 . Consequently, the controller  670  of the mobile terminal  600  can perform a control operation to achieve pairing between the mobile terminal  600  and the content transmission device  100   a.    
     The pairing signal, the pairing response signal, and the signals that are transmitted and received between the mobile terminal  600  and the content transmission device  100   a  after pairing may be RF signals. After pairing has been completed, the controller  670  of the mobile terminal  600  can display a content playback setting screen  820 , including an item related to the at least one content reception device, an item related to at least one of the input terminals through which the at least one content reception device is connected to the content transmission device  100   a , and a thumbnail image corresponding to the item related to the at least one of the input terminals, in response to the input for the execution of the content playback application. 
     As shown in  FIG. 8B , the content playback setting screen  820  may include items related to a plurality of content reception devices, such as TV 1 , TV 2 , STB (a set-top box), BD (a Blu-ray player), and Pad (a tablet device). As shown in  FIG. 8B , the content playback setting screen  820  may also include items related to a plurality of input terminals, such as RF (corresponding to an antenna terminal), HDMI, USB, LAN (a wired communication terminal), Wi-Fi (a wireless communication terminal), Composite, and AV, which are provided in the content transmission device  100   a.    
     Further, as shown in  FIG. 8B , the content playback setting screen  820  may include thumbnail images corresponding to RF, HDMI, USB, LAN, Wi-Fi, Composite, and AV. That is, the content playback setting screen  820  may include thumbnail images of content data that are input through the terminals, such as RF, HDMI, USB, LAN, Wi-Fi, Composite, and AV. 
     The controller  670  of the mobile terminal  600  can select a content reception device and an input terminal in response to an input for selecting the content reception device and an input for selecting the input terminal (S 620 ). Subsequently, the controller  670  of the mobile terminal  600  can transmit content data received through the selected input terminal to the selected content reception device (S 630 ). 
     When the content playback setting screen  820  is displayed, the controller  670  of the mobile terminal  600  can select an item related to a first content reception device from among the items related to the content reception devices in the content playback setting screen  820 , and select an item related to a first input terminal from among the items related to the input terminals in the content playback setting screen  820 , in response to a user&#39;s touch input. 
     When the item related to the first content reception device has been selected from among the items related to the content reception devices in the content playback setting screen  820  and the item related to the first input terminal has been selected from among the items related to the input terminals in the content playback setting screen  820 , the controller  670  of the mobile terminal  600  can transmit the selected information to the content transmission device  100   a.    
     As a result, the content transmission device  100   a  can wirelessly transmit content data, received through the first input terminal, to the first content reception device based on the information about the selection of the first content reception device and the information about the selection of the first input terminal, received from the mobile terminal  600 . When transmitting the content data, the content transmission device  100   a  may use a specific frequency band, which is set based on the operation shown in  FIG. 7 . 
     Next,  FIG. 7  is a flowchart showing a method of operating the content transmission device  100   a . Referring to this figure, the controller  170  of the content transmission device  100   a  can transmit a pairing signal to the first content reception device  100   ba  through the communication unit  135 , and can receive a pairing response signal from the first content reception device  100   ba  through the communication unit  135 . 
     As a result, the controller  170  of the content transmission device  100   a  can perform pairing between the content transmission device  100   a  and the first content reception device  100   ba . After pairing has been completed, the controller  170  of the content transmission device  100   a  can check a first frequency band for the transmission of content data (S 710 ). 
     The first frequency band may be a frequency band of 2.4 GHz for Wi-Fi communication. For example, the controller  170  of the content transmission device  100   a  can transmit a reference signal of the first frequency band to the first content reception device  100   ba , and can receive a response signal from the first content reception device  100   ba.    
     The controller  170  of the content transmission device  100   a  can compare the response signal with the reference signal in order to check a data transfer rate, the state of the frequency band, etc. The controller  170  of the content transmission device  100   a  can determine whether the first frequency band is usable by checking the frequency band (S 715 ). Upon determining that the first frequency band is usable, the controller  170  of the content transmission device  100   a  can transmit content data to the first content reception device  100   ba  in the first frequency band (S 720 ). 
     When the content data are stably transmitted to the first content reception device  100   ba  in the first frequency band, the controller  170  of the content transmission device  100   a  can transmit information about the transmission in the first frequency band to the mobile terminal  600 . Consequently, when the transmission is being performed in the first frequency band, as shown in  FIG. 8H , the controller  670  of the mobile terminal  600  can display a first object  888  indicating that the transmission is being performed in the first frequency band. 
