| 摘要 |
PURPOSE:To visually estimate a distance to a target by displaying a road map including a present position based on the detected present position of a vehicle and stored map data, and displaying a graduated scale of orthogonal coordinates with the present position as an origin by using a contraction scale of the map. CONSTITUTION:A display driving circuit 22 is driven based on present position data, bearing data from a GPS receiver 2 and unit map data stored in a RAM 16, a road map is displayed on a display screen 8a at the present position as a center, and the present position is marked. Then, the present position and an advancing direction are calculated from data of the receiver 2, the necessity of updating of the unit map data, the altering of a contraction scale is judged based on it, and it is switched as required. Thereafter, the circuit 22 is driven based on the present position data and the contraction scale of the unit map data, and a graduated scale of orthogonal coordinates with the present position as an origin is displayed along a lower side, a right side of the screen 8a. Since the scale is always displayed with the present position as the origin, a distance from the present position to a target is easily visually estimated. |
