JPS62151880A - Vehicle navigator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vehicle navigation device that displays map information on a display device and guides a vehicle to a predetermined destination.

[Summary of the Invention] The present invention provides a vehicle navigation device that digitizes map information and stores it in a predetermined storage medium, reads out the map information from the storage medium, and displays the map information converted into an image signal on a display device. Projection method 1: Multiple maps drawn for each predetermined area using a projection method such as the conic projection are arranged side by side in the east-west direction on a predetermined plane, with the reference latitude lines of each area located on the same horizontal line. At the same time, the reference meridians on the reference latitude lines are located on the same straight line perpendicular to the horizontal line, so that they are placed next to each other in the north-south direction,
A position on a map is specified by orthogonal coordinates on a plane, thereby providing a vehicle navigation device with good operability.

[Conventional technology]

Recently, research and development have been conducted on vehicle navigation devices that record map information on a CD-ROM or the like, read out the map information, display it on a display device along with the vehicle's current location, and guide the vehicle to a predetermined destination. . In such vehicle navigation devices, when map information is digitized and recorded on a CD-ROM, the meridians and latitudes on the map are used as standards for east-west and north-south directions in order to reduce errors in the distance between two points. was.

[Problem that the invention seeks to solve]

Conventional devices use the meridians and latitudes on the map as standards for the east-west and north-south directions, which reduces the error in the distance between two points. First, the direction display does not match the sense of the operator, resulting in poor operability. Further, the calculations for identifying a predetermined point on the map are complicated, and the device becomes large and expensive.

[Means for solving problems]

FIG. 1 is a block diagram of a vehicle navigation system according to the present invention. In the figure, reference numeral 1 denotes a CD-ROM (including its drive device) as a recording medium or storage medium, on which digitized map information is recorded. CD
-Data from ROMI interface 2. Memory (RAM) 5 via address bus 3, data bus 4, etc.
is stored in the memory. Reference numeral 6 denotes an information processor (CPU), which processes various image data and also operates the keyboard 12. Peripheral devices are also controlled in response to commands input via the interface 13. 7 is a direction sensor that detects the direction of the vehicle from geomagnetism, etc.

8 is a speed sensor that detects the speed of the vehicle. 9 is GP
S (Global Positioning S
system), which detects the current position of the vehicle from latitude, longitude information, etc. 10 is a navigation processor (CPU), which corrects the data of the direction sensor 7, speed sensor 8, etc., calculates the amount of movement of the vehicle from these data, and when the GPS device 9 cannot detect latitude and longitude information. etc., the current position is calculated from the input data. Alternatively, the current location that has been set and input is corrected in accordance with information from the GPS device 9. processor 1
o and the processor 6 are capable of mutually transmitting and receiving data. 11 is a ROM that stores programs and other necessary information for these processors 6 and 10; 14 is each circuit 1;
Control logic that supplies necessary timing signals to means, devices, etc. '15 is the graphic display controller (GDC
), reads the necessary data from the memory 5, , fi
- Draw a predetermined image on eS (VRAM) 16.17. 18 is a parallel/serial (P/S) conversion circuit that selects data from one of the memories 16 and 17 and converts it from a parallel signal to a serial signal. A color palette register 19 serves as a color conversion circuit, and converts the 3-bit color signal in the video signal supplied from the P/S conversion circuit 18 into a prespecified 5-bit color signal. The video signal into which the color signal has been converted is transferred to the memory (VRAM) 20, and further transferred from the memory 2o to the memory (VRAM) 21, and the video signal stored in the memory 21 is divided into red (R), green (G), blue ( B) D/A conversion circuit 26 for each of the three primary colors.
The digital signal is converted into an analog signal by 27.28.

It is displayed on a display device 29 such as a CRT. Although not shown, a touch sensor made of a transparent electrode or the like is provided on the front surface of the screen of the display device 29.

