JPH0785247B2 - Image display device - Google Patents

Description

The present invention relates to an image display device for displaying predetermined image information stored in a storage medium on a display device.

[Outline of Invention]

The present invention relates to an image display device that digitizes image information, stores it in a predetermined storage medium, displays the image information read from the storage medium and converted into an image signal on a display device, and outputs data of the image information in a predetermined range. Is evenly divided by a horizontal line and a vertical line orthogonal to the horizontal line, each divided area is given a predetermined coding according to a predetermined law, and the divided area is further divided in the same manner, and the coding is performed. Then, the data is stored in a storage medium so that the data in each area can be easily read.

[Conventional technology]

Recently, a vehicle navigation device has been researched and developed in which map information is recorded on a CD-ROM or the like, and the map information is read out and displayed on a display device together with the current location of the vehicle to guide the vehicle to a predetermined destination. . Such an apparatus prepares a plurality of maps corresponding to a predetermined area so that a predetermined area can be displayed on different scale maps as needed.

[Problems to be solved by the invention]

However, the conventional device digitizes and stores a plurality of maps corresponding to a predetermined area, but simply divides them by scale, so that a map of an area including a predetermined point such as the present location and a destination is stored. Searching for had the drawback of being time consuming.

[Means for solving problems]

In order to solve the above problems, the present invention digitizes map information and stores it in a predetermined storage medium, reads out the map information corresponding to the position coordinates input from the outside from the storage medium, and converts it into an image signal. In the image display device for displaying on the display device, the Xth image on the map corresponding to the map information.
(X = positive integer: initial value 1) is divided into n equal parts (n = 2) in the horizontal direction by a horizontal line and a vertical line orthogonal to the horizontal line.
The above integer) and divides into n × m (X + 1) -th regions divided into m equal parts (m = integer of 2 or more) in the vertical direction Y times (Y = positive integer). The first area to the (Y + 1) th area, a code for associating the first area to the (Y + 1) th area with each other, and a code for associating with the actual position coordinates. Data of the map information corresponding to each of the (Y + 1) th areas and at least the data of the map information corresponding to the (Y + 1) th area and the codes assigned to the first area to the (Y + 1) th area are stored in the storage medium. Desirably, including the input position coordinate from the first region to the (Y + 1) th region based on the input position coordinate and the code from the map information data stored in the storage medium. Map information corresponding to the area Searching data, configured to convert the image signal.

[Action]

According to the present invention, the X-th map on the map corresponding to the map information
(X = positive integer; initial value 1) is divided into n equal parts (n = 2) in the horizontal direction by a horizontal line and a vertical line orthogonal to the horizontal line.
The above integer) and divides into n × m equal (X + 1) regions divided into m equal parts (m = integer of 2 or more) in the vertical line direction Y times (Y = positive integer). The first area to the (Y + 1) th area, a code for associating the first area to the (Y + 1) th area with each other, and a code for associating with the actual position coordinates. The map information data assigned to each of the (Y + 1) th regions and at least the data of the map information corresponding to the (Y + 1) th region and the codes assigned to the first to (Y + 1) th regions are stored in the storage medium.

As a result, the image display device receives the input from the first area to the (Y + 1) th area based on the input position coordinates and the code from the map information data stored in the storage medium. Data of the map information corresponding to a desired area including position coordinates is searched and converted into the image signal.

In this case, the codes assigned to the first area to the (Y + 1) th area are the first area to the (Y +) th area, respectively.
1) Since each of the areas is related to each other and is related to the actual position coordinates, by inputting the position coordinates of a predetermined point such as the current position and the destination from the outside, a simple calculation can be performed. The first based on the input position coordinates and code
It becomes possible to retrieve the data of the map information corresponding to the desired region including the input position coordinates from the region to the (Y + 1) th region, and convert it into an image signal based on the retrieved data. .

As a result, it becomes possible to display the map information of the predetermined area including the input position coordinates at a desired scale.

