Patent Publication Number: US-2022217436-A1

Title: Display device and display system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Pursuant to  35  U.S.C. §  119 (a), this application claims the benefit of earlier filing date and right of priority to Korean Patent Application No.  10 - 2021 - 0002101  filed on Jan.  7 ,  2021 , the contents of which are hereby incorporated by reference herein in its entirety. 
     BACKGROUND 
     The present disclosure relates to a display device and a display system. 
     Recently, a digital TV service using a wired or wireless communication network has come into wide use. The digital TV service may provide various services which cannot be provided by an existing analog broadcast service. 
     For example, an Internet protocol television (IPTV) service or a smart TV service which is a digital TV service provides interactivity for enabling a user to actively select a type of a program to be viewed, a viewing time, etc. The IPTV service or the smart TV service may provide various additional services, e.g., Internet search, home shopping, online games, etc. based on such interactivity. 
     In general, such an IPTV is supported in a form in which an external device such as a set-top box is connected to a display device. In order to allow users to control a display device and a set-top box connected thereto more conveniently, when a power button of a remote control device (remote controller) is pressed, the remote control device may transmit an IR signal for controlling power to each of the display device and the set-top box. Each of the display device and the set-top box may receive an IR signal and control power to be turned on or off. 
     Meanwhile, only one of the display device and the set-top box may not be able to receive the IR signal due to a directivity problem or a device status. In this case, the power of one of the display device and the set-top box is turned on, but the other power is turned off, so that power synchronization is not performed. 
     In addition, when the power button of the remote control device is pressed again without power synchronization, the remote control device transmits the IR signal for controlling the power to each of the display device and the set-top box. Thus, the device that is in a power-on state is turned off, and the device that is in a power-off state is turned on. Consequently, the problem of the power state mismatch occurs repeatedly. 
     Meanwhile, as the prior art for improving the above-described problem, Korean Patent Registration No. 10-2094252 discloses a configuration for transmitting and receiving ultrasonic audio signals or signals of inaudible frequencies. In this case, there is a problem in that various signals such as ultrasonic audio signals or signals of inaudible frequencies are excessively released in the air. 
     SUMMARY 
     The present disclosure aims to solve the above-described problems. 
     The present disclosure aims to synchronize power states of a display device and an external device connected to the display device. In more detail, the present disclosure attempts to synchronize power of a display device with power of an external device connected to the display device with one power button provided in a remote control device. 
     The present disclosure aims to solve a problem in which power supplies of a display device and an external device connected to the display device operate reversely. 
     A display device according to an embodiment of the present disclosure comprises an external device interface connected to an external device, a user input interface configured to receive a power signal from a remote control device, and a controller configured to process the power signal to control power of the display device to be turned on or off, wherein, when the power signal is received, the controller is configured to determine whether to process the power signal based on whether a signal is inputted from the external device. 
     The power signal is a power control signal transmitted via infrared ray (IR) for controlling the power of the display device, and wherein the controller is configured to process the power control signal according to the presence or absence of the signal inputted from the external device. 
     When the power control signal is received in a state in which an elapsed time after the power of the display device is switched to on is within a reference time and the signal is not inputted from the external device, the controller is configured to maintain the power of the display device in an on state for a predetermined time after the power control signal is received. 
     When the power control signal is received in a state in which an elapsed time after the power of the display device is switched to on is within a reference time and the signal is not inputted from the external device, the controller is configured not to process a power control signal received for a predetermined time after the power control signal is received. 
     When the predetermined time has elapsed, the controller is configured to control the power of the display device to be turned off according to the received power control signal. 
     When the power control signal is received in a state in which the elapsed time after the power of the display device is switched to on is after the reference time and the signal is inputted from the external device, the controller is configured to maintain the power of the display device in an on state for a predetermined time after the power control signal is received. 
     When the power control signal is received in a state in which the elapsed time after the power of the display device is switched to on is after the reference time and the signal is inputted from the external device, the controller is configured not to process a power control signal received for a predetermined time after the power control signal is received. 
     When the predetermined time has elapsed or when the signal is not inputted from the external device before the elapse of the predetermined time, the controller is configured to control the power of the display device to be turned off. 
     The power signal is a power button detection signal of the remote control device transmitted through Bluetooth communication, and wherein the controller is configured to control the remote control device not to transmit the power control signal to the display device according to the presence or absence of the signal inputted from the external device. 
     When the power button detection signal is received in a state in which an elapsed time after the power of the display device is switched to on is within a reference time and the signal is not inputted from the external device, the controller is configured to control the remote control device to transmit a power control signal for controlling only the external device for a predetermined time after the power button detection signal is received. 
     When the power button detection signal is received in a state in which an elapsed time after the power of the display device is switched to on is within a reference time and the signal is inputted from the external device, the controller is configured to control the power of the display device to be turned off for a predetermined time after the power control signal is received. 
     When the power button detection signal is received in a state in which an elapsed time after the power of the display device is switched to on is after a reference time and the signal is inputted from the external device, the controller is configured to control the remote control device to transmit a power control signal for controlling only the external device. 
     When the power button detection signal is received in a state in which an elapsed time after the power of the display device is switched to on is after a reference time and the signal is inputted from the external device, the controller is configured to control the power of the display device to be turned off according to the power button detection signal. 
     A display system according to an embodiment of the present disclosure comprises a display device connected to an external device, and a remote control device configured to transmit a power signal to the display device, wherein, when the power signal is received from the remote control device, the display device is configured to determine whether to process the power signal based on whether a signal is inputted from the external device. 
     The remote control device is configured to when an input of a power button is detected, determine a power state of the display device based on whether the remote control device is connected to the display device via Bluetooth, and transmit a power signal to the display device through infrared ray (IR) or Bluetooth communication according to the power state of the display device. 
