JPH0423794B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a map display device that can change the display form of a map in accordance with a specified scale and density. [Prior Art] Recently, devices have been developed that display maps for driving guidance on vehicles such as automobiles. In conventional map display devices, so-called image data consisting of route information and point information is stored as map data for each map to be displayed, and is used to display a specified map. [Problems to be Solved by the Invention] For this reason, in conventional map display devices, in order to be able to enlarge or reduce the displayed map or change the coarseness or density of the map, it is necessary to There was a problem in that various types of map data were required, leading to an increase in the size of the storage medium for storing the map data. Furthermore, since it is not possible to display a map of a scale or density that is not stored as map data, there is also the problem that it is not possible to fully meet the needs of users. Therefore, the inventor of the present application has developed a map display device that can arbitrarily change the display form of the map, such as reducing or enlarging the map, or changing the coarseness or fineness, using a single piece of map data stored in advance. The following four inventions have been completed for the purpose of providing the following. [Means for Solving the Problem] That is, as illustrated in FIG. 1, the first invention of the present application displays a route by displaying connecting lines between a plurality of constituent points for forming a route, and A map display device configured to display a map by combining a plurality of routes, comprising: display means for displaying the map; designation means for designating a scale of the map to be displayed; and the plurality of combinations for forming the route. For each of the constituent points, the point coordinates defined as a point in an absolute coordinate system with the specific point as the origin and the point level that determines the relative importance of whether or not the constituent points are used for map display are memorized. storage means; area specifying means for specifying a specific area in the absolute coordinate system corresponding to a map to be displayed on the display means; , extraction means for extracting from the storage means point coordinates of constituent points having the point level that has a degree of importance to be displayed with respect to the scale; and a display coordinate system determined for the display means and the area specifying means. coordinate conversion means for converting the coordinates of each point extracted by the extraction means into display coordinates of the display coordinate system based on the relationship with the specific area specified by the coordinate conversion means; and display coordinates converted by the coordinate conversion means. A plurality of routes are formed by displaying connecting lines on the display means for each route between a plurality of display points on the display coordinate system defined by The gist of the invention is a map display device comprising: a map display control means for displaying a map on the display means at a designated scale; A map display device that displays a route by displaying lines and displays a map by multiple combinations of the routes, the device comprising: a display means for displaying the map; and a specification means for specifying the density of the map to be displayed. , For each of the plurality of constituent points for forming the route, point coordinates determined as points in an absolute coordinate system with a specific point as the origin and the relative importance of whether or not the constituent points are used for map display. storage means for storing point levels at which degrees are determined; area specifying means for specifying a specific area in the absolute coordinate system corresponding to a map to be displayed on the display means; extracting means for extracting from the storage means point coordinates of constituent points having the point level that is related to the density specified by the means and has a degree of importance to be displayed with respect to the density; and for the display means. coordinate conversion means for converting the coordinates of each point extracted by the extraction means into display coordinates of the display coordinate system based on the relationship between the determined display coordinate system and the specific area specified by the area identification means; A plurality of routes are formed by displaying connecting lines on the display means for each route between a plurality of display points on the display coordinate system defined by the display coordinates converted by the conversion means, and forming a plurality of routes. The gist of the present invention is a map display device comprising: a map display control means for displaying a map of the specific area on the display means at the specified density according to a route; a display means, a designation means for specifying the scale of the map to be displayed, and a relative importance of whether or not to use each route in the map display for each route that constitutes a map by a combination of display of a plurality of routes; a storage means that stores a route level with a defined route level and point coordinates of a plurality of points for forming the route, where the point coordinates are defined as points in an absolute coordinate system with the specific point as the origin; an area specifying means for specifying a specific area in the absolute coordinate system corresponding to a map to be displayed on the display means; and an area specifying means for specifying a specific area in the absolute coordinate system corresponding to a map to be displayed on the display means; extraction means for extracting the plurality of point coordinates for forming the route from the storage means for each route having the route level having a degree; a display coordinate system defined for the display means; coordinate conversion means for converting each of the plurality of point coordinates extracted by the extraction means into display coordinates of the display coordinate system based on the relationship with the specific area specified by the area specification means; A plurality of routes are formed by displaying