〔Example〕

 Next, preferred embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram when the image display device of the present invention is applied to a vehicle navigation device. 1 in the figure
Is a CD-ROM (including its drive device) as a recording medium or a storage medium, in which digitized map information is recorded. The data from the CD-ROM 1 is stored in the memory (RAM) 5 via the interface 2, the address bus 3, the data bus 4 and the like. An information processor (CPU) 6 performs various kinds of image data processing and also controls peripheral devices in response to commands input via the keyboard 12 and its interface 13. Reference numeral 7 is a direction sensor that detects the direction of the vehicle from the geomagnetism and the like, and 8 is a speed sensor that detects the speed of the vehicle. 9 is GPS (Global Positionin)
g System) device, which detects the current position of the vehicle from latitude and longitude information. 10 is a navigation processor (CP
U), correction of data of the direction sensor 7, speed sensor 8 and the like, calculation of the amount of movement of the vehicle from those data, and when GPS device 9 cannot detect latitude and longitude information The current position is calculated from the obtained data. Alternatively, the current position set and input is corrected according to the information from the GPS device 9. The processor 10 and the processor 6 can exchange data with each other.
Reference numeral 11 is a ROM for storing the programs of the processors 6 and 10 and other necessary information, and 14 is a control logic for supplying a timing signal required for each circuit, means, device and the like.

Reference numeral 15 is a graphic display controller (GDC), which reads necessary data from the memory 5 and uses the memory (VR
AM) 16 and 17 draw a specified image. 18 is memory 16, 17
It is a parallel / serial (P / S) conversion circuit that selects data from one of them and converts the parallel signal into a serial signal. A color palette register 19 as a color conversion circuit converts a 3-bit color signal in the video signal supplied from the P / S conversion circuit 18 into a pre-specified 5-bit color signal. The video signal converted from the color signal is transferred to the memory (VRAM) 20, and further transferred from the memory 20 to the memory (VRAM) 21, and the video signal stored in the memory 21 is red (R),
D / A conversion circuits 26 and 2 for each of the three primary colors of green (G) and blue (B)
The digital signal is converted into an analog signal by 7, 28 and 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.

Reference numeral 24 is a sync signal generation circuit that generates a horizontal sync signal (HSYNC), a vertical sync signal (VSYNC), and a dot clock (DCK) that are mutually synchronized, and sets the addresses of the register 19, memories 20, 21 and the like. It outputs to address counters 23, 25, etc. 22 is an offset resist, the memory 16,
The offset position of the part to be transferred to the memory 20 among the stored images of 17 is set. Reference numerals 30 to 37 are buffers inserted at predetermined positions.

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. Reference numeral 51 is a navigation (NAVI) key operated when executing a navigation operation, and 52 is a help (!) Key operated when outputting an explanation image of the operation to the display device 29. 53 is a guide (GUIDE) key, a parking lot,
It is operated when displaying symbols such as hotels and gas stations on the map. 54 is a destination (DEST) key,
It is operated when setting the destination. 55 is a set
A key, which is operated when registering an item designated by the cursor displayed on the display device 29 or a position on the map. A cancel (CANCEL) key 56 is arranged to return to the previous screen when operated on a limited predetermined screen. Reference numeral 57 is a reduction key, and 58 is an enlargement key, which are operated when reducing or enlarging the map displayed on the display device 29. 59 is a scroll key, up and down,
When moving the cursor to the left or right, the keys 59a to 59d are operated. Reference numeral 60 denotes a TEXT key, which is operated when displaying information related to the driving of the vehicle. The program when the above keys are operated is managed by the processor 6.

On the other hand, a CD key 61 operated when operating the compact disc player, a TV key 62 operated when receiving a television broadcast, an AM / FM key 63 operated when receiving an AM or FM broadcast, and equalization of reproduced sound. A sound select (SOUND SEL) key 64 that is operated when selecting a characteristic from among predetermined characteristics, a muting key 65 that instantly mutes the reproduced sound, a volume 66 that adjusts the volume of the reproduced sound, and an air conditioning An air conditioning (A / C) key 67 that is operated when the apparatus is operated is provided, and a predetermined operation is executed by a CPU (not shown).

