Vehicle-mounted navigator

Claim 2

A vehicle-mounted navigator comprising: distance sensor means for detecting the running distance of the vehicle; direction sensor means for detecting the travelling direction of the vehicle; calculation means responsive to detection signals from said distance sensor means and said direction sensor means for calculating a present position of the vehicle; memory means for storing map data including a plurality of road maps corresponding to the vehicle's travelling regions; display means for electronically displaying a road map corresponding to one of said plurality of travelling regions on a display surface thereof; present position display control means for allowing said display means to display the present position of the vehicle calculated by said calculation means on the road map displayed on the display surface thereof; decision means for deciding whether the present position of the vehicle displayed on said display surface exists in one of a plurality of adjacent regions located in the periphery of said display surface; road map display control means for reading the map data of the adjacent region corresponding to the decided adjacent region from said memory means and for allowing said display means to display the road map of the adjacent region adjacent to the presently displayed vehicle travelling region instead of the display of the present road map, when said decision means decides that the displayed present position exists in one of said adjacent regions; and correction means for automatically correcting said displayed present position in accordance with the positional relation between the presently displayed region and the adjacent region which is to be displayed, when said road map display control means changes the display of the presently displayed road map to the adjacent region.

Claim 3

A vehicle-mounted navigator according to claim 1, wherein: said memory means stores the map data corresponding to the plurality of vehicle travelling regions and stores position data indicative of the positional relation among respective travelling regions; and said correction means corrects said displayed present position on the basis of said position data indicating the positional relation between the presently displayed region and the adjacent region which is to be displayed.

Claim 4

A vehicle-mounted navigator according to claim 2, wherein: said position data includes coordinate data indicating a coordinate between a given position and a predetermined specific point at the respective travelling regions; and said correction means decides a coordinate conversion value on the basis of respective coordinate data of the presently displayed region and the adjacent region which is to be displayed and corrects said displayed present position on the basis of said coordinate conversion value.

Claim 5

A vehicle-mounted navigator according to claim 1, wherein: said memory means stores, in addition to the map data corresponding to a plurality of the vehicle travelling regions, a map numeral of the present travelling region and a map numeral for each one of the plurality of travelling regions adjacent to the present travelling region; and said road map display control means reads the map data of the adjacent region from the map numeral corresponding to the adjacent region at which the displayed present position exists.

Claim 6

A vehicle-mounted navigator comprising: distance detection means for detecting a running distance of the vehicle; direction detection means for detecting a travelling direction of the vehicle; calculation means responsive to detection signals from said distance detection means and said direction detection means for calculating the present position of the vehicle; memory means for storing map data including a plurality of road map corresponding to the vehicle travelling regions; display means for electronically displaying a road map corresponding to one of said plurality of vehicle travelling regions on a display surface thereof; present position display control means for allowing said display means to display the present position calculated by said calculation means on the road map displayed on the display surface; alternation command means for generating a command for map alternation; road map display control means responsive to the alternation command of said alternation command means for selecting one adjacent region to be displayed from a plurality of adjacent regions adjacent to the presently displayed vehicle travelling region in accordance with the positional relation between the displayed present position of the vehicle and the periphery of said display surface, for reading the map data of the adjacent region from said memory means, and for allowing said display means to display the road map of the adjacent region instead of the presently displayed road map; and correction means for automatically correcting the displayed present position of the vehicle in accordance with the positional relation between the presently displayed region and the adjacent region which is to be displayed, when road map display control means changes the display of the said road map from the presently displayed region to that of the adjacent region.

Claim 7

A vehicle-mounted navigator comprising: distance detection means for detecting a running distance of the vehicle; direction detection means for detecting a travelling direction of the vehicle; calculation means responsive to detection signals from said distance detection means and said direction detection means for calculating the present position of the vehicle; memory means for storing map data including a plurality of road map corresponding to the vehicle travelling regions; display means for electronically displaying a road map corresponding to one of said plurality of vehicle travelling regions on a display surface thereof; present position display control means for allowing said display means to display the present position calculated by said calculation means on the road map displayed on the display surface; alternation command means for generating a command for map alternation; road map display control means responsive to the alternation command of said alternation command means for selecting one adjacent region to be displayed from a plurality of adjacent regions adjacent to the presently displayed vehicle travelling region in accordance with the positional relation between the displayed present position of the vehicle and the periphery of said display surface, for reading the map data of the adjacent region from said memory means, and for allowing said display means to display the road map of the adjacent region instead of the presently displayed road map; and correction means for automatically correcting the displayed present position of the vehicle in accordance with the positional relation between the presently displayed region and the adjacent region which is to be displayed, when road map display control means changes the display of the said road map from the presently displayed region to that of the adjacent region.

Claim 8

A vehicle-mounted navigator according to claim 5, further comprising: decision means for deciding whether the present position of the vehicle displayed on said display surface exists in one of a plurality of adjacent regions located in the periphery of said display surface; and wherein said road map display control means selects the adjacent region which is to be displayed in accordance with the decided adjacent region, when said alternation command means generates the alternation command and said decision means decides that said displayed present position exists on any one of said adjacent regions.

Claim 9

A vehicle-mounted navigator according to claim 5 wherein: said memory menas stores the map data corresponding to the plurality of vehicle travelling regions and further stores position data indicating the positional relation among respective vehicle travelling regions; and said correction means corrects said displayed present position on the basis of said position data indicating the positional relation between the presently displayed vehicle travelling region and the adjacent vehicle travelling region which is to be displayed.

Claim 10

A vehicle-mounted navigator according to claim 7, wherein: said position data includes coordinate data indicating a coordinate between a given position and a predetermined specific point at the respective vehicle travelling regions; and said correction means decides a coordinate conversion value on the basis of respective coordinate data of the presently displayed region and the adjacent region which is to be displayed and corrects said displayed present position on the basis of said coordinate conversion value.

Claim 11

A vehicle-mounted navigator according to claim 5, wherein: memory means stores, in addition to the data map corresponding to the plurality of vehicle travelling regions, a map number for the vehicle's present travelling region and a map numeral for each one of a plurality of travelling regions adjacent to the vehicle present travelling region; and said road map display control means reads the map data of the adjacent section from the map numeral corresponding to the adjacent region where the displayed present portion exists.

Claim 12

A vehicle-mounted navigator according to claim 6 wherein: said memory means stores the map data corresponding to the plurality of vehicle travelling regions and further stores position data indicating the positional relation among respective vehicle travelling regions; and said correction means corrects said displayed present position on the basis of said position data indicating the positional relation between the presently displayed vehicle travelling region and the adjacent vehicle travelling region which is to be displayed.