Patent ID: 8442768

Claim:
A navigation system for providing route information including an actual location of a vehicle, the navigation system comprising an in-vehicle device mounted on the vehicle and a portable terminal device carried by a passenger, the in-vehicle device including: a vehicle-information providing unit that collects and provides position information and movement information of the vehicle to the portable terminal device, the portable terminal device including: a setting unit that receives, from the passenger, a setting related to a scale size of map information to be acquired from a map center device, wherein the setting related to the scale size of the map information, inputted by the passenger, is a plurality of correspondences between scale sizes and speed ranges; a scale-size determining unit that determines a scale size requested to the map center device based on the setting received by the setting unit and the movement information sent from the vehicle-information providing unit of the in-vehicle device; a map-information acquiring unit that acquires map information whose scale size is determined by the scale-size determining unit from the map center device; an actual-location calculating unit that calculates the actual location of the vehicle based on the position information and the movement information sent from the vehicle-information providing unit of the in-vehicle device; and an image-data generating unit that generates the image data in which the actual location calculated by the actual-location calculating unit is superposed on the map information acquired by the map-information acquiring unit, and sends the generated image data to the in-vehicle device, the in-vehicle device further including a display unit that displays the image data sent from the portable terminal device.