Next, the operation will be described. First navigation key 51
The basic operation when is operated will be described. The operation in this case is managed, for example, according to the flowchart shown in FIG. As a first step, it is determined whether or not the current location is set. The display routine is executed when the current position is already set, and the current position setting routine is executed when the current position is not set. These routines will be described later. Next, a key input waiting state is entered, and if there is no key input, the display routine is further executed, and then the key waiting state is entered again.

If there is a key input, it is next judged whether or not there is a mode change,
When there is a mode change, the routine goes to that mode. The modes include a navigation mode, text mode, AV mode and the like. If there is no mode change, the command is determined next, and the destination set, drive guide, help, scaling, correction,
Each routine such as position output is executed. After that, it returns to the state of waiting for key input again, and the display routine is executed until there is a key input.

The routine for setting the present location is executed according to the flowchart shown in FIG. First, it is judged whether or not the cancel key 56 is operated, the current position until then is reset, and a predetermined position set in advance is set as a temporary current position. Also the scale of the map
Is set to a predetermined value (1 / 1.6 million in this case). And a map centering on the predetermined place is displayed on the display device 29.
Is displayed in.

When the cancel key 56 is not operated, it is next determined whether or not the current location has been set. If the current location has already been set, a map with a preset scale (1 / 20,000 in this example) centered on the current location is displayed on the display device 29.If the current location is not set, it is set in advance. The given location is set as the provisional current location, and a map centered on that location and having a predetermined scale (in this example, 1 / 200,000) is displayed.

When the map is displayed on the display device 29, the input key is determined next, and processing such as scale setting, cursor movement, setting, place name guide setting, and cancellation is performed corresponding 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 set. If the center position is not set, the scale specified by Carson is set, and the scale set in which the map of that scale is displayed is executed. If it is a set of center positions, place name,
Similar to the case where the guide set key 53 is operated, the determination of the current position is made next. If it is the current location set, the operation of the current location set is performed, and if it is not the current location set, the destination set is performed.

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

Eight kinds of map scales are prepared, and when the reduction key 57 is operated during scale setting, the display device 29
Image is rewritten to a map at 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. Two cursors are shown in the same figure for convenience. However, only one cursor is actually displayed). When the reduction key 57 is further operated, the size of the cursor becomes equal to the size of the screen of the furniture display device 29, so that the cursor disappears from the screen, but when the reduction key 57 is further operated, the cursor is displayed again on the screen. To be done.

When the enlargement key 58 is operated, a cursor indicating the scale range one step higher is displayed. When the expand key 58 is further operated, the cursor becomes smaller successively. For example, as shown in FIG. 23, the cursor shown on the outer side changes to the size shown on the inner side, and further operation makes it smaller. If, for example, the scroll key 59 is operated in such a state, the position of the cursor does not change in the center of the screen as it is, but the map moves vertically and horizontally. In this way, find the desired position, and with the cursor displayed, press the Set key 55.
When is operated, the range displayed by the cursor is displayed on the screen at the reduced scale, and at this time the cursor changes to a + character (Fig. 24). Further scroll keys 59
Is operated to move the map up, down, left and right, the desired position is made to correspond to the cursor in the center, and the set key 55 is operated to set the present location or destination to that point.

FIG. 25 shows the changes in the screen caused by the operations of the reduction key 57, the enlargement key 58, and the set key 55 described above. In the figure, the block indicated by the upward arrow indicates the enlargement operation, the block indicated by the downward arrow indicates the reduction operation, and the block indicated by the character SET indicates the set operation.
Represents each. And if the screen changes horizontally in the figure, it means that the scale of the map does not change, the top row is 1 / 1.6 million, the following rows are 1 / 800,000, 1/40 Ten thousand one
The scale is 200,000, 100,000, 150,000, 1 / 25,000, and 1 / 12,500.

It is also possible to move the cursor instead of the map when the scroll key 59 is operated. However, when doing so, for example, when moving the cursor while searching for a predetermined destination, when it is found that the destination is outside the displayed map, an operation for rewriting the displayed map is separately performed. It becomes necessary, operation is interrupted, and operability deteriorates. Therefore, as in the example, fix the cursor at the approximate center of the screen and move the map,
It is preferable to be able to search for the destination only by operating the scroll key 59 continuously.

