JPH08194432A - Map displaying apparatus - Google Patents

Abstract

PURPOSE: To display signs easy to be seen by human beings without applying excessive load to a computing process of an apparatus even if the respective signs are displayed at angle along a road by determining the fonts of the signs based on detection results by a direction detecting means. CONSTITUTION: A direction detecting means detects the display direction of a row of signs set corresponding to a road as one of a prescribed number of discrete directions. Font data for sign display has a plurality of types of fonts produced by altering the display angles for same signs corresponding to the prescribed number of discrete directions. Consequently, based on the detected results by the direction detecting means, a font determining means determines the fonts for signs, which are subjects to be displayed, so that the display angle of each sign can be altered along the road. Moreover, the display angle is changed not by calculation but selection of fonts among a plurality of types of fonts produced by changing the display angles, excessive load of calculation process is not applied to a display apparatus.

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 example, in a map display device such as a navigation device,
The present invention relates to a map display device for displaying a road name along with a road display by using symbols such as letters for indicating the road name.

[0002]

2. Description of the Related Art A map display device such as a navigation device mounted on a vehicle displays a current position of the vehicle on a map in real time to give useful information for a driver to reach a desired place. .

In such a map display device, by displaying the name and type of the road, the driver is given information about the traveling road and surrounding roads.

[0004]

When the display for the road is made by symbols such as letters, particularly when two or more symbols are arranged and displayed, the display should be along the road. This is preferable because it makes it easier to understand the correspondence with existing roads.

However, the roads displayed on the display are not always displayed parallel to the X axis and the Y axis.
In addition, not only straight roads exist, but curved roads and bent roads are common. Therefore, in order to make the symbol string to be displayed along the road, not only the symbols are arranged along the road, but also the display angle of the symbol itself is the arrangement direction of the symbol string (hereinafter also referred to as the display direction). ) It was important to rotate the display to an angular position adapted to), and to display the corresponding road easily.

The vector display used in the past is suitable for such a request, and the symbol is represented by a line using the data representing the pattern of the symbol, so that the desired angle can be easily displayed. did it. However, in the map display device which is generally used at present, the raster scan display is predominant because it is necessary to fill the surface because of the necessity of displaying and because it is necessary to display using a large number of colors. In a raster scan display, symbols are displayed by dots using font data. If you try to rotate and display a symbol displayed with dots simply like a vector display, the calculation processing for rotation will be overloaded, and if you rotate the symbol represented by dots, In general, the display of each symbol is disturbed and it is generally difficult to see.

For this reason, in the map display device displaying the symbols by dots, the angle of each symbol cannot be changed along the road, and there is a surface lacking the recognizability of the corresponding road. The present invention provides a map display device capable of displaying symbols that are easy for humans to see, even if each symbol is displayed at an angle along a road, without imposing an excessive burden on the calculation processing of the device. .

[0008]

According to the first aspect of the present invention,
As illustrated in FIG. 12, a map display device for displaying a symbol string in dots along a route displayed on a display device, wherein a display direction of the symbol string set corresponding to the route is set to a predetermined direction. An azimuth detecting means for detecting one of a plurality of discrete azimuths, and a plurality of types of fonts created by changing the display angle of the same symbol corresponding to the predetermined number of discrete azimuths. A map display device comprising: symbol display font data; and font determining means for determining the font of a symbol to be displayed based on the detection result of the direction detecting means.

According to a second aspect of the present invention, the font of the original direction is used by converting the font of the direction different from the discrete direction by 90 °, 180 ° or 270 °. It is a display device.

According to the third aspect of the invention, the font for the azimuth different by 90 ° or 270 ° among the discrete azimuths is used by converting the font of the original azimuth and using 180 °.
The map display device according to claim 1, wherein the font for the different orientation uses the font of the original orientation as it is.

The invention according to claim 4 is the map display device according to any one of claims 1 to 3, wherein the discrete directions are 16 directions. In the invention according to claim 5, the 16 azimuths are 0 ° ± 11.25 °, 22.5 ° ± 11.25 °,
45 ° ± 11.25 °, 67.5 ° ± 11.25 °, 9
0 ° ± 11.25 °, 112.5 ° ± 11.25 °, 1
35 ° ± 11.25 °, 157.5 ° ± 11.25 °,
180 ° ± 11.25 °, 202.5 ° ± 11.25
°, 225 ° ± 11.25 °, 247.5 ° ± 11.2
5 °, 270 ° ± 11.25 °, 292.5 ° ± 11.
25 °, 315 ° ± 11.25 ° and 337.5 ° ±
The map display device according to claim 4, wherein the map display device has an azimuth of 11.25 °.

