Patent Publication Number: US-2022232278-A1

Title: Display device for providing speech recognition service

Description:
TECHNICAL FIELD 
     The present disclosure relates to a display device capable of recommending utterance words to a user when providing a speech recognition service. 
     BACKGROUND ART 
     Digital TV services using wired or wireless communication networks are becoming common. 
     Digital TV services are capable of providing various services that could not be provided by the existing analog broadcasting services. 
     For example, Internet Protocol Television (IPTV) and smart TV services, which are types of digital TV services, provide interactivity so that users can actively select the types of programs, the viewing time, and the like. 
     The IPTV and smart TV services can provide various additional services, such as Internet search, home shopping, and online games, based on such interactivity. 
     In addition, recent TVs provide a speech recognition service that recognizes a speech uttered by a user and performs a function corresponding to the speech. 
     A conventional speech recognition service induces a user&#39;s utterance by providing limited utterance words that do not reflect the user&#39;s viewing history, viewing situation, and utterance history. 
     However, the provision of such limited utterance words has a limitation in effectively providing the speech recognition service, and furthermore, the use of the speech recognition service is limited for users who have difficulty in using speech. 
     DISCLOSURE OF INVENTION 
     Technical Problem 
     The present disclosure aims to provide a display device capable of recommending utterance words suitable for a user based on at least one of a user&#39;s viewing history, utterance history, or viewing situation. 
     The present disclosure aims to provide a display device capable of facilitating access to a speech recognition service by recommending utterance words suitable for a user even for a user having difficulty in using speech. 
     Technical Solution 
     A display device for providing a speech recognition service according to an embodiment of the present disclosure can include a storage unit configured to store a user&#39;s viewing history, a display unit, and a control unit configured to acquire a plurality of recommended utterance words based on the stored viewing history information, receive a command for requesting the speech recognition service, and display the plurality of acquired recommended utterance words on the display unit according to the received command. The viewing history information may include a viewing time of content and a genre of the content. 
     When the content of the genre is viewed a preset number of times or more for the viewing time, the control unit can be configured to acquire a text including the viewing time and the genre as a recommended utterance word. 
     The control unit can be configured to receive a voice command and perform an operation corresponding to a recommended utterance word when the received voice command is any one of the plurality of recommended utterance words. 
     The control unit can be configured to further acquire viewing situation information and acquire a recommended utterance word based on the viewing situation information. The viewing situation information can include at least one of information on an external device capable of interworking with the display device, a user&#39;s schedule information, or weather information. 
     The storage unit can be configured to store an utterance history including utterance words previously uttered by the user at the time of using the speech recognition service, and the control unit can be configured to acquire the utterance history stored in the storage unit as a recommended utterance word. 
     The plurality of recommended utterance words can be acquired based on the viewing history information, the utterance history information, and viewing situation information, the control unit can be configured to list each of the plurality of recommended utterance words in the order of priority, and a priority of a first recommended utterance word based on the viewing history information can be higher than a priority of a second recommended utterance word based on the utterance history information, and the priority of the second recommended utterance word can be higher than a priority of a third recommended utterance word based on the viewing situation information. 
     The plurality of recommended utterance words can be personalized utterance words. A recommended utterance word including a blank among the plurality of recommended utterance words can be displayed separately from other recommended utterance words. The blank can be provided to induce the user to utter an utterance word corresponding to the blank, and the control unit can be configured to perform no operation when the recommended utterance word including the blank is selected. 
     Each of the plurality of recommended utterance words can be selected through a remote control device, or is selected through a user&#39;s voice command. 
     The display device can further include a wireless communication unit, wherein the control unit can be configured to receive the command for requesting the speech recognition service from a remote control device through the wireless communication unit. 
     The control unit can be configured to transmit the viewing history information to a server and receive the plurality of recommended utterance words from the server. 
     When receiving the command for requesting the speech recognition service, the control unit can be configured to transmit the viewing history information to the server, and receive the plurality of recommended utterance words from the server. 
     Advantageous Effects 
     According to embodiments of the present disclosure, recommended utterance words are provided to a user by using a user&#39;s viewing history, viewing situation, utterance history, and the like, thereby allowing the user to more easily use a speech recognition service function. 
     In addition, the speech recognition service function can be conveniently provided to a user who has difficulty in using a speech recognition service. 
    
    
     
       BRIEF DESCRIPTION OF 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 illustrating an example of utilizing a remote control device according to an embodiment of the present disclosure. 