In this way, since the two types of cursors are used to perform enlargement, reduction and scrolling, not only the display is easy to see, but also the operability is improved. Further, at the time of enlarging, the drawing operation (which takes time) to be described later on the memory is started when the set key 55 is operated after the target scale is set, 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 and the speed sensor 8
The current position 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, and the data is constantly updated. Next, it is judged whether or not there is a map centered on the current location in the memory 5 for storage.
Loaded on.

When a map centered on the current location is stored in the memory 5,
Next, it is judged whether the map centered on the current location is within the range of the map drawn in the memories 16 and 17, and when it is not within the range, the back side of the memory 16 or 17 (data is being supplied to the memory 20 is being supplied. Drawing (rewriting) is performed by the controller 15 in the memory of the other person.

If a map centered on the current location is written in the memories 16 and 17, it is next determined whether or not another scale map is loaded in the memory 5, and when it is not loaded, the CD-
It is loaded from ROM1 onto the memory 5.

When another scale map is written on the memory 5, the current location calculated by the processor 10 is next superimposed on the map on the front side (the one transferring the data to the memory 20) of the memories 16 or 17. The vehicle mark is written by the processor 6 in response to, and this data is further stored in the memory on the front side.
Transferred to 20. For example, as shown in the center of FIG. 21, this own vehicle mark is a mark whose traveling direction can be recognized (the figure shows a state in which the vehicle is traveling northward (upward)). The map and the vehicle mark thus written in the memory 20 are further transferred to the memory 21, and the image stored in the memory 21 is displayed on the display device 29. After the routines such as enlargement and reduction are processed, the process proceeds to the next step.

By the same operation, the direction of the destination viewed from the present location is displayed as indicated by an arrow at the upper right of FIG.

The step of loading map data from the CD-ROM 1 (shown by A in the figure) in the above display routine is shown in more detail in FIG. That is, as shown in FIG. 16, first, an area (indicated by a broken line in the figure) in a predetermined range centering on the current position P is set, and a file number of a map in the area is set.

As shown in Fig. 16, the specified range (8000H x 8000H; H is 16
The map data (in units of bases) is equally divided into four lines by two straight lines, a horizontal line and a line orthogonal to it. The lower left area is 0, the lower right area is 1, the upper left area is 2, and the upper right area is. The numbers 3 correspond to each other. Each of the four areas is similarly divided into four smaller areas, similarly numbered, the first number is represented by the first digit, the next number is represented by the second digit, and so on. And the numbering (file number) is done. Therefore, point P in Fig. 16
The data of the area centering on is 0 (map of the scale of 1 / 1.6 million), 03 (map of the scale of 1 / 800,000), 030,031,032,033
It will be present in the map represented by each file number such as (1 / 400,000 scale map). However, 1-800,000 for CD-ROM1,
Only maps of each scale of 1 / 20,000, 150,000, 1/125, 000 are prepared, and maps of each scale of 1 / 1,600,000, 1 / 400,000, 100,000 and 1 / 25,000 are available. The map data of the above-mentioned reduced scale is thinned out and drawn. The distance between two points on this map is calculated as an orthogonal coordinate system with reference to a predetermined unit latitude and longitude near the center (4000H, 4000H).

In this way, the map data including the current position of each scale (four scales) to which the file numbers as described above are attached is read from the CD-ROM 1 and written in the memory 5. Further, as shown in FIG. 18, a predetermined range centered on the current position (the range shown by the diagonal lines in the figure) is clipped on the memory 5, and the clipped range is written on the back side of the memory 16 or 17. .

Since the current position moves as the vehicle travels, the steps of calculating the current position and displaying the own vehicle mark are interrupted every predetermined time in these flows.

