Display device for transmitting a UIBC trigger and operation method thereof

A display device comprising:

• a wireless communication interface configured to perform wireless communication with a mobile terminal;
• a display configured to display a mirroring image based on an image being displayed by the mobile terminal;
• and
• a controller configured to receive a user input signal while displaying the mirroring image, determine whether the received user input signal is a user input back channel (UIBC) trigger for execution of a UIBC function, and transmit the UIBC trigger to the mobile terminal through the wireless communication interface when the received user input signal is determined as the UIBC trigger for execution of the UIBC function,
• wherein the UIBC trigger is configured to cause the mobile terminal to output an accessibility settings pop-up window,
• wherein the accessibility settings pop-up window includes at least one menu for setting the UIBC function, and
• wherein the controller is further configured to:
• recognize the received user input signal as the UIBC trigger by determining whether the received user input signal corresponds to at least one preset user input having an intention to use the UIBC function;
• and
• cause the mobile terminal, via a software development kit (SDK) executed on the mobile terminal and an application (APP) executed on the mobile terminal, to automatically display the accessibility settings pop-up window in response to the UIBC trigger without a separate entry screen for UIBC settings.