Patent ID: 6546334
Filing Date: 2003-04-08
Classification: G01C,Y10S

Abstract:
A car navigation map update system comprising:map update data delivery equipment including a map update data management section for managing a database containing rewritable map data, and a map update data broadcasting section for broadcasting map update data rewritten by the map update data management section; a car navigation terminal that receives the map update data broadcast by said map update data delivery equipment, stores the map update data in a map update data storing medium, and utilizes the map update data stored in the map update data storing medium in connection with map information data stored in a map data recording medium to form at least a partial map; said car navigation terminal forms an entire map by assembling partial map areas that are small subdivisions of map areas, and update the map on a partial map area basis by attaching an area identifier and a version number to each of the partial map areas; and wherein said car navigation terminal comprises a received data processor, and said received data processor compares the area identifiers and version numbers of the received map update data with those of the map information data stored in the map data recording medium and with those of the map update data stored in the map update data storing medium; additionally stores a received map update data block into the map update data storing medium, when the received map update data block has a version number that is newer than that of a corresponding map information data block stored in the map data recording medium, and has an area identifier that disagrees with area identifiers of all map update data blocks on the map update data storing medium, and rewrites a map update data block on the map update data storing medium by a newly received map update data block, when the received map update data block has area identifier that agrees with that of the map update data block stored in the map update data storing medium, and has version number that is newer than that of the map update data block stored in the map update data storing medium.