According to a sixth aspect of the present invention, the symbol display font data is 90 ° or 180 ° out of the 16 directions.
The map display device according to claim 4 or 5, wherein the map display device is composed of four types of fonts corresponding to four orientations that are not in a relationship different by 270 °.

In the invention according to claim 7, the four directions are 0.
° ± 11.25 °, 22.5 ° ± 11.25 °, 45 °
7. The map display device according to claim 6, wherein the map display device has ± 11.25 ° and 67.5 ° ± 11.25 °.

[0014]

In the map display device according to the present invention, the azimuth detecting means sets the display azimuth of the symbol string set corresponding to the route to one of a predetermined number of discrete azimuths.
Detect as one. Further, the symbol display font data has a plurality of types of fonts created by changing the display angle of the same symbol in correspondence with the predetermined number of discrete directions.

Therefore, the font determining means determines the font of the symbol to be displayed based on the detection result of the azimuth detecting means, whereby the display angle of each symbol can be changed along the road. Moreover, since the display angle is not changed by calculation but selected from a plurality of types of fonts created by changing the display angle, the calculation process is not overloaded.

It is not necessary to create the font from the beginning for all of the predetermined number of discrete orientations.
A font is created in advance only for a specific direction out of the above predetermined number of discrete directions, and the direction for which a font that is not difficult to see is obtained by simple calculation from the fond data is calculated after that. It may be calculated or calculated when necessary.

For example, of the discrete azimuths, 90 °,
As for the fonts for different directions of 180 ° or 270 °, the font of the original direction may be converted and used. 90
For fonts having different azimuths of 180, 270, or 270, the conversion calculation from the original font can be performed by simply replacing the X coordinate and the Y coordinate and changing the sign. Alternatively, when displaying the symbols, the output of the original orientation font array can be modified to display the symbols for orientations that differ by 90 °, 180 ° or 270 °. For example, from the upper left corner of the font to the right, and 1
Dot data is read out downward line by line, and the read data can be written 90 ° clockwise (270 ° counterclockwise) clockwise by writing dot data from the top right to the bottom and one line to the left. You can display the symbol. As described above, if the order and place of reading and writing from the font are changed, it is not necessary to create the font for all of the predetermined number of discrete directions.

Therefore, in this case, the calculation does not impose an excessive burden on the apparatus, and it is not necessary to prepare fonts for that amount in advance, which saves memory. In addition, the font for the azimuth that differs by 180 ° is
The original orientation font may be used as it is. 180 °
If the different orientations are simply adapted to 180 ° to transform the pattern of symbols, the symbols are displayed upside down.
The reverse display may be useful for distinguishing roads in some cases, but it is preferable to use the same font as the original font without reversing it, because the recognition of the symbol itself is improved.

The discrete directions may be 16 directions. The 16 azimuths are 0 ° ± 11.25 °, 22.5 ° ± 11.25 °, in which all azimuths are evenly distributed.
45 ° ± 11.25 °, 67.5 ° ± 11.25 °, 9
0 ° ± 11.25 °, 112.5 ° ± 11.25 °, 1
35 ° ± 11.25 °, 157.5 ° ± 11.25 °,
180 ° ± 11.25 °, 202.5 ° ± 11.25
°, 225 ° ± 11.25 °, 247.5 ° ± 11.2
5 °, 270 ° ± 11.25 °, 292.5 ° ± 11.
25 °, 315 ° ± 11.25 ° and 337.5 ° ±
Those having an azimuth of 11.25 ° are preferable. Of course, other numbers such as 8 and 32 directions may be used.

In particular, by having a font for 16 directions (including the case where it is obtained by the above calculation), the symbol display corresponding to the road facing almost any direction does not impose an excessive burden on the device by calculation. It becomes possible. As described above, the font for the azimuth different by 90 °, 180 °, or 270 ° among the above discrete azimuths causes almost no calculation load even if the font of the original azimuth is converted and used. , The symbol display font data is
Of the 16 orientations, the fonts may be composed of four types of fonts corresponding to four orientations that are not in a relationship different by 90 °, 180 °, or 270 °. As the four directions, for example,
0 ° ± 11.25 °, 22.5 ° ± 11.25 °, 45
° ± 11.25 ° and 67.5 ° ± 11.25 °.

