| 摘要 |
PROBLEM TO BE SOLVED: To provide a navigation system, in which the possibility that map information is interrupted in an incommunicable region is reduced, without increasing storage capacity by acquiring only required map information. SOLUTION: The navigation system is provided with a telephone 21, which can receive the map information by a communication; a RAM 25 in which the received map information is stored; a present-position detection means 20 which detects a present position; and a control unit 27, which controls the telephone part 21, the RAM 25 and the detection means 20. The navigation system is constituted, in such a way that the control unit 27 can assume a state where the telephone 21 receives the map information on a prescribed region, a state where the received map information on the prescribed region is erased by the RAM 25, and a state where the map information on regions other than the prescribed region is erased by the RAM 25. |
