Abstract: The present invention provides a mobile terminal device, an antenna switching method, and a program capable of realizing appropriate antenna switching compared to the conventional technique by coping with various use states in the antenna switching of a mobile phone including a plurality of antennas. A mobile terminal device including a plurality of antennas and performing antenna switching includes: a device state detection unit for detecting a device state of the mobile terminal device; an accessory connection detection unit for detecting an accessory connected to the mobile terminal device; a communication state detection unit for detecting a communication state of the mobile terminal device; and an antenna switching unit for selecting an appropriate antenna from the plurality of antennas and switching to it based on respective detection results detected by the device state detection unit, the accessory connection detection unit and the communication state detection unit.

Abstract: The mobile communication terminal has a main body unit and an attachment. When the main body unit separates from the attachment, the attachment transmits a predetermined radio signal. The main body unit receives the radio signal and determines whether its distance from the attachment exceeds specified distance. When the main body unit is at a distance from the attachment exceeding the specified distance, predetermined operation of the main body unit, for example, entering operation using a keypad, memory read-out operation, data transmission and data reception, are disabled. In this manner, it is possible to prevent unauthorized use by third parties or information leaks to third parties when the main body unit has been lost.

Abstract: The mobile communication terminal has a main body unit and an attachment. When the main body unit separates from the attachment, the attachment transmits a predetermined radio signal. The main body unit receives the radio signal and determines whether its distance from the attachment exceeds specified distance. When the main body unit is at a distance from the attachment exceeding the specified distance, predetermined operation of the main body unit, for example, entering operation using a keypad, memory read-out operation, data transmission and data reception, are disabled. In this manner, it is possible to prevent unauthorized use by third parties or information leaks to third parties when the main body unit has been lost.