JPH05181414A - Map display device - Google Patents

Abstract

PURPOSE:To obtain a map display device for a navigation system which can evade a state wherein characters on a displayed map overlap with the display of roads in the vicinity of the position of the device in use. CONSTITUTION:The map display device is equipped with a road map holding means 10 which holds image data for displaying the road map including the display of the roads, a position holding means 12 which displays the position of the device, a character data holding means 14 which holds data on characters indicating a display body displayed on the map and the display position, a character data selecting means 16 that selects data which do not overlap with the display of the roads nearby the position indicated by the position data among the data held in the character data holding means 14, and a display means 18 which displays the road map, signs, and characters one over another according to the image data and character data and the data selected by the character data selecting means 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a map display device for a navigation system which automatically displays a road map and its own position on the road map for route guidance.

[0002]

2. Description of the Related Art In a navigation system, a road map and a sign indicating its own position are automatically displayed on the road map. On the road map, names of intersections, place names, station names, route names, etc. on the map are displayed in characters. Conventionally, these characters were displayed at fixed positions on the road map.

FIG. 7 is a diagram showing an example of an image displayed on a display in a conventional navigation system. As shown in the figure, roads 120, railroads 122 and the like are displayed on the display, along with letters such as intersection names 124 and route names 126.
The position of the own vehicle is displayed by a sign 128 which is represented by a graphic whose traveling direction is known, and when the position of the own vehicle moves, the display position is automatically updated.

Conventionally, an intersection name 124 and a route name 1
The characters displayed on the map such as 26 were displayed at a fixed position with respect to the map.

[0005]

In the conventional navigation system, for example, under the situation shown in FIGS. 7A and 7B, the characters on the road near the own vehicle are overlapped with the characters displayed on the road near the own vehicle. The situation may be difficult to see. Although the road shown in the figure is simplified, the actual road usually has fine branches, and the overlapping of characters on the road makes it difficult to see the state of the branch and impairs the navigation function.

By making it possible to select the type of display characters,
For example, if you can select to display only the place name and only the intersection name, you can suppress the occurrence of the above situation,
But there are limits. Therefore, an object of the present invention is to provide a map display device for a navigation system, which can avoid a situation in which a displayed character on a map overlaps with a display of a road near its own position.

[0007]

FIG. 1 is a block diagram showing the basic configuration of the present invention. In the figure, the map display device of the present invention is for displaying a road map holding means 10 for holding image data for displaying a road map including a road display, and for displaying a sign indicating its own position on the road map. Position holding means 12 for holding the position data of, and a character data holding means 14 for holding a plurality of sets of characters representing the display object displayed on the road map and data indicating the display position for each display object. Character data selecting means 16 for selecting, from the plurality of sets of data held by the character data holding means 14, one which does not overlap the display of the road near the position indicated by the position data held by the position holding means 12, According to the image data and position data held by the road map holding means 10 and the position holding means 12, respectively, and the character data selected by the character data selecting means 16, the road Map,
It is characterized by comprising a sign and a display means 18 for displaying characters in an overlapping manner.

[0008]

By selecting and displaying character data that does not overlap the road display near the user's position from a plurality of sets of data, it is possible to avoid a situation in which the character is overlapped on the road display near the user's position and is difficult to see.

[0009]

FIG. 2 is a block diagram showing the configuration of a navigation system equipped with a map display device according to an embodiment of the present invention. The CD-ROM microcomputer 20 is a CD-RO
The map data stored in M 22 is controlled via the decoder 24. The map data includes image data for displaying a map, data regarding characters representing a display object on the map, and road data including coordinates of intersections and the like.

The location microcomputer 26 sequentially calculates the current position from the data of the traveling direction input from the geomagnetic sensor 28 and the data of the moving distance from the wheel speed sensor 30, and periodically, via the communication bus 34, the main microcomputer. 32
Send to. The initial value of the current position is given from the main microcomputer 32 via the communication bus 34, and by performing map matching processing based on the road data received from the CD-ROM microcomputer 20 via the communication bus 34, the initial value and A process of calculating a current position in which the accumulated error included in the current position calculated from the information from the sensor is corrected is performed.