24 is a synchronization signal generation circuit, which generates a mutually synchronized horizontal synchronization signal (HSYNC) and vertical synchronization signal (VSYNC).
, generates a dot clock (DCK) and registers 19.
, the address of the memory 20.21, etc. is output to the address counter 23.25. 22 is an offset register, which sets the offset position of the portion of the image stored in the memories 16 and 17 to be transferred to the memory 20. 30 to 37 are buffers inserted at predetermined positions, respectively.

On the other hand, FIG. 2 shows the structure of the keyboard 12. As shown in the figure, each operation key is arranged on the outer periphery of the display device 29. 51 is a navigation (WAVE) key operated when performing a navigation operation; 52 is a help key operated when outputting an operation explanation image to the display device 29; 53 is a guide (GUID'E);
This key is used to display symbols such as parking lots, hotels, gas stations, etc. on the map. 54 is a destination (DEST) key, which is operated when setting a destination. Reference numeral 55 denotes a SET key, which is operated when registering an item specified by the cursor displayed on the display device 29 or a position on the map. Reference numeral 56 denotes a cancel (CANCEL) key, which, when operated on a limited number of predetermined screens, returns one screen to the previous screen. 57 is a reduction key, and 58 is an enlargement key.

Each is operated to reduce or enlarge the map displayed on the display device 29. 59 is a scroll key, up and down,
When moving the cursor left and right, use keys 59a to 5, respectively.
9d is operated. Reference numeral 60 denotes a text (TEXT) key, which is operated when displaying information related to the running of the vehicle. The program when each of the above keys is operated is managed by the processor 6.

On the other hand, the CD key 61 is operated when operating the compact disc player. TV key 62 that is operated when receiving television broadcasting. AM and FM keys 63 that are operated when receiving AM or FM broadcasts. Sound select (SOUND 5EL) key 64, which is operated to select the equalization characteristic of the reproduced sound from among predetermined characteristics, muting key 65, which instantly mutes the reproduced sound, and adjusts the volume of the reproduced sound. volume 66
An air conditioning (A/C) key 67 is provided, which is operated when operating the air conditioner, and predetermined operations are executed by a CPU (not shown).

[Effect]

The effect will now be explained. First, the basic operation when the navigation key 51 is operated will be explained. The operations in this case are managed according to a flowchart as shown in FIG. 3, for example. As a first step, it is determined whether the current location has been set. When the current location has already been set, a display routine is executed, and when it has not been set, a current location setting routine is executed. These routines will be described later.

Then it enters the state of waiting for key power, and if there is no key power, after further display routines are executed.

It will be waiting for a key again.

If there is a key human power, next it is determined whether there is a mode change,
When a mode change occurs, the routine shifts to that mode. Modes include navigation mode, text mode, AV mode, etc. If there is no mode change, the command is next determined, and the destination setting 5 drive guide, help, scaling, correction, position output, and other routines are executed in response to the command. Thereafter, the system returns to the state of waiting for the key force, and the display routine is executed until the key force is applied.

The routine for setting the current location is executed according to the flowchart shown in FIG. First, cancel key 56
The presence or absence of the operation is determined, and when the operation becomes numb, the current location is reset and a predetermined position is set as the temporary current location. Further, the scale of the map is set to a predetermined value (1/1.6 million in this case). A map centered on the predetermined location is then displayed on the display device 29.

When the cancel key 56 is not operated, it is determined whether or not the current location has been set.

If the current location has been set, a map of a preset scale (1/200,000 in this example) centered around the current location is displayed on the display W29. If the current location has not been set, a predetermined location is set as the temporary current location, and a map of a predetermined scale (1/200,000 in this example) centered at that location is displayed.

When the map is displayed on the display device 29, the input key is then determined, and processes such as setting the scale, moving the cursor, setting, setting the place name guide, and canceling are performed in response to the input key. When the cancel key 56 is operated, the process returns to the first step. When the set key 55 is operated, it is further determined whether or not the center position is to be set. If the center position is not set, the scale specified by the cursor is set, and a scale set is executed to display a map of that scale. If it is a set of center positions,
Similar to the case where the place name and guide set key 53 is operated, a determination is then made to set the current location. If the current location is set, the current location is set, and if the current location is not set, the destination is set.

