JP3576305B2 - Map display device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a map display device capable of displaying a bird's-eye map obtained by converting a planar map into a display format based on a bird's-eye view method.
[0002]
BACKGROUND OF THE INVENTION
In this specification, a vehicle road map display device will be described as an example. 2. Description of the Related Art When a road map is displayed on a display device, a vehicle map display device that displays a road map by a so-called bird's-eye view method that displays a road map around a current location of a vehicle at a greater magnification than a distant place is known ( For example, see JP-A-2-244188). The device disclosed in the above publication places a viewpoint behind the current position of the vehicle, and displays a state in which the vehicle looks down in the traveling direction from the viewpoint on a screen of a display device. When such a map display based on the bird's-eye view method (hereinafter, a map displayed by the bird's-eye view method is referred to as a bird's-eye map and distinguished from a plan map displayed as a plan view), map information around the current location is displayed in an enlarged manner. Since it is possible to display a wide area from the current position to a distant place, it is easy to visually grasp the connection status of the road map. In addition, it is possible to display a realistic road map as if the driver were looking down at the road map.
[0003]
In Japanese Patent Application No. 6-277379, the applicant divided the screen area of the display monitor into upper and lower parts, and in the lower area, a bird's-eye view road map using map data and various names such as prefecture names and road names were used. A map display device is proposed in which data is displayed, a sky is displayed in an upper region, and a sense of perspective and depth is expressed by a road map displayed in a bird's eye view.
[0004]
SUMMARY OF THE INVENTION An object of the present invention is to provide a map display device that displays various data such as a symbol or a pattern imitating a mountain with a bird's-eye view map in the lower area of the screen and a mountain in the upper area against the sky without discomfort.
[0005]
[Means for Solving the Problems]
The present invention provides a map storage means for storing map data relating to a plane map and various data having display coordinate positions associated with the plane map, and a predetermined look-up direction in a predetermined look-down direction so that a map by a bird's eye view method is displayed. A bird's-eye map data conversion unit that reads map data of a bird's-eye map drawing range that spreads out from a map storage unit and converts the map data into bird's-eye map data based on the bird's-eye view method, and a map based on the bird's-eye view method based on the bird's-eye map data along with various data. The present invention is applied to a map display device having a display monitor for displaying.
(1) Then, the screen area of the display monitor is divided into upper and lower parts, the lower area displays a road map and various data based on the map data of the bird's-eye map drawing range, and the upper area displays various data against the sky. And display control means for displaying, when various data is found in a predetermined range in the direction of looking down from the bird's-eye map drawing range, the various data is displayed in contact with the upper region in contact with the boundary with the lower region. Correction means for correcting the display coordinate position of various data as described above.
(2) Mountain data representing a mountain pattern can be used as various data.
(3) When there are a plurality of mountain data, it is desirable to perform drawing by superimposing in order from the farther mountain data to the closer mountain data.
(4) The various data can be name data representing a name.
(5) The bird's-eye view map data conversion means sets the viewpoint above the current location on the planar map, and determines assuming a case where the planar map is looked down from the viewpoint at a predetermined looking down angle and a predetermined spread angle in a predetermined looking down direction. The map data read from the trapezoidal bird's-eye map drawing range on the flat map can be converted to bird's-eye map data.
(6) The bird's-eye map data conversion means includes clipping means for clipping a rectangular area including a trapezoidal bird's-eye map drawing range, and the correction means uses a long side and a rectangular area of the trapezoidal bird's-eye map drawing range. Various data may be searched for in the enclosed area.
(7) The various data have map coordinate positions on a planar map, and the display control means can convert the map coordinate positions into display coordinate positions and display the various data at the display coordinate positions.
