JPS62151890A - Image output unit - 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 an image output device for outputting and displaying a predetermined image on a display device using a computer or the like.

[Summary of the invention]

The present invention provides an image output device that includes a first memory that stores a video signal, a second memory that has a smaller capacity than the first memory that stores the video signal, and a device that draws a predetermined image in the first memory. A controller, a specifying means for specifying a part of the image drawn in the first memory, a transfer means for transferring the part of the image specified by the specifying means to a second memory, and a transfer means for transferring the part of the image specified by the specifying means to the second memory. The display device is provided with a display device for displaying the displayed image, so that the drawing operation can be performed independently of the display operation on the display device, and the number of times the drawing operation is performed is reduced.

[Conventional technology]

Recently, various images have been created using computers.

2. Description of the Related Art Image output devices that output and display images on a display device such as a CRT are becoming popular. In these devices, a predetermined image is drawn using a graphic display controller (GDC) or the like, and the data is stored in a memory such as a VRAM or a frame memory.

The image stored in the memory is then displayed on the display device.

[Problem that the invention seeks to solve]

However, in conventional devices, the image data to be displayed on the display device is directly drawn in the memory that stores it, so in order to prevent the image displayed on the display device from flickering, it is necessary to use a horizontal or vertical synchronization signal. The image had to be rewritten during the retrace interval, which had the disadvantage that rewriting took time. Furthermore, if rewriting is performed outside of this period, the image may flicker or the display screen must be erased until the drawing operation is completed, resulting in poor operability. In order to eliminate this drawback, it may be possible to provide separate memory for drawing and memory for display, but this would increase the number of times the drawing operation would be repeated if the displayed image changes relatively quickly. However, there was a drawback that the load on the arithmetic unit increased.

[Means for solving problems]

FIG. 1 is a block diagram when the image output device of the present invention is applied to a vehicle navigation device.

In the figure, 1 is a recording medium or C as a storage medium.
The D-ROM (including its drive device) records digitized map information. CD-ROM
Data from I is interface 2, address bus 3
, and stored in a memory (RAM) 5 via a data bus 4 and the like. Reference numeral 6 denotes an information processor (CPU) that processes various image data, and also operates a keyboard 12. Peripheral devices are also controlled in response to commands input via the 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 Position
This device detects the current position of the vehicle from latitude, longitude information, etc. 10 is a navigation processor (CPU), which corrects the data of the direction sensor 7, speed sensor 8, etc., calculates the amount of movement of the vehicle from these data, and also prevents the GPS device 9 from detecting latitude and longitude information. In some cases, 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 are these processors 6
．． ROM that stores 10 programs and other necessary information
, 14 is a control logic that supplies necessary timing signals to each circuit, means, device, etc.

15 is a graphic display controller (G D
C"), reads the necessary data from the memory 5,
Draw a predetermined image on Memo U (VRAM) 16.17. 18 is a parallel/serial (P/S) conversion circuit that selects data from one of the memories 16 and 17 and converts it from a parallel signal to a serial signal. 19 is a color palette register as a color conversion circuit, and P/S
1 for converting the 3-bit color signal in the video signal supplied from the conversion circuit 18 into a prespecified 5-bit color signal;
The video signal into which the color signal has been converted is stored in a memory (VRAM) 20.
Then, the video signal is 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 circuit 26 for each of the three primary colors of green (G) and blue (B)
．． 27. The digital signal is converted into an analog signal by 28.

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

24 is a synchronization signal generation circuit, which generates a mutually synchronized horizontal synchronization signal (H5YNC) and vertical synchronization signal (VSY
NC) and dot clock 07 (DCK) are generated and output to address counters 23, 25, etc., which set the addresses of the register 19, memories 2o, 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 (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 is operated to reduce or enlarge the map displayed on the display device 29. 59 is a scroll key, up and down,
When moving the cursor left and right, use keys 59a to 5, respectively.
9d is operated. Reference numeral 60 denotes a text (TEXT) key, which is operated when displaying information related to the running of the vehicle. The program when each of the above keys is operated is managed by the processor 6.

On the other hand, the CD key 61 is operated when operating the compact disc player, 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. When selecting a characteristic from among predetermined characteristics,
S E L ) key 64, muting key 65 to instantly mute the playback sound, volume 66 to adjust the volume of the playback sound, the air that is produced when the air conditioner is operated! 51 (A/C) key 67 is provided, and a predetermined operation is executed by a CPU (not shown).