     The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features will be apparent from the description and drawings, and from the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram illustrating a configuration of a display device according to an embodiment of the present disclosure. 
         FIG. 2  is a block diagram illustrating a remote control device according to an embodiment of the present disclosure. 
         FIG. 3  is a view illustrating an actual configuration of a remote control device according to an embodiment of the present disclosure. 
         FIG. 4  is a view of utilizing a remote control device according to an embodiment of the present disclosure. 
         FIGS. 5 to 7  are flowcharts illustrating an operating method of a display system according to a first embodiment of the present disclosure. 
         FIGS. 8 to 10  are flowcharts illustrating an operating method of a display system according to a second embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Hereinafter, embodiments relating to the present disclosure will be described in detail with reference to the accompanying drawings. The suffixes “module” and “interface” for components used in the description below are assigned or mixed in consideration of easiness in writing the specification and do not have distinctive meanings or roles by themselves. 
       FIG. 1  is a block diagram illustrating a configuration of a display device according to an embodiment of the present disclosure. 
     Referring to  FIG. 1 , a display device  100  can include a broadcast reception module  130 , an external device interface  135 , a storage  140 , a user input interface  150 , a controller  170 , a wireless communication interface  173 , a voice acquisition module  175 , a display  180 , an audio output interface  185 , and a power supply  190 . 
     The broadcast reception module  130  can include a tuner  131 , a demodulator  132 , and a network interface  133 . 
     The tuner  131  can select a specific broadcast channel according to a channel selection command. The tuner  131  can receive broadcast signals for the selected specific broadcast channel. 
     The demodulator  132  can divide the received broadcast signals into video signals, audio signals, and broadcast program related data signals and restore the divided video signals, audio signals, and data signals to an output available form. 
     The network interface  133  can provide an interface for connecting the display device  100  to a wired/wireless network including internet network. The network interface  133  can transmit or receive data to or from another user or another electronic device through an accessed network or another network linked to the accessed network. 
     The network interface  133  can access a predetermined webpage through an accessed network or another network linked to the accessed network. That is, it can transmit or receive data to or from a corresponding server by accessing a predetermined webpage through network. 
     Then, the network interface  133  can receive contents or data provided from a content provider or a network operator. That is, the network interface  133  can receive contents such as movies, advertisements, games, VODs, and broadcast signals, which are provided from a content provider or a network provider, through network and information relating thereto. 
     Additionally, the network interface  133  can receive firmware update information and update files provided from a network operator and transmit data to an internet or content provider or a network operator. 
     The network interface  133  can select and receive a desired application among applications open to the air, through network. 
     The external device interface  135  can receive an application or an application list in an adjacent external device and deliver it to the controller  170  or the storage  140 . 
     The external device interface  135  can provide a connection path between the display device  100  and an external device. The external device interface  135  can receive at least one of image and audio outputted from an external device that is wirelessly or wiredly connected to the display device  100  and deliver it to the controller. The external device interface  135  can include a plurality of external input terminals. The plurality of external input terminals can include an RGB terminal, at least one High Definition Multimedia Interface (HDMI) terminal, and a component terminal. 
     An image signal of an external device inputted through the external device interface  135  can be outputted through the display  180 . A sound signal of an external device inputted through the external device interface  135  can be outputted through the audio output interface  185 . 
     An external device connectable to the external device interface  135  can be one of a set-top box, a Blu-ray player, a DVD player, a game console, a sound bar, a smartphone, a PC, a USB Memory, and a home theater system but this is just exemplary. 
     Additionally, some content data stored in the display device  100  can be transmitted to a user or an electronic device, which is selected from other users or other electronic devices pre-registered in the display device  100 . 
     The storage  140  can store signal-processed image, voice, or data signals stored by a program in order for each signal processing and control in the controller  170 . 
     Additionally, the storage  140  can perform a function for temporarily store image, voice, or data signals outputted from the external device interface  135  or the network interface  133  and can store information on a predetermined image through a channel memory function. 
     The storage  140  can store an application or an application list inputted from the external device interface  135  or the network interface  133 . 
     The display device  100  can play content files (for example, video files, still image files, music files, document files, application files, and so on) stored in the storage  140  and provide them to a user. 
     The user input interface  150  can deliver signals inputted from a user to the controller  170  or deliver signals from the controller  170  to a user. For example, the user input interface  150  can receive or process control signals such as power on/off, channel selection, and screen setting from the remote control device  200  or transmit control signals from the controller  170  to the remote control device  200  according to various communication methods such as Bluetooth, Ultra Wideband (WB), ZigBee, Radio Frequency (RF), and IR. 
     Additionally, the user input interface  150  can deliver, to the controller  170 , control signals inputted from local keys (not shown) such as a power key, a channel key, a volume key, and a setting key. 
     Image signals that are image-processed in the controller  170  can be inputted to the display  180  and displayed as an image corresponding to corresponding image signals. Additionally, image signals that are image-processed in the controller  170  can be inputted to an external output device through the external device interface  135 . 
     Voice signals processed in the controller  170  can be outputted to the audio output interface  185 . Additionally, voice signals processed in the controller  170  can be inputted to an external output device through the external device interface  135 . 
     Besides that, the controller  170  can control overall operations in the display device  100 . 
     Additionally, the controller  170  can control the display device  100  by a user command or internal program inputted through the user input interface  150  and download a desired application or application list into the display device  100  in access to network. 
     The controller  170  can output channel information selected by a user together with processed image or voice signals through the display  180  or the audio output interface  185 . 
     Additionally, according to an external device image playback command received through the user input interface  150 , the controller  170  can output image signals or voice signals of an external device such as a camera or a camcorder, which are inputted through the external device interface  135 , through the display  180  or the audio output interface  185 . 