The destination setting routine is performed as shown in FIG. First, it is determined whether the destination has been set, and if it has not been set, the routine for setting the current location is called.
A destination is set during that routine, and if completed, a map centered on the destination will be displayed. Next, the distance from your current location to your destination is calculated and displayed. Thereafter, the operation of the cancel key 56 is determined, and when the cancel key 56 is operated, the process returns to the first step, and when the cancel key 56 is not operated, a map centered on the destination is displayed.

Eight types of map scales are available.

If the reduction key 57 is operated when setting the scale,
The image on the display device 29 is rewritten to a map with a scale one step lower, and a cursor indicating the range of the scale before rewriting is displayed (indicated by a square in Fig. 23; for convenience, two cursors are shown in Fig. 23). (However, only one cursor is actually displayed.) When the reduction key 57 is further operated, the cursor size becomes equal to the screen size of the furniture display device 29, so the cursor disappears from the screen, but when the reduction key 57 is further operated, the cursor is displayed on the screen again. be done.

When the enlargement key 58 is operated, a cursor indicating the range of one scale higher is displayed. When the enlargement key 58 is further operated, the cursor becomes smaller one by one. For example, as shown in FIG. 23, the cursor shown on the outside changes in size to the size shown on the inside, and as the cursor is further operated, it becomes even smaller.

For example, if the scroll key 59 is operated in such a state.

The cursor position remains in the center of the screen and does not change, but
The map moves up and down and left and right. When the desired position is found in this way and the set key 55 is operated with the cursor displayed, the range displayed by the cursor is displayed on the screen at that scale, and at this time the cursor changes to a cross mark. (Figure 24). Furthermore, operate the scroll key 59 to move the map up and down, left and right, match the desired position to the center cursor, and press the 2 set key 55.
If you operate , your current location or destination will be set to that location.

The above reduction key 57, enlargement key 58 and set key 55
If the changes in the screen due to each operation are displayed together, the 25th
The result will be as shown in the figure. In the figure, blocks indicated by upward arrows represent enlargement operations, blocks indicated by downward arrows represent reduction operations, and blocks indicated by the letters SET represent set operations. If the screen changes horizontally in the diagram, it means that the scale of the map does not change, - the first row is 1/1.6 million, and the following rows are 1/1.6 million.
/800,000, 1/400,000, 1/200,000, 1/100,000, 11
The scales are 50,000, 1/25,000, and 1/1,250,000.

It is also possible to move the cursor instead of the map when the scroll key 59 is operated. However, if you do this, for example, when moving the cursor while searching for a predetermined destination, if you find that the destination is outside the displayed map, you will need to perform a separate operation to redraw the displayed map. This results in interruptions in operation and poor operability. Therefore, as in the example, the cursor is fixed at approximately the center of the screen and the map is moved.
Preferably, the destination can be searched simply by continuously operating the scroll key 59.

In this way, two types of cursors are used to perform enlargement, reduction, and scrolling, which not only makes one display easier to see, but also improves operability. Furthermore, when enlarging, after the target scale is set, the drawing operation to the memory (which takes time), which will be described later, starts when the set key 55 is operated, so that the operation can be performed smoothly.

Next, the display routine will be described.The display routine is performed according to the flowchart shown in FIG. In this routine, first the direction sensor 7, the speed sensor 8
The current location of the vehicle is calculated by the processor 10 from such information. Alternatively, when latitude and longitude information is input from the GPS device 9, the current location can be specified from this information. Calculation of the current location is performed at regular intervals, and the data is constantly updated. Next, it is determined whether or not there is a map centered on the current location in the storage memory 5, and if not, the data is loaded onto the memory S from the CD-ROM 1.