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a block diagram of an embodiment in which a map display device according to the present invention is applied to a vehicle navigation device. In FIG. 1, reference numeral 1 denotes a current position detecting device for detecting a current position of a vehicle, for example, a direction sensor for detecting a traveling direction of the vehicle, a vehicle speed sensor for detecting a vehicle speed, and a GPS signal from a GPS (Global Positioning System) satellite. It consists of a GPS sensor and the like. Reference numeral 2 denotes a map storage memory for storing data relating to a planar road map, which is composed of, for example, a CD-ROM and a reading device therefor. The road map data stored in the map storage memory 2 mainly includes road data, name data, background data, and the like on a planar map.
[0007]
Reference numeral 3 denotes a control circuit for controlling the entire apparatus, which comprises a microprocessor and its peripheral circuits. Reference numeral 4 denotes an input device having various switches for inputting a destination of the vehicle and the like, and is arranged around a display screen in this example. Note that, as a remote control method, a command may be transmitted to the control circuit wirelessly or wired. Here, the detail / wide area switches 4a and 4b are switches for displaying the display map in detail or for wide area display. In this example, switching from the most detailed to the widest area is possible in five steps, and in the case of a bird's-eye map display, the height of the viewpoint described later is set to 350 m, 700 m, 1400 m, 2800 m, and 5600 m for each step. .
[0008]
Reference numeral 5 denotes a plane map data memory for storing plane road map drawing data for displaying the plane road map viewed from directly above. The plane map drawing data is plane road map data read from the map storage memory 2. Created based on Reference numeral 6 denotes a bird's-eye map data memory for storing bird's-eye map drawing data for displaying a plane road map in a bird's-eye view method. The bird's-eye map drawing data is created based on the plane road map data read from the map storage memory 2. Is done. Reference numeral 7 denotes an image memory for storing image data to be displayed on a display monitor 8, which will be described later. This image data is created from data for drawing a planar map or drawing a bird's-eye map. The image data stored in the image memory 7 is read as appropriate and displayed on the display monitor 8. Reference numeral 9 denotes a storage memory for storing a code representing a mountain pattern described later.
[0009]
The road map data stored in the map storage memory 2 mainly includes road data, name data, background data, and the like, and each has a predetermined data structure. The road data is data for displaying various roads. Name data includes names of administrative divisions such as prefectures and cities, names of roads such as expressways and national roads, names of railways such as railway lines and stations, and names of water systems such as rivers, lakes, and harbors. In addition to the names of mountains, bridges, and tunnels. Background data is structures, railways, seas, rivers, parks, and the like. In this embodiment, the main mountain design is stored in the storage memory 9 separately from the background data. In addition, besides the mountains, symbols of terrain with a certain height such as hills, as well as symbols of large structures, bridges, iron towers and other structures that are very noticeable in the surrounding situation are displayed in a plane or three-dimensionally. In this case, it can be stored in the storage memory 9 in the same manner as the mountain pattern.
[0010]
The road data has four types of map data having different scales. The road data with the largest scale showing the narrow streets in detail is called Level 1, and the road data with the smallest scale showing only major roads is called Level 4, Between level 4 and level 2, map data of level 2 and level 3 are provided. The name data has two types of data having different numbers of data. Name data in which various names are stored in detail is called level 2, and name data in which only the names of prefectures and major roads are stored is called level 4.
[0011]
The structure of the road data will be described with reference to FIG. 2 showing the data structure of the road data stored in the map storage memory 2 and FIG. 3 showing an example of the road data. As shown in FIG. 2, the road data is divided into three data areas of "point", "data type", and "X1, Y1...". In the “data type” area, for example, codes indicating the road type of each road, such as “001” for an expressway and “011” for a national road, are stored. In the “X1, Y1...” Area, for example, as shown in FIG. 3, the road is represented by five straight road elements, and XY coordinates of the start point and the end point of the five road elements are stored. . The number of coordinates stored in the “X1, Y1...” Area changes depending on the number of intersections, the number of curves, and the like, and the total number of coordinates is stored in “point”. The map storage memory 2 stores name data composed of the above-mentioned name and XY coordinates indicating the display position. The symbol storage memory 9 stores symbol data including a code representing a symbol imitating the above-described mountain and XY coordinates indicating a display position thereof. FIG. 6 shows the structure of symbol data composed of symbols of Mt. Fuji and Mt. Hoei and position coordinates on the map.