         FIG. 5  is a flowchart for describing an operating method of a display device according to an embodiment of the present disclosure. 
         FIGS. 6 and 7  are views illustrating examples of recommended utterance words acquired based on a user&#39;s viewing pattern according to an embodiment of the present disclosure. 
         FIG. 8  is a view for describing an example of recommended utterance words acquired by additionally considering a viewing situation according to an embodiment of the present disclosure. 
         FIGS. 9 to 11  are views for describing examples of speech recognition service screens including a plurality of recommended utterance words according to various embodiments of the present disclosure. 
         FIGS. 12 and 13  are views for describing an example in which a plurality of recommended utterance words are listed in the order of priority according to an embodiment of the present disclosure. 
         FIG. 14  is a view for describing an example of providing personalized recommended utterance words to each of a plurality of users according to an embodiment of the present disclosure. 
         FIG. 15  is a view for describing an example of recommended utterance words including blanks according to an embodiment of the present disclosure. 
         FIG. 16  is a view for describing a process of receiving recommended utterance words from a server according to another embodiment of the present disclosure. 
     
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     Hereinafter, embodiments relating to the present disclosure will be described in detail with reference to the accompanying drawings. 
     The suffixes “module” and “unit” 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. 
     A display device according to an embodiment of the present disclosure, for example, as an artificial display device that adds a computer supporting function to a broadcast receiving function, can have an easy-to-use interface such as a writing input device, a touch screen, or a spatial remote control device as an Internet function is added while fulfilling the broadcast receiving function. 
     Then, with the support of a wired or wireless Internet function, it is possible to perform an e-mail, web browsing, banking, or game function in access to Internet and computers. 
     In order to perform such various functions, standardized general purpose OS can be used. Accordingly, since various applications are freely added or deleted on a general purpose OS kernel, a display device described herein, for example, can perform various user-friendly functions. 
     The display device, in more detail, can be a network TV, Hybrid Broadcast Broadband TV (HBBTV), smart TV, light-emitting diode (LED) TV, organic light-emitting diode (OLED) TV, and so on and in some cases, can be applied to a smartphone. 
       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 unit  130 , an external device interface unit  135 , a storage unit  140 , a user interface unit  150 , a control unit  170 , a wireless communication unit  173 , a display unit  180 , an audio output unit  185 , and a power supply unit  190 . 
     The broadcast reception unit  130  can include a tuner  131 , a demodulation unit  132 , and a network interface unit  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 demodulation unit  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 external device interface unit  135  can receive an application or an application list in an adjacent external device and deliver it to the control unit  170  or the storage unit  140 . The external device interface unit  135  can provide a connection path between the display device  100  and an external device. 
     The external device interface unit  135  can receive at least one an image or audio output from an external device that is wirelessly or wiredly connected to the display device  100  and deliver it to the control unit  170 . 
     The external device interface unit  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 input through the external device interface unit  135  can be output through the display unit  180 . 
     A sound signal of an external device input through the external device interface unit  135  can be output through the audio output unit  185 . 
     An external device connectable to the external device interface unit  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. 
     The network interface unit  133  can provide an interface for connecting the display device  100  to a wired/wireless network including the Internet network. 
     The network interface unit  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. 
     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 network interface unit  133  can access a predetermined webpage through an accessed network or another network linked to the accessed network. 
     That is, the network interface unit  133  can transmit or receive data to or from a corresponding server by accessing a predetermined webpage through the network. 
     Then, the network interface unit  133  can receive contents or data provided from a content provider or a network operator. 
     That is, the network interface unit  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 unit  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 unit  133  can select and receive a desired application among applications open to the air, through network. 
     The storage unit  140  can store signal-processed image, voice, or data signals stored by a program in order for each signal processing and control in the control unit  170 . Additionally, the storage unit  140  can perform a function for temporarily storing image, voice, or data signals output from the external device interface unit  135  or the network interface unit  133  and can store information on a predetermined image through a channel memory function. 
     The storage unit  140  can store an application or an application list input from the external device interface unit  135  or the network interface unit  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 unit  140  and provide them to a user. 
     The user interface unit  150  can deliver signals input by a user to the control unit  170  or deliver signals from the control unit  170  to a user. 
