Patent ID: 8489332

Claim:
A car navigation system comprising: a central processing unit; map data storing means for storing map data of a plurality of areas into respective map data files; display means for displaying the map data; location acquisition means for acquiring a self-location; and destination determination means for determining a destination; the car navigation system searching a guided route from the self-location to the destination by referring to the map data storing means, and displays the guided route on the display means, the central processing unit executing processes for: identifying a map data file that includes the destination, the guided route and its vicinity, necessary for executing an application program, per each application program in the car navigation system, from a plurality of map data files stored in the map data storing means; monitoring an update status of the identified map data file when updating map data files stored on the map data storing means; preparing information in which the update status of the map data file obtained by the above monitoring process and identification data of the map data file are associated with the application program, and storing the information into a storage device as management information for managing the operation consistency of the application program; and in a case of updating map data files of which identification data is included in the management information, updating the map data file with reference to the execution status of the application program, and in a case of updating map data files of which identification data is not included in the management information, updating the map data file without reference to the execution status of the application program; wherein the central processing unit, in a case of executing an application program for guidance, refers to the management information and judges whether or not updating a map data file associated to the application program is completed, and when the update is completed, retries a route search using the updated map data file; and wherein, when the central processing unit judges that the updating of the map data file associated with the application program is not completed, the central processing unit determines whether road data is consistent with guidance data by comparing the road data to the guidance data for the guided route, and when the road data and the guidance data are inconsistent a notification of possible mismatches between the guided route and an actual route is provided to a user of the car navigation system.