     Moreover, the controller  170  can control the display  180  to display images and control broadcast images inputted through the tuner  131 , external input images inputted through the external device interface  135 , images inputted through the network interface, or images stored in the storage  140  to be displayed on the display  180 . In this case, an image displayed on the display  180  can be a still image or video and also can be a 2D image or a 3D image. 
     Additionally, the controller  170  can play content stored in the display device  100 , received broadcast content, and external input content inputted from the outside, and the content can be in various formats such as broadcast images, external input images, audio files, still images, accessed web screens, and document files. 
     Moreover, the wireless communication interface  173  can perform a wired or wireless communication with an external electronic device. The wireless communication interface  173  can perform short-range communication with an external device. For this, the wireless communication interface  173  can support short-range communication by using at least one of Bluetooth™, Radio Frequency Identification (RFID), Infrared Data Association (IrDA), Ultra Wideband (UWB), ZigBee, Near Field Communication (NFC), Wireless-Fidelity (Wi-Fi), Wi-Fi Direct, and Wireless Universal Serial Bus (USB) technologies. The wireless communication interface  173  can support wireless communication between the display device  100  and a wireless communication system, between the display device  100  and another display device  100 , or between networks including the display device  100  and another display device  100  (or an external server) through wireless area networks. The wireless area networks can be wireless personal area networks. 
     Herein, the other display device  100  can be a mobile terminal such as a wearable device (for example, a smart watch, a smart glass, and a head mounted display (HMD)) or a smartphone, which is capable of exchanging data (or inter-working) with the display device  100 . The wireless communication interface  173  can detect (or recognize) a communicable wearable device around the display device  100 . Furthermore, if the detected wearable device is a device authenticated to communicate with the display device  100 , the controller  170  can transmit at least part of data processed in the display device  100  to the wearable device through the wireless communication interface  173 . Accordingly, a user of the wearable device can use the data processed in the display device  100  through the wearable device. 
     The voice acquisition module  175  can acquire audio. The voice acquisition module  175  may include at least one microphone (not shown), and can acquire audio around the display device  100  through the microphone (not shown). 
     The display  180  can convert image signals, data signals, or OSD signals, which are processed in the controller  170 , or images signals or data signals, which are received in the external device interface  135 , into R, G, and B signals to generate driving signals. 
     Furthermore, the display device  100  shown in  FIG. 1  is just one embodiment of the present disclosure and thus, some of the components shown can be integrated, added, or omitted according to the specification of the actually implemented display device  100 . 
     That is, if necessary, two or more components can be integrated into one component or one component can be divided into two or more components and configured. Additionally, a function performed by each block is to describe an embodiment of the present disclosure and its specific operation or device does not limit the scope of the present disclosure. 
     According to another embodiment of the present disclosure, unlike  FIG. 1 , the display device  100  can receive images through the network interface  133  or the external device interface  135  and play them without including the tuner  131  and the demodulator  132 . 
     For example, the display device  100  can be divided into an image processing device such as a set-top box for receiving broadcast signals or contents according to various network services and a content playback device for playing contents inputted from the image processing device. 
     In this case, an operating method of a display device according to an embodiment of the present disclosure described below can be performed by one of the display device described with reference to  FIG. 1 , an image processing device such as the separated set-top box, and a content playback device including the display  180  and the audio output interface  185 . 
     The audio output interface  185  receives the audio processed signal from the controller  170  and outputs the sound. 
     The power supply  190  supplies the corresponding power throughout the display device  100 . In particular, the power supply  190  supplies power to the controller  170  that can be implemented in the form of a System On Chip (SOC), a display  180  for displaying an image, and the audio output interface  185  for outputting audio or the like. 
     Specifically, the power supply  190  may include a converter for converting an AC power source into a DC power source, and a DC/DC converter for converting a level of the DC source power. 
     Then, referring to  FIGS. 2 and 3 , a remote control device is described according to an embodiment of the present disclosure. 
       FIG. 2  is a block diagram illustrating a remote control device according to an embodiment of the present disclosure and  FIG. 3  is a view illustrating an actual configuration of a remote control device according to an embodiment of the present disclosure. 
     First, referring to  FIG. 2 , a remote control device  200  can include a fingerprint recognition module  210 , a wireless communication interface  220 , a user input interface  230 , a sensor  240 , an output interface  250 , a power supply  260 , a storage  270 , a controller  280 , and a voice acquisition module  290 . 
     Referring to  FIG. 2 , the wireless communication interface  220  transmits/receives signals to/from an arbitrary any one of display devices according to the above-mentioned embodiments of the present disclosure. 
     The remote control device  200  can include an RF module  221  for transmitting/receiving signals to/from the display device  100  according to the RF communication standards and an IR module  223  for transmitting/receiving signals to/from the display device  100  according to the IR communication standards. Additionally, the remote control device  200  can include a Bluetooth module  225  for transmitting/receiving signals to/from the display device  100  according to the Bluetooth communication standards. Additionally, the remote control device  200  can include an NFC module  227  for transmitting/receiving signals to/from the display device  100  according to the Near Field Communication (NFC) communication standards and a WLAN module  229  for transmitting/receiving signals to/from the display device  100  according to the Wireless LAN (WLAN) communication standards 
     Additionally, the remote control device  200  can transmit signals containing information on a movement of the remote control device  200  to the display device  100  through the wireless communication interface  220 . 
     Moreover, the remote control device  200  can receive signals transmitted from the display device  100  through the RF module  221  and if necessary, can transmit a command on power on/off, channel change, and volume change to the display device  100  through the IR module  223 . 
     The user input interface  230  can be configured with a keypad button, a touch pad, or a touch screen. A user can manipulate the user input interface  230  to input a command relating to the display device  100  to the remote control device  200 . If the user input interface  230  includes a hard key button, a user can input a command relating to the display device  100  to the remote control device  200  through the push operation of the hard key button. This will be described with reference to  FIG. 3 . 