[0012]
FIG. 4 is a diagram for explaining the outline of the bird's-eye view map displayed on the display monitor 8. FIG. 4 shows an example in which the road map is an XY plane, the viewpoint M is placed on the Z axis orthogonal to the XY plane, and the angle of looking down from the viewpoint M is φ. The illustrated rectangle abcd indicates the display range of the display monitor 8 so as to be enlarged and displayed in FIG. 5, and the trapezoid ABCD of FIG. 4 indicates the road map range displayed on the display monitor 8. Conversion to bird's-eye view map data is performed as follows.
[0013]
That is, the height Z of the viewpoint M, the angle of view φ from the viewpoint M, and the spread angle 2θ from the viewpoint are determined so that all the road map data in the trapezoidal area ABCD of FIG. 4 can be displayed on the display monitor 8. Using these parameters, bird's-eye view map data projected on the rectangular area abcd in FIG. 5 is created. At this time, the look-down angle φ is set such that the vicinity of the center line connecting the middle points of the upper side and the lower side of the display screen of the display monitor 8 is approximately 1.2 km ahead of the vehicle.
[0014]
According to FIG. 4, a wide-area road map can be displayed by a bird's-eye view map, and the road map on the lower side ab of the display monitor 8 is displayed at a larger scale than that on the upper side cd, that is, enlarged, so that the current position of the vehicle is displayed. Is displayed on the lower side ab, the vicinity of the current position can be displayed in a larger scale. Therefore, the driver can grasp the road map information around the present location in detail, and can also grasp the wide area road map in the direction of the destination at the same time.
[0015]
When a road map is displayed by the bird's-eye view method, road map data in a display format by the bird's-eye view method (hereinafter, referred to as bird's-eye map data) may be stored in the map storage memory 2 in advance, but the data amount becomes enormous. I will. Therefore, in the present embodiment, normal, that is, planar road map data (hereinafter, referred to as planar map data) stored in the map storage memory 2 is converted into bird's-eye map data by software processing, and stored in the bird's-eye map data memory. 6, and a part of the data is transferred to the image memory 7 and displayed on the display monitor 8.
[0016]
As shown in FIG. 7, in the present embodiment, the display range of the display monitor 8 is divided into four regions. When the X-axis direction of the display screen of the display monitor 8 is 500 dots, the Y-axis direction is 400 dots, and the lower left corner of the screen is the origin of the coordinates, the first area of the four areas has the coordinates in the Y-axis direction. The range of 0 to 200 dots, the second area has a range of 200 to 300 dots in the Y-axis direction, the third area has a range of 300 to 350 dots in the Y-axis direction, and the fourth area has coordinates of the Y-axis direction. Is in the range of 350 to 400 dots. The first to third areas are defined as a road map display area, and the fourth area is defined as an empty display area.
[0017]
Further, in the present invention, a pattern or a city name imitating a mountain, a hill, a large structure, or the like that is farther than an area located in the third area of the display screen is displayed in the fourth area. Hereinafter, for simplicity, a case will be described in which a symbol imitating a mountain and a city name are displayed in the fourth area. In order to perform such display, as shown in FIG. 4, a rectangular area CDGH in contact with the long side of the trapezoidal area ABCD described above is set, and a symbol imitating a mountain located in the rectangular area CDGH is stored in a symbol memory memory of the mountain. 9 and a city name from the map storage memory 2 and display it in the fourth area. Further, if the display coordinates of the mountain data and the city name data located in the rectangular area CDGH are used as they are, the mountain design and the city name will float in the air as shown in FIG. The Y coordinate positions are corrected so as to be in contact with the boundary between the third area and the fourth area.
[0018]
As described above, since the scale is gradually increased toward the upper side of the screen, the level of the planar map data used for the bird's-eye view map data of each area is changed depending on the size of the area to be displayed, that is, the viewpoint height. are doing. One example is shown in FIG. FIG. 8B shows an example of the name data.
