Display device, user terminal device, display system including the same and control method thereof

A display system, comprising:

• a display device configured to display a content;
• and
• an external device configured to sense a motion for controlling the display device and transmit motion information based on the sensed motion to the display device,
• wherein the display device is configured to:
• based on a trigger signal and the motion information transmitted by the external device, change a display viewpoint area of the content, wherein the display viewpoint area of the content is changed in a first motion direction based on the first motion direction corresponding to a motion direction of the external device and included in the motion information, and
• in response to a predetermined event being occurred, control the display to terminate changing the display viewpoint area.

A method of controlling a display device, the method comprising:

• receiving, from an external device, a trigger signal for changing a display viewpoint area of content and motion information;
• changing, by the display device, the display viewpoint area of the content displayed on the display device in a first motion direction based on the first motion direction corresponding to a motion direction of the external device and included in the motion information;
• and
• in response to a predetermined event being occurred, terminating the changing of the display viewpoint area by the display device.