| 摘要 |
PURPOSE: To display the latest map by acquiring updated map information on topographic change, newly constructed roads, traffic stops, etc., by communication from the outside and automatically updating the built-in map information. CONSTITUTION: This car navigation device recognizes the present position of an automobile by a present position recognizing section 3 and a GPS antenna 5 and displays the map having the center at the present position on a display 13. The device is periodically connected via a modem 7 at a host station to receive the updated map data according to the new construction, works, etc., of the roads. The data provided with term of validity is stored in an updated map data storage section 17b and the permanent data is rewritten into a basic map data storage section 17a. The map data stored in the updated map data storage section 17b is subjected to management of the term of validity by the management table registered in a RAM 2 and is used for display only within the term of validity. The data of which the term of validity runs out is deleted. |