     Referring to  FIG. 3 , the remote control device  200  can include a plurality of buttons. The plurality of buttons can include a fingerprint recognition button  212 , a power button  231 , a home button  232 , a live button  233 , an external input button  234 , a voice adjustment button  235 , a voice recognition button  236 , a channel change button  237 , a check button  238 , and a back button  239 . 
     The fingerprint recognition button  212  can be a button for recognizing a user&#39;s fingerprint. According to an embodiment of the present disclosure, the fingerprint recognition button  212  can perform a push operation and receive a push operation and a fingerprint recognition operation. The power button  231  can be button for turning on/off the power of the display device  100 . The power button  231  can be button for moving to the home screen of the display device  100 . The live button  233  can be a button for displaying live broadcast programs. The external input button  234  can be button for receiving an external input connected to the display device  100 . The voice adjustment button  235  can be button for adjusting the size of a volume outputted from the display device  100 . The voice recognition button  236  can be a button for receiving user&#39;s voice and recognizing the received voice. The channel change button  237  can be a button for receiving broadcast signals of a specific broadcast channel. The check button  238  can be a button for selecting a specific function and the back button  239  can be a button for returning to a previous screen. 
     Again,  FIG. 2  is described. 
     If the user input interface  230  includes a touch screen, a user can touch a soft key of the touch screen to input a command relating to the display device  100  to the remote control device  200 . Additionally, the user input interface  230  can include various kinds of input means manipulated by a user, for example, a scroll key and a jog key, and this embodiment does not limit the scope of the present disclosure. 
     The sensor  240  can include a gyro sensor  241  or an acceleration sensor  243  and the gyro sensor  241  can sense information on a movement of the remote control device  200 . 
     For example, the gyro sensor  241  can sense information on an operation of the remote control device  200  on the basis of x, y, and z axes and the acceleration sensor  243  can sense information on a movement speed of the remote control device  200 . Moreover, the remote control device  200  can further include a distance measurement sensor and sense a distance with respect to the display  180  of the display device  100 . 
     The output interface  250  can output image or voice signals corresponding to a manipulation of the user input interface  230  or corresponding to signals transmitted from the display device  100 . A user can recognize whether the user input interface  230  is manipulated or the display device  100  is controlled through the output interface  250 . 
     For example, the output interface  250  can include an LED module  251  for flashing, a vibration module  253  for generating vibration, a sound output module  255  for outputting sound, or a display module  257  for outputting an image, if the user input interface  230  is manipulated or signals are transmitted/received to/from the display device  100  through the wireless communication interface  220 . 
     Additionally, the power supply  260  supplies power to the remote control device  200  and if the remote control device  200  does not move for a predetermined time, stops the power supply, so that power waste can be reduced. The power supply  260  can resume the power supply if a predetermined key provided at the remote control device  200  is manipulated. 
     The storage  270  can store various kinds of programs and application data necessary for a control or operation of the remote control device  200 . If the remote control device  200  transmits/receives signals wirelessly through the display device  100  and the RF module  221 , the remote control device  200  and the display device  100  transmits/receives signals through a predetermined frequency band. 
     The controller  280  of the remote control device  200  can store, in the storage  270 , information on a frequency band for transmitting/receiving signals to/from the display device  100  paired with the remote control device  200  and refer to it. 
     The controller  280  controls general matters relating to a control of the remote control device  200 . The controller  280  can transmit a signal corresponding to a predetermined key manipulation of the user input interface  230  or a signal corresponding to a movement of the remote control device  200  sensed by the sensor  240  to the display device  100  through the wireless communication interface  220 . 
     Additionally, the voice acquisition module  290  of the remote control device  200  can obtain voice. 
     The voice acquisition module  290  can include at least one microphone  291  and obtain voice through the microphone  291 . 
     Then,  FIG. 4  is described. 
       FIG. 4  is a view of utilizing a remote control device according to an embodiment of the present disclosure. 
       FIG. 4A  illustrates that a pointer  205  corresponding to the remote control device  200  is displayed on the display  180 . 
     A user can move or rotate the remote control device  200  vertically or horizontally. The pointer  205  displayed on the display  180  of the display device  100  corresponds to a movement of the remote control device  200 . Since the corresponding pointer  205  is moved and displayed according to a movement on a 3D space as show in the drawing, the remote control device  200  can be referred to as a spatial remote controller. 
       FIG. 4B  illustrates that if a user moves the remote control device  200 , the pointer  205  displayed on the display  180  of the display device  100  is moved to the left in correspondence thereto. 
     Information on a movement of the remote control device  200  detected through a sensor of the remote control device  200  is transmitted to the display device  100 . The display device  100  can calculate the coordinates of the pointer  205  from the information on the movement of the remote control device  200 . The display device  100  can display the pointer  205  to match the calculated coordinates. 
       FIG. 4C  illustrates that while a specific button in the remote control device  200  is pressed, a user moves the remote control device  200  away from the display  180 . Thus, a selection area in the display  180  corresponding to the pointer  205  can be zoomed in and displayed largely. 
     On the other hand, if a user moves the remote control device  200  close to the display  180 , a selection area in the display  180  corresponding to the pointer  205  can be zoomed out and displayed reduced. 
     On the other hand, if the remote control device  200  is away from the display  180 , a selection area can be zoomed out and if the remote control device  200  is close to the display  180 , a selection area can be zoomed in. 
     Additionally, if a specific button in the remote control device  200  is pressed, the recognition of a vertical or horizontal movement can be excluded. That is, if the remote control device  200  is moved away from or close to the display  180 , the up, down, left, or right movement can not be recognized and only the back and fourth movement can be recognized. While a specific button in the remote control device  200  is not pressed, only the pointer  205  is moved according to the up, down, left or right movement of the remote control device  200 . 
     Moreover, the moving speed or moving direction of the pointer  205  can correspond to the moving speed or moving direction of the remote control device  200 . 
