JPS62153888A - Map information display - 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 map information display device that displays map information stored in a storage medium on a display device.

[Summary of the invention]

The present invention provides a map information display 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. , prepare at least line segment data that displays rivers, coastlines, etc., and display the river or coastline with a solid line that displays the river or coastline itself, and a broken line that is spaced a predetermined distance from the solid line toward the river or sea side. In this way, the capacity of the memory for storing map information can be reduced, and rivers, coasts, etc. can be displayed quickly.

[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. . Such devices are equipped with at least line segment data and are capable of displaying roads, railways, rivers, oceans, etc. in predetermined colors.

[Problem that the invention seeks to solve]

However, when displaying a river, sea, lake, etc. in color, conventional devices, for example, give directionality to the line representing the shore of the river, sea, lake, etc., and color areas such as the left and right sides of the line. This has the drawback that the calculations are complicated and it takes time to apply the colors. It would be possible to omit the colors, but this would make it difficult to distinguish between land and water, making the map difficult to read.

[Means for solving problems]

FIG. 1 is a block diagram when the map information display device of the present invention is applied to an inter-vehicle navigation device. In the figure, 1 is a recording medium or CD-ROM as a storage medium.
(including its drive device) and records digitized map information. Data from the CD-ROMI is stored in a memory (RAM) 5 via an interface 2, an address bus 3, a data bus 4, etc. 6 is an information processor (C
PU) and performs various image data processing,
Peripheral devices are also controlled in response to commands input via the keyboard 12 and its interface 13. Reference numeral 7 indicates a direction sensor that detects the direction of the vehicle from geomagnetism or the like, and reference numeral 8 indicates a speed sensor that detects the speed of the vehicle.

9 is GPS (Global Positioning)
This is a device that detects the current position of the vehicle from latitude, longitude information, etc. 10 is a navigation processor (CPU), which includes a direction sensor 7 and a speed sensor 8.
The current position is calculated from the input data when the GPS device 9 cannot detect latitude and longitude information. Or change the current location entered in the settings
Correction processing is performed in accordance with information from the PS device 9. The processor 10 and the processor 6 are capable of mutually transmitting and receiving data. Reference numeral 11 represents a ROM for storing programs and other necessary information for the processors 6 and 10, and reference numeral 14 represents a control logic for supplying necessary timing signals to each circuit 1 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 the memory (VRAM) 20, and from the memory 20 to the memory (VRAM) 21, and the video signal stored in the memory 21 is converted into red (R) and green (G).
), D/A conversion circuits for each of the three primary colors of blue (B) 26.27
．． The digital signal is converted into an analog signal by 28 and displayed on a display device 29 such as a CRT. Although not shown, a touch sensor made of transparent m11 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.
．． 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 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 (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 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 (CAMCEL) 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 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. Reference numeral 60 denotes a text (TEXT) key, and the processor 6 manages a program when each of the six or more keys operated to display information related to the running of the vehicle is operated.

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, the AM and FM keys 63 are operated when receiving AM or FM broadcasting, and equalization of reproduced sound. Sound select (SOUND 5EL) key 6 operated when selecting a characteristic from among predetermined characteristics
4. A muting key 65 that instantly mutes the playback sound, a volume 66 that adjusts the volume of the playback sound, and an air conditioning (A/C) key 6 that is operated when operating the air conditioner.
7 is provided, 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 explained 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 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 the destination is set according to the command.

Routines such as drive guide, help, scaling, correction, and position output are executed. 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 determined whether or not the current location has been set.

If the current location has been set, a map of a preset scale (1/20,000 in this example) centered around 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 (1/200,000 in this example) centered at that location is displayed.

Display device! When the map is displayed at 29, the input key is then determined, and processes such as scale setting, cursor movement, set, place name guide set, and cancellation 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 the center position is to be set, then the current location is determined to be set, similarly to the case where the place name and guide set key 53 is operated. 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
If you further operate the reduction key 57, the size of the cursor 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.

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.6 For example, as shown in FIG. 23, the cursor shown on the outside changes to the size shown on the inside, and when the enlargement key 58 is operated further, the cursor becomes smaller.

For example, when the scroll key 59 is operated in such a state, the cursor position remains unchanged at the center of the screen, but the map moves vertically and horizontally. 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, by operating the scroll key 59, the map is moved up and down, left and right, the desired position is made to correspond to the central cursor, and the cent key 55 is operated to set the current location or destination at that point.

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 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 above - is 1/1
600,000, and the rows below are 1/800,000, 1/400,000, 1
/2o million, 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 so, for example when moving the cursor while searching for a predetermined destination.

