JPS62151882A - 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 navigation device that displays map information on a display device to guide 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 the map information from the storage medium, and displays the map information converted into an image signal on a display device. line segment data that displays the location, and place name data that displays the location name of the predetermined location.
Prepare at least symbol data that displays mountains as symbols, and display mountains as symbols instead of contour lines as line segments. This prevents the map from becoming difficult to read, and also saves memory for storing the map. This allows for a smaller capacity.

[Conventional technology]

Recently, research and development has been carried out 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. . Conventional vehicle navigation devices digitize the base map almost as is, so if the base map had contour lines, they were displayed as lines.

[Problem that the invention seeks to solve]

However, with conventional devices, if there are contour lines on the original map, they are displayed as lines, which not only requires a large capacity memory to store the map, but also makes it difficult for vehicle navigation. When the screen area of the display device is limited, as in the case of a device, there is a drawback that the map displayed there becomes difficult to see.

[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 ROM l is transferred to memory (RAM) via interface 2, address bus 3, data bus 4, etc.
5 is stored. Reference numeral 6 denotes an information processor (CPU) which not only processes various image data, but also controls peripheral devices in response to commands input via the keyboard 12 and its 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; and 69 is a GPS (Global
This is a positioning system) that detects the current position of the vehicle from latitude, longitude information, etc. 1
0 is a navigation processor (CPU), which corrects data from 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. The processor 10 and the processor 6 are capable of mutually transmitting and receiving data. 11 is a ROM that stores programs and other necessary information for the processors 6 and 10, and 14 is a control logic that supplies necessary timing signals to each circuit, means, device, etc.

15 is a graphic display controller (GDC)
), reads necessary data from the memory 5, and draws a predetermined image in the memory (VRAM) 16, 17. 18
selects data from one of memories 16 and 17,
This is a parallel/serial (P/S) conversion circuit that converts parallel signals to serial signals. Reference numeral 19 denotes a color palette register as a color conversion circuit, which converts the 3-bit color signal in the video signal supplied from the P/S conversion circuit 18 into
Converts to a prespecified 5-bit color signal. The video signal into which the color signal has been converted is transferred to a memory (VRAM) 20, and further from the memory 20 to a memory (VRAM) 21.
The video signals stored in the memory 21 are red (R) and green (G).
, D/A conversion circuits for each of the three primary colors of blue (B) 26.27.
28 converts the digital signal into an analog signal.

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 W29, which is displayed on a display device 29 such as a CRT.

24 is a synchronization signal generation circuit, which generates a mutually synchronized horizontal synchronization signal (H5YNC) and vertical synchronization signal (VSYNC).
) and a dot clock (DCK) are generated, and register 19. It outputs to address counters 23, 25, etc., which set the addresses of the memory 20, 21, etc. 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 2o. 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 (NAVI) 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 (GUIDE) key; , is operated when displaying 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. 55 is a SET key. and 1 display device 2
It is operated when registering the item specified by the cursor displayed at 9 or the position on the map. 56 is a cancel (CANCEL) key, and when operated on a limited predetermined screen, the screen returns to the previous screen. 57 is a reduction key, and 58 is an enlargement key, each of which is operated to reduce or enlarge the map displayed on the display device 29. 59 is a scroll key, and keys 59a to 59d are used to move the cursor up and down, left and right, respectively.
is manipulated. 6o is 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, the TV key 62 is operated when receiving television broadcasting, and the AM and FM keys 63 are operated when receiving AM or FM broadcasting. A sound select (SOUND 5EL) key 64 that is operated to select the equalization characteristic of the reproduced sound from among predetermined characteristics, a muting key 65 that instantly mutes the reproduced sound, and a muting key 65 that 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. If the current location has already been set, a display routine is executed, and if the current location has not been set, a current location setting routine is executed. These routines will be described later.

Next, the system enters a key wait state, and if there is no key power, the display routine is further executed, and then the key enters the wait state again.

If there is key human power, the presence or absence of a mode change will be determined in the first step,
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 determined, and each routine such as destination setting, drive guide, help, scaling, and correction 1 position output is 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 is performed, 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 then determined whether 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 on the current location is displayed on the display device 29. 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 (1/20,000 in this example) centered on 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,
In the same way as when the place name and guide set key 53 is operated, the current location is determined to be set first. 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, and when 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 the range of the scale before rewriting is changed. A cursor indicating the
Only one.

Is displayed). When the reduction key 57 is further operated.

Since the size of the cursor becomes equal to the size of the screen of the furniture display device 29, the cursor disappears from the screen, but when the reduction key 57 is further operated, the cursor is displayed on the screen again.

When the enlargement key 58 is operated, a cursor indicating the scale range one step higher is displayed.6 When the enlargement key 58 is further operated, the cursor becomes smaller one by one.6For example, as shown in FIG. The cursor shown in will change to the size shown inside, and if you operate it further, it will become 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, make the desired position correspond to the center cursor, and press the set key 55.
If you operate , your current location or destination will be set to that location.