     Furthermore, a pointer in this specification means an object displayed on the display  180  in correspondence to an operation of the remote control device  200 . Accordingly, besides an arrow form displayed as the pointer  205  in the drawing, various forms of objects are possible. For example, the above concept includes a point, a cursor, a prompt, and a thick outline. Then, the pointer  205  can be displayed in correspondence to one point of a horizontal axis and a vertical axis on the display  180  and also can be displayed in correspondence to a plurality of points such as a line and a surface. 
     The remote control device  200  may operate as an integrated remote controller. The integrated remote controller may refer to a remote control device capable of controlling both the display device  100  and an external device connected to the display device  100 . The external device may refer to a device connected through the external device interface  135 . For example, the remote control device  200  may operate as an integrated remote controller capable of controlling the display device  100  and a set-top box connected to the display device  100 . 
     In order for the remote control device  200  to operate as an integrated remote controller, a series of integrated remote controller setting procedures may be required. Hereinafter, it is assumed that the remote control device  200  to be described later is an integrated remote controller set to control both the display device  100  and the external device such as the set-top box. 
     When the power button  231  is input as illustrated in  FIG. 3 , an IR signal (infrared ray signal) for turning on/off power may be transmitted to the display device  100  and the external device. However, only one of the display device  100  and the external device may receive the IR signal due to various causes, and in this case, there may be a problem that the power of the display device  100  and the power of the external device operate differently. Examples of various causes may include a directivity problem of an IR signal, a device internal state, and the like, but this is only an example. 
     As described above, as long as the power of the display device  100  and the power of the external device are once controlled differently, a state in which the power of the display device  100  and the power of the external device operates differently is repeated unless the power of either the display device  100  or the external device is separately changed. Therefore, there is a problem in that a user has to separately control any one power source in order to match the power states of the display device  100  and the external device. 
     Accordingly, the display device  100  and the display system according to the embodiment of the present disclosure attempt to synchronize the power states of the display device  100  and the external device connected to the display device  100  only by inputting the power button  231  provided in the remote control device  200 . 
     More specifically, the controller  170  of the display device  100  may control power of the display device  100  to be turned on or off according to the control signal received from the remote control device  200 . In particular, when receiving the control signal from the remote control device  200 , the controller  170  may determine whether to process the power signal based on whether the signal is inputted from the external device  300 . The power signal may be a power control signal or a power button detection signal, the power control signal may be a signal transmitted from the remote control device  200  via IR so that the power of the display device  100  is controlled, and the power button detection signal may be a signal transmitted via Bluetooth so as to inform the display device  100  whether the power button  231  provided in the remote control device  200  is inputted. 
     Meanwhile, in the present disclosure, the display system may include at least the display device  100  and the remote control device  200 . 
       FIGS. 5 to 7  are flowcharts illustrating an operating method of a display system according to a first embodiment of the present disclosure. 
     Referring to  FIG. 5 , the remote control device  200  may detect the input of the power button  231  (S 101 ). 
     According to the first embodiment of the present disclosure, when the input of the power button  231  is detected, the remote control device  200  may transmit a power control signal to each of the display device  100  and the external device  300  (S 102 ). 
     The external device  300  refers to a device connected to the display device  100  by wire or wirelessly. For example, the external device  300  may be a set-top box connected to the display device  100  by HDMI, but this is only an example, and the external device  300  is not limited thereto. That is, the external device  300  may have various types such as a DVD player in addition to the set-top box, and a method of connecting to the display device  100  is also not limited to HDMI. 
     The power control signal transmitted from the remote control device  200  to each of the display device  100  and the external device  300  may be an IR signal (infrared ray signal). 
     The remote control device  200  may sequentially transmit an IR signal to the display device  100  and the external device  300 , and the order of transmitting the IR signal may be changed. 
     The external device  300  may control power by receiving the power control signal from the remote control device  200 . Specifically, the external device  300  may change the power state of the external device  300  when receiving the power control signal. For example, when the external device  300  receives the power control signal in the power on state, the external device  300  may switch the power from on to off, and when the external device  300  receives the power control signal in the power off state, the external device  300  may switch the power from off to on. That is, in operations S 108  and S 110 , the external device  300  may control power according to the received power control signal. 
     Likewise, the display device  100  may receive the power control signal from the remote control device  200 . When the display device  100  receives the power control signal, the display device  100  may change the power state. For example, if the display device  100  receives the power control signal when the power is on, the display device  100  may switch the power from on to off, and if the display device  100  receives the power control signal when the power is off, the display device  100  may switch the power from off to on. 
     In operation S 102 , it is assumed that the display device  100  receives the power control signal from the remote control device  200  when the power is turned off. Accordingly, when the display device  100  receives the power control signal from the remote control device  200 , the display device  100  may switch the power from off to on (S 103 ). 
     Specifically, the display device  100  may receive the power control signal from the remote control device  200  through the user input interface  150 , and the controller  170  may process the power control signal to switch the power of the display device  100  from off to on. 
     Even after the power of the display device  100  is turned on, the remote control device  200  may detect the input of the power button  231  (S 104 ). 
     When the input of the power button  231  is detected, the remote control device  200  may transmit the power control signal to each of the display device  100  and the external device  300  (S 105 ). 
     When the controller  170  of the display device  100  receives the power control signal in the power on state, the controller  170  may determine whether a reference time has elapsed after the power is switched to on (S 106 ). 
     The controller  170  may determine whether the elapsed time after the power is switched to on is within a reference time. 
     The reference time may refer to a time that is a criterion for determining the intention of the user to press the power button  231 . For example, the reference time may be 6 seconds, but this is only an example and the present disclosure is not limited thereto. 