     Upon determining at step S 715  that the first frequency band is not usable, step S 725  is performed. That is, the controller  170  of the content transmission device  100   a  can check a second frequency band for the transmission of content data (S 725 ). The second frequency band may be a frequency band of 5 GHz for Wi-Fi communication. For example, the controller  170  of the content transmission device  100   a  can transmit a reference signal of the second frequency band to the first content reception device  100   ba , and can receive a response signal from the first content reception device  100   ba.    
     The controller  170  of the content transmission device  100   a  can compare the response signal with the reference signal in order to check a data transfer rate, the state of the frequency band, etc. The controller  170  of the content transmission device  100   a  can determine whether the second frequency band is usable by checking the frequency band (S 728 ). Upon determining that the second frequency band is usable, the controller  170  of the content transmission device  100   a  can transmit content data to the first content reception device  100   ba  in the second frequency band (S 730 ). 
     When the content data are stably transmitted to the first content reception device  100   ba  in the second frequency band, the controller  170  of the content transmission device  100   a  can transmit information about the transmission in the second frequency band to the mobile terminal  600 . Consequently, when the transmission is being performed in the second frequency band, as shown in  FIG. 8I , the controller  670  of the mobile terminal  600  can display a second object  889  indicating that the transmission is being performed in the second frequency band. 
     Upon determining at step S 728  that the second frequency band is not usable, step S 735  is performed. That is, the controller  170  of the content transmission device  100   a  can check a third frequency band for the transmission of content data (S 735 ). The third frequency band may be a frequency band of 50 GHz for WiGig or WiHD communication. 
     For example, the controller  170  of the content transmission device  100   a  can transmit a reference signal of the third frequency band to the first content reception device  100   ba , and can receive a response signal from the first content reception device  100   ba . The controller  170  of the content transmission device  100   a  can compare the response signal with the reference signal in order to check a data transfer rate, the state of the frequency band, etc. 
     The controller  170  of the content transmission device  100   a  can determine whether the third frequency band is usable by checking the frequency band (S 738 ). Upon determining that the third frequency band is usable, the controller  170  of the content transmission device  100   a  can transmit content data to the first content reception device  100   ba  in the third frequency band (S 740 ). When the content data are stably transmitted to the first content reception device  100   ba  in the third frequency band, the controller  170  of the content transmission device  100   a  can transmit information about the transmission in the third frequency band to the mobile terminal  600 . 
     Consequently, when the transmission is being performed in the third frequency band, as shown in  FIG. 8J , the controller  670  of the mobile terminal  600  can display a third object  891  indicating that the transmission is being performed in the third frequency band. 
     Since three frequency bands are used, as described above, content data may be stably transmitted from the content transmission device  100   a  to the first content reception device  100   ba . Also, since three frequency bands are used, the video display system based on the wireless transmission of content data shown in  FIG. 1  may be named a three-band system. 
     Next,  FIG. 8A  shows a video display system  10  based on the wireless transmission of content data as shown in  FIG. 1 . In an embodiment of the present invention, the mobile terminal  600  can select an input terminal of the content transmission device  100   a  and a content reception device. 
     The mobile terminal  600  can select one of the content reception devices  100   ba ,  100   bb , . . . , and select one of the input terminals provided in the content transmission device  100   a . When the execution of a content playback application is input and a content playback execution screen is displayed on the mobile terminal  600 , as shown in  FIG. 8B , the controller  670  of the mobile terminal  600  can execute the content playback application, and can display a content playback setting screen  820 , as shown in  FIG. 8B . 
     As shown in  FIG. 8B , the content playback setting screen  820  may include items related to a plurality of content reception devices, such as TV 1 , TV 2 , STB (a set-top box), BD (a Blu-ray player), and Pad (a tablet device). As shown in  FIG. 8B , the content playback setting screen  820  may also include items related to a plurality of input terminals, such as RF (corresponding to an antenna terminal), HDMI, USB, LAN (a wired communication terminal), Wi-Fi (a wireless communication terminal), Composite, and AV, which are provided in the content transmission device  100   a . As shown in  FIG. 8B , the content playback setting screen  820  may include thumbnail images corresponding to RF, HDMI, USB, LAN, Wi-Fi, Composite, and AV. That is, the content playback setting screen  820  may include thumbnail images of content data that are input through the terminals, such as RF, HDMI, USB, LAN, Wi-Fi, Composite, and AV. 