     For example, the user interface unit  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 control unit  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 interface unit  150  can deliver, to the control unit  170 , control signals input 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 control unit  170  can be input to the display unit  180  and displayed as an image corresponding to corresponding image signals. Additionally, image signals that are image-processed in the control unit  170  can be input to an external output device through the external device interface unit  135 . 
     Voice signals processed in the control unit  170  can be output to the audio output unit  185 . Additionally, voice signals processed in the control unit  170  can be input to an external output device through the external device interface unit  135 . 
     Besides that, the control unit  170  can control overall operations in the display device  100 . Additionally, the control unit  170  can control the display device  100  by a user command or internal program input through the user interface unit  150  and download a desired application or application list into the display device  100  in access to network. 
     The control unit  170  can output channel information selected by a user together with processed image or voice signals through the display unit  180  or the audio output unit  185 . 
     Additionally, according to an external device image playback command received through the user interface unit  150 , the control unit  170  can output image signals or voice signals of an external device such as a camera or a camcorder, which are input through the external device interface unit  135 , through the display unit  180  or the audio output unit  185 . 
     Moreover, the control unit  170  can control the display unit  180  to display images and control broadcast images input through the tuner  131 , external input images input through the external device interface unit  135 , images input through the network interface unit, or images stored in the storage unit  140  to be displayed on the display unit  180 . 
     In this case, an image displayed on the display unit  180  can be a still image or video and also can be a 2D image or a 3D image. 
     Additionally, the control unit  170  can play content stored in the display device  100 , received broadcast content, and external input content input 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 unit  173  can perform a wired or wireless communication with an external electronic device. 
     The wireless communication unit  173  can perform short-range communication with an external device. 
     For this, the wireless communication unit  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 unit  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 unit  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 control unit  170  can transmit at least part of data processed in the display device  100  to the wearable device through the wireless communication unit  173 . 
     Accordingly, a user of the wearable device can use the data processed in the display device  100  through the wearable device. 
     The display unit  180  can convert image signals, data signals, or on-screen display (OSD) signals, which are processed in the control unit  170 , or images signals or data signals, which are received in the external device interface unit  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 unit  133  or the external device interface unit  135  and play them without including the tuner  131  and the demodulation unit  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 input 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 unit  180  and the audio output unit  185 . 
     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 unit  210 , a wireless communication unit  220 , a user input unit  230 , a sensor unit  240 , an output unit  250 , a power supply unit  260 , a storage unit  270 , a control unit  280 , and a sound acquisition unit  290 . 
     Referring to  FIG. 2 , the wireless communication unit  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 a radio frequency (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 a Near Field Communication (NFC) module  227  for transmitting/receiving signals to/from the display device  100  according to the 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 unit  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 unit  230  can be configured with a keypad button, a touch pad, or a touch screen. 
     A user can manipulate the user input unit  230  to input a command relating to the display device  100  to the remote control device  200 . 
     If the user input unit  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 home button  232  can be a 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 a button for receiving an external input connected to the display device  100 . 
     The voice adjustment button  235  can be a button for adjusting the size of a volume output 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, referring to  FIG. 2 , if the user input unit  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 unit  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 unit  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 unit  180  of the display device  100 . The output unit  250  can output image or voice signals in response to manipulation of the user input unit  230  or image or voice signals corresponding to signals transmitted from the display device  100 . 
     A user can recognize whether the user input unit  230  is manipulated or the display device  100  is controlled through the output unit  250 . 
     For example, the output unit  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 unit  230  is manipulated or signals are transmitted/received to/from the display device  100  through the wireless communication unit  220 . 
     Additionally, the power supply unit  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 unit  260  can resume the power supply if a predetermined key provided at the remote control device  200  is manipulated. 
     The storage unit  270  can store various kinds of programs and application data necessary for 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 control unit  280  of the remote control device  200  can store, in the storage unit  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 control unit  280  controls general matters relating to control of the remote control device  200 . 
     The control unit  280  can transmit a signal corresponding to a predetermined key manipulation of the user input unit  230  or a signal corresponding to movement of the remote control device  200  sensed by the sensor unit  240  to the display device  100  through the wireless communication unit  220 . 
     Additionally, the sound acquisition unit  290  of the remote control device  200  can obtain voice. 
     The sound acquisition unit  290  can include at least one microphone and obtain voice through the microphone  291 . 
     Next,  FIG. 4  is described. 
       FIG. 4  is a view illustrating an example of utilizing a remote control device according to an embodiment of the present disclosure. 