1 when a map centered on the current location is stored in memory 5
Next, it is determined whether the map centered on the current location is within the range of the map drawn in memory 16 or 17, and if it is not within the range, the back side of memory 16 or 17 (memory 20
One stroke is drawn (rewritten) by the controller 15 in the memory of the memory which is not supplying data to the other memory.

If a map centered on the current location is written in the memory 16 or 17, it is first determined whether a map of another scale is loaded in the memory 5, and if it is not loaded in the memory 16 or 17, the CD-ROM 1 is 5.

When a map of another scale is written on the memory 5, it is first superimposed on the map on the front side of the memory 16 or 17 (the one whose data is being transferred to the memory 20), and the processor 10
A military mark is written by the processor 6 corresponding to the current location calculated by the processor 6.

This data is further transferred from the front side memory to the memory 2°. For example, as shown in the center of Figure 21, this own vehicle mark is a mark that allows the vehicle to travel in the direction of M-'2 m (the figure shows the vehicle traveling northward (upwards)). ing). The map and military marks written in the memory 20 in this manner are further transferred to the memory 21, and the images stored in the memory 21 are displayed on the display device 29. After further enlargement, reduction, etc. routines are processed 1
Move on to the next step.

By a similar operation, the direction from the current location to the apparent location is displayed as shown by the arrow in the upper right corner of FIG.

The step (indicated by A in the figure) of loading map data from the CD-ROMI in the above display routine is shown in more detail in FIG. 7. That is, the first
As shown in FIG. 6, first, a predetermined area (indicated by a broken line in the figure) is set around the current location P, and the file number of the map within that area is set.

As shown in Fig. 16, the predetermined range (8000H
The map data of 00H (H is a hexadecimal unit) is equally divided into four by two straight lines, the horizontal line and the line perpendicular to it.
The lower left area is 0. The lower right area corresponds to number 1, the upper left area corresponds to number 2, and the upper right area corresponds to number 3. Each of the four areas is then further divided into four smaller areas, which are numbered in the same way, with the first number being represented by the first digit, the second number being represented by the second digit, and so on. are divided and numbered (file numbers). Therefore, the data in the area centered on point P in Fig. 16 is O(
(1/1.6 million scale map).

03 (1/800,000 scale map), 030,031
．． 032,033 (1/400,000 scale map) L:, exists in the map represented by each file number, such as 1/400,000 scale map.However, LcD-ROM1 has 1/'800,000.

Only maps of 1/200,000, 1.15 million, 1/1,250,000 scales are available, 1/1.6 million, 1/4゜0,000, and 1/1o.
Maps at scales of 10,000 and 1/25,000.

It is expressed by thinning out and drawing the data of the map at the above-mentioned scale. The distance between two points on this map is based on predetermined units of latitude and longitude near the center (4000H, 4000H).

Calculated as a Cartesian coordinate system.

In this way, map data including the current location at each scale (four scales) to which the file numbers as described above are assigned is read from the CD-ROMI and written into the memory 5. Further, as shown in FIG. 18, a predetermined range on the memory 5 centered on the current location (range indicated by diagonal lines in the figure)
is clipped, and this clipped range is written to the back side of the memory 16 or 17.

Please note that your current location will change as the vehicle moves.

In these flows, the steps of calculating the current location and displaying the own army mark are interrupted at predetermined time intervals.

The details of the step of rewriting data in the memories 16 and 17 (indicated by reference numeral B in the figure) shown in FIG. 6 are as shown in FIG. 8, for example. In other words, the memory 16 and 17 are on the back side when drawing is done by the controller 15, and the memory 2 is on the back side when drawing is completed.
The side that is transferring data to 0 is considered to be the front side, and the controller 15 always draws in the memory on the back side, and when the drawing is completed, the front side and the back side are reversed. For example, the 18th
As shown in the figure, only a part of the image drawn on the front side of the memories 16 and 170 within a predetermined range is transferred to the memory 20 and further to the memory 21 and displayed on the first display device 29.