The main microcomputer 32 sends the image data received from the CD-ROM microcomputer 20 via the communication bus 34 to the driver 34, whereby the LCD display 36.
Draw a map on top. When the user gives the current position of the own vehicle by operating the operation switch 38, the current position is sent to the location microcomputer 26, and thereafter, the location microcomputer 26 periodically sends the current position and the own vehicle by the processing described above. Since the data about the direction is sent, the marker is displayed at the position and the direction corresponding to it on the map. At the same time, as will be described later in detail, appropriate data corresponding to the position of the vehicle is selected from the data regarding the characters (character data) read by the CD-ROM microcomputer 20 and displayed on the map.

Note that such a vehicle position calculation method is an example, and for example, in the case of satellite navigation in which radio waves from a plurality of satellites are received to calculate the position of the vehicle, the vehicle position is calculated without giving an initial value. The calculation of the vehicle position starts. FIG. 3 is a diagram showing an example of character data stored for each display object such as an intersection on a map. FIG. 3A shows a case of a character with an arrow. The x mark indicates the position of the display object, and four character display positions of upper left (), upper right (), lower left () and lower right () are stored. FIG. 3B shows a case of a character without an arrow, and four character display positions of upper (), left (), right () and lower () are stored.

FIG. 4 is a flow chart showing the processing of the main microcomputer 32. In the figure, after drawing a map with image data from the CD-ROM microcomputer 20 (step a), if the operation switch 38 is operated (step b), the corresponding process is performed (step c). This includes the above-described operation for setting the initial position and processing corresponding thereto. When data concerning the current position is received from the location microcomputer 26 (step d), marker display and character drawing processing based on the data is performed (step e), and the process returns to step b.

FIG. 5 is a flow chart showing the details of the marker display and character drawing processing (step e) in FIG. In the figure, after displaying the marker based on the data of the position and orientation of the vehicle (step a),
One of the stored character data is taken out (step b), and the positional relationship between the position of the display object represented by the character and the position of the vehicle is checked (step c). If it is determined that the position of the display object is at the upper left of the own vehicle, the display position displayed at the upper left of the display object, that is, in FIG. 3A is selected (step d), and if it is the lower left, the lower left 3 (a) is selected (step e), and if the upper right is selected, the upper right is selected (step f), and if the lower right is selected, the lower right is selected (step g). Draw (step h). If there is a character for which the output process is not completed (step i), steps b to h are repeated, and if the output process for all the characters is completed, the process ends.

It should be noted that in steps d to g of FIG.
Although the character display in the form of (a) has been described, FIG.
Similar processing is performed for the character display in the format (b). FIG. 6 is a diagram showing an example of a map displayed on the map display device according to the present invention, and shows an example of the display in the situation described in FIG. 7A. In this case, since the intersection of "Higashijiri Pond" is located on the lower left of the marker 128 representing the own vehicle, the lower left character is selected and displayed. As a result, it is possible to prevent the characters from overlapping the road near the marker 128.

[0016]

As described above, according to the present invention,
This makes it easy to understand the condition of the road near the marker indicating the position of the vehicle and maximizes the functions of the navigation system.

[Brief description of drawings]

FIG. 1 is a block diagram showing a principle configuration of the present invention.

FIG. 2 is a block diagram showing a configuration of a navigation system to which the present invention is applied.

FIG. 3 is a diagram illustrating an example of a character display position stored for each display object on a map.

4 is a flowchart of a process of a main microcomputer 32 of FIG.

FIG. 5 is a flowchart showing details of the marker display / character drawing processing of FIG.

FIG. 6 is a diagram showing an example of a display by the map display device of the present invention.

FIG. 7 is a diagram showing a display example in a conventional navigation system.

[Explanation of symbols]

 120 ... Road 122 ... Railway 124 ... Intersection name 126 ... Route name 128 ... Own vehicle marker

Claims (1)

[Claims] 1. A road map holding means (10) for holding image data for displaying a road map including a road display.
And a position holding means (12) for holding position data for displaying a sign indicating its own position on the road map, and a character representing a display object displayed on the road map and its display position. The position holding means (12) holds the character data holding means (14) for holding a plurality of sets of data for each display object and the plurality of sets of data held by the character data holding means (14). Character data selecting means (16) for selecting a road that does not overlap the display of the road near the position indicated by the position data, the road map holding means (10) and the position holding means (1).
2) image data and position data respectively retained and display means (18) for superimposing and displaying the road map, the sign, and characters according to the character data selected by the character data selection means (16). Characteristic map display device.