| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a navigation system for reducing an effect on an environment, and efficiently updating stored data. <P>SOLUTION: The navigation system comprises: a car navigation apparatus for storing the data indicating an image displayed to passengers in a vehicle or a sound output to the passengers in the vehicle after the data is received through a power line; and a power supply switching apparatus for determining whether the data can be communicated through the power line by transmitting and receiving packets used for the communication, and switching power supplied to the car navigation apparatus from a vehicle power supply supplied by the vehicle equipped with the car navigation apparatus to a power supply supplied by the power line if it determines that a communication is enabled. Since the car navigation apparatus communicates and updates the data by using the power supply supplied from the power line, the power supply can be stably supplied while the effect on the environment is reduced, and the data can be efficiently communicated by using the power line. <P>COPYRIGHT: (C)2010,JPO&INPIT |