Therefore, in this flow as well, as the vehicle travels, the steps of calculating the current location and displaying the own vehicle mark are interrupted at predetermined intervals.
．． 17, it is not necessary to rewrite the data very often. When the range displayed on the first display device 29 exceeds the range written in the front memory as the vehicle travels, it becomes necessary to rewrite the data. However, rewriting the data requires some time. Therefore, as shown in FIG.
9 (the range shown by the solid line in the figure) by a predetermined distance D (distance gt on the memory).
(indicated by a broken line in the figure), and when this outer range exceeds the range of the map drawn in the front side memory, a map centered on the current location at that time is read from the memory 5 and drawn in the back side memory. do. Further, this distance is changed depending on the scale of the map. Therefore, the smaller the scale (the more the map is enlarged), the faster the display position of your vehicle's mark on the map will move, but writing to the memory on the back side will be done faster, so the map will not be displayed on one screen. This prevents parts from being displayed with missing parts.

Furthermore, the step of transferring the map drawn in the memories 16 and 17 to the memory 20 in FIG. 6 (indicated by C in the figure) is shown in more detail in FIG. 9. That is, first, in the front side memory of the memories 16 and 17, the data of the range (16×16 dots) in which the own army mark at the center of the range to be transferred to the memory 20 (FIG. 18) is displayed is temporarily saved to the memory 5. And there processor 6
In response to the command, the controller 15 draws the own army mark. At this time, the own army mark is displayed in a direction corresponding to the traveling direction of the vehicle detected by the calculation of the processor 1o.

The map centered on the vehicle mark drawn in the front side memory in this way is transferred to the memory 20. The range to be transferred is specified by the offset register 22 (and therefore the address counter 23). That is, under the control of the processor 6, the offset register 22 stores predetermined coordinate values that change in accordance with the current location. This value is the 18th
As shown in the figure, the position (X) of the dot where the controller 15 starts transferring on one horizontal scanning line, and the position (Y) of the horizontal scanning line where the controller 15 starts transferring on one field.
). Therefore, for example, if we focus on one horizontal scanning line.

As shown in FIG. 19, counting of dots is started at the timing of the horizontal synchronization signal, and when a predetermined offset value be transferred. Also, focusing on the field, as shown in FIG. 20, the processor 6
When a transfer command is output to the controller 15, counting of horizontal synchronization signals is started at the timing of the vertical synchronization signal of the controller 15 that arrives after that, and after counting a predetermined offset value Y, a predetermined number of horizontal synchronization signals are started from the next scanning line. The data in the scanning line range is transferred to the memory 20. When the data is transferred to the memory 20, at the timing of the vertical synchronization signal of the display device 29 that comes after that, the data is transferred to the memory 20 over the time of one field of the display device 29.
Transferred to 1.

The data written in the memory 21 is read out and displayed on the display device 29.6 The display device 29 is now driven by a synchronizing signal such as the NTSC system so that it can also display images of normal television broadcasting. ing. Therefore, the memory 21 that outputs data to the display device 29 is also driven by a clock having the same frequency as the synchronization signal of the NTSC system or the like. On the other hand, the synchronization signal of the controller 15 controlled by the processor 6 as a computer (for example, the frequency of the horizontal synchronization signal is 24.83kHz) is generally the synchronization signal of the NTSC system (for example, the frequency of the horizontal synchronization signal of the NTSC system is 15.83kHz). 75kHz), the controller 15
It is not possible to drive the display device 29 (memory 21) with the synchronization signal. Therefore, a memory 2o is arranged as a buffer between the memory 21 and the memory 16.17, and the writing is performed using the same clock as the memory 16.17, and the reading is performed using the same clock as the memory 21.