       FIG. 8C  shows when a TV 1  item  831  in the content playback setting screen  820  is selected by a finger  800  of the user. That is,  FIG. 8C  shows when a first content reception device  100   ba  is selected from a plurality of content reception devices. In addition,  FIG. 8D  shows when an HDMI item in the content playback setting screen  820  is selected by the finger  800  of the user. That is,  FIG. 8D  shows when an HDMI terminal is selected as an input terminal. 
     The controller  670  of the mobile terminal  600  can display a thumbnail image  852  corresponding to content data input through the HDMI terminal in a highlighted state, as shown in  FIG. 8D , in response to the selection of the HDMI item. 
     In addition,  FIG. 8E  shows when the thumbnail image  852  corresponding to the HDMI item in the content playback setting screen  820  is selected by the finger  800  of the user. As a result, the controller  670  of the mobile terminal  600  can transmit information about the selection of the first content reception device  100   ba  corresponding to the TV 1  item  831  and information about the selection of the HDMI terminal of the content transmission device  100   a  to the content transmission device  100   a.    
     The controller  170  of the content transmission device  100   a  can transmit content data input through the HDMI terminal of the content transmission device  100   a  to the first content reception device  100   ba , which corresponds to the TV 1  item  831  based on the information received from the mobile terminal  600 . 
     When the thumbnail image  852  corresponding to the HDMI item in the content playback setting screen  820  is selected by the finger  800  of the user in  FIG. 8E , the controller  670  of the mobile terminal  600  can display a screen  860  for wireless pairing, as shown in  FIG. 8F . 
     That is, the controller  670  of the mobile terminal  600  can display a screen  860  for wireless pairing between the content transmission device  100   a  and the first content reception device  100   ba  in response to the selection of the first content reception device  100   ba  from among the at least one content reception device  100   b  and the selection of the first input terminal from among the input terminals. 
     The screen  860  for wireless pairing may include an item related to the status of the transmission device, an item related to the status of the reception device, a thumbnail image  892  corresponding to content data to be transmitted, and a pairing item  883 . 
       FIG. 8F  shows when the pairing item  883  in the screen  860  for wireless pairing is selected by the finger  800  of the user. Consequently, the controller  670  of the mobile terminal  600  can transmit a control signal for performing pairing between the content transmission device  100   a  and the first content reception device  100   ba  to the content transmission device  100   a.    
     The controller  170  of the content transmission device  100   a  can receive the control signal from the mobile terminal, and can perform pairing between the content transmission device  100   a  and the first content reception device  100   ba  based on the received control signal. 
     As described above, the controller  170  of the content transmission device  100   a  can transmit a pairing signal to the first content reception device  100   ba , and can perform pairing based on a pairing response signal received from the first content reception device  100   ba.    
     The controller  170  of the content transmission device  100   a  can transmit a pairing completion signal to the mobile terminal  600  after pairing has been completed. When wireless pairing between the content transmission device  100   a  and the first content reception device  100   ba  has been completed, the controller  670  of the mobile terminal  600  can display a transmission start object  886  for the transmission of content data, as shown in  FIG. 8G . 
     Alternatively, when wireless pairing between the content transmission device  100   a  and the first content reception device  100   ba  has been completed, the controller  670  of the mobile terminal  600  can perform a control operation to switch the pairing item shown in  FIG. 8F  to a start item  884  and then to display the start item  884 . When the start item  884  is selected by the finger  800  of the user, as shown in  FIG. 8G , the controller  670  of the mobile terminal  600  can transmit a data transmission start signal to the content transmission device  100   a.    
     The controller  170  of the content transmission device  100   a  can transmit content data input through the HDMI terminal of the content transmission device  100   a  to the first content reception device  100   ba  based on the data transmission start signal from the mobile terminal  600 . As a result, content data desired by the user can be transmitted, thereby improving user convenience. 
     When the content data are stably transmitted to the first content reception device  100   ba  in a first frequency band, the controller  170  of the content transmission device  100   a  can transmit information about the transmission in the first frequency band to the mobile terminal  600 . Consequently, when the transmission is being performed in the first frequency band, as shown in  FIG. 8H , the controller  670  of the mobile terminal  600  can display a first object  888  indicating that the transmission is being performed in the first frequency band. 
