Method and navigation sytem for display of sections of a digital map data base as well as an improved operating unit and interface for same

摘要

A method, operating unit, navigation system and interface for displaying a predetermined section of a digital map database, which represents a real geographic area, on a display device are described. The digital map database contains data representing various geographic elements. An attribute, which defines a display priority, is assigned to each geographic element. An evaluation is then performed to determine whether or not particular geographic elements in the predetermined section to be displayed should or should not be visible on the display device. A particular geographic element is made visible on the display device when it is located in the predetermined section and when its display-priority-determining attribute satisfies certain selection criteria or selection rules. This method prevents display of too many geographic elements, which would otherwise make the display congested thus producing an unclear display.