JP3291300B2 - Map display method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a map display method suitable for a map display device for displaying a map of a predetermined area on a screen.

[0002]

2. Description of the Related Art As a conventional example of a map display device, for example, JP-A-59-64985 (H04N5 / 93) or a magazine "Nikkei Electronics", March 24, 1986.
What is described on pages 92 to 95 of the Japanese edition is known. In such a map display device, map data is digitally recorded on a medium such as a disk or a magnetic tape. The map display device reproduces the medium and displays a map of a predetermined area on a screen. Here, on the screen, for example, road information, terrain information such as rivers and mountains, facility information such as railways and bridges, and character information for place names and road names are displayed.

[0003] Such a map display device has recently been commercialized for use in a vehicle. In such a vehicle-mounted map display device, additional traffic information such as one-way traffic is superimposed and displayed on a map as auxiliary information during traveling. Such auxiliary information may be digitally recorded on a medium or transmitted by radio waves from outside the vehicle. The map display device reproduces the additional information, and displays the additional information in a corresponding place in an identifiable manner.

[0004] Among the auxiliary information, information on a road such as one-way traffic or closed roads is provided with an identification symbol indicating the content at the start position of the corresponding road section, and a line image capable of identifying the road section is displayed on the road. It is common to superimpose and display on a map by attaching along a section.

[0005]

The on-vehicle map display device has a function of enlarging and displaying a specific portion of a display map. This allows the user to know the map of the specific area in more detail. However, in such an enlarged display, only a part of the area on the map is enlarged. Therefore, the starting end of the road section to which the auxiliary information is added may be out of this area. In such a case, only the line image attached along the road section is displayed on the screen on the map, and the identification symbol attached at the top is not displayed. For this reason, the user knows that this road section has some kind of auxiliary information, but cannot know what the additional information is. An object of the present invention is to solve such disadvantages in the conventional device.

[0006]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention displays a map of a predetermined area on a screen of a map display device, and additionally provides one-way or the like to a predetermined road section on the map. In the map display method for overlaying traffic information, when an end portion of the road section is displayed on a screen due to a change in the map display, a symbol representing the content of the traffic information of the section is displayed at the end portion. When the boundary of the map display area and the road section intersect due to the change of the map display, a symbol representing the content of the traffic information of the section is overlapped and displayed at the intersection. And

[0007]

[0008]

According to the present invention, even if an end of a road section to which traffic information is attached protrudes from the map display area due to a change in the map display, a portion where the boundary between the road section and the map display area intersects. Is attached to the traffic information symbol, the user can know the contents of the traffic information of the road section by looking at the traffic information symbol attached to the boundary.

[0009]

[0010]

FIG. 1 is a block diagram of a map display device. In the figure, reference numeral 1 denotes a CD-ROM disc on which map information is digitally recorded. The map information includes traffic information added to a predetermined road section together with the road information. Reference numeral 2 denotes a CD-ROM playback device which reads map information of a designated area from the disk 1 in accordance with an instruction from the control unit 3 and transfers it to the data memory 4. The transferred road information and additional traffic information are numerical data as shown in FIGS.

Here, a road is defined by connecting corresponding nodes. One-way information is shown as an example of the additional traffic information. This one-way road section is defined by connecting corresponding nodes in the same manner as the road. The one-way direction is defined by the order of the nodes in the one-way table read from the disk 1. In the one-way table, the uppermost node number of the node group having a predetermined one-way record number is the highest. The one-way direction is a direction from the uppermost node to the lowermost node. Therefore,
In the one-way table shown in Table 3, node number "2" is a one-way entrance and node number "4" is a one-way exit.

The map information transferred to the data memory 4 is:
The image information is processed by the image creation unit 6 based on the instruction from the control unit 3. Here, the control unit 3 issues a command for information processing to the image creation unit 5 in response to a command from the input unit 5 by the user. After this image information is sent to the image memory 7, it is displayed on the CRT 8 in response to a command from the control unit 3. Here, the control unit 3 determines which of the map areas stored on the image memory 7 is to be displayed on the CRT 8 based on a command from the input unit 5.

In the first embodiment according to the present invention, the contents of the one-way traffic and the symbol indicating the direction of the one-way traffic are superimposed and displayed on both ends of the road section to which the one-way traffic information is added.
FIG. 2 shows a display example of the present embodiment on the CRT 8. In the one-way road section, a folding line along the road is superimposed and displayed. The entrance and exit of a one-way road section are given symbols shown in FIGS. 4 and 5 according to traffic rules. The user can know the direction of one-way traffic in the road section only by looking at one of the symbols. Therefore, even if the area surrounded by the dotted line is enlarged and displayed on the display screen of FIG. 2 and the display screen is switched to the screen of FIG. 3, since the sign on the entrance side indicating the one-way direction is displayed, the traffic information is displayed. The user can know that the content of the road section marked with is one-way and the direction of the one-way. Of course, the same effect can be obtained even when only the sign on the exit side indicating the one-way direction is displayed.

