Navigation system

摘要

At the first data access by a navigation unit to a recording medium that records updating right information necessary for updating map data in a rewritable data area in which map data are recorded, the updating right information is read from the data area and is deleted from the data area, and a map updating due date created based on the read updating right information is written in a memory of the navigation unit together with the medium identification information read from a non-rewritable management area.