| 摘要 |
PURPOSE:To display by using data of present position before a key switch is opened without setting the present position every time the switch is closed. CONSTITUTION:A present position of a vehicle is operated by a microcomputer 4 based on detection signals from an azimuth detector 1, a distance sensor 2. A road map and the present position are displayed on a CRT display unit 6 by data for indicating the operated present position and map data read from a cassette tape 3a. In this case, the data for indicating the present position and the map data are power-backed up to a graphic memory of a CRT controller 5, and nonvolatile-stored. Accordingly, since the data are stored as they are even if a key switch is opened and closed, operations for setting the present position and searching the map to be displayed every time the switch is closed are eliminated, and its operability is improved. |