The above reduction key 57. Enlarge 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 same figure, the blocks indicated by upward arrows are for enlargement operations.

A block indicated by a downward arrow represents a reduction operation, and a block indicated by the letters SET represents a set operation. If the screen changes horizontally in the map, it means that the scale of the map does not change, and the line you are visiting is 1/1
600,000, and the rows below are 1/800,000, 1/400,000, 1
/200,000, 1/100,000, 1,150,000, l/25,000, 1/
Each scale is 12,500.

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, since two types of cursors are used to perform enlargement, reduction, and scrolling, one display is not only easy to see, but also has good 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 explained. 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.

Data is constantly updated. Next, it is determined whether or not there is a map centered on the current location on the storage memory S, 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 2
Drawing (rewriting) is performed by the controller 15 in the memory of the memory (the one that is not supplying data to o).

When a map centered on the current location is written in the memory 16.17, it is first determined whether or not a map of another scale is loaded in the memory 5, and if it is not loaded, the map is read from the CD-ROM l into the memory. 5.

When a map of another scale is written on the memory 5, it is superimposed on the map on the front side of the memory 16 or 17 (the one whose data is being transferred to the memory 2o), and the processor 1
The processor 6 writes an own army mark corresponding to the current location calculated by 0, and this data is further transferred from the front side memory to the memory 2°. This own army mark, for example, as shown in the center of FIG. 21, is a mark that allows the direction of movement of the vehicle to be recognized (the figure shows the vehicle moving northward (upwards)). The map and army marks written in the memory 20 in this way are further transferred to the memory 20.
1 and stored in the memory 21 is displayed on the display device 29. After further processing of routines such as enlargement and reduction, the process moves 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, and the lower right area is 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 and numbered in the same way, with the first number being represented by the first digit, the next number being represented by the second digit, and so on. are divided and numbered (file numbers). Therefore, the data of 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) etc.), etc.). However, the price for CD-ROM 1 is 1/800,000.

Only maps with scales of 1/200,000, 1.15 million, 1/1, and 250,000 are available, including 1/1.6 million, L/400,000, and 1/10.
Maps at scales of 1,000, 1/2, and 50,000.

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 calculated as a rectangular coordinate system based on predetermined units of latitude and longitude near the center (4000H, 4000H).

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 chrysopinned range is written to the back side of the memory 16 or 17.

Since the current location moves as the vehicle travels, the steps of calculating the current location and displaying the own army mark are interrupted at predetermined intervals in these flows.

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 o 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 memory 16 and 17 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.
A range (indicated by a broken line in the figure) that is a predetermined distance D (distance on the memory) outside the range displayed in 9 (the range indicated by a solid line in the figure) is defined, and this outer range is drawn in the memory on the front side. When the area of the map is exceeded, a map centered on the current location is read from the memory 5 and drawn in the memory on the back side. Further, this distance iwD is changed in accordance with the scale of the map. Therefore, the smaller the scale (the more the map is enlarged), the faster the display position of your army's mark will move on the map, but writing to the memory on the back side will be done faster, so only a portion of the map will be visible on the screen. is prevented from being displayed as being missing.

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 this command, the controller 15 draws the own vehicle mark. At this time, the own vehicle mark is displayed in a direction corresponding to the traveling direction of the vehicle detected by the calculation of the processor 10.

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 controller 15 determines the dot position l (X) on one horizontal scanning line and 1
The position of the horizontal scan line in the field where the transfer begins (
Y). Therefore, for example, if we focus on one horizontal scanning line.

As shown in FIG. 19, dot counting 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 counted from the primary scanning line. The data in the scanning line range is transferred to the memory 20. When the data is transferred to the memory 2o, at the timing of the vertical synchronization signal of the display device 29 that arrives thereafter, the data is transferred to the memory 2o 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. The display device 29 is driven by a synchronizing signal such as the NTSC system so that it can also display images of normal television broadcasting. 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). 75k)Iz), controller 1
It is not possible to drive the display device 29 (memory 21) with the synchronization signal of No. 5. So memory 21 and memory 16.17
A memory 20 is arranged as a buffer between them, and the same clock as the memory 16 and 17 is used for writing, and the same clock as for the memory 21 is used for reading.

Further, when data is transferred to the memory 20, the color signals of 3g colors, each represented by a 3-bit signal, are converted by the color palette register 19 into a 15-bit color signal. This 15-bit color signal is specified by the processor 6. Therefore, the eight low gradation colors represented by three bits are R.

It is converted to one of 32 high gradation colors represented by 5 bits each of G and B, and by appropriately mixing the 3 primary colors, it is possible to specify any 8 colors out of 32768 colors. Become. Address counter 25 outputs predetermined address signals to color palette register 19 and memory 20, 21 in order to specify the position of each dot undergoing color conversion. The digital data of the map and military marks written in the memory 21 is transferred to the D/A conversion circuits 26 and 27.
．． 28 converts it into an analog signal and displays it on a display device 29. As mentioned above, the maps do not overlap in this area where the vehicle mark is displayed.

