| 摘要 |
PROBLEM TO BE SOLVED: To provide a map data using system capable of realizing a map data use process suitable for a current network state while reducing a process load. SOLUTION: When performing route calculation, map data of the area used for the route calculation are read from a recording medium into a RAM (S10), and updating map data are read from an external memory into a RAM (S20). If there exists the updating map data that belong to the area of "map data used for route calculation" that have been read at S10 (S30:YES), the updating map data are used to perform updating process with "map data used for route calculation" that have been read at S10 on an RAM (S40). After the map data updating process is performed, the map data that have been updated are used for route calculation (S50). COPYRIGHT: (C)2005,JPO&NCIPI |