Further, when data is transferred to the memory 20, the color signals of the three primary colors, each represented by a 3-bit signal, are converted into a 15-bit color signal by the color palette register 19. This 15-bit color signal is specified by the processor 6. Therefore, 8 types of low gradation colors represented by 3 bits are converted to any of 32 types of high gradation colors represented by 5 bits each of R2O and B, and by appropriately mixing afi colors, 32768 colors are converted. It becomes possible to specify any eight types of colors from among the colors. An address counter 25 supplies eight predetermined address signals to the color palette register 19 and memories 20 and 21 to specify the location of each dot to be subjected to color conversion. The digital data of the map and own vehicle mark written in the memory 21 are converted into analog signals by the D/A conversion circuits 26, 27, and 28.
It is displayed on the display device 29. As described above, since the maps do not overlap in this own vehicle mark display area, it is possible to prevent the display of the own army mark from becoming unattractive on the screen (FIG. 21).

When the transfer from the front side memory to the memory 20 is completed,
The map data saved in the memory 5 is returned to the front side memory again. In this way, the evacuation and return of the map data in the area where the own army mark is displayed is repeated as the vehicle moves.

The amount of calculations and the capacity of memory used can be reduced. Furthermore, the number of times the CD-ROMI is accessed is reduced, allowing smooth display.

The map data written to the memory 5 has a scale of 1/8o.
10,000 + 1/200,000 and 1,150,000 are 8ooxsoo
These are 1/1,600,000 and 1/1,000,000, respectively.
Memory 16.17 scaled to 400,000 and 1/100,000
When drawn, it is assumed to be 400×400 dots. Also, map data with a scale of 1/1°250,000 is 1600X16
00 dots, and when this is scaled to 1/25,000 and drawn in memory 16.17, it is 5oox8.
00 dots. Smallest scale (enlarged) 1/
1.2: The number of dots on the 50,000 map has been increased compared to other large scale (reduced) maps.

Of course, the number of dots can be the same, but the current location will move faster on a smaller scale map. Therefore, as in the example, if the number of dots is increased in the case of a small scale than in the case of a large scale, the C.
The frequency of access to D-ROMI can be reduced accordingly.

On the other hand, the drawing memory 16.17 is 640 x 400 dots (high resolution or large capacity), the display memory 20.21 is 256 x 256 dots (low resolution or small capacity), and the screen of the display device 29 is, for example, 256 x 216 dots. Ru.

The processor 6 can directly write, for example, a photographic image of an intersection, etc. recorded on the CD-ROMI into the memory 20. In this case as well, since the image data being displayed on the display device 29 is output from the memory 21, one displayed image is not affected by the writing operation. Either images drawn in the memories 16 and 17 by the controller 15 or images drawn directly in the memory 20 by the processor 6 can be selectively displayed.

Next, an example of recording map data will be described. As is well known, a map is a flat representation of the state of the earth on a spherical surface. There are various ways to express it, but the maps published by the Geospatial Information Authority of Japan use the Transverse Mercator projection for relatively small scale maps (relatively enlarged maps) of 1/200,000 or less. Also, relatively large scale maps exceeding 1:200,000 (relatively reduced maps) are based on the conic projection. Therefore, for example, as shown in FIG.

If multiple maps of a given range are arranged on a plane so that the left and right boundaries do not separate, the distance between two points can be accurately expressed, but the north-south direction and east-west direction are mutually exclusive. If each map is digitized as it is, it will be necessary to display the north-south direction and east-west direction on the screen of one display device 29 at an angle with respect to the vertical or horizontal direction, which will create a big difference from the user's perception. occurs, and operability deteriorates. Moreover, if this is done, the calculations for specifying the current location on the map become complicated, increasing the burden on the processor IQ. Therefore, in the present invention, as shown in FIG. 11, a plurality of maps drawn for each predetermined region using a projection method such as the Transverse Mercator projection or the conic projection are drawn on a predetermined plane, and the reference latitude line in each region is are placed adjacent to each other in the east-west direction so that they are located on the same horizontal line, and placed adjacent to each other in the north-south direction so that the reference meridian on the reference latitude line is located on the same straight line perpendicular to the horizon, and on that plane. The location on the map is specified using rectangular coordinates. Figure 11 (a) is an example where the lower left point of each map in a predetermined range is set as the reference point B of the latitude and longitude lines, and Figure 11 (b) is an example where the reference point B is the reference point 0 of the middle line. This is an example of B. However, in any case, when calculating the distance between two points on the map, use the unit approximately at the center point 0 (for example, 10 km)
Based on the length per latitude (longitude).