This prevents the display of the own vehicle 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. This is because the operation of saving and returning the map data in the area where the own vehicle 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-ROM 1 is accessed is reduced, allowing smooth display.

The map data written to the memory 5 has a scale of 1/8o.
1/200,000, 1/200,000 and 1,150,000 are considered 8ooxsoo dots, and these are 1/1,600,000 and 1/4, respectively.
When drawn in the memory 16.17 at a scale of 00,000 and 1/100,000, it is 400×400 dots. Also, map data with a scale of 1/1° 250,000 is 1600X160
0 dot, and when this is scaled to 1/2,50,000 and drawn in memory 16.17, it is 80o x 80.
It is considered as 0 dot. Smallest scale (enlarged) 1/1
, the number of dots on the 250,000 map is increased compared to other large-scale (reduced) maps.6 Of course, it is also possible to have the same number of dots, but on a small-scale map, the movement of the current location is It gets faster. Therefore, if the number of dots is increased in the case of a small scale than in the case of a large scale as in the embodiment, the frequency of access to the CD-ROMI can be correspondingly reduced compared to the case where the number of dots is the same. .

On the other hand, the drawing machine T-'J16.17 is 640X400
Memory for displaying one dot (high resolution or large capacity) 20.
21 is 256x256 dots (low resolution or small capacity),
The screen of the display device 29 is, for example, 256×216 dots.

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 an image drawn in the memory 16, 17 by the controller 15 or an image drawn directly in the memory 20 by the processor 6 can be selectively displayed below.

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 Figure 10, if multiple maps of a predetermined range are arranged on a plane so that the left and right boundaries are not far apart, the distance between two points can be accurately expressed. , the north-south direction and the east-west direction are not perpendicular to each other, and if each map is digitized as is, it is necessary to display the north-south direction and the east-west direction on the screen of the display device 29 with the north-south direction and the east-west direction tilted with respect to the vertical or horizontal direction. This results in a large discrepancy between the user's sensation and the operability. Moreover, if this is done, the calculations for specifying the current location on the map become complicated, increasing the burden on the processor 1°. Therefore, in the present invention, as shown in FIG.
Transverse Mercator projection 1 Multiple maps drawn for each predetermined area using a projection such as the conic projection are plotted in the east-west direction on a predetermined plane, with the latitude of the basic priest in each area located on the same horizontal line. and the reference meridian on the reference latitude 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 the orthogonal tower on that plane. I have to. FIG. 11(a) is an example where the lower left point of each map in a predetermined range is set as the base W point B of the reference latitude and longitude line,
The figure (b) is an example in which the substantially central point ○ is set as the reference point B.

However, in any case, when calculating the distance between two points on the map, the length per unit (for example, 10 km) of latitude (longitude) at approximately central point O is used as a reference.

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) as point A on the map of the area east of it.
is replaced by point A. 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 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. Each stroke data is expressed by the number of cylinders of a line segment serving as a unit, 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 point 2 in order, and 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. In other words, the symbols are also packaged into predetermined symbols, and end marks (e e e
e h) are arranged. The number of symbol packages is limited to 256 or less. Each package contains a 7-bit serial number of the symbol (for example, a serial number among symbols representing a mountain) and an 8-bit symbol pattern corresponding to each symbol (for example, what number is the mountain symbol? Each symbol corresponds to one number) as the header, followed by the number of symbols (always 1 in this example) and the coordinates where the symbol will be displayed. is located.

FIGS. 21 and 22 show examples in which a mountain symbol is displayed. Mountains are generally displayed as contour lines on maps. However, if it is represented as contour lines, not only does the amount of map data increase, but also the screen of the display device 29 used as a vehicle navigation device cannot be made very large, making it difficult to read.

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 a vehicle navigation system 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. , prepare line segment data that displays railways, etc., place name data that displays the place name of a given place, and symbol data that displays at least a mountain as a symbol, and display mountains as symbols instead of contour lines as line segments. As a result, it is possible to prevent the map from becoming unrecognizable and to reduce the memory capacity for storing the map. Therefore, it is especially suitable for vehicle navigation devices used in relatively narrow spaces. suitable.

[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, and Fig. 13 is an explanatory diagram of the line segment data, No. 141i!
il is an explanatory diagram of the symbol data, FIG. 15 is an explanatory diagram of the place name data, FIG. 16 is an explanatory diagram of how the map is divided, FIG. 17 is a schematic explanatory diagram of the memory, and FIG. 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: Prepare line segment data for displaying roads, railways, etc. as map information, place name data for displaying place names of predetermined places, and symbol data for displaying at least mountains as symbols, and do not display contour lines using the line segments. A vehicle navigation device characterized by displaying a mountain using the symbol.