The selection of the font of the symbols along the road may be performed by setting a series of symbol strings as one unit and displaying the symbol string in one font corresponding to the road direction. It is also possible to select a font corresponding to a nearby road direction and display it in a different font for each symbol.

[0022]

【Example】

[Embodiment 1] FIG. 1 is a block diagram showing the overall configuration of a vehicle-mounted navigation device 2 according to an embodiment of the present invention. The vehicle-mounted navigation device 2 includes a position detector 4, a map data input device 6, an operation switch group 8, a control circuit 10 connected to these, and an external memory 1 connected to the control circuit 10.
2 and a display unit 14. The control circuit 10
Is configured as an ordinary computer, and is internally provided with a CPU, a ROM, a RAM, an I / O, and a bus line connecting these configurations.

The position detector 4 is a well-known geomagnetic sensor 1
6, gyroscope 18, distance sensor 20, and GPS that detects the position of the vehicle based on radio waves from satellites
GPS receiver 2 for (Global Positioning System)
Have two. These sensors 16, 18, 20,
Since each 22 has an error with a different property, it is configured to be used while being interpolated by a plurality of sensors. Depending on the accuracy, it may be configured by a part of the above, and further, a rotation sensor for steering, a wheel sensor for each rolling wheel, etc. may be used.

The map data input device 6 includes so-called map matching data for improving the accuracy of position detection, map data including display symbol string data, font data of symbols such as characters to be displayed in a map, and route. It is a device for inputting various data including guidance. As a medium,
A CD-ROM is generally used because of the amount of data, but other media such as a memory card may be used.

The position detector 4, the map data input device 6, the operation switch group 8, the control circuit 10, the display 14 and the like constitute a so-called navigation device. The display device 14 can display the vehicle position information input from the position detector 4 and the map data input from the map data input device 6 in an overlapping manner.

Further, the on-vehicle navigation device 2 is
When a waypoint including a destination is sequentially input by the operation switch group 8 from the near side, a route is formed by connecting the waypoint from the current position to the destination by a straight line to display a guide route, a so-called route guidance function. Is also equipped. The operation switch group 8 is, for example, a touch switch integrated with the display 14 or a mechanical switch, and is used for various inputs.

Further, an FM receiver 24 is provided to receive various traffic information, particularly traffic jam information here, from the FM station. The control circuit 10 receives the traffic congestion information, and if there is a road corresponding to the map displayed on the display device 14 based on the road number included in the traffic congestion information, a figure, a character, etc. along the road. The traffic jam is indicated by the symbol.

When the power switch of the vehicle-mounted navigation device 2 is turned on, a desired process is selected and executed from the processes of the traffic information display device by menu selection after a predetermined initial setting. Here, the driver of the vehicle is about to start traveling, and the guide route is displayed on the display unit 1.
When the route setting process is selected for displaying on the display 4, and the route is set by the operation switch group 8, a map around the current position is displayed on the display unit 14. On the map, the locations of roads and buildings, etc., which serve as landmarks when the vehicle is running are displayed by being distinguished by colors and patterns, and the names of the roads, buildings, etc. are written and displayed. Further, the set guide route and the current position of the vehicle are displayed in an overlapping manner on this. The driver will start traveling toward the destination while checking the current position and the guide route. The control circuit 10 of the on-vehicle navigation device 2 detects the traveling direction and traveling distance by the position detector 4 according to traveling, obtains a traveling locus, and performs processing for moving the current position mark on the map. Further, at a required timing, the road pattern on the map information and the traveling locus obtained by the position detector 4 are compared (pattern matching) to correct the display position of the current position.

At the same time as these processes, the control circuit 10
A process of displaying a traffic jam is executed based on the traffic jam information received from the FM station at the FM receiver 24. In the vehicle-mounted navigation device 2, in the above-described processing, when a display necessary for a road, such as a road name or a traffic jam display, is performed, the road name is displayed along the direction of the road as described below. It is carried out.

The road data display processing is shown in the flowchart of FIG. First, when the process is started, data attached to a new display road for displaying a name or the like is acquired (step 100). This data includes a display symbol string such as a name, a display starting point of the symbol string with respect to an attached road, a display azimuth indicating an azimuth in which the symbol string is arranged, and the like. For example, FIG. 4 shows the display orientation indicated by the display start point SP and the display reference line SL for the road 50. This display azimuth is represented by an angle θ between the display reference line SL and the horizontal line VL of the screen. The display azimuth θ is set so that the display reference line SL is formed substantially along the azimuth of the road with the display reference line SL being appropriately separated from the road 50.