     When the content data are stably transmitted to the first content reception device  100   ba  in a second frequency band, the controller  170  of the content transmission device  100   a  can transmit information about the transmission in the second frequency band to the mobile terminal  600 . Consequently, when the transmission is being performed in the second frequency band, as shown in  FIG. 8I , the controller  670  of the mobile terminal  600  can display a second object  889 , indicating that the transmission is being performed in the second frequency band. 
     When the content data are stably transmitted to the first content reception device  100   ba  in a third frequency band, the controller  170  of the content transmission device  100   a  can transmit information about the transmission in the third frequency band to the mobile terminal  600 . Consequently, when the transmission is being performed in the third frequency band, as shown in  FIG. 8J , the controller  670  of the mobile terminal  600  can display a third object  891 , indicating that the transmission is being performed in the third frequency band. As a result, the user can easily recognize the frequency band in which the transmission is being performed. 
     The controller  170  of the content transmission device  100   a  can transmit information about the content data that are being transmitted to the mobile terminal  600 . In addition, the controller  670  of the mobile terminal  600  can receive the content data, and can display the received content data in a portion of the screen. 
     Specifically, the controller  670  of the mobile terminal  600  can display a thumbnail image  1161  corresponding to the content data that are being transmitted on another screen, e.g. an Internet screen  1162 , in an overlaying fashion. The controller  670  of the mobile terminal  600  can transmit information set based on a setting input of at least one selected from among the image size, playback time, fast-forward, and volume of a video based on the displayed content data to the content transmission device  100   a.    
     Next,  FIG. 8L  shows when the thumbnail image  1161  is selected by the finger  800  of the user. When the thumbnail image  1161  is selected by the finger  800  of the user, the controller  670  of the mobile terminal  600  can display a playback time setting object  1163  in addition to the display of an enlarged thumbnail image  1161   a , as shown in  FIG. 8I . 
     When the current time P 1  is not selected but the previous time P 2  is selected in the playback time setting object  1163  by the finger  800  of the user, the controller  670  of the mobile terminal  600  can transmit information about the previous time P 2  to the content transmission device  100   a.    
     The controller  170  of the content transmission device  100   a  can perform a control operation to content data from the changed playback time are transmitted to the first content reception device  100   ba  based on information about the changed playback time from the mobile terminal  600 . Consequently, the user can directly view the content data from a desired time. 
     When the playback time is changed, the controller  170  of the content transmission device  100   a  can transmit corresponding content data to the mobile terminal  600 . As a result, the controller  670  of the mobile terminal  600  can display a thumbnail image corresponding to the content data, the playback time of which has been changed. The controller  670  of the mobile terminal  600  can sequentially display thumbnail images corresponding to the items related to the input terminals in the content playback setting screen  820  based on thumbnail images that are sequentially received from the content transmission device  100   a.    
     Next,  FIG. 9A  shows when only two thumbnail images  851  and  852  are displayed in a content playback setting screen  820   b  at the time T 1  and other thumbnail images  859  are not displayed, and  FIG. 9B  shows when only three thumbnail images  851 ,  852 , and  853  are displayed in a content playback setting screen  820   b  at the time T 2  and other thumbnail images  858  are not displayed. 
     The controller  670  of the mobile terminal  600  can display thumbnail images corresponding to items related to input terminals in the content playback setting screen  820  when the number of the thumbnail images is changed based on the item related to the content reception device  100   b  that is selected. 
       FIG. 10A  shows when a TV 1  item  831  is selected in the content playback setting screen  820 , with the result that the number of thumbnail images corresponding to input terminals through which content data can be transmitted is 7, and  FIG. 10B  shows when a Pad item  835  is selected in the content playback setting screen  820 , with the result that the number of thumbnail images corresponding to input terminals through which content data can be transmitted is 3. 
     The controller  170  of the content transmission device  100   a  can receive information about the selected content reception device from the mobile terminal  600 , and recognize input terminals through which content data can be transmitted based on the information about the selected content reception device. When the TV 1  item is selected, as shown in  FIG. 10A , the controller  170  of the content transmission device  100   a  can transmit information indicating that all input terminals are usable or thumbnail images corresponding to the usable input terminals to the mobile terminal  600 , since all content data can be received and displayed for TV. In addition, the controller  670  of the mobile terminal  600  can perform a control operation to the thumbnail images are activated and displayed, as shown in  FIG. 10A . 