Details of the data rewriting step (indicated by symbol B in the figure) of the memories 16 and 17 shown in FIG. 6 are as shown in FIG. 8, for example. That is, in the memories 16 and 17, the one drawn by the controller 15 is the back side, and the one having completed the drawing and transferring the data to the memory 20 is the front side, and the controller 15 always draws in the memory on the back side and the drawing is completed. At this time, the front side and the back side are reversed. For example, as shown in Figure 18,
Of the images drawn on the front side of the memories 16 and 17, only a part within a predetermined range is transferred to the memory 20 and further to the memory 21,
Displayed on the display device 29. Therefore, even in this flow, the steps of calculating the current position and displaying the own vehicle mark are interrupted at predetermined time intervals as the vehicle travels. The data does not need to be rewritten too 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 needs to be rewritten. However, it takes some time to rewrite the data. Therefore, as shown in FIG. 17, a predetermined distance D (distance in the memory) from the range transferred to the memory 20 of the front side memory, that is, the range displayed on the display device 29 (the range indicated by the solid line in the figure). ) Only the outer range (indicated by the broken line in the figure) is defined, and when the outer range exceeds the range of the map drawn in the memory on the front side,
A map centering on the current location at that time is read from the memory 5 and drawn in the memory on the back side. The distance D is changed according to the scale of the map. Therefore, when the scale is smaller (when the map is enlarged), the display position of the vehicle mark on the map moves faster, but writing to the memory on the back side is faster, so that the map It is possible to prevent a part from being displayed as missing.

Furthermore, the step of transferring the map drawn in the memories 16 and 17 to the memory 20 in FIG. 6 (indicated by reference symbol C in the figure)
Is shown in more detail in FIG. That is, first, in the memory on the front side of the memories 16 and 17, the memory 20
The data in the range (16 × 16 dots) for displaying the own vehicle mark in the center of the range (FIG. 18) to be transferred to is temporarily saved in the memory 5. Then, the controller 15 draws the own vehicle mark in accordance with a command to the processor 6 there. At this time, the vehicle mark is displayed in the direction corresponding to the traveling direction of the vehicle detected by the calculation of the processor 10. In this way, the map centered on the own vehicle mark drawn in the front memory is transferred to the memory 20. The range transferred is offset register 22
(Hence the address counter 23). That is, the offset register is controlled by the processor 6.
A predetermined coordinate value that changes corresponding to the current location is stored in 22. This value is defined by the dot position (X) where the controller 15 starts the transfer on one horizontal scanning line and the horizontal scan line position (Y) at which the transfer starts in one field, as shown in FIG. To be done. So for example 1
Focusing on one horizontal scanning line, as shown in FIG. 19, when the counting of dots is started at the timing of the horizontal synchronizing signal and a predetermined offset value X is counted, it is represented by a predetermined number of dots from the next dot. Video signal of range is memory 20
Transferred to. Focusing on the fields, as shown in FIG. 20, the transfer instruction from the processor 6 is sent to the controller.
When it is output to 15, the counting of the horizontal synchronizing signal is started at the timing of the vertical synchronizing signal of the controller 15 which arrives thereafter, and after counting the predetermined offset value Y, the range of the predetermined number of scanning lines from the next scanning line. Data of the above is transferred to the memory 20. When the data is transferred to the memory 20, at the timing of the vertical synchronizing signal of the display device 29 that arrives thereafter, the data is further transferred to the memory 21 by spending one field time of the display device 29.

The data written in the memory 21 is read out and displayed.
Displayed on 29. The display device 29 is driven by a synchronizing signal of, for example, the NTSC system so that an image of a normal television broadcast can be displayed. Therefore, the memory 21 which outputs data to the display device 29 is also driven by the clock having the same frequency as the synchronizing signal of the NTSC system or the like. On the other hand, the sync signal of the controller 15 controlled by the processor 6 as a computer (for example, the frequency of the horizontal sync signal is 24.83 kHz).
In general, unlike the NTSC sync signal (for example, the frequency of the NTSC horizontal sync signal is 15.75 kHz), the sync signal of the controller 15 cannot drive the display device 29 (memory 21). Therefore, the memory 20 is arranged as a buffer between the memory 21 and the memories 16 and 17, and writing is performed by the memory 16 and
The same clock as 17 is used, and the same clock is used for reading as the memory 21.