Next, the display start point and the display orientation data are converted based on the state of the screen display (step 110).
Normally, various data for display are registered so that the true north side is on the screen, so if the display is not on the true north side, the display start point and display direction data cannot be used as they are. Therefore, depending on the state of the screen, that is, the orientation of the upper side of the screen,
The display start point and the display azimuth data are converted to obtain the display start point and the display azimuth data that are adapted to the display state of the screen.

Next, which of the 16 orientations on the screen indicated by the numerical values "0" to "15" in FIG. 3 (hereinafter also referred to as "screen orientation") the display orientation data belongs to. Is determined (step 120). The azimuth shown in FIG. 3 indicates a screen azimuth obtained by equally dividing all azimuths 360 ° on the screen into 16 parts. Screen orientation “0” is in the range of 0 ° ± 11.25 °, “1” is in the range of 22.5 ° ± 11.25 °, and “2” is in the range of 45 ° ± 11.25 °. Yes,
“3” is in the range of 67.5 ° ± 11.25 °,
“4” is in the range of 90 ° ± 11.25 °, “5” is in the range of 112.5 ° ± 11.25 °, and “6” is 1
The range is 35 ° ± 11.25 °, and “7” is 157.
The range is 5 ° ± 11.25 °, and “8” is 180 ° ±
The range is 11.25 °, and “9” is 202.5 ° ± 1.
The range is 1.25 °, and “10” is 225 ° ± 11.
The range is 25 °, and “11” is 247.5 ° ± 11.
The range is 25 °, and “12” is 270 ° ± 11.25.
The range is °, and "13" is 292.5 ° ± 11.25.
The range is °, “14” is the range of 315 ° ± 11.25 °, and “15” is the range of 337.5 ° ± 11.25 °. However, the boundary part of each range belongs to the screen direction on the counterclockwise side.

For example, if the azimuth after conversion of the display azimuth data in step 110 is as shown in FIG.
The display orientation θ (here, 15 °) corresponds to “1” of the screen orientation. As described above, in the determination of the screen orientation, the display orientation value may be simply compared with the 16 orientations to determine which one belongs, but as in the following equation (1),
Calculated from the value of display direction θ,
You may ask as.

[0034]

[Equation 1]

However, (θ + 11.25 °) is 0 ° ≦
It is assumed that it has been converted into the range of (θ + 11.25 °) <360 °. Next, a display font is selected based on the display orientation data (step 130). Four types of display fonts are registered in the CD-ROM set in the map data input device 6. These four types are the screen orientation δ in FIG.
Is a font corresponding to "0", "1", "2", "3". The display font corresponding to the screen orientation "0" is a font in which the symbol is directly above the screen (90 ° direction), as shown in the outer peripheral portion of each screen orientation number in FIG. That is, the font is a normal display.
Also, the display font corresponding to the screen orientation "1" is
It is a font in which the shape of the symbol whose screen orientation is “0” is rotated to the left (counterclockwise) by about 22.5 °. The display font whose screen orientation is "2" is a font in which the shape of the symbol whose screen orientation is "0" is rotated to the left by about 45 °. The display font whose screen orientation is "3" is a font in which the shape of the symbol whose screen orientation is "0" is rotated to the left by about 67.5 °.

Therefore, "0", "1", "2",
If the screen orientation corresponds to any of “3”, the corresponding display font is selected as it is. However, if the corresponding display font does not exist, step 140
A negative decision is made in step S11, and an alternative font is selected (step 150). That is, when the remaining screen orientations of "4" to "15" are met, a negative determination is made in step 140, and then in step 150, the corresponding screen is selected from the fonts of "0" to "3". Azimuth δ and 90 °, 18
Select a display font that has a misorientation of 0 ° or 270 °. For example, if the screen orientation is "4", the display font of the screen orientation "0" having an orientation difference of 90 ° is selected. If the screen orientation is "5", the display font of the screen orientation "1" having a 90 ° orientation difference, and if the screen orientation is "6", the display font of the screen orientation "2" having a 90 ° orientation difference, If the screen orientation is "7", the display font of the screen orientation "3" having a 90 ° orientation difference, and 18 if the screen orientation is "8"
The display font of the screen orientation "0" with 0 ° orientation difference,
If the screen orientation is "9", the display font of the screen orientation "1" that has a 180 ° orientation difference, and 1 if the screen orientation is "10"
Display font of screen orientation "2" with 80 ° orientation difference, 180 ° with screen orientation "11" Display font of screen orientation "3" with orientation difference, 270 ° with screen orientation "12" A display font with a screen orientation "0" having a heading difference, a display font with a screen orientation "1" having a 270 ° heading if the screen orientation is "13", and a screen font "14"
Then, the display font of the screen orientation “2” having a 270 ° azimuth difference is selected, and the display font of the screen orientation “3” having a 270 ° azimuth difference is selected if the screen orientation is “15”.

