JP3188294B2 - Electronic map device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic map device.

[0002]

2. Description of the Related Art In recent years, miniaturization of electronic equipment, CD-ROM
, Map data is converted to CD-ROM as a form of map information storage means, a map is displayed on a portable display device using the map data, and the positioning function of the positioning means and Combined,
2. Description of the Related Art There has been proposed an electronic map device for displaying a self-position on a map and searching for a map of a destination.

A conventional electronic map device will be described below. FIG. 2 is a configuration diagram of a conventional electronic map device. In FIG. 2, 1 is a CPU for controlling the whole, 2 is a system ROM containing a processing program, 3 is a system RAM used in the processing program, 4 is an image memory for storing image display data, and 5 is an image display device. , A display driver 6 for driving an image display device such as a CRT, and a CD-R 7
A CD-ROM reading buffer memory for storing data read from the OM, a CD-ROM reading device 8, a keyboard 9 for inputting processing instructions, and an external interface 10 for inputting positioning information.

When the power is turned on, first, the entire system is initialized. Next, the CD-ROM is read to determine whether the data is map data. If the data is not map data, the display and the standby state are made until the CD-ROM containing the map data is inserted.

When an appropriate CD-ROM 2 is inserted,
CD-R corresponding to the area specified by the user
The position on the OM 2 is calculated, the data is read into the buffer memory 7 by the CD-ROM reader 8, converted into image data, and developed in the image memory 4. The data developed in the image memory 4 is displayed as map data on the image display device 6 through the display driver 5.

The current position display function specifies the current position based on the information of the positioning device input from the external interface 10, searches and displays the corresponding map data, and plots the current position on a map. is there.

[0007]

In general, when a public transportation system such as an airplane is used as a means of transportation and crosses a time-change line, an announcement of a time change is issued. There is a problem that if you equip it and cross the time change line, you will not know it.

[0008]

According to an aspect of the present invention, there is provided an electronic map apparatus, comprising: a positioning means for measuring a current position; a map information storage means for storing map information; An electronic map device having display means for displaying current position information, provided with a time change line memory,
When calculating the current position by the positioning means, based on the latitude / longitude information of the current position, a time zone for determining which time zone of the time change line obtained from the information of the time change line memory It is characterized in that a judgment means and a means for displaying or warning when the time is different from the time zone of the previous calculation due to the movement of the current position are provided.

[0009]

According to the present invention, it is possible to notify the user of the change of the local time by issuing a warning when the time zone is different from the previous position by moving the current position and crossing the time change line by the above means. Becomes

[0010]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of an electronic map device according to one embodiment of the present invention. In FIG. 1, reference numeral 12 denotes a time change line memory for storing time change line data. When calculating the current position, the CPU 11 determines which time zone of the time change line is included as time zone determination means, Compare the time zone obtained by the previous calculation with the current time zone obtained by moving the current position. If the information of these two time zones is different,
A function is added to display or notify by a warning sound when the time change line is crossed. The other device configuration is the same as that of the conventional example.

Next, the operation according to the above configuration will be described with reference to the flowchart of FIG. 2, a diagram of FIG. 3 for explaining a method of determining the time zone to which the current position belongs, and a diagram of FIG. This will be described with reference to FIG. FIG. 4 shows a time change line expressed by a function of y = f (x), where the intersection of the Greenwich longitude and the equator is taken as the coordinate origin, the longitude direction is represented by x, and the latitude direction is represented by y.

In FIG. 2, a current position is first calculated in step 21. Next, at step 22, as shown in FIG. 3, the time change line is sequentially arranged in the longitude direction of x from the date change line of FIG. 4 using the equation of y = f (x) based on the latitude of the current position. Calculate the longitude of At this time, the calculation result is smaller than the current longitude until the time change line n shown in FIG. 3, but when the next time change line m is reached, the calculation result is larger than the current longitude. Therefore, in step 23, this calculation result is compared with the current longitude. If the calculation result is smaller than the current longitude in step 24, the longitude calculation of the next time change line is continued in step 25.

Next, if it is determined in step 24 that the calculation result has become larger than the current longitude, time zone information of the current position is obtained in step 26, and the time zone information enclosed by the time change lines n and m After confirming that the user is present, the CPU holds this time zone information as the immediately preceding time zone information.

Next, in step 27, the corresponding map data is read from the CD-ROM, image display processing is performed in step 28, and in step 29 the current position is plotted on the display screen. At that time, in step 30, the CPU extracts the immediately preceding time zone information, determines in step 31 whether the time zone information newly calculated this time has changed, and does nothing if it is the same. If the time zone is different, it is determined that the current position has been moved and the time change line has been crossed, and a warning message is displayed on the screen in step 32. Or generate an audible alarm. Then, in step 33, the immediately preceding time zone information is updated to prepare for the next position measurement. In this way, the notification of the time zone change to the user is realized.

For example, in the United States and the like, when the time division differs depending on the region, it is possible to notify the user of the time change information other than the current position information when moving, so that not only the map but also the time management device can be used. Use is also possible.

Although the present embodiment has been described on the assumption that the moving means is traveling east, the present invention can be similarly applied to a case where the traveling means is traveling west.

[0017]

As described above, according to the present invention, the time zone of the current location of the user is calculated by using the electronic map device that automatically changes the display map as the current location moves and displays the current location. By doing so, if you cross the time change line,
This is an excellent electronic map device that notifies the user of the fact and makes it easy to check the local time.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an electronic map device according to an embodiment of the present invention.

FIG. 2 is a flowchart in the electronic map device.

FIG. 3 shows a method of determining a time zone to which a current location belongs. The longitude of a time change line is sequentially calculated in the longitude direction based on the latitude of the current location, and the time change line FIG. 7 is a diagram for explaining whether or not there is a current point, and thereby determining a time zone.

FIG. 4 shows an example of expressing time change line data;
When the intersection of Greenwich longitude and the equator is taken as the coordinate origin, the longitude direction is represented by x, and the latitude direction is represented by y, the time change line is represented by y
FIG. 4 is a diagram for explaining that it can be expressed by a function of = f (x).

FIG. 5 is a configuration diagram of a conventional electronic map device.

[Explanation of symbols]

 2 System ROM 3 System RAM 4 Image memory 5 Display driver 6 Image display device 7 CD-ROM reading buffer memory 8 CD-ROM reading device 9 Keyboard 10 External interface 11 CPU 12 Time change line memory

Claims (1)

(57) [Claims] 1. A positioning means for positioning a current position, and a map information
Map information storage means for storing information, map information and current position
An electronic map device having display means for displaying information.
Te, the time change line memory is provided, the current by the positioning means
When calculating the position, based on the latitude and longitude information of the current position
To, time zone determining means for determining whether included which time zone of the time change line obtained from the information of the time change line memory
And a means for displaying or warning a time zone different from the time zone calculated by the previous calculation due to the movement of the current position.