| 摘要 |
PURPOSE:To select whether data displayed on a screen is employed or discarded according to the extent of the scale of a map by providing a data processing part with a rank decision and selection part and a scale selection and setting part. CONSTITUTION:A map data memory part 70 is divided into memory parts 71-73, where specific map data based upon different ranks classified by importance and scale are stored by the ranks. A data processing part 81 is provided with the rank decision and selection part 82 and scale selection and setting part 83, and the map corresponding to map data including a current position is displayed on the screen according to the scale (three kinds, i.e. extension, standard, and contraction) of the map. The data is employed or discarded selectively. Consequently, the processing part 81 calculates the current position of a moving body and the map data including the current position is read out of the memory part 70 and displayed. Therefore, a map corresponding to map data regarding, for example, the road where the moving body moves is prevented from being inconspicuous in a map corresponding to other map data which are not important so much. |