connecting lines on the display means for each route between a plurality of display points on the display coordinate system defined by the display coordinates that have been coordinate-converted, and the plurality of routes are used to The gist of the present invention is a map display device comprising: map display control means for displaying a map of a specific area on the display means at the designated scale; , a specification means for specifying the density of the map to be displayed, and a relative importance of whether or not to use the route in the map display for each route that constitutes a map by combining the display of a plurality of routes. a storage means storing a route level and point coordinates of a plurality of points for forming the route, where the point coordinates are defined as points in an absolute coordinate system with a specific point as the origin; and the display means. area specifying means for specifying a specific area in the absolute coordinate system corresponding to a map to be displayed on the map; and an area specifying means for specifying a specific area in the absolute coordinate system, which corresponds to a map to be displayed on the map, and a degree of importance to be displayed for the density in relation to the density specified by the specifying means. extraction means for extracting the plurality of point coordinates for forming the route from the storage means for each route having the route level; and a display coordinate system defined for the display means and the area specifying means. coordinate conversion means for converting each of the plurality of point coordinates extracted by the extraction means into display coordinates of the display coordinate system based on the relationship with the area specified by the coordinate conversion means; A plurality of routes are formed by displaying connecting lines on the display means between a plurality of display points on the display coordinate system defined by the display coordinates for each route, and a map of the specific area is formed by the plurality of routes. The gist of the present invention is a map display device comprising a map display control means for displaying the map on the display means at the designated density. [Operation] In the first invention of the present application configured as described above, when the specifying means specifies the scale of the map to be displayed, the extracting means first selects the important map to be displayed for the specified scale. The coordinate conversion means converts each of the extracted point coordinates into display coordinates in the display coordinate system, and displays the coordinates on the map. The control means displays connecting lines between display points defined by the display coordinates based on the display coordinates obtained by the coordinate conversion, and displays a map for the area specified by the area specifying means at a specified scale. Display on means. Further, in the second invention of the present application, when the density of the map to be displayed is specified by the specifying means, the extracting means first extracts absolute coordinates having a point level having a level of importance to be displayed with respect to the specified density. The point coordinates of the constituent points in the system are extracted from the storage means, the coordinate conversion means converts each of the extracted point coordinates into display coordinates in the display coordinate system, and the map display control means converts the coordinates into display coordinates in the display coordinate system. Based on the display coordinates, connecting lines are displayed between display points defined by the display coordinates, and a map for the area specified by the area specifying means is displayed on the display means at a specified density. Furthermore, in the third invention of the present application, when the specifying means specifies the scale of the map to be displayed, the extracting means first selects the route level that has the importance to be displayed for the scale specified by the specifying means. For each route having , a plurality of point coordinates for forming the route are extracted from the storage means, and the coordinate conversion means converts each of the extracted point coordinates into display coordinates in a display coordinate system, The map display control means forms a plurality of routes by displaying connecting lines for each route between the display points defined by the display coordinates based on the display coordinates obtained by the coordinate conversion, and the area specifying means uses the plurality of routes. A map for the area specified in is displayed on the display means at the specified scale. Furthermore, in the fourth invention of the present application, when the density of the map to be displayed is specified by the specifying means, the extracting means first selects a route having a degree of importance to be displayed with respect to the density specified by the specifying means. For each route having a level, extract coordinates of a plurality of points for forming the route from the storage means,
The coordinate conversion means converts each of the extracted point coordinates into display coordinates in the display coordinate system, and the map display control means converts each of the extracted point coordinates into display coordinates in the display coordinate system.
A plurality of routes are formed by displaying connecting lines for each route between the display points defined by the display coordinates, and a map for the area specified by the area specifying means is displayed at a specified density using the plurality of routes. Display on means. [Example] Hereinafter, with reference to the drawings after FIG.
An embodiment of a vehicle map display device to which the fourth invention is applied will be described. FIG. 2 shows a block diagram of this embodiment. In the figure, 1 is a display for displaying a map, 2 is a map data storage medium in which predetermined map data is stored in advance, 7 is an operating unit operated by a driver etc. when using the device, 8 9 is a direction sensor that detects the traveling direction of the vehicle, that is, the geomagnetic direction relative to the own vehicle; 9 is a distance sensor that detects the distance traveled by the vehicle; 10 is a CPU, ROM, RAM,
Microcomputer 10-1 consisting of I/O etc.
