Patent ID: 6636802
Filing Date: 2003-10-21
Classification: G01C

Abstract:
A terminal device for reading a cartographic file from a storage device in which cartographic files are stored as digital data generated about individual units defined by dividing a map into a plurality of areas, wherein:each said unit containing a road network represented by nodes and links, each of the cartographic file comprises node records generated for respective nodes and link records generated for respective links; the node records each containing information about a non-neighboring node representing an intersection on the road network or information about a neighboring node defining a connection of roads between its unit and another unit adjoining said unit; and the information about the neighboring node being coordinate information about the neighboring node; said terminal device comprising: an input device responsive to an operation by a user for generating information specifying a map area; a data processing portion for specifying a record region where a necessary cartographic file is stored on the basis of the information generated by said input device; and a read control portion for reading the cartographic file from said storage device on the basis of the record region specified by said data processing portion; wherein said data processing portion performs a given process by using the node records and the link records recorded in the cartographic file read by said read control portion; and wherein said data processing portion traces a connection from a road in one unit to a road in another neighboring unit on the basis of the coordinate information about the neighboring nodes of the one unit and the neighboring another unit.