       FIG. 4( a )  illustrates that a pointer  205  corresponding to the remote control device  200  is displayed on the display unit  180 . 
     A user can move or rotate the remote control device  200  vertically or horizontally. 
     The pointer  205  displayed on the display unit  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 control device. 
       FIG. 4( b )  illustrates that if a user moves the remote control device  200 , the pointer  205  displayed on the display unit  180  of the display device  100  is moved to the left according to the movement of the remote control device  200 . 
     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. 4( c )  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 unit  180 . 
     Thus, a selection area in the display unit  180  corresponding to the pointer  205  can be zoomed in and displayed larger. 
     On the other hand, if a user moves the remote control device  200  close to the display unit  180 , a selection area in the display unit  180  corresponding to the pointer  205  can be zoomed out and displayed in a reduced size. 
     On the other hand, if the remote control device  200  is moved away from the display unit  180 , a selection area can be zoomed out and if the remote control device  200  is moved closer to the display unit  180 , a selection area can be zoomed in. 
     Additionally, if a specific button in the remote control device  200  is pressed, recognition of a vertical or horizontal movement can be excluded. 
     That is, if the remote control device  200  is moved away from or closer to the display unit  180 , the up, down, left, or right movement cannot be recognized and only the back and forth 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 unit  180  in response 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 unit  180  and also can be displayed in correspondence to a plurality of points such as a line and a surface. 
     Next, an embodiment of recommending utterance words to a user when a speech recognition service is provided will be described with reference to the accompanying drawings. 
       FIG. 5  is a flowchart for describing an operating method of the display device according to an embodiment of the present disclosure. 
     The control unit  170  of the display device  100  acquires viewing history information including a user&#39;s viewing time and information on content viewed at the corresponding viewing time (S 501 ). 
     The viewing history information can include at least one of the viewing time for which a user views the content through the display device  100 , channel information of the content, the genre of the content viewed for the viewing time, the name of the content, the name of the application used when viewing the content, or the usage history of the content provider (or the content provider&#39;s application) used when viewing the content. 
     The content can include a broadcast program, a web video viewed through a web service, and the like. 
     When the content is a broadcast program, the control unit  170  can acquire the name of the program and the genre of the program from an electronic program guide (EPG). When the content is a web moving picture, the control unit  170  can identify the genre of the web moving picture by using the name of the content. 
     In an embodiment, the control unit  170  can acquire the genre of the content only for the content that has been reproduced for a predetermined time or longer. 
     That is, the control unit  170  may not collect content information for the content viewed by the user&#39;s temporary channel change. 
     On the other hand, the user&#39;s viewing history information can be stored in the storage unit  140 . 
     The user&#39;s viewing history information can be periodically updated. 
     The control unit  170  acquires a plurality of recommended utterance words based on the viewing history information (S 503 ). 
     In an embodiment, the control unit  170  can acquire, based on the viewing history information, one or more recommended utterance words to be provided to the user when the speech recognition service is provided. 
     For example, the control unit  170  may acquire a plurality of recommended utterance words by analyzing the viewing history information by itself. 
     As another example, the control unit  170  can transmit the viewing history information to a server (not shown), and the server can acquire a plurality of utterance words by analyzing the viewing history information. The control unit  170  can receive the plurality of recommended utterance words from the server. 
     The control unit  170  can identify the user&#39;s viewing pattern from the viewing history information, and can acquire recommended utterance words matching the identified viewing pattern. 
       FIGS. 6 and 7  are views illustrating examples of recommended utterance words acquired based on the user&#39;s viewing pattern according to an embodiment of the present disclosure. 
       FIG. 6  illustrates viewing history information  610  acquired by the control unit  170  and a recommended utterance word list  630  including a plurality of recommended utterance words acquired based on the viewing history information  610 . 
     The control unit  170  may identify the genre of content that the user views through the display device  100  at a specific time zone during a predetermined period of time. Here, the predetermined period of time can be one month, but this is just exemplary. For example, if the number of times the user viewed drama content at 7 pm during one month is a certain number of times or more, the control unit  170  can acquire the viewing history information  610  of &lt;7 pm, drama content is mainly viewed&gt;. 
     The control unit  170  can acquire recommended utterance words such as &lt;Show a drama that airs at 7 o&#39;clock&gt; and &lt;Show a drama channel&gt; that match the acquired viewing history information  610 . 
     That is, the control unit  170  may acquire a text including the viewing time and the genre as the recommended utterance words. 