[0019]
Also, when all the data in the road map data is used in the conversion processing to the bird's-eye view map data, the upper side of the display monitor 8 having a small scale factor is too large to display because the data amount is too large. Therefore, in this embodiment, the road data, the name data, and the background data included in the road map data are classified according to the priority of each data type, and only the data having the higher priority is displayed on the upper side of the display screen. On the lower side, data including low priority data is displayed.
[0020]
The road data is prioritized based on the road type in the “data type” area stored in the map storage memory 2. The third area on the upper side of the display monitor 8 displays a high-priority expressway, a toll road, a national highway, or the like, the second area further displays a prefectural road, and the first area. General local roads are also displayed in addition to the above roads. In this way, in a bird's-eye view map in which the scale is gradually changed from the lower side to the upper side of the screen, the road display on the upper side of the screen that is reduced and displayed becomes simpler and easier to see.
[0021]
Priority is also given to name data based on the road type in the “data type” area stored in the map storage memory 2. The third area of the display monitor 8 displays the name of the expressway, the name of the toll road, or the name of the national road or the number of the national road corresponding to the road data. The second area also displays the name of the prefectural road. In one area, the names of general local roads are displayed in addition to the above road names. A prefecture name may be displayed in the third area. The fourth area can have the same priority as the third area, but here, only the city name is displayed together with the mountain pattern.
[0022]
FIG. 9 is a flowchart showing the main processing of the control circuit 3, and the operation of the present embodiment will be described below based on this flowchart. The control circuit 3 starts the processing in FIG. 9 when the key is operated to the ignition on position.
In step S1 of FIG. 9, a recommended route and a destination are set. The destination is set by the operator via the input device 4, and the recommended route is automatically set by calculation using, for example, the well-known Dijkstra method. Alternatively, recommended route candidates may be stored in advance in a ROM or the like, and any one of them may be selected as the recommended route.
[0023]
In this case, the position detected by the current value detection device 1 can be used as the current value. For example, when a GPS sensor is provided inside the current position detecting device 1, the current position is detected by so-called GPS navigation using the GPS sensor, and when a vehicle speed sensor and a direction sensor are provided instead of the GPS sensor, The present location is detected by a so-called self-contained navigation method for finding a traveling locus of the vehicle. Alternatively, the current position may be detected by combining GPS navigation and self-contained navigation.
[0024]
In step S2, the current position of the vehicle is detected using the current position detection device 1. In step S3, the display direction angle for displaying the bird's-eye map is calculated.
[0025]
FIG. 14 is a diagram illustrating a method of calculating the display direction angle α. The illustrated XY axes indicate the road map plane, the origin O indicates the starting point of the vehicle, the coordinates G (X0, Y0) indicate the current position of the vehicle, and the coordinates P1 (X1, Y1) indicate the destination. As shown in the figure, the display direction angle α is an angle between a line (dotted line in the figure) connecting the current position G and the destination P1 and the X axis, and is expressed by equation (1).
(Equation 1)
tan α = {(Y1-Y0) / (X1-X0)} (1)
In the above-described step S3, the display direction angle α is obtained based on the equation (1). Even when the destination is outside the trapezoidal area ABCD as in P2, the display direction angle α can be similarly obtained.
[0026]
In step S4, road map data around the current position is read from the map storage memory 2 based on the recommended route calculated in step S1, the current position detected in step S2, and the display direction angle α calculated in step S3. For example, it reads road map data of several tens km square including the current location. For example, as shown in FIG. 15, road map data of a rectangular area A'B'C'D 'that inscribes the trapezoid area ABCD and the rectangular area CDGH is read. In step S5, data used for displaying a bird's-eye view map is selected from the road map data read in step S4 in the trapezoidal area ABCD and the rectangular area CDGH.
