Importance

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Abstract

A navigation system 2 includes a map-gain timing judging part 15 to calculate a traveling speed the position of a vehicle detected by a GPS unit 13. A moving distance of the vehicle during the renewal of map is calculated by the traveling speed and a renewal time necessary for gaining the map information from the server 11 of a map information delivery apparatus 1. The system 2 further calculates a traveling direction of the vehicle by the position of the vehicle and also calculates a road distance from the present position of the vehicle to the margin of a map on display. When the road distance agrees with moving distance, it is started to gain a new map information from the server. Thus, when the vehicle reaches the margin of the map on display, the renewal of the map information is completed.

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First Claim