| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent a control circuit from being started up by erroneous detection of a radio signal and to execute control by the control circuit corresponding to start timing of transmission of the radio signal, in a receiver which detects the radio signal on the basis of the signal level of reception signals and starts up the control circuit. <P>SOLUTION: As a radio signal detection circuit 8, two detector circuits 10 and 20 of different detection sensitivities are provided. When the second detector circuit 20 having a lower detection sensitivity to detect the radio signal accurately detects the radio signal, a CPU 6 is started up. When the first detector circuit 10 having a higher detection sensitivity to detect the radio signal earlier than the second detector circuit 20 detects the radio signal, a time counter 9 starts to count time. After being started up, the CPU 6 acquires a time difference between the radio signal detection by the first detector circuit 10 and the start-up from the time counter 9, determines the start timing of radio signal transmission by a transmitter based on the time difference, and outputs control information after the lapse of the predetermined time thereafter. <P>COPYRIGHT: (C)2010,JPO&INPIT |