[0027]
FIG. 11 is a flowchart showing details of the road map selection processing in step S5. In step S101 shown in the figure, data that has not been subjected to the processing of step S102 and subsequent steps is selected from the road map data read in step S4 of FIG. In step S102, it is determined whether the data type of the data selected in step S101 is to be displayed on the display monitor 8. For example, if the data selected in step S101 is road data, it is determined whether the priority of the road type of the road data is higher than the national road. By the processing in step S102, the amount of road map data displayed on the display monitor 8 can be reduced. The priority is set for each of the first to third areas on the display monitor 8.
[0028]
If the determination in step S102 is affirmative, the process proceeds to step S103, and it is determined whether or not the data selected in step S101 is within the range displayed on the display monitor 8. That is, it is determined whether or not the data selected in step S101 is within the range of the trapezoidal area ABCD in FIG. In step S4, since the road map data is read by clipping the rectangular area A'B'C'D 'in FIG. 15, the data of the area other than the trapezoid ABCD is included. Therefore, in step S103, it is necessary to remove the data in the area other than the trapezoid ABCD. If the determination in step S103 is affirmative, the process proceeds to step S104, in which the data selected in step S101 is selected as data for converting to a bird's-eye view map. When the processing in step S104 is completed, when the determination in step S102 is denied, or when the determination in step S103 is denied, the process proceeds to step S105, and the data is read from the map storage memory 2 in step S4 in FIG. It is determined whether or not the processing in steps S101 to S104 has been performed for all of the data. If the determination is affirmative, the process returns. If the determination is negative, the process returns to step S101.
[0029]
As described above, in the map data selection process in FIG. 11 (the process in step S5 in FIG. 9), only the data whose data type satisfies the predetermined condition is extracted from the road map data read from the map storage memory 2, and Further, data for bird's-eye view map display is selected from the extracted data.
[0030]
Returning to FIG. 9, in step S6, the road map data selected in step S5 is converted into bird's-eye view map data. The outline of the conversion method is as described with reference to FIG. Next, in step S7, the bird's-eye view map data converted in step S5 is converted into final map image data to be displayed on the display monitor 8.
[0031]
FIG. 12 is a flowchart showing details of the process of converting the bird's-eye view map data to image data in step S7. In step S201 in FIG. 12, data that has not been converted into map image data is selected from the bird's-eye view map data obtained by the processing in step S6 in FIG. In step S202, the number of divided areas of the display monitor 8 is substituted for a variable N. In the present embodiment, the display area is divided into four as shown in FIG.
[0032]
In step S203, it is determined whether or not the display position of the data selected in step S201 belongs to the N-th area. If the determination is negative, the process proceeds to step S204, and a value obtained by subtracting 1 from the variable N is set as a new N, and the process returns to step S203. If the determination in step S203 is affirmative, the process proceeds to step S205, where the bird's-eye view map data is converted into map image data based on the value of the variable N. For example, the road data in the first area has a line width of 4 points, the road data in the second area has 2 points, and the road data in the third area has a line width of 1 point. In the fourth area, an image showing a mountain pattern and a city name is displayed with the sky as a background in a manner described later. Here, all road data included in the fourth area is deleted and a blue background image representing the sky is displayed. Create In step S206, it is determined whether or not all of the bird's-eye view map data has been converted to map image data. If the determination is negative, the process returns to step S201, and if the determination is positive, the process returns.
[0033]
As described above, in the process of FIG. 12, since the line width of the bird's-eye map is changed for each region of the display monitor 8 divided into a plurality of regions, a more three-dimensional bird's-eye map can be displayed, and the sense of distance can be easily grasped. Become. In particular, since the image showing the sky is displayed without displaying the road map in the fourth area closest to the upper side of the display screen, the bird's-eye view map can have more depth.