When the data is transferred to the memory 20, the color signals of the three primary colors represented by the 3-bit signals are converted by the color palette register 19 into 15-bit color signals. this
The 15-bit color signal is specified by the processor 6. Therefore, 8 kinds of low gradation color represented by 3 bits are
It is possible to specify any 8 kinds of colors from 32768 colors by converting to any of 32 kinds of high gradation color represented by 5 bits of R, G and B and by appropriately mixing the 3 primary colors. It will be possible. The address counter 25 is used to specify the position of each dot on which color conversion is performed.
And a predetermined address signal is output to the memories 20 and 21.
The digital data of the map and the own vehicle mark written in the memory 21 are converted into analog signals by the D / A conversion circuits 26, 27, 28 and displayed on the display device 29. As described above, since the maps do not overlap in this vehicle mark display portion, it is possible to prevent the display of the vehicle mark on the screen from being difficult to see (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 retracting and returning the map data in the range where the vehicle mark is displayed is repeated with the movement of the vehicle, so the amount of calculation and the capacity of the memory used can be reduced. In addition, the number of times to access the CD-ROM1 is reduced and smooth display is possible.

The map data written in the memory 5 has a scale of 1 / 800,000,
Those of 1 / 200,000 and 1 / 50,000 have 800 × 800 dots, and these are drawn in the memories 16 and 17 at the scales of 1 / 1.6 million, 1 / 400,000 and 1 / 100,000, respectively. If it is set to 400 x 400 dots. Map data with a scale of 1 / 12,500 is 1600 x 16
It is set to 00 dots, and when this is scaled to 1 / 25,000 and drawn in the memories 16 and 17, it is set to 800 × 800 dots. The number of dots in the smallest scaled (enlarged) 1 / 12,500 map is increased compared to other large scaled (scaled down) maps. Of course, it is possible to use the same number of dots, but in a small scale map, the current position moves faster. Therefore, in the case of the small scale as in the embodiment, by increasing the number of dots as compared with the case of the large scale, the frequency of access to the CD-ROM 1 can be reduced by that amount as compared with the case where the number of dots is the same. . On the other hand, memory 16 and 17 for drawing is 640
× 400 dots (high resolution or large capacity), display memory 2
0 and 21 are 256 × 256 dots (low resolution or small capacity), and the screen of the display device 29 is 256 × 216 dots, for example.

The processor 6 can directly write an image of a photograph, such as an intersection, recorded on the CD-ROM 1 into the memory 20. In this case also, since the image data being displayed on the display device 29 has been output from the memory 21, the display image is not affected by the writing operation. In this way, the display device 29 can selectively display either the image drawn in the memories 16 and 17 by the controller 15 under the control of the processor 6 or the image drawn by the processor 6 directly in the memory 20. It has become.

Next, an example of recording map data will be described. As is well known, a map represents the state of the earth on a spherical surface on a plane. There are various ways to express it, but the map issued by the Geographical Survey Institute of Japan is a horizontal Mercator projection for maps with a relatively small scale of 1 / 200,000 or less (relatively enlarged map). In addition, maps with a relatively large scale exceeding 1 / 200,000 (relatively reduced maps) are based on the conic projection. Therefore, for example, as shown in FIG. 10, when a plurality of these maps within a predetermined range are arranged on a plane so that the left and right boundary lines are not separated, the distance between two points can be accurately expressed. , North-south direction and east-west direction are not perpendicular to each other.
It is necessary to display the north-south direction and the east-west direction on the screen of 29 with being tilted with respect to the vertical or horizontal direction, which causes a large gap from the user's sense and deteriorates operability. Further, in this case, the calculation for specifying the current position on the map becomes complicated, and the load on the processor 10 increases. Therefore, in the present invention, as shown in FIG. 11, a plurality of maps drawn for each predetermined area by a projection such as a lateral Mercator projection or a conic projection, on a predetermined plane, a reference latitude line in each area. Are aligned on the same horizontal line in the east-west direction, and the reference meridian on the standard latitude line is aligned on the same straight line perpendicular to the horizontal line. The position on the map is specified by the rectangular coordinates at. Fig. 11 (a) shows the latitude line based on the lower left point of each map in the prescribed range,
This is an example in which the reference point B of the meridian is used, and FIG. 7B shows an example in which the point O at the substantially center is used as the reference point B. However, in either case, when calculating the distance between two points on the map, the length per unit (for example, 10 km) latitude line (meridian) at the point O at the approximate center is used as a reference.