Thus, 90 °, 180 ° or 27
To select a display font with a 0 ° azimuth difference, use the display font with a 90 °, 180 ° or 270 ° azimuth difference and simply replace the X coordinate with the Y coordinate or change the sign. This is because the font of the corresponding screen orientation can be obtained by extremely simple calculation. Alternatively, when displaying the symbols, the output of the font array of the original screen orientation can be changed to display the symbols for the orientations different by 90 °, 180 ° or 270 °.

Therefore, in this case, even if the calculation is performed, the on-vehicle navigation device 2 is not overloaded, and it is not necessary to prepare the font for that amount in advance, which saves the memory. However, as shown in FIG. 3, the screen orientations “5” to “11” are upside down when the symbol shape is simply rotated according to the orientation, so it is difficult to display the symbol upside down. So 180 °
The shape is further rotated. That is, the font is the same as the original font. Therefore, it is not necessary to obtain the display font by calculation as described above, and for the screen orientation "8", the display font with the screen orientation "0" may be used as it is. Similarly, screen orientation "9" displays the screen orientation "1" display font, screen orientation "10" displays the screen orientation "2" display font, and screen orientation "11" displays the screen orientation "3". You can use the fonts for printing as they are.

Next, the display start point obtained as described above,
Road data is displayed based on the display orientation and the selected font (step 160). An example of this display is shown in FIG. FIG. 5 shows a state in which the name of the road 50 is displayed when the road 50 is displayed as in FIG.

That is, the symbol string "ABCDEFGHI" is displayed from the display start point SP along the display reference line SL of the display orientation θ.
Is displayed. Each symbol is displayed with the lower left corner of the display area (indicated by a solid rectangular line) in which the font is written as the display reference line SL. In this case, the display azimuth θ is 15 °, and the display azimuth δ = discretely set.
Since it corresponds to "1", as shown in FIG. 3, the symbol string "ABCDEFGHI" is displayed in a symbol-shaped font rotated 22.5 ° to the left (counterclockwise) from the normal posture.

As described above, each symbol has a posture in which the actual rectangular display area is parallel to the X coordinate or the Y coordinate of the screen with respect to the road 50, and the road 50 (or the display reference line SL). ) Is relatively tilted to the right, but the symbols actually appearing on the screen are rotated about 22.5 ° to the left with respect to the rectangular display area. (Or the display reference line SL) seems to stand substantially vertically. Therefore,
It is easy to see that the display corresponds to the road 50, and since the shape of the symbol itself originally uses a font created in advance, the display becomes easy to see.

Next, it is judged whether or not the road to be displayed next has ended (step 170), and if there is another road for which the road data is displayed, a negative judgment is made and the step 100 is again executed. If the road for which the road data is displayed is completed by repeating the processing, an affirmative decision is made and the processing is completed.

FIG. 6 shows another display example in the road data display processing. In this case, the road 5 shown in FIG.
0 is rotated by about 63 ° to the left, and the azimuth θ of the display reference line SL is about 78 °. 78 ° corresponds to “3” in the screen orientation δ. Therefore, step 130
As the display font selected in, the font having the shape shown on the outer periphery of the screen orientation "3" in FIG. 3 is used. In this font, the symbol is in a posture in which it rotates about 67.5 ° to the left.

Therefore, when each symbol is displayed with the lower left corner of the rectangular display area on the display reference line SL as described above, it is still standing substantially perpendicular to the road 50. Looks like. Therefore, it is easy to understand that the display corresponds to the road 50, and since the shape of the symbol itself originally uses the font created in advance, the display is easy to see.