[0034]
Returning to FIG. 9, in step S8, data (hereinafter, vehicle information image data) for displaying the current position mark (triangular arrow in FIG. 7) and the destination mark (P1 or P2 in FIG. 7) of the vehicle on the display monitor 8 ). As shown in FIG. 7, when the destination is within the range displayed on the display monitor 8, a flag mark P1 is displayed at a display position corresponding to the destination, and when the destination is not within the display range. Displays the flag mark P2 at the display position that is in the direction of the destination and is closest to the destination on the display screen. Thus, the flag mark can be always displayed regardless of the distance from the current position to the destination, and the driver can always grasp the direction of the destination. Further, since the size of the flag mark is changed according to the display position in the display screen, the flag mark does not hinder the display of other map information.
[0035]
Returning to FIG. 9, in step S9, a mountain pattern and a city name to be displayed in the fourth area of the screen with the sky as the background are selected. In this embodiment, the area of the rectangular area CDGH shown in FIGS. 4 and 15 is searched to select a mountain pattern from the pattern data and a city name from the name data.
[0036]
FIG. 13 is a flowchart showing the details of step S9. In step S901, the symbol data and the name data of the rectangular area CDGH in FIGS. 4 and 15 are read. In step S902, coordinates on the map of all the read data are converted into coordinates on the display screen. In step S903, the Y coordinate of the coordinates converted in step S902 is corrected so that the symbol of the mountain and the city name are in contact with the boundary between the third area and the fourth area. In step S905, the data is arranged and stored in a predetermined area so that the symbols and city names of the mountains are displayed in such a manner as to be superimposed and displayed in order from the data farthest from the current position on the background sky, and this processing ends.
[0037]
Returning to FIG. 9, in step S10, the map image data converted in step S7, the vehicle information image data created in step S8, and the mountain pattern and city name selected in step S9 are stored in the image memory 5. I do. Next, the process proceeds to step S11 in FIG. 10, and drawing is performed on the display monitor 8 based on the data stored in the image memory 5. As a result, as shown in FIG. 7, a bird's-eye view map is displayed in the lower first to third areas on the display monitor 8, and a mountain pattern and a city name are displayed in the upper fourth area against the sky. Is displayed in contact with the boundary between the third area and the fourth area, which is the boundary between the ground and the sky.
[0038]
Returning to FIG. 10, in step S12, the current position of the vehicle is detected as in step S2. In step S13, it is determined whether the vehicle has traveled a predetermined distance or more. If the determination is affirmative, the process returns to step S3, and if the determination is negative, the process proceeds to step S14. In step S14, the map image data on the display monitor 8 is left as it is, and only the display position of the mark indicating the current position of the vehicle is changed according to the traveling distance of the vehicle. Then, the process returns to step S12. As described above, in steps S13 and S14, only the vehicle mark is rewritten without rewriting the road map until the vehicle travels a predetermined distance, so that the load on the control circuit 3 can be reduced.
[0039]
The processing of the embodiment described above is summarized as follows.
When the vehicle starts running, the control circuit 3 detects the current position of the vehicle and obtains a display direction angle when displaying a bird's-eye map from the positional relationship between the current position and the destination. Next, road map data is read from the map storage memory 2 based on the current location, the destination, and the display direction angle, and from the read road map data, data whose data type satisfies a predetermined condition is extracted. Is converted to bird's-eye view map data. In this case, data of a level corresponding to the first to third areas is used.
[0040]
Next, the bird's-eye view map data is processed for each area of the display monitor 8 divided into a plurality of areas and converted into map image data. For example, the road line width in the lower side area of the display screen is increased, and the road line width in the upper side area is reduced. Next, vehicle information image data for displaying marks indicating the current location and the destination of the vehicle is created. At that time, if the destination is within the display range, mark data is created to display a mark at the display position corresponding to the destination, and if the destination is not within the display range, the mark is generated in the direction of the destination, In addition, mark data is created so that the mark is displayed at the display position closest to the destination.
[0041]
When the creation of the map image data and the vehicle information image data is completed, image data for displaying a mountain pattern and a city name is created in the fourth area at the top of the screen. In this case, after converting the coordinates on the map to the coordinates on the screen so that the mountain design and city name are displayed in contact with the boundary line (horizontal line) between the ground and the sky with the sky as the background, Correct the Y coordinate. Then, after a map based on the bird's eye view method is displayed on the display monitor 8 based on the image data, the current position of the vehicle is detected again. If the vehicle has not traveled a predetermined distance or more, only the display position of the vehicle position mark is changed, and if the vehicle has traveled a predetermined distance or more, the map image data is rewritten.