Then, as shown in FIG. 12 (b), the discontinuous portions generated in the left and right adjacent maps are corrected so that the portions are located on a vertical straight line. The point A ₁ of a result for example 1/20 of thousands of the top right corner of the map (northeast), the point A ₁ in the map of the region of the East
The upper left (northwest) point A ₂ (corresponding to) is replaced with the point A ₃ . In this way, the earth coordinates can be converted into Cartesian coordinates (x,
When converted to y), for example, the error that occurs in a map of 1 / 200,000 becomes a maximum of ± 70 m, and the error is a predetermined range in the north-south direction (the shaded area in the figure) as shown in Figure 12 (a). Locally concentrate on). As a result, the error in the distance in this vicinity becomes large, but the east-west direction is generally horizontal,
The north-south direction can be displayed vertically, which improves the operability in accordance with the user's feeling and facilitates the calculation of the current location.

Data represented on the map include line segments,
Symbols and place names are prepared. Line segment data is No. 13
It is configured as shown in the figure. In other words, line segment data includes 8 types of line types (represented by 8-bit data) such as major national roads, local roads, other roads, coastlines, and railways, and attributes such as tunnels and trams (represented by 7 bits). ), And are packaged. A package is prepared for each type of line to be displayed such as a red line, and a predetermined number of packages are set as one set, and end data (dddd h) is arranged at the end of each set. Further, in each package, data of attribute and line type is arranged at the head of the package, next is the total number of strokes in the package, and further next is each stroke data. One stroke represents one continuous line segment.
Each stroke data is represented by the number of line segments as a unit, and its start point and end point as coordinates in units of 10 m (the same applies hereinafter). Since the end point of the line segment that is one unit that constitutes one stroke is the start point of the line segment that is the next unit, the coordinate data of the start point of the line segment that is each unit and the end point of the line segment that is the last unit The data of one stroke is composed of.

Two types of line types are prepared for river or coastline data. That is, as shown in Fig. 22, the river and coastline itself are represented by a solid line, and the broken line is placed at a place separated from the solid line to the river or the sea side by a predetermined distance, so that the broken line side is the river or the sea side. Is represented. Since such display does not take time, it is performed when it is necessary to increase the drawing speed (for example, when the traveling speed of the vehicle is higher than the scale of the map). On the other hand, when it is not necessary to increase the drawing speed so much, the dots are colored until the scanning line intersects the solid line representing the coastline by sequentially operating horizontally from the point Z on the basis of the predetermined point Z on the broken line. . In this way, it takes some time to color the river, the sea, etc., but in a shorter time than the conventional method of orienting the solid line representing the river and the coastline and coloring one side of it. Coloring can be done. Moreover, the calculation for that becomes easy.

Roads are expressed in different colors for each scale even on the same road, and only predetermined roads (roads housed in a predetermined package) are displayed at a predetermined scale.

Symbols such as ski resorts, hotels, mountains, gas stations, and parking lots are available. The symbol data is constructed as shown in FIG. That is, the symbols are also packaged for each predetermined symbol, and end marks (eeee h) are arranged at the end portions of the predetermined number of packages. The number of symbol packages is limited to 256. In each package, the symbol serial number of 7 bits (for example, the serial number in the symbol representing the mountain) and the symbol pattern of 8 bits corresponding to each symbol (for example, the number of the mountain symbol, The number of a symbol of a hotel, such as one number, one number corresponds to one symbol) is used as a header, followed by the number of symbols (in this example, it is always 1) and the coordinates at which the symbol is displayed. Are arranged.

