Mobile communication terminal and control method therefor

A mobile communication terminal that performs communication with another mobile communication terminal, comprising:

• a near field communication unit that performs near field communication with the other mobile communication terminal and obtains a communication distance to the other mobile communication terminal based on communication strength of the near field communication;
• a telecommunication unit that is connected to the Internet and performs telecommunication with the other mobile communication terminal;
• a communication mode switching unit that switches to communication by the telecommunication unit when the communication with the other mobile communication terminal by the near field communication unit cannot be performed;
• an information acquisition unit that acquires information on the other communication terminal by the near field communication unit, or acquires information on the other mobile communication terminal by the telecommunication unit and acquires information on the mobile communication terminal when the communication distance to the other mobile communication terminal by the near field communication unit is equal to or more than a threshold;
• an abnormality determination unit that determines an abnormal state of the mobile communication terminal based on the information acquired by the information acquisition unit;
• and
• a lock unit that locks the mobile communication terminal, the other mobile communication terminal, or both of the mobile communication terminals when the abnormality determination unit determines that the mobile communication terminal is in the abnormal state.

A control method for a mobile communication terminal that performs communication with another mobile communication terminal, comprising:

• a step of performing near field communication with the other mobile communication terminal and obtaining a communication distance to the other mobile communication terminal based on communication strength of the near field communication;
• a step of acquiring information on the other mobile communication terminal by the near field communication, information on the mobile communication terminal, or both of the information when the communication distance to the other mobile communication terminal is equal to or more than a threshold;
• a step of determining an abnormal state of the mobile communication terminal based on the acquired information;
• and
• a step of locking the mobile communication terminal, the other mobile communication terminal, or both of the mobile communication terminals when it is determined that the mobile communication terminal is in the abnormal state.