[0042]
As described above, in this embodiment, when displaying a mountain pattern and a city name with the sky as the background, the display position is corrected so that they are displayed in contact with the boundary (horizontal line) between the ground and the sky. Thus, the symbol of the mountain and the city name are prevented from being displayed floating in the sky as shown in FIG. 16, and are displayed without discomfort as shown in FIG. 7. Further, since a distant mountain or city name is displayed so as to be hidden by a nearby mountain or city name, a display similar to an actual interval can be provided.
[0043]
In addition, even if the destination is far away so that it is not displayed on the screen, a flag mark indicating the destination is displayed at a predetermined place on the screen in the direction of the destination, so that the driver can always grasp the direction of the destination. This makes it difficult for the vehicle to leave the route. Further, since the size of the flag mark indicating the destination is changed depending on the display position of the flag mark, the display of other map information is not disturbed by the flag mark. Furthermore, the display range of the display monitor 8 is divided into a plurality of regions, and the data type to be displayed is selected separately for each region, so that detailed map information can be displayed around the current position and the destination direction can be displayed. Can display only important map information, and the map display on the display monitor 8 can be easily viewed. In addition, since the road line width is changed for each area, a bird's-eye view map with a three-dimensional effect can be displayed.
[0044]
In step S5 in FIG. 9, data within the trapezoidal area ABCD in FIG. 4 is extracted as bird's-eye view map data. However, in order to improve the processing speed, the rectangular area A′B′C′D ′ in FIG. 17A, data of a rectangular area A′B′C′D ′ including a trapezoidal area ABCD may be extracted as bird's-eye view map data, and the entire range of the extracted rectangular area may be subjected to coordinate conversion. FIG. 17B shows an example in which the square area of FIG. 17A is coordinate-transformed. A rectangular area abcd at the center of FIG. 17B indicates a range actually displayed on the display monitor 8. As described above, when the road map data in a range wider than the display range of the display monitor 8 is converted into the bird's-eye view map data, if the vehicle moves after the display, if it is within the square range shown in FIG. Since it is only necessary to shift the rectangular area in FIG. 17B and display it without performing the processing in step S6 in FIG. 9, the rewriting speed of the bird's-eye map is improved.
[0045]
When clipping as shown in FIG. 17A is performed, if mountain data and a city name in the area CDC ′ are searched, the mountain data against the sky is set without setting the rectangular area CDGH as in the above embodiment. And city names.
[0046]
In the above, the case where mountain data and city names are displayed in the uppermost area of the screen that displays the sky has been described. However, other structures and names can be displayed in the same manner. The design may be three-dimensional. The map display device according to the present invention is not limited to vehicles. The present invention is not limited to a road map, and is effective when various maps such as a mountain map, a river map, and a marine chart are displayed in a bird's eye view. Further, the planar map data is converted to the bird's-eye map data to display the bird's-eye map, but the bird's-eye map data may be stored in a memory such as a CD-ROM in advance and the conversion process may be omitted.
[0047]
In the embodiment configured as described above, the map storage memory 2 is used as the map storage means, the control circuit 3 is used as the bird's-eye map data conversion means, particularly, step S6 in FIG. Step S903 corresponds to the correction means, and the processing for displaying the image on the monitor among the processing of FIGS. 9 and 10 corresponds to the display control means.
[0048]
【The invention's effect】
As described in detail above, according to the present invention, when displaying various data such as a symbol or a pattern imitating a mountain with a sky background in the upper area and a bird's-eye map in the lower area of the screen, the symbol and name of the mountain are displayed. And so on are in contact with the boundary line (horizontal line) between the map and the sky, so that these data are displayed without discomfort.