(Operation) The operation will now be explained. First, the basic operation when the navigation key 51 is operated will be explained. The operation in this case is managed according to the flowchart shown in FIG. 3, for example. As a step, it is determined whether the current location has been set or not. If the current location has already been set, the display routine is executed, and if it has not been set, the current location setup routine is executed. The routine will be explained 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 a key human power, next it is determined whether there is a mode change,
When a mode change occurs, the routine shifts to that mode. Modes include navigation mode, text mode, AV mode, etc. If there is no mode change, the command is 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 where it is waiting for a key input, and the display routine is executed until there is a key input.

The routine for setting the current location is executed according to the flowchart shown in FIG. First, it is determined whether or not the cancel key 56 has been operated, and when the cancel key 56 has been operated, the current 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 (1/200,000 in this example) centered at that location is displayed.

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

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

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

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

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

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

The above reduction key 57, enlargement key 58 and set key 55
If the changes in the screen due to each operation are displayed together, the 25th
The result will be as shown in the figure. In the 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, l/400,000, 1
/2o million, 1/1o million, 1,150,000, 1/25,000, 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, not only one display is easy to see, but also operability is improved. 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 in the storage memory 5, and if not, the data is loaded onto the memory 5 from the CD-ROM 1.

1 when a map centered on the current location is stored in memory 5
Next, it is determined whether the map centered on the current location is within the range of the map drawn in memory 16 or 17, and if it is not within the range, the back side of memory 16 or 17 (memory 20
Drawing (rewriting) is performed by the controller 15 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 5, it is then superimposed on the map on the front side of the memory 16 or 17 (the one whose data is being transferred to the memory 20), and the processor 10
A vehicle mark is written by the processor 6 in accordance with the current location calculated by the processor 6, and this data is further transferred from the front side memory to the memory 20. This own army mark, for example, is a mark that allows the direction of movement to be recognized, as shown in the center of Figure 21 (the figure shows the vehicle traveling northward (upwards)). Memory 2
The map and army mark written in 0 are further stored in memory 21.
The image transferred to and stored in the memory 21 is displayed on the display device 2.
9 will be displayed. Further, after routines such as enlargement and reduction are processed, the process moves to the first 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 specified range (8000H x 80
The map data of 00H (H is a hexadecimal unit) is equally divided into four by two straight lines, the horizontal line and the line perpendicular to it.
The lower left area is 0, the lower right area is 1, and the upper left area is 2. The upper right area corresponds to the number 3, respectively. Each of the four areas is then further divided into four smaller areas, which are numbered in the same way, with the first number being represented by the first digit, the second number being represented by the second digit, and so on. are divided and numbered (file numbers). Therefore, the engineering and rear data centered on point P in Fig. 16 are 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, 1 for CD-ROM1
/80,000.

Only maps with a scale of 1/20,000, 1,150,000, and 1/12,000 are available, as well as 1/1,600,000, 1/400,000, and 1/10.
Maps at scales of 10,000 and 1/25,000.

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

Calculated as a Cartesian coordinate system.

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

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

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

The details of the step of rewriting data in the memories 16 and 17 (indicated by reference numeral B in the figure) shown in FIG. 6 are as shown in FIG. 8, for example. In other words, the memory 16 and 17 are on the back side when drawing is done by the controller 15, and the memory 2 is on the back side when drawing is completed.
The side that is transferring data to 0 is considered to be the front side, and the controller 15 always draws in the memory on the back side, and when the drawing is completed, the front side and the back side are reversed. For example, the 18th
As shown in the figure, only a part of the image drawn on the front side of the memory 16 and 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 army mark are interrupted at predetermined intervals, but once the memory 16
．． 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 front memory, 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 map exceeds the range of the map, the map centered on the current location is read out 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 vehicle's mark on the map will move, but the writing to the memory on the back will be done faster, so the map will not be displayed on the screen. This prevents parts from being displayed with missing parts.

Furthermore, in FIG. 6, the step of transferring the map drawn in the memory 16, 17 to the memory 2o (indicated by reference numeral 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 2o (FIG. 18) is displayed is temporarily saved to the memory 5. And there processor 6
In response to the command, the controller 15 draws the own army mark. At this time, the own army mark is displayed in a direction corresponding to the traveling direction of the vehicle detected by the calculation of the processor 10.

The map centered on the own army mark drawn in the memory on the front side in this manner is transferred to the memory 20. The range to be transferred is specified by the offset register 22 (and therefore the address counter 23). That is, under the control of the processor 6, the offset register 22 stores predetermined coordinate values that change in accordance with the current location. This value is the 18th
As shown in the figure, the position (X) of the dot where the controller 15 starts transferring on one horizontal scanning line, and the position (Y) of the horizontal scanning line where the controller 15 starts transferring on one field.
). Therefore, for example, focusing 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 represented range is transferred to the memory 2o.