and a display controller 10-2, each representing a control device that functionally executes arithmetic processing and display control. The operation unit 7 has an enlargement key for instructing to enlarge the currently displayed map by one rank, a reduction key for reducing the currently displayed map by one rank, and a reduction key for making the currently displayed map sparse by one rank. It has a sparse key for , and a dense key for making the currently displayed map one rank denser. The direction sensor 8 is a ring-shaped permalloy core,
It includes an excitation coil and two coils orthogonal to each other, and outputs an azimuth signal to the control device 10 for detecting the traveling direction of the vehicle relative to the earth's magnetism based on the output voltages of the two coils. The distance sensor 9 indirectly detects the rotation of the speedometer cable as an electrical signal using a reed switch, magnetic sensing element, or photoelectric conversion element, or detects the rotation of the output shaft of the transmission as an electrical signal using the same means as described above. A distance signal used in calculating the distance traveled by the vehicle is output to the control device 10. The map data storage medium 2 is a ROM (Read Only
Memory) consists of a package. The data structure of the map data stored in advance in the map data storage medium 2 is, for example, as shown in FIG. , a route information column 13 related to routes such as national highways, and an article information column 14 related to various services. The point information string 12 has prefecture point information strings for prefectures belonging to the region, such as the Aichi prefecture point information string 15 for Aichi Prefecture. It has city point information strings for cities belonging to the prefecture, such as Nagoya city point information string 16 for Nagoya city to which it belongs, and among the city point information strings, for example, Nagoya city point information string 16 is the main points belonging to Nagoya city. Point information about 17-1, 17
It has a point information group consisting of -2,..., and each point information 17-1, 17-2 has a point number, point level,
It consists of information on the point type, the X component, and the Y component of the earth coordinates of the point. The route information string 13 includes #1 route information string 18-1, #2 route information string 18-2,...
..., #N route information string 18-N, and 1 for these route information strings 18-1, 18-2, ..., 18-N.
Pointers 19-1, 19-2, ... corresponding to pair 1
..., 19-N, each route information string 18-
1, 18-2, . . . , 18-N consists of a route number, a route level, a route type, a group of point numbers for points forming the route, and the end of the route. The article information column 14 is the intersection name information column 20-
1. Route name information string 20-2, ..., landmark name information string 20-M, and these name information strings 20-1,
It consists of pointers 21-1, 21-2, ..., 21-M that correspond one-to-one to points 20-2, ..., 20-M, and the intersection name information string 20-1 is a point number,
Name level, intersection information 21-1 of intersection name,
It has an intersection information group consisting of 21-2,...,
The route name information column 20-2 includes route information 22-1, 22- of route number, name level, and route name.
The landmark name information string 20-M has a landmark information group consisting of landmark information 23-1, 23-2, . . . of point number, name level, and landmark name. . Here, the above route types are national roads, expressways,
It indicates the type of route such as general road, railway, coastline, etc. The above point types include general intersection, grade-level intersection of general road, interchange,
This indicates the type of point, such as an intersection between a general road and an expressway, or an intersection between a general road and a railway. The control device 10 receives an instruction signal from the operation unit 7, a direction signal from the direction sensor 8, a distance signal from the distance sensor 9, and map data from the map data storage medium 2, and performs a predetermined process as described later in FIG. In addition to executing the processing, it also performs display control on the display 1 and outputs a video signal to the display 6. Display 1 is CRT (Cathode Ray Tube)
A map and the like are displayed on the display screen by a video signal from the control device 10. In the above configuration, the relationship between the level information in the map data on the map data storage medium 2 and the size specified by key operation is as shown in the following table (a).

[Table] To be more specific, if size 0, which corresponds to a scale of 1/1 million, is specified by operating the enlargement key or reduction key, only routes and points for which "0" is given as level information in advance will be displayed. If size 1, which corresponds to a scale of 1/500,000, is specified as an object that can be displayed on display 1, only routes and points whose level information is "0" or "1" will be displayed, and other The relationship between the size specification and the display target is also the same as above. Normally, the relationship between size and level is as shown in table (a) above, but when a sparse key or a dense key is operated, the relationship between the two is determined by one operation of each key. ), (c) are updated. Note that the table (b) corresponds to the case where the secret key is operated once.

【table】

[Table] To be more specific, for example, if a sparse key is operated once when a map corresponding to size 3 is currently displayed, the previous level will be set to "0",
Points or routes with levels ``1'', ``2'', or ``3'' were to be displayed, but points or routes with levels ``0'', ``1'', or ``2'' were displayed. Therefore, level 3 points or routes are excluded from display targets, and the displayed map becomes sparse. On the other hand, when the secret key is operated once while a map designated as size 3 is displayed, a new level "4" point or route is added to the display target.