     When the elapsed time after the power is switched to on is within the reference time, the controller  170  may determine that the received power control signal is a signal for synchronizing the powers of both the display device  100  and the external device  300  to on. Meanwhile, when the reference time has elapsed after the power is switched to on, the controller  170  may determine that the received power control signal is a signal for synchronizing the powers of both the display device  100  and the external device  300  to off. 
     First, a case in which the controller  170  receives the power control signal in a state in which the elapsed time after the power is switched to on is within the reference time will be described in detail. 
       FIG. 6  is a flowchart illustrating a method by which a display device is operated to be controlled to power-on with an external device according to a first embodiment of the present disclosure. 
     Referring to  FIG. 6 , when the controller  170  of the display device  100  receives the power control signal in a state in which the elapsed time after the power is switched to on is within the reference time, the controller  170  may determine that the signal inputted from the external device  300  exists (S 107 ). 
     That is, the controller  170  may detect the signal inputted from the external device  300  and determine whether the signal inputted from the external device  300  exists. 
     When the external device  300  is in the power on state, the external device  300  may output a signal (e.g., an HDMI signal) to the display device  100 . In contrast, when the external device  300  is in the power off state, the external device  300  cannot output a signal to the display device  100 . 
     When the signal inputted from the external device  300  does not exist, the controller  170  of the display device  100  may determine whether a predetermined time has elapsed (S 109 ). 
     The predetermined time may refer to a reference time for grasping the intention of power synchronization between the display device  100  and the external device  300 . For example, the predetermined time may be 6 seconds, but this is exemplary for convenience of description and the present disclosure is not limited thereto. 
     The controller  170  may determine whether a predetermined time has elapsed by counting a time from a time point when the power control signal is transmitted or a time point when the power is switched from off to on according to the power control signal. That is, the reference time point at which the controller  170  starts counting the predetermined time may be changed according to embodiments. 
     When the signal inputted from the external device  300  is not detected and the predetermined time has not elapsed, the controller  170  may maintain the power in an on state (S 111 ). 
     Specifically, when no signal is inputted from the external device  300 , the controller  170  may not process the power control signal received for a predetermined time. When no signal is inputted from the external device  300 , the controller  170  may ignore the power control signal for a predetermined time. 
     That is, the display device  100  may ignore the signal because the display device  100  determines that the power control signal received for a predetermined time when no signal is inputted from the external device  300  is transmitted by the input of the power button  231  for turning on the power of the external device  300 . 
     Therefore, when the user inputs the power button  231 , but only the power of the display device  100  is turned on and the power of the external device  300  is not turned on, the user may input the power button  231  again within a predetermined time, so as to control the powers of both the display device  100  and the external device  300  to be turned on. That is, according to the present disclosure, there is an advantage of providing user convenience that enables the user to synchronize the powers of the display device  100  and the external device  300  to on just by inputting the power button  231  again. 
     Meanwhile, when the signal inputted from the external device  300  exists, the controller  170  may switch the power to off (S 113 ). 
     Since this is the case in which the power control signal is received when both the display device  100  and the external device  300  are in the power on state, the received power control signal is recognized as the signal for turning off the power of the display device  100 . 
     In addition, when the signal inputted from the external device  300  does not exist, but the power control signal is received after a predetermined time has elapsed, the controller  170  may switch the power to off (S 113 ). 
     Similarly, since this is the case in which the power control signal is received after a predetermined time has elapsed from the power-on of the display device  100 , the received power control signal is recognized as the signal for turning off the power of the display device  100 . 
     Next, a case in which the controller  170  receives the power control signal in a state in which the reference time has elapsed after the power is switched to on will be described in detail. 
       FIG. 7  is a flowchart illustrating a method of operating a display device to control power-off with an external device according to a first embodiment of the present disclosure. 
     Referring to  FIG. 7 , when the controller  170  of the display device  100  receives the power control signal in a state in which the reference time has elapsed after the power is switched to on, the controller  170  may determine that the signal inputted from the external device  300  exists (S 207 ). 
     As described above with reference to operation S 107 , the controller  170  may detect the signal inputted from the external device  300  and determine whether the signal inputted from the external device  300  exists. 
     When the external device  300  is in the power on state, the external device  300  may output a signal (e.g., an HDMI signal) to the display device  100 . In contrast, when the external device  300  is in the power off state, the external device  300  cannot output a signal to the display device  100 . 
     When the signal inputted from the external device exists, the controller  170  of the display device  100  may determine whether a predetermined time has elapsed (S 209 ). 
     As described above with reference to  FIG. 6 , the predetermined time refers to a reference time for grasping the intention of power synchronization between the display device  100  and the external device  300 . The predetermined time may be 6 seconds, but this is only an example for convenience of description, and the present disclosure is not limited thereto. The controller  170  may determine whether a predetermined time has elapsed by counting a time from a time point when the power control signal is transmitted or a time point when the power is switched from off to on according to the power control signal. That is, the reference time point at which the controller  170  starts counting the predetermined time may be changed according to embodiments. 
     When the signal inputted from the external device  300  is detected and the predetermined time has not elapsed, the controller  170  may maintain the power in an on state (S 211 ). 
     Specifically, when the signal is inputted from the external device  300 , the controller  170  may not process the power control signal received for a predetermined time. When the signal is inputted from the external device  300 , the controller  170  may ignore the power control signal for a predetermined time. 
     That is, when the signal is inputted from the external device  300 , it is difficult for the display device  100  to determine whether the user intends to turn off the power of the display device  100 . Therefore, the display device  100  may ignore the power control signal received for a predetermined time and delay the power-off. As the display device  100  does not process the power control signal for a predetermined time, only the external device  300  may respond to the power control signal, so that the powers of the display device  100  and the external device  300  are synchronized. 
     When the signal inputted from the external device  300  does not exist, or when the predetermined time has elapsed, the controller  170  of the display device  100  may switch the power from on to off (S 213 ). 
