Patent ID: 7395150

Claim:
A map updating method for a navigation apparatus, the map updating method comprising: performing multitask control to execute both navigation processing and map-updating processing via the navigation apparatus, the navigation processing being higher in priority than the map-updating processing such that the map-updating processing is performed during periods unoccupied by navigation processing; performing sequential map-updating processing, as part of the map-updating processing, via the navigation apparatus on a plurality of map files utilizing map-updating data, the sequential map-updating processing involving a comparison between an old map file and a corresponding new map file; determining whether or not a necessary map file required for navigation processing contains up-to-date map data based upon the comparison performed by the sequential map-updating processing; and either executing navigation processing by using the necessary map file if the necessary map file contains up-to-date map data, or, if the necessary map file does not contain up-to-date map data, the navigation apparatus interrupts the sequential map-updating processing and then after using the map-updating data to update the necessary map file, the navigation apparatus restarts the sequential map-updating processing and subsequently executes navigation processing using the updated necessary map file.