The displayed map becomes denser. Next, an example of the transition of the display form of the display 1 will be described with reference to FIGS. 4a to 4c and 5a to 5c. When it is specified that the displayed map should be enlarged by the operator's key operation or the internal processing of the control device 10,
For example, if a map as shown in FIG. 4a is currently being displayed, the control device 10
The enlargement process is performed on the area A surrounded by the broken line in the figure, and the map on the first screen of the display is relatively detailed as shown in FIG. 4b, for example. After that, when further enlargement is specified, the enlarging process for the broken line enclosing area B in Fig. 4b is executed, and a more detailed map as shown in Fig. 4c is displayed on the display 1 screen. Make it. Note that points a and b in FIG. 4a represent the same points as points a and b in FIG. 4b, respectively, and points a to h in FIG. 4b represent the same points as points a to h in FIG. 4c, respectively. On the other hand, when it is specified that the displayed map should be reduced, a transition in the display form is performed that is opposite to the transition in the display form caused by the enlargement process as described above. That is, the display map shown in Fig. 4c is changed to the display map shown in Fig. 4b,
Furthermore, the display map is changed to that shown in FIG. 4a. Further, when it is specified that the displayed map should be made denser by the operator's key operation or by the internal processing of the control device 10, if the map shown in FIG. 5a is currently being displayed, the control device 10 Densification processing is executed so that a comparatively detailed map as shown in FIG. 5b, for example, is displayed on one screen of the display. After that, when further densification is specified, further densification processing is executed, for example, the 5th c.
A more detailed map as shown in the figure is displayed. Note that points a' to g' in Fig. 5a
represent the same points as points a' to g' in Fig. 5b, respectively, and points a' to g' in Fig. 5b, respectively.
o' represent the same points as points a' to o' in FIG. 5c, respectively. On the other hand, when it is specified that the displayed map should be made sparse, a transition in the display format is made that is opposite to the transition of the display form due to the densification process as described above. That is, the displayed map shown in FIG. 5c is changed to the displayed map shown in FIG. 5b,
Furthermore, the display map is changed to that shown in FIG. 5a. Next, the processing operation of this embodiment will be explained with reference to the schematic flowchart shown in FIG. Note that the following explanation will be given by taking as an example a case where enlargement is specified by an operator's key operation. When the operator operates the enlargement key of the operation section 7, the microcomputer 10-1 of the control device 10 starts processing as shown in FIG. First, step 101 is executed to read out the contents of the head pointer 19-1 in the route information string 13 of the map data storage medium 2. Next, step 102 is executed and all pointers 19-
It is determined whether the contents of 1 to 19-N have been read. At this point, the contents of the head pointer 19-1 have just been read, so the judgment result is "NO".
Then, step 103 is executed. In step 103, the root level information of the #i root information string (#1 root information string 18-1) pointed to by the #i pointer (first pointer 19-1 at this point) is read. Here, the root level information can be thought of as the relative importance assigned to each route. Next, step 104 is executed to determine whether the root level is a displayable level, in other words, the #i root (#1 root) has the importance to be displayed for the specified size as described above. Determine whether it is the root or not. If the #i route (#1 route) is a route that does not need to be displayed, step 105 is executed to update the pointer, that is, read the contents of the next pointer (#2 pointer 19-2), and step 102 is executed.
Return to On the other hand, if #i route (#1 route) is the route to be displayed, then step 106 is executed,
#i route information string (#1 route information string 18-1)
Read route type information. Next, step 107 is executed to read the point number information (at this point, the first point number information) of the #i route information string (#1 route information string 18-1). Next, step 108 is executed to determine whether the route end information of the #i route information sequence (#1 route information sequence 18-1) has been read out. At this point, since the first point number information has just been read out, the judgment result is "NO", and then step 109 is executed to find the point information string 12 that matches the point number (first point number). Reads the point level information given to the point number,
It is determined whether the point has a degree of importance that should be displayed for the specified size as described above. Even if this point is not displayed, if it is a good point, the process returns to step 107 and reads out the next point number in the #i route information string (#1 route information string 18-1). On the other hand, if this point is the point to be displayed, then step 110 is executed to determine whether it is the first point number extracted in the #i route information string (#1 route information string 18-1). to judge. At this point, since it is the first point number, the judgment result is "YES" and the next step is step 111.
to 114, read the earth coordinate X component and earth coordinate Y component of this point, convert this earth coordinate point (X, Y) to a display coordinate point (X1, Y1),
Furthermore, the area A to which the display coordinate point (X1, Y1) belongs is determined. The above coordinate conversion process is performed using the seventh coordinate system representing the earth coordinate system.
