Head mounted display and method of outputting a content using the same in which the same identical content is displayed

A HMD (head mounted display) comprising:

• a processor configured to control an operation of the HMD;
• a sensor unit configured to detect a marker of an augmented reality image;
• a display unit configured to output the augmented reality image based on the detected marker;
• and
• a communication unit configured to transmit and receive data with an external server,
• wherein the processor is further configured to:
• detect a first marker of a first augmented reality image within a view angle region of the HMD,
• determine a location state of the first marker, the location state comprising a first state in which the first marker is located within the view angle region of the HMD and a second state in which the first marker is located beyond the view angle region,
• when the location state of the first marker is switched from the first state to the second state, start displaying the first augmented reality image on the display unit, and
• when the location state of the first marker is switched from the second state to the first state, stop displaying the first augmented reality image on the display unit.