| 摘要 |
PURPOSE:To provide enlarged display of both a desired area map in a displayed map and an adjacent area map part at a time. CONSTITUTION:By selecting at least two necessary intersecting points of plural intersecting points corresponding to an adjacent area to a part of displayed map out of respective intersecting points formed by respective optical axes P1-Pn and Q1-Qn between respective light emitting elements and light receiving elements to shut down respective luminous beams which through the respective selected intersecting points, two touch switch signals are generated from a touch switch device. As a result, the center of gravity is determined from the respective intersecting points specified with both the touch switch signals, and a map data area in a prescribed area is read out from an enlarged map data in an outside memory device with the center of gravity centered, and then a map area adjacent to the read-out map data is shadowed. At the same time, a nap area specified with the read-out map data area is brightened, and the shadowed map is displayed together with the brightened map. |