Then, as shown in FIG. 12(b), discontinuous portions that occur in left and right adjacent maps are corrected so that the portions are located on a vertical straight line. As a result, for example, point A1 on the upper right (northeast) of the 1/200,000 scale map, and point A2 on the upper left (northwest) corresponding (same) to point A on the map of the area east of it.
is replaced by one point A3. When the earth coordinates are converted into rectangular coordinates (x, y) in this way, the error that occurs on a 1/200,000 scale map, for example, is up to ±70 m, and the error is in the north-south direction as shown in Figure 12 (a). is locally concentrated in a predetermined range (the shaded area in the figure). As a result, the distance error in this area increases, but overall the east-west direction can be displayed horizontally and the north-south direction can be displayed vertically, which matches the user's sense and improves operability.

Calculation of current location becomes easy.

Data expressed on a map includes line segments,
Symbols and place names are provided. The line data is the first
It is configured as shown in Figure 3.

In other words, line segment data includes major national roads, local roads, other roads,
Classified into eight types of lines (represented by 8-bit data), such as coastlines and railways, and attributes (represented by 7-bits), such as tunnels and streetcars, and compiled into packages. Packages are prepared for each type of line to be displayed, such as a red line, for example, a predetermined number of packages form one set, and end data (d d d d h) is arranged at the end of each set.

Further, in each package, attribute and line type data are arranged as a header at the beginning, followed by the total number of strokes in the package, and then each stroke data.

One stroke represents one continuous line segment, and each stroke data is expressed by the number of cylinders of the unit line segment and the coordinates of the starting point and end point in units of 10 m (the same applies hereinafter). The end point of a line segment that is one unit that makes up one stroke is the start point of the next unit line segment, so the coordinate data of the start point of each unit line segment and the end point of the last unit line segment is The data of one stroke is composed of the following.

Two types of line types are available for river or coastline data. In other words, as shown in Fig. 22, rivers and coastlines themselves are represented by solid lines, and by placing a broken line at a predetermined distance away from the solid line toward the river or sea, it can be shown that the side of the broken line is the river or sea side. is expressed. Since such display does not take much time, it is performed when it is necessary to increase the drawing speed (for example, when the traveling speed of the vehicle is fast compared to the scale of the map). On the other hand, if there is no need to significantly increase the drawing speed, use a predetermined point Z on the dashed line as a reference, and operate horizontally from one point Z to color each dot until the scanning line intersects with the solid line representing the coastline. . Although it takes some time to color rivers, oceans, etc. in this way, it takes less time than the conventional method of directionalizing solid lines representing rivers and coastlines and coloring one side of them. Can be colored. Also, the calculations for this purpose become easier.

Even the same road is expressed in a different color depending on the scale, and only predetermined roads (roads contained in a predetermined package) are displayed at a predetermined scale.

Symbols representing ski resorts, hotels, mountains, gas stations, parking lots, etc. are available. The symbol data is structured as shown in FIG. That is, symbols are also packaged into predetermined symbols, and an end mark (eeee) is placed at the end of a predetermined number of packages.
h) is placed. Number of symbol packages is 2
It is said to be within 56 pieces. In each package, 7
The serial number of the symbol consisting of bits (for example, the serial number among the symbols representing mountains) and the symbol pattern consisting of 8 bits corresponding to each symbol (for example, what number is the mountain symbol, what is the number of the hotel symbol? etc., 1
(one number corresponds to one symbol) is used as a header, followed by the number of symbols (always 1 in this example) and the coordinates at which the symbol is displayed.