     When the display device  100  is turned on before or after 7 pm, the control unit  170  may display, on the display unit  180 , the recommended utterance word list  630  including the recommended utterance words. 
       FIG. 7  illustrates viewing history information  710  acquired by the control unit  170  and a recommended utterance word list  730  including a plurality of recommended utterance words acquired based on the viewing history information  710 . 
     The control unit  170  can acquire, as the viewing history information  710 , the name of the content that the user most recently viewed through the display device  100  and the name of the application (or the name of the content provider) used when viewing the content. On the basis of the acquired viewing history information  710 , the control unit  170  can acquire the recommended utterance word list  730  including the recommended utterance words such as &lt;Play when a romance starts&gt;, &lt;Find a drama starring Jessy&gt;, and &lt;Find a romance in application A&gt; that match the viewing history information  710 . 
     That is, the control unit  170  can generate the recommended utterance words by reflecting the viewing history information  710  including the name of the drama that the user recently viewed, the name of the main character appearing in the drama, and the name of the application providing the drama. 
     That is, according to an embodiment of the present disclosure, instead of the utterance words for simple search such as the name of the content, the user-customized utterance words such as the genre of the content, the characters of the content, and the name of the content provider providing the content can be provided. 
     On the other hand, according to another embodiment of the present disclosure, the control unit  170  may acquire recommended utterance words by further considering the viewing situation information in addition to the viewing history information. 
     The viewing situation information can be information on the viewing situation of the display device  100 . 
     The viewing situation information can include one or more of information on an external device capable of interworking with the display device  100 , status information on a home appliance, user&#39;s schedule information, and weather information at the time of viewing content. 
       FIG. 8  is a view for describing an example of recommended utterance words acquired by additionally considering the viewing situation according to an embodiment of the present disclosure. 
     It is assumed that the viewing history information  610  according to the embodiment of  FIG. 6  is used. 
     In addition, the viewing situation information can be information about a situation (dim processing) in which the light in the house is dimly adjusted when the user views drama content at 7 pm. 
     The control unit  170  can acquire, as the viewing situation information  810 , a situation in which the light is dimly adjusted when the light in the house is dimmed more than a certain number of times when the user views the drama content at 7 pm. 
     The control unit  170  can acquire recommended utterance words based on the viewing history information  610  and the viewing situation information  810 . 
     That is, the control unit  170  can acquire, in addition to the recommended utterance words such as &lt;Show a drama that airs at 7 o&#39;clock&gt; and &lt;Show a drama channel&gt; that match the viewing history information  610 , a recommended utterance word list  830  including recommended utterance words such as &lt;Dim the lights&gt; that match the viewing situation information  810 . 
     As another example, the control unit  170  can receive weather information from the server and can acquire recommended utterance words based on the weather information. 
     For example, if the current weather is rainy, the control unit  170  may acquire recommended utterance words such as &lt;Play a music channel that is good to listen to on a rainy day&gt;. 
     According to another embodiment of the present disclosure, the control unit  170  can acquire one or more recommended utterance words based on the utterance history. The control unit  170  can collect utterance words uttered by the user and can acquire the collected utterance words as the recommended utterance words. 
     The control unit  170  can acquire, as the recommended utterances, only utterance words uttered a certain number of times or more among the collected utterance words. According to another embodiment of the present disclosure, the control unit  170  can acquire the recommended utterance words based on the location of the display device  100 . 
     For example, when the location of the display device  100  is a specific area, a channel or a name of a program broadcast only in the specific area can be acquired as the recommended utterance words. 
     According to another embodiment of the present disclosure, the control unit  170  may acquire, as the recommended utterance words, an utterance word that the user does not use. 
     The control unit  170  can acquire, as the recommended utterance words, an utterance word that the user does not use and the manufacturer of the display device  100  can provide. 
     Again,  FIG. 5  is described. 
     The control unit  170  receives a command for requesting a speech recognition service (S 505 ), and displays a plurality of recommended utterance words on the display unit  180  according to the received command (S 507 ). 
     In an embodiment, the control unit  170  may receive, from the remote control device  200 , a command for requesting a speech recognition service. 
     The user can select the voice recognition button  236  provided in the remote control device  200 . 
     The remote control device  200  may transmit, to the display device  100 , a signal requesting the provision of the speech recognition service according to the selection of the voice recognition button  236 . 