As shown in Figure A and Figure 7B showing the display coordinate system, first, (1) the shaded area in the display coordinate system (corresponding to the map display area of the display 1);
(MPOS,
(BPOS), then (2) the found point (MPOS,
Displays the earth coordinates (LPOS, APOS) of the current target point based on the point (X1, APOS) of the coordinate system.
Coordinates are converted to Y1). Here, the above points (MPOS, BPOS) are obtained as follows. First, the current location or the center point of the administrative district point group in the case of administrative district designation (9th
Figure a) is determined as the display map center coordinates (MAPCENX, MAPCENY) in the earth coordinate system, and then this coordinate information MAPCENX, MAPCENY,
Number of dots a and b on the map display screen of display 1
(Figure 9b), the number of dots per unit longitude LDOT determined according to the specified size, and the number of dots per unit latitude ADOT are used as parameters: MPOS=MAPCENX-b/LDOT BPOS=MAPCENY+a/ADOT Find the point (MPOS, BPOS) from The point (X, Y) is found from the following equation: X1=(LPOS-MPOS)×LDOT Y1=(BPOS-APOS)×ADOT. The coordinates of the center point of the administrative district designation map shown in Figure 9a can be calculated from the earth coordinates of the four points (α, β, γ, δ) of the administrative district at the east end, west end, north end, and south end using the following formula MAPCENX=( It is determined by MAPCENY = (Longitude of the east end - Longitude of the west end) /2 MAPCENY = (Latitude of the north end - Latitude of the south end) /2. On the other hand, the area determination process is performed at the display coordinate point (X1, Y
1) is divided into areas O as shown in FIG. 8a.
This is done by determining which region it belongs to. In addition, in this FIG. 8a, the area corresponds to the diagonally shaded area shown in FIG. 7b, that is, the map display area. In step 114 described above, the display coordinate point (X1, Y
Once the area A to which 1) belongs is determined, the next step is
Returning to step 107, the next point number in the #i route information string (#1 route information string 18-1) is read. Next, step 108 is executed and it is determined whether the route has ended or not. If the route has not ended, the next step is executed.
109 is executed, and it is determined whether the point level of this point number is a displayable level or not. If it is not a displayable level, the process returns to step 107. On the other hand, if it is a displayable level, step 110 is executed next. death,
It is determined whether this point number is the first point number extracted in the #i route information string (#1 route information string 18-1). At this point, the first point number has already been extracted, so the judgment result is "NO", and steps 115 to 118 are then executed sequentially, and the same process as steps 111 to 114 above is performed. Processing takes place. In other words, this point number (#j
Display the earth coordinates (X, Y) of the point number)
2, Y2) and display coordinates (X2, Y2).
2) Find the region B to which it belongs. Next, execute step 119 and set the point (X1, Y1)
It is determined whether or not to perform a connected display of and point (X2, Y2), that is, whether or not the area A and the area B have a specific relationship. Here, as shown in FIGS. 8a and 8b, this judgment process is performed, for example, if the display coordinates (X1, Y1) belong to the 0th area,
and other display coordinates (X2, Y2) are 0th,
, , if it belongs to any of the areas, it does not have a specific relationship (
Indicated by a mark. ), and display coordinates (X1, Y
1) belongs to the 0th area and other display coordinates (X
2, Y2) belongs to any of the regions, it is determined that they have a specific relationship (indicated by a circle in FIG. 8b).
