| 摘要 |
PROBLEM TO BE SOLVED: To provide a map display device which promptly switching the scale of the road map displayed on the display screen in compliance with an external instruction. SOLUTION: A CPU 12 is operated to read two kinds of map data stored in a CD-ROM different in scale when instructed externally and, based on each of map data, generates each of the image data for displaying road maps on a display device 4 and stores them into VRAMs 30a, 30b. The image data stored in these VRAMs are transformed into video signals by video controllers 32a, 32b, which causes a display switching SW 34 to select one of the transformed video signals and output the selected signal to a display device 4. As the result, the scale of the road map displayed on the display device 4 can be instantaneously switched over. In addition, it is possible to change the scale of the road map for each of VRAMs 30a, 30b by inputting an instruction of change in the state where the road map is displayed. |