21 and 22 show an example in which the mountain symbol is displayed. Mountains are generally displayed as contour lines on the map. However, when represented as contour lines, not only the amount of map data increases, but especially the display device 29 used as a vehicle navigation device cannot be made too large in its screen, which makes it difficult to see. Therefore, it is preferable to display the mountain as a symbol having a relatively small shape as in the embodiment.

The place name data is structured as shown in FIG. That is, as in the case described above, the end mark (ffff h) is arranged at the end of the data in which a predetermined number of packages are collected. An 8-bit place name level is arranged as a header of the place name package. Eight kinds of place name levels are prepared, and only a place name of a predetermined place name level that is predetermined at a predetermined scale is displayed on the display device 29. Next to the place name level, the number of place names contained in the package and place name data are arranged. The location name data includes the coordinates for displaying the location name, the number of characters (up to 6), and the kanji code.

The case where the present invention is applied to the vehicle navigation device has been described above as an example. However, the application range of the present invention is not limited thereto, and the present invention stores image information other than map information in a predetermined storage medium, The present invention can also be applied to the case of reading out as needed.

〔effect〕

According to the present invention, the codes assigned to the first area to the (Y + 1) th area are the first area to the (Y + 1) th area, respectively.
Since it is related to each other in each area and is related to the actual position coordinates, it is possible to input the position coordinates of a predetermined point such as the current position and the destination from the outside by a simple calculation. Based on the retrieved data, the map information data corresponding to the desired region including the input position coordinates is searched from the first region to the (Y + 1) th region based on the retrieved data. It is possible to convert the image information into an image signal and display the map information of a predetermined area including the input position coordinates at a desired scale.

[Brief description of drawings]

FIG. 1 is a block diagram when the image display device of the present invention is applied to a vehicle navigation device, FIG. 2 is a plan view of the display device and a keyboard, FIGS. 3 to 9 are flowcharts thereof, and FIGS. FIG. 12 is an explanatory diagram for explaining the conversion of the earth coordinates into rectangular coordinates, FIG. 13 is an explanatory diagram for the data of the line segment, FIG. 14 is an explanatory diagram for the symbol data, and FIG.
FIG. 16 is an explanatory view of the place name data, FIG. 16 is an explanatory view explaining the state of the map division, FIG. 17 is a schematic explanatory view of the memory, FIG. 18 is a schematic view of reading and writing of data Explanatory diagram for explaining, FIG. 19 is its waveform diagram, FIG. 20 is its timing chart, FIGS. 21 to 24 are plan views of its display screen, and FIG. 25 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 …… Sync signal generation circuit 26, 27, 28 …… D / A conversion circuit 29 …… Display device

Front page continued (72) Inventor Masaki Kakihara, 3-1, Shinchi Fuchu-cho, Aki-gun, Hiroshima Prefecture, Mazda Co., Ltd. (72) Inventor Tadashi Masaji, 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture (56) ) Reference JP-A-58-142382 (JP, A) JP-A-58-214186 (JP, A) JP-A-61-62177 (JP, A)

Claims (1)

[Claims] 1. The map information is digitized and stored in a predetermined storage medium, the map information corresponding to the position coordinates input from the outside is read from the storage medium, converted into an image signal and displayed on a display device. In the image display device, the Xth (X = a positive integer; initial value 1) on the map corresponding to the map information is divided into n equal parts in the horizontal direction by a horizontal line and a vertical line orthogonal to the horizontal line. (N = integer of 2 or more) and divide it into n × m (X + 1) th regions divided into m equal parts (m = integer of 2 or more) in the vertical line direction Y times (Y = (A positive integer) to obtain the first to (Y + 1) th regions, and to associate the first to the (Y + 1) th regions with each other and to assign a code for associating with the actual position coordinates. It is given to each of the first area to the (Y + 1) th area, At least the data of the map information corresponding to the (Y + 1) th area and the code assigned to the first area to the (Y + 1) th area are stored in the storage medium, and the map information stored in the storage medium is stored. Data of the map information corresponding to a desired area including the input position coordinate from the first area to the (Y + 1) th area based on the input position coordinate and the code from the data Is displayed and converted into the image signal.