When it is determined that the destination is outside the displayed map, a separate operation is required to redraw the displayed map, which interrupts the operation and deteriorates operability. Therefore, as in the embodiment, it is preferable to fix the cursor at approximately the center of the screen and move the map so that the user can search for the destination simply by continuously operating the scroll key 59.

In this way, since two types of cursors are used to perform enlargement, reduction, and scrolling, the 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 these information.The calculation of the current location is performed at regular intervals.

The data is constantly updated. Next, it is determined whether or not a map centered on the current location exists in the storage memory S. If not, the data is transferred from the CD-ROM 1 to the memory 5. loaded.

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
The controller 15 performs drawing (rewriting) in the memory of the memory (to which data is not supplied).

If a map centered on the current location is written in the memory 16, 17, then it is determined whether or not a map of another scale is loaded in the memory 5, and if it is not loaded, the map is transferred from the CD-ROMI to the memory 5. loaded on top.

When a map of another scale is written on the memory S, 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 20), and the processor 1o
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 20. This own vehicle mark, for example, as shown in the center of Figure 21, is a mark that allows the direction of travel of the vehicle to be recognized (
The figure shows the vehicle traveling north (up).The map and army marks written in the memory 20 in this way are further transferred to the memory 21 and stored therein. The image is displayed on 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 middle broken line) 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 specified range (8000H x 80
00H; Hit hexadecimal number (1) unit) (7) Earth W
The i y'-ta is equally divided into four by two straight lines, the horizontal line and the line perpendicular to it, and the lower left area is numbered O1, the lower right area is numbered 1, the upper left area is numbered 2, and the upper right area is numbered 3. Each corresponds to 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 for the area centered on point P in Figure 16 is O (1/1.6 million scale map),
03 (1/800,000 scale map), 030,031.
032.033 (map with a scale of 1/400,000), etc., exists in the map represented by each file number. However, the CD-ROMI only has maps of 1/800,000, 1/200,000, 1,150,000, and 1/1250,000 scales;
Maps of 1.6 million, 1/400,000, 1/100,000, and 1/25,000 scales are represented by thinning out and drawing data of the maps of the above-mentioned scales. 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-ROM 1 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.

Since the current location moves as the vehicle travels, the steps of calculating the current location and displaying the own vehicle 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 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 portion of the image drawn on the front side of the memory 16 , 17 within a predetermined range is transferred to the memory 20 and further to the memory 21 and displayed on the 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.As the vehicle travels, when the range displayed on the display device 29 exceeds the range written in the memory on the front side, the data is Rewriting will be necessary. 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 exceeds the range of the map.

A map centered on the current location at that time is read from the memory 5 and drawn in the memory on the back side. 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 army's mark on the map will move, but since writing to the memory on the back side is done faster, only a portion of the map can be displayed on one 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. Then, the controller 15 draws the own army mark therein according to the command from the processor 6. 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 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 first
As shown in FIG. 8, it is defined by the dot position II (X) at which the controller IS starts transfer on one horizontal scanning line and the position (Y) of the horizontal scanning line at which transfer starts in one field. 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 synchronizing signal, and when a predetermined offset value X is counted, a predetermined number of dots are counted from the next dot. The video signal in the range represented by the dots is transferred to the memory 20. Also, focusing on the fields, when a transfer command is output from the processor 6 to the controller 15, as shown in FIG. After counting the offset value Y, data in a predetermined number of scanning lines from the next scanning line is transferred to the memory 2o. Once the data is transferred to the memory 20, the data is further transferred to the memory 21 at the timing of the vertical synchronization signal of the display device 29 that arrives after that, taking the time of one field of the display device 29.

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). 75kHz), the controller 15
It is not possible to drive the display device 29 (memory 21) with the synchronization signal. Therefore, the memory 20 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 3M colors, 32768 colors are converted. The address counter 25 sends a predetermined address signal to the color palette register 19 and memory 20.21 in order to specify the position of each dot for which color conversion is performed. is outputting. The digital data of the map and military marks written in the memory 21 are converted into analog signals by D/A conversion circuits 26, 27, and 28, and 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 operation of saving and returning the map data in the range in which the own army mark is displayed is repeatedly performed as the vehicle moves, so that the amount of calculations and the capacity of the memory used can be reduced. Also CD-ROMI
The number of accesses is reduced, allowing smooth display.