Further, another display example is shown in FIG. In this case, the road 50 shown in FIG. 5 is displayed rotated by about 124 ° to the left, and the azimuth θ of the display reference line SL is approximately 13 °.
It is 9 °. 139 ° corresponds to “6” in the screen orientation δ. The font created in advance has only the screen orientation δ of “0” to “3”. Therefore, step 130
The display font is not selected in. Therefore, a negative determination is made in step 140, and the alternative font is selected in step 150. That is, 90 °, 180 °
Alternatively, a font having a screen orientation δ different by 270 ° is selected as an alternative font. The alternative font of screen orientation “6” is a font of screen orientation “2” that is different by 90 °.

In step 160, the font of the screen orientation "2" is converted to the font of the screen orientation "6", and the symbol string "ABCDEFGHI" is aligned with the display start point SP at the end of the symbol string, and the rear of the symbol string. To display from. The method of converting the font of the screen orientation “2” into the font of the screen orientation “6” is simply to switch the X coordinate and the Y coordinate and change the sign of the X coordinate in the calculation. Also, since this font has a square display area of 12 × 12 dots, dot data is read from the upper left corner of the font of screen orientation “2” to the right and gradually downward line by line,
If the dot data is written on the screen from the top right to the bottom and one column to the left of the read data, the screen orientation "6" is based on the font of the screen orientation "2" without any calculation. The font of can be displayed.

The symbol string "ABCDEFGHI" is
Since it is not displayed upside down, for screen orientations "5" to "11" that are displayed upside down when simply rotated, when displaying the symbol string, the tail end of the symbol string is aligned with the display start point SP. Display from the rear of the symbol string. That is, "I" is displayed in accordance with the display start point SP from "H" to "A".

As a result, as shown in FIG. 7, the symbols are not turned upside down, and the symbol string is displayed in a state of being hung substantially vertically on the road 50. Therefore, the symbol can be easily recognized, the display corresponding to the road 50 can be easily understood, and the shape of the symbol itself is originally created in advance, so that the display is easy to see.

As described above, the display is easy to see, and the font of the symbol string displayed here is selected from the fonts created in advance corresponding to the screen orientation, or the XY coordinates are exchanged as described above. It can be obtained by an extremely simple calculation such as inversion of the sign or the sign, or can be displayed by an extremely simple display process. Therefore, it is possible to display road data that is easy for humans to see, without imposing an excessive load on the vehicle-mounted navigation device 2.

Step 120 corresponds to the processing as the direction detecting means, and the processing of steps 130 to 150 corresponds to the processing as the font determining means. [Second Embodiment] FIG. 8 shows a flowchart of road data display processing according to the second embodiment. This flow chart shows the first embodiment.
2 instead of the road data display processing of FIG. The present embodiment is the same as the first embodiment except for this road data display processing, and therefore its explanation is omitted.

First, a new display road is selected (step 200). That is, of the roads displayed on the screen, roads for which road data has not yet been displayed are selected. Next, the display symbol string of the road is acquired (step 210). Next, new segment coordinate data on the road is acquired (step 220).

Normally, a plurality of segments are set for each road for drawing. This is as already shown in FIG. 4, where the road 50 has segments Seg00, Seg01,
It is composed of Seg02, Seg03, Seg04, Seg05, .... Therefore, in step 220, the coordinate data of this segment Seg00 is first acquired as a new segment. The coordinate data includes start point coordinates and end point coordinates of the segment. In FIG. 9 in which the main part of FIG. 4 is enlarged, the coordinates of the starting point P00 of the first segment Seg00 are (x00, y00) and the coordinates of the ending point P01 are (x01, y0).
1).

Next, in order to set the display start position of the symbol string to the second and subsequent segments, that segment is set to 2
It is determined whether or not it is the th or later (step 230). If it is the first, the process returns to step 220 and the coordinate data of the next segment is acquired. The next segment is the segment Seg01, and the coordinates of its start point P01 are (x01, y01) and the coordinates of its end point P02 are (x02, y02).

Next, the screen orientation δ in FIG. 3 of the corresponding segment is determined based on these coordinate data (step 240). This calculation process is performed, for example, by the following equation (2),
It is performed as in (3).

[0055]

[Equation 2]

However, (θn + 11.25 °) is 0 ° ≦
It is assumed that it has been converted into the range of (θn + 11.25 °) <360 °. Where dxn is the X component of the nth segment (x02-x01 for segment Seg01), dyn
Is the Y component of the nth segment (y02-y01 for segment Seg01), θn is the azimuth (angle) of that segment,
δn is the screen orientation of the nth segment. In addition, the calculation of the formula (3) is rounded down after the decimal point.