Other combinations are as shown in FIG. 8b. If area A and area B do not have a specific relationship, then steps 120 to 121 are executed;
Area update processing and coordinates (X
1, Y1) to (X2, Y2) is performed, and the process returns to step 107. On the other hand, if there is a specific relationship, then step 122 is executed, and the point (X1, Y1) and the point (X2,
Y2) is displayed on the display screen according to the route type. That is, for example, if route #i (route #1) is a national highway, the route is displayed with higher brightness than other routes. Then, steps 120 and 121 are executed to perform area update processing and coordinate update processing, and the process returns to step 107. From then on, until the end of route #i route (#1 route) is read, the route consisting of steps 107, 198, 109 or steps 107, 108, 109 and steps 110, 115 or 122 (excluding 122 in some cases) ) is selected and executed, and the route for #i route (#1 route) is displayed. Then, when the end of route #i route (#1 route) is read out, the determination result of step 108 is reversed to "YES", so step 105 is executed next, the pointer is updated, and the next route ( The processing for route #2) is performed in the same way as the processing for route #1. Thereafter, the same processing as above is executed for each route information string in sequence, and when the processing for #N route information string 18-N is completed, it is determined in step 102 that the contents of all pointers have been read,
The process shown in FIG. 6 is completed. As is clear from the above description, the control device 10
When receiving an enlargement designation from the switching means, for example, the operation unit 7, the map data storage medium 2 selects a route having a level corresponding to the designation from among the route information strings in the map data storage medium 2 and corresponds to the designation. Extract points with a level, perform coordinate transformation on the extracted points, judge whether two adjacent points have a specific relationship, and if they have a specific relationship, change the coordinates according to the route type. Connects and displays two points using brightness. Therefore, when the display mode is the scale mode of enlargement or reduction, the display pattern as shown in FIGS. 4a to 4c can be displayed in the sparse,
If it is in the dense mode, see Figures 5a to 5.
A display pattern as shown in Figure c can be obtained. Note that the display is not limited to CRT, but can also include liquid crystal,
It may be a display device such as EL. Further, although ROM is shown as the map data storage medium, magnetic tape, magnetic disk, magnetic valve, etc. may also be used. Needless to say, in this case, a reading device is required to read the map data. Furthermore, although a direction sensor that detects the earth's magnetic field is shown, a gyro type sensor that detects the relative direction of movement of the vehicle may also be used. Further, in the above embodiment, the earth coordinates are given as absolute longitude and absolute latitude, but the present invention also includes cases in which the coordinates of a point are expressed as spherical coordinates for a specific point (for example, Tokyo) or orthogonal coordinates for a specific point. . Note that the above-mentioned terrestrial coordinates, spherical coordinates, and orthogonal coordinates correspond to absolute coordinates with a specific point as the origin. In addition, when comparing each component described in the claims with the description of the embodiment, the enlargement key, reduction key, sparse key, and dense key of the operation unit 7 correspond to the designation means, and the display 1 corresponds to the display means. Correspondingly, the current value or the center point and size of the administrative district corresponds to the area specifying means, the processing in steps 113 and 117 in Fig. 6 corresponds to the coordinate conversion means, and steps 119 and 122 in Fig. 6 correspond to the display control. It corresponds to the means. [Effects of the Invention] According to the present invention, a so-called vector map data structure is realized in which a route is displayed by displaying connecting lines between a plurality of constituent points for forming a route, and a map is displayed by a plurality of combinations of the routes. By doing so, it is possible to display a map with a smaller storage capacity of map data than in the case of a conventional image data structure, and furthermore, each invention described in the claims has the following effects. . According to the invention described in claim 1, by extracting points according to the scale of the map, it is possible to create a route shape according to the scale. According to the invention described in claim 3, by selecting a route according to the scale of the map, it becomes possible to selectively display a route according to the scale. According to the invention described in claim 4, by selecting a route according to the density of the map, it becomes possible to selectively display a route according to the density.

[Brief explanation of drawings]

Figure 1 is a diagram showing the overall configuration of the present invention, Figure 2 is a diagram showing the overall configuration of the present invention.
Figures 8 to 8b show an embodiment of the present invention, Figure 2 is a block diagram, Figure 3 is a configuration diagram of map data, and Figures 4a to 4c are display formats when the display mode is scale mode. Figures 5a to 5c are diagrams showing the display form when the display mode is density mode, Figure 6 is a flowchart for explaining the processing operation, and Figures 7a and 7b are Figures 8a and 8b are diagrams for explaining the coordinate transformation from the earth coordinate system to the display coordinate system, Figures 8a and 8b are diagrams for explaining the connection conditions between two points in the display coordinate system, and Figure 9a
9 and 9b are explanatory diagrams for explaining a method for determining the earth coordinates (MPOS, BPOS) corresponding to the origin (O, O) of the map display screen, respectively. DESCRIPTION OF SYMBOLS 1...Display, 2...Map data storage medium, 7...Operation unit, 8...Direction sensor, 9...Distance sensor, 10...Control device, 10-1...Microcomputer, 10-2... display controller.