The map data written to the memory 5 has a scale of 1/80.
1/1,600,000, 1/200,000, and 1,150,000 dots are 800 x 800 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 1/25,000 and drawn in memory 16.17, it is 800x80.
It is considered as 0 dot. Smallest scale (enlarged) 1/1
．． This increases the number of dots on the 250,000 map 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 2o. In this case as well, the image data being displayed on the display device 29 is output from the memory 21, so the displayed image is not affected by the writing operation. Either an image drawn in the memory 16 or 17 by the controller 15 or an image drawn directly in the memory 20 by the processor 6 can be alternatively 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, maps with relatively large scales exceeding 1/200,000 (relatively reduced maps) are based on the conic projection method, so for example, as shown in Figure 10, these maps within a predetermined range are mapped with left and right boundaries that are far apart. If multiple maps are lined up on a flat surface so that there is no difference, the distance between two points can be accurately expressed, but the north-south direction and the east-west direction are not perpendicular to each other, so if each map is digitized as is, It becomes necessary to display the north-south direction and the east-west direction on the screen of the display device 29 while being inclined with respect to the vertical or horizontal direction, resulting in a large discrepancy with the user's sense and deteriorating 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 drawn in the east-west direction on a predetermined plane so that the reference latitude lines for each area are 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 located next to each other in the north-south direction, and the positions on the map are specified by rectangular coordinates on that plane. There is. FIG. 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 reference latitude and longitude line,
The figure (b) is an example in which the point ◯ of the middle man is set as the reference point B.

However, in any case, when calculating the distance between two points on the map, use the unit (for example, 10 km) at approximately the middle point O
Based on the length per line (meridian).

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 at the upper right (northeast) of a 1/200,000 scale map, and point A2 at the upper left (northwest) corresponding (same) to point A1 on the map of the area east of it.
is replaced by point A. If you convert the earth coordinates to rectangular coordinates (x, y) in this way, for example, 1/20
The maximum error that occurs on the 10,000 map is ±70m.

As shown in FIG. 12(a), the error is locally concentrated in a predetermined range in the north-south direction (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 senses, improves operability, and facilitates calculation of the current location.

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 set includes a predetermined number of pancakes, and end data (dddd 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 start point and end point in units of lom (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 Figure 22, the river or coastline itself is represented by a solid line, and by placing a broken line at a predetermined distance 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 increase the drawing speed, the dots are colored sequentially horizontally from point Z using a predetermined point 2 on the broken line as a reference 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 oriented solid lines representing rivers and coastlines and coloring one side of them. You can color it with . 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 it is represented as contour lines, the amount of map data not only increases, but also the display device 29, which is used as a vehicle navigation device, cannot have a large screen, so it becomes less visually appealing. 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.

Although the present invention has been described above by way of example in which it is applied to a vehicle navigation device, the scope of application of the present invention is not limited thereto.

〔effect〕

As described above, the present invention provides a map information display 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. Prepare at least line segment data to display roads, railways, rivers, coastlines, etc., and display rivers or coastlines.

By displaying a solid line representing the river or coastline itself, and a dashed line spaced a predetermined distance away from the solid line toward the river or sea, calculations are simplified and rivers, coastlines, etc. can be quickly and easily viewed. can be displayed. Therefore, it is particularly effective for a vehicle navigation system that moves and displays a map as the vehicle travels. Furthermore, the capacity of the memory for storing map information can be reduced, the device can be made smaller, and the cost can be reduced.

[Brief explanation of drawings]

FIG. 1 is a block diagram when the map information display device of the present invention is applied to a vehicle navigation device, FIG. 2 is a plan view of the display device and keyboard, FIGS. 3 to 9 are flowcharts, and FIG. 10 12 to 12 are explanatory diagrams for explaining the conversion of earth coordinates to orthogonal coordinates, FIG. 13 is an explanatory diagram for the line segment data, and FIG. 14 is an explanatory diagram for the symbol data. Fig. 15 is an explanatory diagram of the place name data, Fig. 16 is an explanatory diagram to explain how the map is divided, Fig. 17 is a schematic explanatory diagram of the memory, and Fig. 18 is a schematic diagram of data reading and writing. An explanatory diagram to explain, FIG. 19 is a waveform diagram,
Figure 20 is the timing chart, Figures 21 to 2
FIG. 4 is a plan view of the display screen, and FIG. 25 is an explanatory diagram of the 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 and above Figure 2 - V Figure 8 Figure 9 Figure 10 γ □ (b) 1 I i Figure 12 (a) [ (b)

Claims (1)

[Scope of Claims] A map information display 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: The map information includes at least line segment data that displays roads, railways, rivers, coastlines, etc., and the river or coastline includes a solid line that displays the river or coastline itself, and a predetermined line on the river or sea side from the solid line. A map information display device characterized by displaying broken lines separated by a distance of .