     In particular, in  FIG. 7 , slightly differently from  FIG. 6 , even if the signal inputted to the external device  300  exists, when the predetermined time has elapsed from the time point when the power control signal is received, the controller  170  may process this situation as timeout and turn off the power. That is, in  FIG. 7 , when the controller  170  receives the power control signal for controlling the power to be turned off, but the signal is inputted from the external device  300 , the controller  170  delays the power-off for a predetermined time and only the external device  300  operates according to the power control signal while the power-off of the display device  100  is delayed. Therefore, the powers of both the display device  100  and the external device  300  may be controlled to be off 
     As described above, according to the first embodiment, the display device  100  may match the power state with the remote control device  200  by not processing the signal received from the remote control device  200  for a predetermined time. 
     Next,  FIGS. 8 to 10  are flowcharts illustrating an operating method of a display system according to a second embodiment of the present disclosure. 
     Referring to  FIG. 8 , the remote control device  200  may detect the input of the power button  231  (S 301 ). 
     According to the second embodiment, when the input of the power button  231  is detected, the remote control device  200  may determine whether the remote control device  200  is connected to the display device  100  via Bluetooth (S 303 ). 
     Specifically, according to the second embodiment, the display device  100  may perform a Bluetooth connection with the remote control device  200  when the power is switched from off to on. That is, the display device  100  may be connected to the remote control device  200  via Bluetooth while the power is on. Therefore, when the input of the power button  231  is detected, the remote control device  200  may recognize the power state of the display device  100  by determining whether the remote control device  200  is connected to the display device  100  via Bluetooth before transmitting the power control signal to the display device  100 . 
     When the remote control device  200  determines that the remote control device  200  is not connected to the display device  100  via Bluetooth, the remote control device  200  may transmit the power control signal to each of the display device  100  and the external device  300  (S 305 ). 
     In this case, the power control signal may be an IR signal. 
     The external device  300  may receive the power control signal from the remote control device  200 . When the external device  300  receives the power control signal, the power state of the external device  300  may be changed. For example, when the external device  300  receives the power control signal in the power-on state, the external device  300  may switch the power from on to off, and when the external device  300  receives the power control signal in the power-off state, the external device  300  may switch the power from off to on. 
     Likewise, the display device  100  may receive the power control signal from the remote control device  200 . When the display device  100  receives the power control signal, the power state of the display device  100  may be changed. For example, if the display device  100  receives the power control signal when the power is on, the display device  100  may switch the power from on to off, and if the display device  100  receives the power control signal when the power is off, the display device  100  may switch the power from off to on. 
     That the display device  100  receives the IR signal for controlling the power in operation S 305  means that the power control signal is received when the power of the display device  100  is turned off as described above, and when the display device  100  receives the IR signal for controlling power, the display device  100  may switch the power from off to on (S 307 ). 
     When the controller  170  of the display device  100  switches the power to on, the controller  170  may perform a Bluetooth connection with the remote control device  200  (S 309 ). 
     In this manner, the remote control device  200  may detect the input of the power button  231  when the remote control device  200  is in a state of being connected to the display device  100  via Bluetooth. 
     When the input of the power button  231  is detected, the remote control device  200  may determine whether the remote control device  200  is connected to the display device  100  via Bluetooth (S 303 ). 
     If the remote control device  200  is in a state of being connected to the display device  100  via Bluetooth when the input of the power button  231  is detected, the remote control device  200  may transmit a power button detection signal to the display device  100  through Bluetooth communication (S 313 ). 
     The power button detection signal is a signal including information indicating that the input of the power button  231  provided in the remote control device  200  has been detected. The power button detection signal may be transmitted from the remote control device  200  to the display device  100  via Bluetooth. 
     That is, if the remote control device  200  detects the input of the power button  231  in a state of being connected to the display device  100  via Bluetooth, the remote control device  200  may transmit the power button detection signal to the display device  100  via Bluetooth, instead of immediately transmitting the IR signal for controlling the power to the display device  100 . 
     When the display device  100  receives the power button detection signal from the remote control device  200  through Bluetooth communication, the display device  100  may determine whether a reference time has elapsed after the power is switched to on (S 315 ). 
     The controller  170  may determine whether the elapsed time after the power is switched to on is within a reference time. 
     Similar to that described above with reference to  FIG. 5 , the reference time may refer to a time that is a criterion for determining the intention of the user to press the power button  231 . For example, the reference time may be 6 seconds, but this is only an example and the present disclosure is not limited thereto. 
     When the elapsed time after the power is switched to on is within the reference time, the controller  170  may determine that the received power control signal is a signal for synchronizing the powers of both the display device  100  and the external device  300  to on. Meanwhile, when the elapsed time after the power is switched to on exceeds the reference time, the controller  170  may determine that the received power control signal is a signal for synchronizing the powers of both the display device  100  and the external device  300  to off. 
     First, a case in which the controller  170  receives the power button detection signal from the remote control device  200  through Bluetooth communication in a state in which the elapsed time after the power is switched to on is within the reference time will be described in detail. 
       FIG. 9  is a flowchart illustrating a method by which a display device is operated to be controlled to power-on with an external device according to a second embodiment of the present disclosure. 
     Referring to  FIG. 9 , when the controller  170  of the display device  100  receives the power button detection signal in a state in which the elapsed time after the power is switched to on is within the reference time, the controller  170  may determine that the signal inputted from the external device  300  exists (S 401 ). 
     The external device  300  outputs a signal (e.g., an HDMI signal) to the display device  100  when the power is on, and does not output a signal to the display device  100  when the power is off. Therefore, the controller  170  of the display device  100  detects the signal inputted from the external device  300  and determines the power state of the external device  300 . 
     When the signal inputted from the external device  300  does not exist, the controller  170  of the display device  100  may determine whether a predetermined time has elapsed (S 403 ). 