If the data farther from the current position is sequentially superimposed on the sky as in the invention of claim 3, the closest data is displayed as it is, and the distant data is displayed so as to be hidden behind the closer data, The expression becomes more realistic.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment of a map display device according to the present invention.
FIG. 2 is a diagram illustrating the structure of road data.
FIG. 3 is a diagram for explaining a concept of storing road data;
FIG. 4 is a view for explaining conversion into bird's-eye view map data.
FIG. 5 is an enlarged view of a rectangular area abcd shown in FIG. 4;
FIG. 6 is a view for explaining the structure of mountain data.
FIG. 7 is a diagram showing a screen display example when a bird's-eye map is displayed.
FIG. 8 is a diagram for explaining a level of road data and a level of name data;
FIG. 9 is a flowchart showing main processing.
FIG. 10 is a flowchart showing a main process following FIG. 9;
FIG. 11 is a flowchart showing map data selection processing.
FIG. 12 is a flowchart showing processing for converting bird's-eye view map data into image data.
FIG. 13 is a flowchart showing mountain and city name selection processing.
FIG. 14 is a diagram illustrating a method of calculating a display direction angle of a bird's-eye map.
FIG. 15 is a diagram illustrating an example of clipping of road map data of a rectangular area including a trapezoidal area.
FIG. 16 is a view for explaining a problem of the conventional method corresponding to the bird's-eye view map display example of FIG. 7;
FIG. 17 is a diagram illustrating clipping of road map data of a rectangular area including a trapezoidal area.
[Explanation of symbols]
1 Current location detector
2 Map storage memory
3 Control circuit
4 Input device
4a Detailed switch
4b Wide area switch
5 Memory for planar map data
6 Bird's-eye view map data memory
7 Image memory
8 Display device
9 Mountain design memory

Claims (7)

Map storage means for storing map data relating to the planar map and various data having display coordinate positions accompanying the planar map,
A bird's-eye view map which reads a map data of a bird's-eye map drawing range extending in a predetermined look-down direction and a predetermined area so as to display a map by the bird's-eye view from the map storage means and converts the map data into bird's-eye view map data by the bird's-eye view. Data conversion means;
A map display device comprising: a display monitor that displays a map based on the bird's-eye view method based on the bird's-eye map data together with the various data.
The screen area of the display monitor is vertically divided into two, a lower area displays a road map and the various data based on the map data of the bird's-eye map drawing range, and an upper area displays the various data with a sky background. Display control means,
When the various data is searched for in a predetermined range ahead of the bird's-eye map drawing range in the looking-down direction, the various data is displayed in contact with a boundary between the upper region and the lower region. A map display device comprising: a correction unit configured to correct a display coordinate position of the various data. The map surface device according to claim 1,
The map display device, wherein the various data is mountain data representing a mountain pattern. The map surface device according to claim 2,
A map display device, wherein, when a plurality of mountain data exists in the predetermined range in front of the looking-down direction, the data is superimposed and drawn in order from the more distant mountain data to the closer mountain data. The map surface device according to claim 1,
The map display device, wherein the various data is name data representing a name. The map display device according to any one of claims 1 to 4,
The bird's-eye view map data conversion means is determined by assuming a case where the viewpoint is placed above the current location on the plane map and the plane map is looked down at a predetermined look-down angle and a predetermined spread angle from the viewpoint in a predetermined look-down direction. And converting the map data read from the trapezoidal bird's-eye map drawing range on the planar map into bird's-eye map data. The map display device according to claim 5,
The bird's-eye map data conversion means includes a clipping means for clipping a rectangular area including the trapezoidal bird's-eye map drawing range,
The map display device, wherein the correction means searches for the various data in a region surrounded by a long side of the trapezoidal bird's-eye map drawing range and the rectangular region. The map display device according to any one of claims 1 to 6,
The various data has a map coordinate position on a planar map, the display control means converts the map coordinate position into a display coordinate position, and displays the various data at the display coordinate position. apparatus.

Images