| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an extension unit which can reduce power consumption in simple configuration and can improve reliability and operability. SOLUTION: When a personal computer(PC) is connected to a PC communication unit at a position where the communication between the PC and a PC communication circuit 3 is enabled, a connection detecting circuit 7 detects the completion of connection between the PC and the PC communication unit. When the connection detecting circuit 7 detects the completion of connection between the PC and the PC communication unit, first and second switching circuits 23 and 24 are turned on and power is supplied to an extension unit control circuit 30 and a PC power supply circuit 5. Then the communication with the PC is performed through the PC communication unit by the PC communication circuit 3.</p> |