     When the Pad item is selected, as shown in  FIG. 10B , the controller  170  of the content transmission device  100   a  can transmit information indicating that some input terminals are usable or thumbnail images corresponding to the usable input terminals to the mobile terminal  600 , since some content data can be received and displayed on Pad (a tablet device). In addition, the controller  670  of the mobile terminal  600  can perform a control operation to the thumbnail images are activated and displayed, as shown in  FIG. 10B . 
     Next,  FIG. 11A  shows when information about an input for the execution of a content playback application is transmitted to the mobile terminal  600  when a specific key  201  of the remote controller  200  is operated. As the result of the input for the execution of the content playback application, as shown in this figure, a content playback setting screen  1120  can be displayed on the mobile terminal  600 . That is, the controller  670  of the mobile terminal  600  can display a content playback setting screen  1120 , including a power on item, a power off item, an input item, and a thumbnail image corresponding to the input item, in response to the input for the execution of the content playback application, as shown in  FIG. 11A . 
     The controller  670  of the mobile terminal  600  can transmit content data received through the first input terminal of the content transmission device  100   a  to the content reception device  100   b  based on the selection of the first input terminal as the input item. As shown in  FIG. 11A , the content playback setting screen  1120  may further include a channel setting item, a video setting item, and an audio setting item. 
     Next,  FIG. 11B  shows when information about an input for the execution of a content playback application is transmitted to the mobile terminal  600  when a specific application item  1112  is selected on the mobile terminal  600 . As the result of the input for the execution of the content playback application, the controller  670  of the mobile terminal  600  can display a content playback setting screen  1120 , including a power on item, a power off item, an input item, and a thumbnail image corresponding to the input item, in response to the input for the execution of the content playback application, as shown in  FIG. 11B . 
     In addition, control items  1122 ,  1123 ,  1125 , and  1126  may be further provided for the input item, the channel setting item, the video setting item, and the audio setting item, respectively. As a result, the input item, the channel setting item, the video setting item, and the audio setting item may be controlled. 
     When the power on item is selected in the content playback setting screen  1120 , the controller  670  of the mobile terminal  600  can transmit power on signals Sr 1 , Sr 2 , and Sr 3  to the content transmission device  100   a , the content reception device  100   b , and the display device  180 , respectively, as shown in  FIG. 11C . 
     After the content transmission device  100   a  is powered on in response to the power on signal, the controller  670  of the mobile terminal  600  can display a thumbnail image corresponding to the input item based on the reception of the thumbnail image corresponding to the input item from the content transmission device  100   a . That is, the thumbnail image shown in  FIGS. 11B and 11C  may be a thumbnail image received from the content transmission device  100   a  after the content transmission device  100   a  is powered on and pairing is performed. 
     After the content transmission device  100   a  is powered on in response to the power on signal, the controller  670  of the mobile terminal  600  can transmit a pairing signal to the content transmission device  100   a , and can perform a control operation to the mobile terminal  600  is connected to the content transmission device  100   a  based on a pairing response signal received from the content transmission device  100   a.    
     The controller  670  of the mobile terminal  600  can transmit a remote control signal to the content transmission device  100   a  based on the selection of the first input terminal as the input item in the content playback setting screen  1120 . In addition,  FIG. 11D  shows when a thumbnail image  1161  is highlighted as the result of selecting an RF/HDMI item. In this instance, the controller  670  of the mobile terminal  600  can transmit a remote control signal Sra, including information about the selection of the RF/HDMI item to the content transmission device  100   a.    
     The power on signals Sr 1 , Sr 2 , and Sr 3  shown in  FIG. 11C  and the remote control signal Sra shown in  FIG. 11D  may be based on different communication schemes. Further, the power on signals Sr 1 , Sr 2 , and Sr 3  shown in  FIG. 11C  may be IR signals, and the remote control signal Sra shown in  FIG. 11D  may be an RF signal. When an execution item  1165  shown in  FIG. 11D  is selected, the controller  670  of the mobile terminal  600  can transmit a remote control signal including information about the start of transmission to the content transmission device  100   a.    
