| 摘要 |
PURPOSE:To expand or change the displaying extent of a map in the advancing direction of a vehicle without changing the scale of the map by generating displaying data by reading out map information from a map storing means and referring to coordinate information. CONSTITUTION:A location detecting means 2 is provided with an azimuth storing means 22 which is composed of a GPS receiver for detecting the location of its own vehicle, a vehicle speed and azimuth detector or a geomagnetism detector, etc., and calculates the advancing direction of the vehicle from the variation of the current location of the vehicle and stores the data related to the advancing direction as azimuth information. A control means 3 generates displaying data by reading out map data from a map storing means 1 and referring to coordinate information in a location storing means 21 and, at the same time, controls the map storing means 1, an inputting means 4, the location detecting means 2, and a displaying means 5. When the coordinate information does not correspond to the center or its vicinity of the screen of the displaying means 5 at the time of generating the displaying data, the control means 3 expands the displaying extent by moving the displaying coordinates of the coordinate information on the screen in response to the azimuth information. |