     The control unit  170  can receive, from the remote control device  200 , the signal requesting the provision of the speech recognition service, and can display, on the display unit  180 , a speech recognition service screen for providing the speech recognition service according to the received signal. 
     As another example, the command for requesting the speech recognition service may be received through a user&#39;s voice command. 
     The control unit  170  can receive a voice command requesting the provision of the speech recognition service through a microphone (not shown) provided in the display device  100 . The control unit  170  may recognize the received voice command and display the speech recognition service screen on the display unit  180 . 
     The voice command for requesting the provision of the speech recognition service may be a wake-up command for activating the speech recognition service of the display device  100 . 
     The speech recognition service screen can include a plurality of acquired recommended utterance words. 
       FIGS. 9 to 11  are views for describing examples of speech recognition service screens including a plurality of recommended utterance words according to various embodiments of the present disclosure. 
     First,  FIG. 9  is described. 
     In particular,  FIG. 9  is a view for describing an example of displaying a plurality of recommended utterance words  903  and  905  through an initial provision screen  900  for a speech recognition service. 
     The control unit  170  of the display device  100  can receive, from the remote control device  200 , a command for providing the speech recognition service, and can display, on the display unit  180 , the initial provision screen  900  for the speech recognition service according to the received command. 
     That is, as the microphone-shaped voice recognition button  236  is selected, the remote control device  200  can transmit, to the display device  100 , the command for requesting the speech recognition service. 
     The control unit  170  of the display device  100  can display, on the display unit  180 , the initial provision screen  900  including a plurality of recommended utterance words  903  and  905  according to the command received from the remote control device  200 . 
     The initial provision screen  900  can include the text  901  for inducing the utterance of the voice and the plurality of recommended utterance words  903  and  905 . 
     Each of the plurality of recommended utterance words  903  and  905  can be utterance words generated based on the viewing history information  610  of  FIG. 6 . 
     As described above, according to an embodiment of the present disclosure, the user can be guided to customized utterance words only by selecting the voice recognition button  236  provided in the remote control device  200 . 
     Accordingly, the user can access the content of interest more conveniently and quickly. On the other hand, as the user utters any one of the plurality of recommended utterance words  903  and  905  included on the initial provision screen  900 , the speech recognition service corresponding to the corresponding utterance word can be provided. 
     That is, the display device  100  can receive the recommended utterance words uttered by the user and can display a search result corresponding to the received utterance words. As another example, when the user selects any one of the plurality of recommended utterance words  903  and  905  through the remote control device  200 , the speech recognition service corresponding to the corresponding utterance word may be provided. That is, the display device  100  can display a search result corresponding to the selected utterance word according to the command for selecting the utterance word received from the remote control device  200 . 
       FIG. 10  is a view for describing an example of providing a plurality of recommended utterance words on an utterance guide screen  1000 . 
     When the display device  100  receives a command for requesting a speech recognition service, the display device  100  can display the utterance guide screen  1000  on the display unit  180 . 
     The speech guide screen  1000  can be a screen for guiding a user to utter a suitable utterance word. 
     The utterance guide screen  1000  can include a recommended utterance word list  1010  including recommended utterance words acquired based on at least one of viewing history information or viewing situation information. 
     The user can receive desired content only by reading the recommended utterance words or selecting the recommended utterance words without having to worry about the utterance words through the customized recommended utterance words included in the utterance guide screen  1000 . 
       FIG. 11  is a view for describing an example of providing recommended utterance words through a content search result screen  1100 . 
     When the display device  100  receives a command for requesting content search, the display device  100  can display, on the display unit  180 , the content search result screen  1100  indicating a content search result. 
     The content search result screen  1100  can include recommended utterance words  1101 ,  1103 , and  1105  acquired based on at least one of viewing history information or viewing situation information. 
     The user can receive desired content only by reading the recommended utterance words or selecting the recommended utterance words without having to worry about the utterance words through the customized recommended utterance words included in the content search result screen  1100 . 
     The control unit  170  receives a voice command (S 509 ), and determines whether the received voice command is one of a plurality of recommended utterance words displayed on the display unit  180  (S 511 ). 
     In an embodiment, the control unit  170  may receive the voice command from the remote control device  200 . 
     That is, the user can receive the voice command through a microphone provided in the remote control device  200 , and can transmit the received voice command to the display device  100  through short-range wireless communication. 
     In still another embodiment, the control unit  170  can directly receive a user&#39;s voice command through a microphone provided in the display device  100 . 