FIGS. 21 and 22 show examples in which a mountain symbol is displayed. Mountains are generally displayed as contour lines on maps. However, if the map data is represented as contour lines, the amount of map data not only increases, but also becomes difficult to see, especially since the screen of the display device 29 used as a vehicle navigation device cannot be made very large. Therefore, it is preferable to display the mountain as a relatively small symbol as in the embodiment.

The place name data is structured as shown in FIG. In other words, as in the case described above, an end mark (f f f
f h) are arranged. A place name level consisting of 8 bits is arranged as a header of each place name package. Eight types of place name levels are prepared, and only place names of a predetermined place name level are displayed on the display device 29 at a predetermined scale. Next to the place name level, the number of place name cylinders contained in the package and each place name data are arranged. The name data of each place is
The coordinates where the place name should be displayed, the number of characters (up to 6), and the kanji code are arranged.

〔effect〕

As described above, the present invention provides an east navigation system that digitizes map information and stores it in a predetermined storage medium, and displays the map information read out from the storage medium and converted into one image signal on a display device, using the transverse Mercator projection. 1.Multiple maps drawn for each predetermined area using a projection method such as the conic projection are arranged side by side in the east-west direction on a predetermined plane so that the reference latitude lines of each area are located on the same horizontal line. , the reference meridian on the reference latitude line is located on the same straight line perpendicular to the horizon so that they are adjacent in the north-south direction, and the position on the map is specified by rectangular coordinates on the plane, so the east-west direction The north-south direction and the horizontal direction can be displayed in correspondence with the horizontal direction and the direction perpendicular to the horizontal direction, making it possible to match the operator's sense of direction and improve operability. Further, calculations for specifying a predetermined point on a map can be performed easily, and the device can be made smaller and its cost can be reduced.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the vehicle navigation device of the present invention, FIG. 2 is a plan view of its display device and keyboard, FIGS. 3 to 9 are its flowcharts, and FIGS. 10 to 12
The figure is an explanatory diagram explaining the conversion of the earth coordinates to Cartesian coordinates, Fig. 13 is an explanatory diagram of the line segment data, Fig. 14 is an explanatory diagram of the symbol data, and Fig. 15 is an explanation of the place name data. Fig. 16 is an explanatory diagram explaining how the map is divided, Fig. 17 is a schematic explanatory diagram of the memory, and Fig. 18 is a schematic explanatory diagram of the memory.
19 is a waveform diagram, FIG. 20 is a timing chart, FIGS. 21 to 24 are plan views of the display screen, and FIG. 25 is an explanatory diagram schematically explaining data reading and writing. is an explanatory diagram of enlarged and reduced screens. 1...CD-ROM 2.13...Interface 5.16.17.20.21...Memory 6...Information processor 7...Direction sensor 8.
...Speed sensor 9...GPS device 10...Navigation processor 11...ROM 12...Keyboard 15...
・Graphic display controller 18...Parallel/serial conversion circuit 19...Color palette register 22...Offset register 23.25...Address counter 24...Synchronization signal generation circuit 26.27.28...D /A conversion circuit 29...Display device or higher

Claims (1)

[Scope of Claims] A vehicle navigation device that digitizes map information and stores it in a predetermined storage medium, and displays the map information read from the storage medium and converted into an image signal on a display device, comprising: Multiple maps drawn for each predetermined area using a projection method such as a projection method or a conical projection method are arranged side by side in the east-west direction on a predetermined plane so that the reference latitude lines of each region are located on the same horizontal line. At the same time, the meridian of the reference on the latitude of the reference is located on the same straight line perpendicular to the horizontal line so that they are adjacent to each other in the north-south direction, and the position on the map is specified by rectangular coordinates on the plane. Features of vehicle navigation device.