Patent ID: 6697733
Filing Date: 2004-02-24
Classification: G01C,G09B

Abstract:
A road map display apparatus including a road map information memory for memorizing road map data on a two-dimensional coordinate, detection means for detecting a present position and a travel direction of an automotive vehicle, read-out means for reading out a two-dimensional coordinate of the road map data from the information memory on a basis of the present position and travel direction of the vehicle detected by the detection means, and image display means for displaying a road mapwherein coordinate conversion means is provided to contract a square two-dimensional coordinate at the upper side thereof in relation to the lower side thereof for converting the square two-dimensional coordinate to a trapezoid coordinate for display of a perspective view on a two-dimensional plane without executing any perspective conversion processing taking into account a viewpoint to a coordinate value of the road map data, wherein said coordinate conversion means is arranged to convert the two-dimensional coordinate of the road map data read out by said read-out means to the trapezoid coordinate for display of the perspective view so that said image display means displays a road map in the travel direction of the vehicle defined by the converted trapezoid coordinate in the form of a perspective view on the screen.