| 摘要 |
An apparatus for guiding a vehicle allowing a route sweep is disclosed. The apparatus includes a display which shows a portion of a map. The user may move the map on the display from a start point to a finish point. This movement is termed a route sweep. To carry out a route sweep allowing a user to take cognizance of a route proposed by the apparatus, the maximum rate of sweep of the map on a display screen, the so-called cruising rate (L), desirable to obtain a short sweep time, is first calculated. Then starting from a specified scale (R.S.), the map is moved at an increasing rate in such a way as to arrive at the cruising rate (L) after a predetermined time. Simultaneously, the scale (chain-dotted curve) is reduced so as to arrive after the same time at a scale which is compatible with the cruising rate. The central part of the sweep is then carried out at the cruising rate with compatible scale, and the sweep is terminated while reducing the rate and while enlarging the scale again so as to return to the initial scale.
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