Patent ID: 7630833

Claim:
A map display device mounted in a mobile object comprising: displayable range determination means for determining a displayable range of a road map based on a reference point, a viewpoint, and a viewing angle settled on the road map, wherein the viewpoint has a predetermined height defined by a length perpendicular to a plane including the displayable range, the viewing angle is configured to vary on the plane including the displayable range in a direction orthogonal to a virtual reference line between the viewpoint and the reference point while being centered on the virtual reference line between the viewpoint and the reference point; display control means for displaying a three-dimensional road map on a screen, the three-dimensional road map being generated by applying a coordinate conversion process to a road map belonging to the displayable range; and viewing angle change means for changing the viewing angle for the three-dimensional road map displayed on the screen based on the reference point with the predetermined height of the viewpoint unchanged wherein the reference point is settled on or near a certain road, which is at least one of (i) a road for a mobile object to be positioned and (ii) a road included in a route to a user-input destination, the viewing angle change means changes a viewing angle depending on a road attribute of the certain road, the viewing angle change means changes a viewing angle depending on a road type of the certain road, and a viewing angle for an expressway is smaller than a viewing angle for a general road.