     When the received voice command is any one of the plurality of recommended utterance words, the control unit  170  performs an operation corresponding to the recommended utterance word (S 513 ). 
     The control unit  170  can analyze the intention of the recommended utterance word by using a natural language processing engine of the recommended utterance word, and can perform an operation according to the analyzed intention. 
     For example, when the recommended utterance word is an utterance word corresponding to the content search, the control unit  170  can search for content corresponding to the recommended utterance word and can display the search result on the display unit  180 . On the other hand, the recommended utterance words can be selected through the voice command uttered by the user, or can be selected by the pointer  205  (see  FIG. 2 ) controlled according to the movement of the remote control device  200 . 
     When the received voice command is not included in the plurality of recommended utterance words, the control unit  170  performs an operation corresponding to the voice command (S 515 ). 
     When the received voice command is not any one of the plurality of recommended utterance words, the control unit  170  can analyze the intention of the voice command and can perform an operation according to the analyzed intention. 
     The control unit  170  can analyze the intention of the voice command by using a natural language processing engine, and can perform an operation according to the analyzed intention. 
     According to still another embodiment of the present disclosure, a plurality of recommended utterance words can be listed based on priority. 
       FIGS. 12 and 13  are views for describing an example in which a plurality of recommended utterance words are listed in the order of priority according to an embodiment of the present disclosure. 
     First,  FIG. 12  is described. 
       FIG. 12  is a view for describing the priority as the standard for listing the plurality of recommended utterance words. 
     The control unit  170  can list the plurality of recommended utterance words on the display unit  180  according to the priority. 
     The control unit  170  can determine the priority based on the acquired type of the recommended utterance word. 
     For example, the control unit  170  can set viewing history information, which is the basis for acquiring the recommended utterance words, as the first priority, utterance history information as the second priority, viewing situation information as the third priority, location information as the fourth priority, and the user&#39;s unused utterance words as the fifth priority. 
     The priorities according to the acquired type of the utterance words shown in  FIG. 12  are exemplary and can vary according to a user&#39;s setting. 
     As the priority corresponding to the acquired type of the utterance word is higher, the control unit  170  can arrange the corresponding recommended utterance word at the uppermost position, and as the priority is lower, the control unit  170  can arrange the corresponding recommended utterance word at the lowermost position. 
       FIG. 13  illustrates a recommended utterance word list  1300  displayed on the display unit  180  when the speech recognition service is provided. 
     The control unit  170  can arrange a first recommended utterance word  1301  acquired based on the viewing history information corresponding to the first priority at the uppermost position of the recommended utterance word list  1300 . 
     The control unit  170  can arrange a second recommended utterance word  1303  acquired based on the utterance history information corresponding to the second priority the position below the first recommended utterance word  1301 . 
     In addition, the control unit  170  can arrange a third recommended utterance word  1305  acquired based on the viewing situation information corresponding to the third priority at the position below the second recommended utterance word  1303 . 
     The control unit  170  can arrange a fourth recommended utterance word  1307  acquired based on the position information corresponding to the fourth priority at the position below the third recommended utterance word  1305 . 
     The control unit  170  can arrange the user&#39;s unused utterance word  1309  corresponding to the fifth priority at the lowermost position. 
     On the other hand, the user&#39;s unused utterance word  1309  can be an utterance word corresponding to a speech recognition function recommended by the manufacturer of the display device  100 . 
       FIG. 14  is a view for describing an example of providing personalized recommended utterance words to each of a plurality of users according to an embodiment of the present disclosure. 
     The control unit  170  can provide a personalized recommended utterance word list to each of a plurality of users who use the display device  100 . 
     That is, the control unit  170  can provide personalized recommended utterance words based on at least one of viewing history information, viewing situation information, or utterance history information of each of the plurality of users who use the display device  100 . 
     For example, when a user A logs in to the display device  100 , the control unit  170  can display, on the display unit  180 , a first recommended utterance word list  1410  including the acquired recommended utterance words based on at least one of viewing history information, viewing situation information, or utterance history information of the user A. Similarly, when a user B logs in to the display device  100 , the control unit  170  can display, on the display unit  180 , a second recommended utterance word list  1430  including the acquired recommended utterance words based on at least one of viewing history information, viewing situation information, or utterance history information of the user B. For example, when a user C logs in to the display device  100 , the control unit  170  can display, on the display unit  180 , a third recommended utterance word list  1450  including the acquired recommended utterance words based on at least one of viewing history information, viewing situation information, or utterance history information of the user C.  FIG. 15  is a view for describing an example of recommended utterance words including blanks according to an embodiment of the present disclosure. 