The superimposed display of such traffic information is achieved by data processing in the image creating section 6 in the block diagram shown in FIG. FIG. 6 shows an algorithm of the data processing of the image creating unit 6 in the overlap display of the traffic information. When the one-way information processing is started in step 1,
First, in step 2, one-way information of record number "1" is read from the one-way table stored in the data memory 4. Next, the coordinates corresponding to each node number in the read record are read from a node table (see Table 1) in the data memory (step 3). The read coordinates are sequentially connected by a straight line to obtain a one-way road section as shown in FIG. 7 (step 4). Further, among the coordinates, the figure shown in FIG. 4 is attached to the position of the coordinate corresponding to the highest node number of the node number of one record read from the one-way table (step 5). Similarly,
The figure shown in FIG. 5 is attached to the position of the coordinate corresponding to the lowest node number of the read node numbers of the one record (step 6). Thus, a one-way display as shown in FIG. 8 is obtained. Then, it is determined in step 7 whether or not the reading process has been performed up to the last record number in the one-way table. After the above process has been performed on all records, the routine ends in step 8.

Next, a second embodiment of the present invention will be described. In the second embodiment, when the end of the road section to which the one-way information is attached protrudes from the map display area, the contents of the one-way and the one-way The symbol indicating the direction of is superimposed. In this embodiment, when the area surrounded by the dotted line in the display screen shown in FIG. 2 is enlarged and displayed, the display is performed as shown in FIG.

In this embodiment, the overlap display of traffic information
As in the above-described embodiment, this is achieved by data processing in the image creating unit 6 in the block diagram shown in FIG. FIG. 10 shows an algorithm of the data processing of the image creating unit 6 in the overlap display of the traffic information. The algorithm of this embodiment is different from the algorithm of the above embodiment in steps 3a to 3
The processing of d is different.

When the user sets a map display area via the input means 5, information indicating the range of this area is sent from the control section 3 to the image creation section 6. The image creation unit 6 processes steps 1 to 3 of the algorithm shown in FIG. 10 in the same manner as in the above embodiment, and converts the node for one record in the one-way table into coordinates (one-way coordinates). I do. Thereafter, in steps 3a and 3b, it is determined whether or not the coordinates are outside the map display area. If the coordinates do not run out, the process jumps to step 4 and performs the same processing as in the above embodiment. On the other hand, if the coordinates are out of range, the processing in steps 3c to 3d is performed, and then the processing in step 4 and subsequent steps is performed.

In step 3c, the coordinates of the intersection between the boundary of the map display area and the line segment formed by connecting the one-way coordinates are obtained, and the intersection coordinates are inserted into the corresponding positions of the one-way coordinates. The one-way coordinates are divided into a plurality of groups by the intersection coordinates. For example, when the one-way coordinates for one record are in a state as shown in FIG. 11A, the one-way coordinates are divided as shown in FIG.
In step 3d, as shown in FIG. 3C, only the coordinate group existing in the map display area is selected from the divided one-way coordinate groups, and this coordinate group is replaced with a new road in the one-way information. Set as the coordinate group of the record that defines the section. In steps 4 to 6, for each coordinate group,
The same processing as in the above embodiment is performed. That is, each coordinate group is processed into image information indicating a broken line with a one-way symbol at each end.

Although the embodiment of the present invention has been described above, the present invention is not limited to the embodiment.
Various other changes are possible. For example, in the above-described embodiment, one-way information is shown as added traffic information, but traffic information such as closing a road or under construction may be displayed in a corresponding road section. In the above embodiment, the traffic information is stored in advance on the CD-ROM.
Instead of this, a method of sequentially transmitting the signals to the apparatus by radio waves from the outside may be adopted. Such a method is advantageous when capturing traffic information that changes with the time, such as during construction, into the device.

[0020]

As described above, according to the present invention, even when the end of the road section to which the traffic information is attached protrudes out of the map display area, the user can always know the contents of the traffic information well.

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment.

FIG. 2 is a diagram showing a display screen according to the first embodiment.

FIG. 3 is a diagram showing a display screen according to the first embodiment.

FIG. 4 is a diagram showing display symbols for one-way traffic in the embodiment.

FIG. 5 is a diagram showing display symbols for one-way traffic in the embodiment.

FIG. 6 is a diagram showing an algorithm of data processing in the first embodiment.

FIG. 7 is a diagram showing a one-way road section in the first embodiment.

FIG. 8 is a diagram showing a one-way display state in the first embodiment.

FIG. 9 is a diagram showing a one-way display state in the second embodiment.

FIG. 10 is a diagram illustrating an algorithm of data processing in the second embodiment.

FIG. 11 is a diagram showing a process of dividing a coordinate group in the second embodiment.

FIG. 12 is a diagram illustrating an example of transfer of traffic information in the embodiment.

FIG. 13 is a diagram illustrating an example of transferring traffic information according to an embodiment.

FIG. 14 is a diagram illustrating an example of transferring traffic information according to an embodiment.

[Description of Signs] 1 CD-ROM disc 6 Image creation unit 8 CRT

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-1-226100 (JP, A) JP-A-2-248815 (JP, A) JP-A-2-248814 (JP, A) JP-A-2-248 248813 (JP, A) JP-A 1-127100 (JP, U) JP-A 2-102577 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G09B 29/10 G01C 21 / 00

Claims (1)

(57) [Claims] 1. A map display method for displaying superimposed additional traffic information such as one-way for a given road section on the map and displays a map of a predetermined area on the screen of the map displaying apparatus, wherein The end of the road section is drawn
If it is displayed on the surface,
When a symbol representing the contents of traffic information is superimposed and displayed, and the boundary of the map display area intersects with the road section due to the change of the map display, a symbol representing the contents of the traffic information of the section at the intersection. A map display method, wherein a map is displayed in an overlapping manner.