A display screen indicates a map on a first scale. After a vehicle passes a guide point, determinations are made as to whether or not an on-map position of a next guide point is outside a predetermined large-area indication deciding frame in the display screen, and as to whether or not the on-map position...http://www.google.com/patents/US7463978?utm_source=gb-gplus-sharePatent US7463978 - Navigation apparatus and map-indication control program
