Abstract: A mobile terminal device includes a threshold storing unit for retaining a threshold of field intensity, a comparator for comparing field intensity of a signal received from a base station with the threshold and outputting an electric field existence signal, a demodulation circuit for starting a reception operation according to a specified transition of the electric field existence signal, and a threshold setting unit for changing a threshold retained by the threshold storing unit according to a specified transition of the electric field existence signal.

Abstract: A first counter counts a first clock signal repeatedly in accordance with an external synchronous signal. A second counter counts a second clock signal repeatedly in every predetermined cycle, and generates an internal synchronous signal having the predetermined cycle. A controller adjusts the cycle of counting performed by the second counter by controlling the second counter. By doing so, the controller controls the internal synchronous signal to synchronize with the external synchronous signal in each horizontal period.

Abstract: A first counter counts a first clock signal repeatedly in accordance with an external synchronous signal. A second counter counts a second clock signal repeatedly in every predetermined cycle, and generates an internal synchronous signal having the predetermined cycle. A controller adjusts the cycle of counting performed by the second counter by controlling the second counter. By doing so, the controller controls the internal synchronous signal to synchronize with the external synchronous signal in each horizontal period.