     Consequently, the content transmission device  100   a  can start to transmit content data to the content reception device  100   b . As a result, a corresponding video  1160  can be displayed through the display device  180 . 
     Next,  FIG. 12A  shows a content transmission device  100   a , a plurality of content reception devices  100   ba  and  100   bb , and a plurality of display devices  180   a  and  180   b .  FIGS. 12B and 12C  show when a TV 1  item  831  and an HDMI item are selected in the content playback setting screen  820 . 
     In addition,  FIG. 12D  shows when a TV 2  item  832  and an RF item  841  are further selected when the TV 1  item  831  and the HDMI item are selected in the content playback setting screen  820 . When a second content reception device  100   bb  is further selected from among the at least one content reception device  100   b  and a second input terminal is further selected from among the input terminals, the controller  670  of the mobile terminal  600  can display the first content reception device  100   ba  and the first input terminal, which have already been selected, in a highlighted state, as shown in  FIG. 12D . 
     That is,  FIG. 12D  shows a highlighted TV 2  item  831   a  and a highlighted HDMI item  842   a . When the second content reception device  100   bb  is further selected from among the at least one content reception device  100   b  and the second input terminal is further selected from among the input terminals, the controller  670  of the mobile terminal  600  can transmit second content data received through the second input terminal of the content transmission device  100   a  to the second content reception device  100   bb.    
     Next,  FIG. 12E  shows when a screen for wireless transmission is displayed after a plurality of content reception devices is selected and a plurality of input terminals is selected. The screen for wireless transmission may include a transmission setting item, a reception setting item, thumbnail images  891  and  892  corresponding two content data to be transmitted, and a transmission start item  884 . 
     After wireless pairing between the content transmission device  100   a  and the first content reception device  100   ba  and between the content transmission device  100   a  and the second content reception device  100   bb  has been completed, the controller  670  of the mobile terminal  600  can display a transmission start object  886  for transmission of content data, as shown in  FIG. 12E . 
     As the result of selecting the transmission start item  884 , the content transmission device  100   a  can start to transmit content data to the first content reception device  100   ba  and to the second content reception device  100   bb , and the controller  670  of the mobile terminal  600  can display an object  1289  indicating that content data are being transmitted to the first content reception device  100   ba  and the second content reception device  100   bb  in different frequency bands, as shown in  FIG. 12F . 
     Next,  FIG. 12F  shows when an object  1289  indicating that content data are being transmitted to the first content reception device  100   ba  in a first frequency band and to the second content reception device  100   bb  in a third frequency band is displayed. When the content transmission device  100   a  starts to transmit content data to the first content reception device  100   ba  and to the second content reception device  100   bb  as the result of selecting the transmission start item  884 , a first video  1260   a  can be displayed through the first display device  180   a  corresponding to the first content reception device  100   ba , and a second video  1260   b  can be displayed through the second display device  180   b  corresponding to the second content reception device  100   bb , as shown in  FIG. 12G . As a result, users can view desired videos. 
     As is apparent from the above description, a mobile terminal according to an embodiment of the present invention includes a display unit, a communication unit to transmit a control signal to a content transmission device, and a controller to display a content playback setting screen, including an item related to at least one content reception device, an item related to at least one input terminal through which the at least one content reception device is connected to the content transmission device, and a thumbnail image corresponding to the item related to the at least one input terminal, in response to an input for the execution of a content playback application, wherein the controller performs a control operation to transmit content data received through a first input terminal of the content transmission device to a first content reception device based on the selection of the first content reception device from among the at least one content reception device and the selection of the first input terminal from among the at least one input terminal. Consequently, it is possible to easily perform the transmission of content from the content transmission device. 
     The controller of the mobile terminal performs a control operation to display a screen for wireless pairing between the content transmission device and the first content reception device in response to the selection of the first content reception device from among the at least one content reception device and the selection of the first input terminal from among the at least one input terminal. Consequently, it is possible to perform pairing between the content transmission device and the content reception device before the transmission of content such that the transmission of content can be easily performed. 
     The controller of the mobile terminal performs a control operation to display, when the content transmission device transmits the content data to the first content reception device in a first frequency band, a first object indicating that the content data are being transmitted in the first frequency band, such that when the content transmission device transmits the content data to the first content reception device in a second frequency band, a second object indicating that the content data are being transmitted in the second frequency band is displayed, and such that when the content transmission device transmits the content data to the first content reception device in a third frequency band, a third object indicating that the content data are being transmitted in the third frequency band is displayed. Consequently, it is possible to easily recognize the frequency band in which the content transmission device is transmitting content data to the content reception device. 
