| 摘要 |
PROBLEM TO BE SOLVED: To display an information suitable for travelling during travel on an expressway by making judgement about the expressway and specifying an interchange near a current position at the time of the judgement. SOLUTION: CPU 3a calculates a vehicle travel direction on the basis of signals from a GPS receiver 1, when the GPS receiver 1 is capable of receiving signals from three or more satellites. Then, the CPU 3a makes judgement about an expressway, depending upon whether the expressway key of a key input part 2 is operated, and causes an expressway mode to be indicated. Thereafter, an IC(interchange) nearest a current position is specified. In this case, ROM 3b stores point coordinates, expressway names and IC names for each IC and, therefore, the nearest IC can be specified by composition between the current position coordinates and each point coordinates. Furthermore, the deflection angle of the IC for the vehicle travel direction is obtained and judgement is made about whether the deflection angle is within a prescribed angle range. Then, IC having a deflection angle within the prescribed range is recognized as the next IC and displayed. |