     Recommended utterance words recommended by the display device  100  can include some blanks. 
     This can be for inducing a user to directly utter a name of a person who wants to search for in the blank. 
     For example, referring to a recommended utterance word list  1500  of  FIG. 15 , a recommended utterance word  1503  including blanks among a plurality of recommended utterance words  1501  to  1509  is shown. 
     The recommended utterance word  1503  can include blanks in a portion corresponding to a character in a movie, such as &lt;Find a movie starring 000&gt;. 
     The user can utter a name of a movie actor he or she wants to search for in the blank, and can receive a search result of a movie starring the movie actor. 
     On the other hand, the recommended utterance word  1503  including the blanks can be displayed separately from other recommended utterance words  1501 ,  1505 ,  1507 , and  1509 . 
     In addition, the recommended utterance word  1503  including the blanks can be an utterance word that cannot be selected. 
     That is, the control unit  170  may not perform any operation even if the recommended utterance word  1503  including the blanks is selected. 
     The control unit  170  may display selectable recommended utterance words and non-selectable recommended utterance words in a distinguishing manner. 
       FIG. 16  is a view for describing a process of receiving recommended utterance words from a server according to another embodiment of the present disclosure. 
       FIG. 16  illustrates a server  1600  that is connectable to the network interface unit  133  of the display device  100 . 
     The display device  100  can transmit, to the server  1600 , one or more of viewing history information, viewing situation information, and utterance history information. 
     The corresponding information can be periodically transmitted to the server  1600 . 
     The server  1600  can generate recommended utterance words based on one or more of viewing history information, viewing situation information, and utterance history information, and can transmit the generated recommended utterance words to the display device  100 . 
     On the other hand, when receiving a request for a speech recognition service, the display device  100  can display recommended utterance words received from the server  1600  and stored in advance when network connection delay or network disconnection occurs. 
     That is, even if there is a problem in network connection with the server  1600 , the display device  100  can recommended utterance words to the user by using the recommended utterance words received from the server  1600  and stored in advance. 
     According to still another embodiment of the present disclosure, the display device  100  can acquire recommended utterance words based on the utterance history of an external device capable of interworking with the display device  100 . 
     For example, when the external device capable of interworking with the display device  100  is a user&#39;s smartphone, the display device  100  can receive, from the smartphone, the utterance history uttered by the user through the smartphone having a speech recognition function. 
     The display device  100  can acquire recommended utterance words based on the utterance history received from the smartphone. 
     The display device  100  can recommend utterance words linked to a user&#39;s schedule. Based on schedule information, the display device  100  can display recommended utterance words before the time corresponding to the schedule information. 
     For example, when the user has a meeting at 3 pm, the display device  100  can display recommended utterance words such as &lt;What should I do?&gt; at 2 pm. 
     The schedule information can be information stored in the display device  100 , or can be information received from a user&#39;s smartphone. 
     According to still another embodiment of the present disclosure, the display device  100  can acquire and display recommended utterance words based on viewing history information and an electronic program guide. 
     For example, when it is determined that the user has viewed a baseball game more than a preset number of times, the display device  100  can acquire recommended utterance words for inducing provision of a baseball score. 
     That is, based on the electronic program guide, when the baseball game program is being broadcast at the current time, the display device  100  can acquire recommended utterance words such as &lt;Tell me about the baseball score&gt; and can display the recommended utterance words on the display unit  180 . 
     As described above, according to embodiments of the present disclosure, recommended utterance words are provided to a user by using the user&#39;s viewing history, viewing situation, utterance history, and the like, thereby allowing the user to more easily use the speech recognition service function. 
     In addition, the speech recognition service function can be conveniently provided to a user who has difficulty in using the speech recognition service. 
     According to an embodiment of the present disclosure, the above-described method can be implemented with codes readable by a processor on a medium in which a program is recorded. 
     Examples of the medium readable by the processor include a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, and the like, and can include those implemented in the form of carrier wave (for example, transmission over Internet). The display device described above is not limitedly applicable to the configuration and method of the above-described embodiments, and the embodiments are configured by selectively combining all or part of each of the embodiments such that various modifications can be made.