From the calculation of the above equations (2) and (3), FIG.
In the case of the segment Seg01, the screen orientation is “2”. Next, a display font is selected based on the display orientation data (step 250). As described in the first embodiment, the display font is the CD set in the map data input device 6.
-Four types are registered in the ROM. These four types are fonts whose screen orientation δ in FIG. 3 corresponds to "0", "1", "2", and "3". As the display font corresponding to "2", the display font corresponding to the screen orientation of "2" is selected as shown in the outer peripheral portion of each screen orientation number in FIG. This font is a font in which the shape of the symbol corresponding to the screen orientation "0" is rotated to the left (counterclockwise) by about 45 °.

If the screen orientation δ is "4" to "15", a negative determination is made in step 260, the same processing as in step 150 of the first embodiment is performed, and the alternative font is selected ( Step 270). Next step 25
The screen is displayed based on 0 or the font selected in step 270 (step 280).

This display is, for example, as shown in FIG.
Each segment of road 50 Seg01, Seg02, Seg03, Seg
04, Seg05, ... At a position separated by a predetermined distance d from one of the segments Seg01, Seg02, Seg03, Seg04, Seg05 ,.
Display reference lines parallel to SL01, SL02, SL03, SL04,
SL05, ... Is set, and the display symbol string acquired in step 210 is displayed on it based on the font selected in step 250 or step 270. An example thereof is shown in FIG.

In FIG. 10, one display reference line SL01, ...
, Two symbols are displayed. This is to set the symbol interval to a legible interval. If the character is larger than the display reference line SL01, ..., One symbol is displayed for one display reference line SL01, ... And vice versa. And if it is smaller, for one display reference line SL01, ...
Display three or more symbols. In addition, the display reference line SL01,
Symbols may be arranged at equal intervals on the line connecting the ... Integrally.

In FIG. 10, the display symbol line "ABCDEFGH" is displayed on the display reference line SL01 for the segment Seg01.
The first "AB" of "I" is displayed in the font corresponding to the screen orientation "2". In addition, each symbol is displayed with the center of the lower side of the display area shown by the rectangle in which the font is written being set on the display reference line SL01.

When the display of the first "AB" is completed,
Next, it is determined whether or not the display of the symbol string is completed (step 290). Since there are remaining symbols that are not displayed, a negative determination is made and the process returns to step 220. Next, in step 220, the coordinate data of the segment Seg02 is acquired, in step 240 the screen orientation is determined to be "1", and in step 250 it is displayed as a display font on the outer periphery of the screen orientation "1" in FIG. Selected font is selected. Then, in step 280, "C" next to the display symbol string in the font corresponding to the screen orientation "1" is displayed.
"D" is displayed on the display reference line SL02 corresponding to the segment Seg02, as shown in FIG.

After that, also for the display symbol string "EFGHI", the screen orientation is similarly determined, the font corresponding to the screen orientation is determined, and the symbol is displayed in the corresponding font on the display reference line corresponding to each segment. Is displayed.
In the example of FIG. 10, "EFGH" has a screen orientation of "0" and "I" has a screen orientation of "1", which are displayed in corresponding fonts.

As described above, in the present embodiment, a font adapted to the screen orientation of each segment is displayed on the display reference line along each segment of the displayed road 50.
Each symbol in the symbol string is sequentially displayed. Therefore, in addition to the effect of the first embodiment, a display along the road can be realized more than in the first embodiment, and the display is easier to see.

Step 240 corresponds to the processing as the direction detecting means, and the processing of steps 250 to 270 corresponds to the processing as the font determining means. [Others] As shown in FIG. 3, in order to prevent the symbols from being displayed upside down, when the screen orientation is “5” to “11”, the symbols are rotated further 180 degrees depending on the orientation.
It is rotated by °, but if you can display it upside down, simply rotate the symbol according to the azimuth.
It does not rotate 0 °. This is necessary especially when the display as in the second embodiment is applied to a road that bends at a large angle, because an upside-down symbol display must be made on the way.

