Pennie & Edmonds LLP
Bird's-eye view forming method, map display apparatus and navigation system
 A map display apparatus for displaying perspective image of a map. The apparatus includes an image display device for displaying the perspective image of the map and a map data storage device for storing map data. Map drawing means is included for preparing map drawing data using the map data and for displaying a perspective image of the map on the display device on the basis of the drawing data. The map drawing means transforms coordinate data of a map into data suitable for display of the perspective image of the map. The data transformation is accomplished by perspectively projecting the coordinate data onto a predetermined projection plane with a view point at a desired position. The projection plane is determined on the basis of two predetermined points in the map data, such as the current position of a vehicle and the destination, so that drawing positions of the two points after the perspectively projecting operation are coincident with predetermined positions. 
Hitachi, Ltd. Nissan Motor Co., Ltd. Xanavi Informatics Corporation
G G G G
G01C G09B G01C G01C
inventional inventional inventional inventional
Toshio Motoki Hiroshi Norimasa Masaki Hiroyuki Yoshinori
Fujiwara Hirano Shojima Kishi Watanabe Satake Endo