Navigation system

#The disclosure of the following priority application is herein incorporated by reference:

#Japanese Patent Application No. 2005-292208 filed Oct. 5, 2005

#1. Field of the Invention

#FIG. 1 is a block diagram showing the structure of the navigation system achieved in an embodiment of the present invention;

#FIG. 2 presents an intersection enlargement display that may be brought up in the related art when the next guidance-requiring intersection is a circular intersection;

#FIG. 3 presents an example of an intersection enlargement display according to the present invention that may be brought up in place of the display in FIG. 2

#FIG. 1 shows the structure of the navigation system achieved in an embodiment of the present invention. The navigation system, installed for use in a vehicle, searches for a recommended route to a destination having been set and guides the vehicle to the destination along the recommended route resulting from the search. As the vehicle approaches the next guidance-requiring intersection at which it needs to make a turn, the navigation system creates an abridged map based upon a regular map of the area around the guidance-requiring intersection by simplifying the shapes of the roads present in the area and displays the abridged map as an intersection enlargement. By checking the turning direction indicated with an arrow in the intersection enlargement, the user is able to ascertain at a glance the direction in which the vehicle should advance.

#The navigation system 1 in FIG. 1 includes a control circuit 11, a ROM 12, a RAM 13, a current position detection device 14, an image memory 15, a display monitor 16, an input device 17 and a disk drive 18. A DVD-ROM 19 having recorded therein map data is loaded into the disk drive 18.

#The control circuit 11 constituted with a microprocessor and its peripheral circuits uses the RAM 13 as its work area when executing a control program stored in the ROM 12 to implement various types of processing and control. The control circuit 11 executes processing such as the search for a recommended route to a destination based upon the map data recorded in the DVD-ROM 19. In addition, an abridged map of an area around a guidance-requiring intersection is created as explained later and the abridged map is displayed as an intersection enlargement at the display monitor 16.