Electronic map apparatus and electronic map display method

Abstract

In an electronic map apparatus, an electronic map is displayed in accordance with map data read out from a DVD-ROM. Then, distance display circles which have a common center located at a point on the electronic map and each interconnect points on the electronic map at equal geographical distances from the point are drawn.As a result, it is possible to know an approximate geographical distance to a destination intuitively and easily in the electronic map apparatus which is typically used for car navigation.

Description

BACKGROUND OF THE INVENTION[0001]The present invention relates to an electronic map apparatus and a method of displaying an electronic map.[0002]In an onboard navigation apparatus mounted on a vehicle, a map is displayed on a display unit in accordance with map data read out from a memory such as a CD-ROM. Typically, there is provided a function to draw lines along longitude and latitude lines, superposing the lines on the map at predetermined intervals to form a shape resembling a checkerboard as shown in FIG. 6A.[0003]Thus, by using this drawing function, for example, it is possible to know an approximate geographical distance between the present position of the vehicle and a destination of the vehicle such as a location or a building.[0004]In addition, electronic map viewer application software executed on a personal computer, for example, includes a function for displaying a scale showing a geographical distance outside the frame of a displayed map. By using this distance scale,...

AI Technical Summary

Benefits of technology

The present invention provides an electronic map apparatus that can display a map with a circle or an arc on it. This is done by fetching map data from media and processing the data of the circle or arc using a microcomputer. The technical effect of this invention is that it allows users to easily see the geographical distance of a circle or arc on a map, which can be useful in various applications such as navigation or sports equipment design.

Problems solved by technology

In the case of such a display method, however, in an attempt to know the approximate geographical distance between the present position of the vehicle and the destination of the vehicle such as a location or a building while driving the vehicle, it is difficult to know the geographical distance instantaneously.

Particularly, it is more difficult to know a geographical distance in a direction slanting with respect to a longitude or latitude line.

It is thus much more difficult to intuitively and speedily know an actual geographical distance.

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