     Similar to that described above with reference to  FIGS. 5 to 7 , the predetermined time may refer to a reference time for grasping the intention of power synchronization between the display device  100  and the external device  300 . For example, the predetermined time may be 6 seconds, but this is exemplary for convenience of description and the present disclosure is not limited thereto. 
     When the signal inputted from the external device  300  does not exist and a predetermined time has not elapsed, the controller  170  of the display device  100  may transmit, to the remote control device  200 , a command for transmitting the power control signal only to the external device  300  for a predetermined time (S 405 ). 
     That is, when the signal inputted from the external device  300  does not exist and a predetermined time has not elapsed, the controller  170  of the display device  100  may control the remote control device  200  not to transmit the power control signal to the display device  100  for a predetermined time. 
     Therefore, the remote control device  200  may transmit the power control signal as the IR signal only to the external device  300  in response to the detection of the input of the power button  231  (S 407 ). 
     Therefore, when the user inputs the power button  231 , but only the power of the display device  100  is turned on and the power of the external device  300  is not turned on, the user may input the power button  231  again within a predetermined time, so as to control the powers of both the display device  100  and the external device  300  to be turned on. That is, according to the present disclosure, there is an advantage of providing user convenience that enables the user to synchronize the powers of the display device  100  and the external device  300  to on just by inputting the power button  231  again. 
     Meanwhile, when the signal inputted from the external device  300  exists, the controller  170  of the display device  100  may switch the power to off (S 409 ). 
     Since this is the case in which the power control signal is received when both the display device  100  and the external device  300  are in the power on state, the received power control signal is recognized as the signal for turning off the power of the display device  100 . 
     In addition, when the signal inputted from the external device  300  does not exist, or when the predetermined time has elapsed, the controller  170  of the display device  100  may switch the power to off (S 409 ). 
     Similarly, since this is the case in which the power control signal is received after a predetermined time has elapsed from the power-on of the display device  100 , the received power control signal is recognized as the signal for turning off the power of the display device  100 . 
     Next, a case in which the controller  170  receives the power button detection signal in a state in which the reference time has elapsed after the power is switched to on will be described in detail. 
       FIG. 10  is a flowchart illustrating a method by which a display device is operated to be controlled to power-off with an external device according to a second embodiment of the present disclosure. 
     Referring to  FIG. 10 , when the controller  170  of the display device  100  receives the power button detection signal in a state in which the reference time has elapsed after the power is switched to on, the controller  170  may determine that a signal inputted from the external device  300  exists (S 501 ). 
     Since this is similar to that described above with reference to operation S 401 , redundant descriptions thereof will be omitted. 
     When the signal inputted from the external device  300  does not exist, the controller  170  of the display device  100  may determine whether a predetermined time has elapsed (S 403 ). 
     Since the predetermined time is similar to that described above with reference to  FIGS. 5 to 7 , redundant descriptions thereof will be omitted. 
     When the signal inputted from the external device  300  does not exist and the predetermined time has not elapsed, the controller  170  of the display device  100  may transmit, to the remote control device  200 , a command for transmitting the power control signal only to the external device  300  for a predetermined time (S 505 ). 
     Specifically, when the signal is inputted from the external device  300 , the controller  170  may control the remote control device  200  not to transmit the power control signal to the display device  100  for a predetermined time. 
     That is, when the signal is inputted from the external device  300 , it is difficult for the display device  100  to determine whether the user intends to turn off the power of the display device  100 . Therefore, the display device  100  may delay the power-off of the display device  100  for a predetermined time. Therefore, only the external device  300  may respond to the input of the power button  231  of the remote control device  200 , and the synchronization of the powers of the display device  100  and the external device  300  may be intended. 
     That is, the remote control device  200  may transmit the power control signal only to the external device  300  based on the command received from the display device  100  (S 507 ), and the external device  300  may switch the power from on to off (S 509 ). 
     In this manner, when the power of the external device  300  is controlled to be off, the controller  170  of the display device  100  may determine that the signal inputted from the external device  300  does not exist, and may switch the power from on to off (S 511 ). 
     In addition, the controller  170  of the display device  100  may switch the power from on to off even when the predetermined time has elapsed (S 511 ). 
     Therefore, the display device  100  and the external device  300  may be controlled so that the powers thereof are synchronized to be off 
     According to the present disclosure, as a power button of a remote control device is inputted regardless of a power state of a display device and a power state of an external device, the power of the display device and the power of the external device are synchronized. 
     According to the present disclosure, the power button provided in the remote control device is used as it is, but since an IR signal is transmitted only to one of the display device and the external device according to the situation, there is an advantage that power can be synchronized without an additional button. 
     The present disclosure may be embodied as computer-readable codes on a program-recorded medium. The computer-readable recording medium may be any recording medium that stores data which can be thereafter read by a computer system. Examples of the computer-readable medium may include hard disk drive (HDD), solid state disk (SSD), silicon disk drive (SDD), read-only memory (ROM), random-access memory (RAM), CD-ROM, a magnetic tape, a floppy disk, and an optical data storage device. In addition, the computer may include the controller  170  of the display device  100 . Accordingly, the above detailed description should not be construed as being restrictive in all respects and should be considered illustrative. The scope of the present specification should be determined by rational interpretation of the appended claims, and all changes within the equivalent scope of the present specification fall within the scope of the present specification. 
     The above description is merely illustrative of the technical idea of the present disclosure, and various modifications and changes may be made thereto by those skilled in the art without departing from the essential characteristics of the present disclosure. 
     Therefore, the embodiments of the present disclosure are not intended to limit the technical spirit of the present disclosure but to illustrate the technical idea of the present disclosure, and the technical spirit of the present disclosure is not limited by these embodiments. 
     Each of the embodiments disclosed in this specification may be implemented alone, or in combination with other embodiments. 
     The scope of protection of the present disclosure should be interpreted by the appending claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present disclosure.