Also, if we focus on the field, as shown in Figure 20,
When the transfer command is output from the processor 6 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 thereafter,
After counting a predetermined offset value Y, data in a range of 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 (for example, the frequency of the horizontal synchronization signal is 24.83K) of the controller 15 controlled by the processor 6 as a computer is generally the synchronization signal of the NTSC system (for example, the frequency of the horizontal synchronization signal of the NTSC system is 15.75kHz), 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.

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 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 8 types of low gradation colors represented by 3 bits are converted into any of the 32 types of high gradation colors represented by 5 bits each of R2O and B, and by appropriately mixing the 3 primary colors. It becomes possible to specify any eight types of colors from among 32,768 colors. Address counter 25 outputs a predetermined address signal 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 converted into analog signals by the D/A conversion circuits 26, 27, and 28.
It is displayed on the display device 29. As mentioned above, the maps do not overlap in the area where the own army mark is displayed.

This prevents the display of the own vehicle mark from becoming difficult to see on the screen (FIG. 21).

When the transfer from the front side memory to memory 2o 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.
1/200,000, 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 800 x 80.
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 has 640×400 dots (high resolution or large capacity), and the display memory 20.21 has 256×256 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, the displayed image is not affected by the writing operation. In this way, the display device 29 can alternatively display either an image drawn in the memory 16, 17 by the controller 15 under the control of the processor 6, or an image drawn directly in the memory 2o by the processor 6. It has become.

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 10. Therefore, in the present invention, as shown in FIG.
Multiple maps drawn for each predetermined area using a projection method such as the Transverse Mercator projection or the conical projection are mapped east to west 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 latitudes are located on the same straight line perpendicular to the horizon, so that they are located next to each other in the north-south direction, and the position on the map is specified by the orthogonal coordinates on that plane. I have to. Figure 11 (a) is an example where the lower left point of each map in a predetermined range is set as the reference point B of the latitude and longitude lines, and Figure 11 (b) is an example where the reference point B is the reference point 0 of the middle line. This is an example of B. However, in any case, when calculating the distance between two points on the map, the length per unit (for example, 10 km) latitude (longitude) at point 0 on the map 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, there is a black circle in the upper right (northeast) of the 1/200,000 scale map, and a point A2 in the upper left (northwest) that corresponds (same) to point A1 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 in a 1/20,000 scale map, for example, is a maximum of ±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 (jddd h) is arranged at the end of one 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 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, a predetermined point Z on the dashed line is used as a reference, and each dot is colored by sequentially operating horizontally from point Z 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 represented 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 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 equal straight lines on maps. However, if it is represented as equal straight lines, not only does the amount of map data increase, but the screen of the display device 29 used as a vehicle navigation device cannot be made very large, making it difficult to see. 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 Cffff is placed at the end of the data in which a predetermined number of packages are collected.
h) is placed. 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 place name data includes the coordinates where the place name should be displayed, the number of characters (up to 6), and a Kanji code.

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 an image output device including a first memory for storing video signals, a second memory having a smaller capacity than the first memory for storing video signals, and a predetermined memory for storing video signals in the first memory. a controller for drawing an image, a specifying means for specifying a part of the image drawn in the first memory, a transfer means for transferring a part of the image specified by the specifying means to a second memory, and a second memory. Since a display device is provided for displaying the image transferred to the memory, not only can the drawing operation be performed independently of the display operation on the display device, but also the number of drawing operations can be reduced. Therefore, it is suitable for displaying map information that changes from moment to moment centered on the current location of a moving vehicle.

[Brief explanation of drawings]

FIG. 1 is a block diagram when the image output 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 FIGS. Figure 12 is an explanatory diagram explaining the conversion of the earth coordinates to Cartesian coordinates, Figure 13 is an explanatory diagram of the line segment data, Figure 14 is an explanatory diagram of the symbol data, and Figure 15 is the place name data. 16 is an explanatory diagram illustrating how the map is divided; 17th @ is a schematic illustrative diagram of the memory; FIG. 18 is an explanatory diagram schematically illustrating data reading and writing; FIG. 19 is a waveform diagram thereof, FIG. 20 is a timing chart thereof, FIGS. 21 to 24 are plan views of the 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 1o...Navigation processor 11...ROM 12...Keyboard 15...
・Graphic display controller 8...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)

[Claims] a first memory that stores a video signal; a second memory that has a smaller capacity than the first memory that stores the video signal; a controller that draws a predetermined image in the first memory; a specifying means for specifying a part of the image drawn in the first memory; a transfer means for transferring the part of the image specified by the specifying means to the second memory; An image output device comprising: a display device that displays the transferred image.