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

[0009]In order to solve the problems described above, the present invention provides an electronic map apparatus comprising: data fetching means for fetching map data from media for storing the map data to be displayed as a map; a display device for displaying the map in accordance with the map data; and a microcomputer for processing data of a circle or an arc which has a center at a specified point on the map and links points on the map at equal geographical distances from the center, wherein the circle or the arc is displayed on the map displayed on the display device in accordance with the data processed by the microcomputer.

[0009]In order to solve the problems described above, the present invention provides an electronic map apparatus comprising: data fetching means for fetching map data from media for storing the map data to be displayed as a map; a display device for displaying the map in accordance with the map data; and a microcomputer for processing data of a circle or an arc which has a center at a specified point on the map and links points on the map at equal geographical distances from the center, wherein the circle or the arc is displayed on the map displayed on the display device in accordance with the data processed by the microcomputer.

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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