In each of the above embodiments, each symbol is displayed according to the relationship between the orientation and font shown in FIG. 3, but each symbol is displayed according to the relationship between the orientation and font shown in FIG. You may display it. The difference between FIG. 11 and FIG. 3 is that the azimuth “4” (90 ° ± 11.25 °) in FIG. 3 is 90 ° in FIG.
It is divided into two at azimuth "4-1" (78.75 °
~ 90 °) and azimuth "4-2" (90 ° -101.25)
°) and the azimuth "4-1" adopts the azimuth "4" font in FIG. 3, and the azimuth "4-2" adopts the azimuth "12" font in FIG. And the azimuth “12” (270 ° ± 11.25) in FIG.
11) is divided into two at 270 ° in FIG. 11, and is divided into an azimuth “12-1” (258.75 ° to 270 °) and an azimuth “12-2” (270 ° to 281.25 °). 3 is adopted for the azimuth "12-1", and the azimuth "1" of FIG. 3 is adopted for the azimuth "12-2".
The 2 "font is used.

In this way, among the adjacent orientations, the orientations sandwiching 90 ° or 270 ° in which the font is reversed are subdivided, and the font rotated by 180 ° is set in each of the adjacent orientations. The continuity of the fonts with the directions adjacent to each other on the opposite side is good, and when displayed, display with higher visibility is possible.

[Brief description of drawings]

FIG. 1 is a block diagram showing an overall configuration of a vehicle-mounted navigation device according to an embodiment of the present invention.

FIG. 2 is a flowchart of road data display processing.

FIG. 3 is an explanatory diagram showing a screen orientation and a relationship between the screen orientation and a font.

FIG. 4 is an explanatory diagram of roads, display start points, and display reference lines.

FIG. 5 is an explanatory diagram of a display example of road data.

FIG. 6 is an explanatory diagram of a display example of road data.

FIG. 7 is an explanatory diagram of a display example of road data.

FIG. 8 is a flowchart of road data display processing according to the second embodiment.

FIG. 9 is an explanatory diagram showing a relationship between a road segment and a display reference line.

FIG. 10 is an explanatory diagram of a display example of road data according to the second embodiment.

FIG. 11 is an explanatory diagram showing a screen orientation and a relationship between the screen orientation and a font.

FIG. 12 is a basic illustration of the present invention.

[Explanation of symbols]

2 ... In-vehicle navigation device 4 ... Position detector 6 ... Map data input device 8 ... Operation switch group 10 ... Control circuit 12 ... External memory 14 ... Display device 16 ... Geomagnetic sensor 18 ... Gyroscope 20 ... Distance sensor 22 ... GPS reception Machine 24 ... F
M receiver 50 ... Road

Claims (7)

[Claims] 1. A map display device for displaying a symbol string in dots along a route displayed on a display device, wherein a display direction of the symbol string set corresponding to the route is set to a predetermined number. An azimuth detecting means for detecting as one of the discrete azimuths, and a symbol display having a plurality of types of fonts created by changing the display angle of the same symbol corresponding to the predetermined number of discrete azimuths. A map display device comprising: font data for fonts; and font determination means for determining the font of a symbol to be displayed based on the detection result of the orientation detection means. 2. The map display device according to claim 1, wherein the fonts for the azimuths differing from each other by 90 °, 180 ° or 270 ° among the discrete azimuths are used by converting the fonts of the original azimuths. 3. 90 ° or 27 of the discrete azimuths
The map display device according to claim 1, wherein the font for the azimuth different by 0 ° is used by converting the font of the original azimuth, and the font for the azimuth different by 180 ° uses the font of the original azimuth as it is. 4. The map display device according to claim 1, wherein the discrete directions are 16 directions. 5. The 16 azimuths are 0 ° ± 11.25 °, 2
2.5 ° ± 11.25 °, 45 ° ± 11.25 °, 6
7.5 ° ± 11.25 °, 90 ° ± 11.25 °, 11
2.5 ° ± 11.25 °, 135 ° ± 11.25 °, 1
57.5 ° ± 11.25 °, 180 ° ± 11.25 °,
202.5 ° ± 11.25 °, 225 ° ± 11.25
° 247.5 ° ± 11.25 °, 270 ° ± 11.2
5 °, 292.5 ° ± 11.25 °, 315 ° ± 11.
The map display device according to claim 4, which has an azimuth of 25 ° and 337.5 ° ± 11.25 °. 6. The symbol display font data is the above 1
The map display device according to claim 4 or 5, wherein the map display device is composed of four types of fonts corresponding to four directions out of the six directions that do not differ by 90 °, 180 °, or 270 °. 7. The four azimuths are 0 ° ± 11.25 °, 2
The map display device according to claim 6, wherein the map display device has 2.5 ° ± 11.25 °, 45 ° ± 11.25 ° and 67.5 ° ± 11.25 °.