     The controller of the mobile terminal performs a control operation to display thumbnail images corresponding to the items related to the input terminals in the content playback setting screen in the state in which the number of the thumbnail images is changed based on the item related to the content reception device that is selected. Consequently, it is possible to easily recognize viewable content received through each input terminal. 
     The controller of the mobile terminal performs a control operation to receive the content data and display the received content data in a portion of the screen and such that information set based on a setting input of at least one selected from among the image size, playback time, fast-forward, and volume of a video based on the displayed content data is transmitted to the content transmission device. Consequently, it is possible to improve user convenience. 
     When a second content reception device is further selected from among the at least one content reception device and a second input terminal is further selected from among the at least one input terminal, the controller of the mobile terminal performs a control operation to further transmit second content data received through the second input terminal of the content transmission device to the second content reception device. Consequently, it is possible to transmit a plurality of content data. 
     In addition, a mobile terminal according to another embodiment of the present invention includes a display unit, a communication unit to transmit a control signal to a content transmission device, and a controller to display a content playback setting screen, including a power on item, a power off item, an input item, and a thumbnail image corresponding to the input item, in response to an input for the execution of a content playback application, wherein the controller performs a control operation to transmit content data received through a first input terminal of the content transmission device to a content reception device based on the selection of the first input terminal as the input item. Consequently, it is possible to easily perform the transmission of content from the content transmission device. 
     The controller of the mobile terminal performs a control operation to transmit power on signals to the content transmission device and to the content reception device when the power on item in the content playback setting screen is selected. Consequently, it is possible to power on the content transmission device, etc. 
     After the content transmission device is powered on in response to the power on signal, the controller of the mobile terminal performs a control operation to transmit a pairing signal to the content transmission device and is connected to the content transmission device based on a pairing response signal received from the content transmission device. 
     In addition, a content transmission device according to an embodiment of the present invention includes a communication unit to exchange data with a mobile terminal, an interface unit having a plurality of input terminals to receive content data from a plurality of external devices, and a controller to transmit, when receiving, from the mobile terminal, a remote control signal in response to the selection of a first content reception device from among at least one content reception device and the selection of a first input terminal from among the input terminals, content data received through the first input terminal of the content transmission device to the first content reception device. Consequently, it is possible to easily perform the transmission of content from the content transmission device. 
     In addition, when receiving, from the mobile terminal, the remote control signal in response to the selection of the first content reception device from among the at least one content reception device and the selection of the first input terminal from among the input terminals, the controller of the content transmission device performs a control operation to transmit a pairing signal to the first content reception device and pairing is performed based on a pairing response signal received from the first content reception device, and, after the pairing has been completed, the controller of the content transmission device performs a control operation to transmit the content data received through the first input terminal of the content transmission device to the first content reception device. Consequently, it is possible to easily perform the transmission of content from the content transmission device. 
     The controller of the content transmission device performs a control operation to transmit the content data received through the first input terminal of the content transmission device to the first content reception device in any one selected from among a first frequency band to a third frequency band depending on the state of wireless connection between the content transmission device and the first content reception device. Consequently, it is possible to transmit content data without loss or delay. 
     The operation method of the content transmission device and the mobile terminal according to an embodiment of the present invention may be implemented as code that can be written on a processor-readable recording medium and thus read by a processor provided in each device. The processor-readable recording medium may be any type of recording device in which data are stored in a processor-readable manner. The processor-readable recording medium may include, for example, a read only memory (ROM), a random access memory (RAM), a compact disk read only memory (CD-ROM), a magnetic tape, a floppy disk, and an optical data storage device, or may be implemented in the form of a carrier wave transmitted over the Internet. In addition, the processor-readable recording medium can be distributed over a plurality of computer systems connected to a network such that processor-readable code is written thereto and executed therefrom in a distributed manner. 
     It will be apparent that, although the preferred embodiments have been shown and described above, the present invention is not limited to the above-described specific embodiments, and various modifications and variations can be made by those skilled in the art without departing from the gist of the appended claims. Thus, it is intended that the modifications and variations should not be understood independently of the technical spirit or prospect of the present invention.