Claims (1)

[Scope of Claims] 1. A map display device that displays a route by displaying connecting lines between a plurality of constituent points for forming a route, and displays a map using a plurality of combinations of the routes, comprising: a display means for displaying a map; a specifying means for specifying a scale of the map to be displayed; and a display means for specifying the scale of the map to be displayed; a storage means that stores determined point coordinates and a point level that determines the relative importance of whether or not to use the constituent points for map display; and the absolute coordinate system that corresponds to the map to be displayed on the display means. area specifying means for specifying a specific area within the area; and for each route, constituent points having the point level that is related to the scale specified by the specifying means and has a level of importance to be displayed for that scale. each point extracted by the extraction means from the relationship between the display coordinate system determined for the display means and the specific area specified by the area identification means; a coordinate conversion means for converting coordinates into display coordinates of the display coordinate system; and a coordinate conversion means for converting the coordinates into display coordinates of the display coordinate system; map display control means for displaying a connecting line on the display means for each route to form a plurality of routes, and displaying a map of the specific area on the display means at the specified scale based on the plurality of routes. Map display device. 2. A display means for displaying a map, which is a map display device that displays a route by displaying connecting lines between a plurality of constituent points to form a route, and displays a map using a plurality of combinations of the routes. and specifying means for specifying the density of the map to be displayed; point coordinates and points defined as points in an absolute coordinate system with the specific point as the origin for each of the plurality of constituent points for forming the route; a storage means for storing a point level that determines the relative importance of whether or not to use the constituent points for map display; an area specifying means for specifying; and for each route, storing point coordinates of constituent points having the point level that is related to the density specified by the specifying means and has a degree of importance to be displayed for the density. An extraction means extracts the coordinates of each point extracted by the extraction means from the relationship between the display coordinate system determined for the display means and the specific area specified by the area identification means, in the display coordinate system. coordinate conversion means for converting the coordinates into display coordinates; and a coordinate conversion means for converting the coordinates into display coordinates of A map display device comprising: a map display control means for displaying connecting lines to form a plurality of routes, and for displaying a map of the specific area on the display means at the designated density using the plurality of routes. 3. Display means for displaying a map, specification means for specifying the scale of the map to be displayed, and for each route that constitutes a map by combining the display of multiple routes, whether or not that route is to be used for map display. A route level that determines the relative importance of a route and point coordinates of multiple points to form that route, where these point coordinates are determined as points in an absolute coordinate system with a specific point as the origin. area specifying means for specifying a specific area in the absolute coordinate system corresponding to a map to be displayed on the display means; extracting means for extracting the plurality of point coordinates for forming the route from the storage means for each route having the route level that has a degree of importance to be displayed; coordinate conversion means for converting each of the plurality of point coordinates extracted by the extraction means into display coordinates of the display coordinate system based on the relationship between the display coordinate system and the area specified by the area specification means; A plurality of routes are formed by displaying connecting lines on the display means for each route between a plurality of display points on the display coordinate system defined by the display coordinates converted by the coordinate conversion means, and forming a plurality of routes. map display control means for displaying a map of the specific area on the display means at the designated scale according to the route. 4. A display means for displaying a map, a specifying means for specifying the density of the map to be displayed, and for each route that constitutes a map by combining the display of multiple routes, whether or not that route is to be used for map display. A route level that determines the relative importance of a route and point coordinates of multiple points to form that route, where these point coordinates are determined as points in an absolute coordinate system with a specific point as the origin. area specifying means for specifying a specific area in the absolute coordinate system corresponding to a map to be displayed on the display means; extracting means for extracting the plurality of point coordinates for forming the route from the storage means for each route having the route level that has a degree of importance to be displayed; coordinate conversion means for converting each of the plurality of point coordinates extracted by the extraction means into display coordinates of the display coordinate system based on the relationship between the display coordinate system and the area specified by the area specification means; A plurality of routes are formed by displaying connecting lines on the display means for each route between a plurality of display points on the display coordinate system defined by the display coordinates converted by the coordinate conversion means, and forming a plurality of routes. map display control means for displaying a map of the specific area on the display means at the designated density according to the route.