JP2001174274A - Method and apparatus for display of map - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an obstacle due to a building when a three-dimensional map is displayed. SOLUTION: Road data on a guide point is extracted from a map database 13, and an image for three-dimensional display is formed. A display change means 17 displays the building 37 so that a road 33 to be used as a course is visible when the building 37 obstructs the road 33 to be used as the course. The building is displayed to be semitransparent or in a wire frame shape. Alternatively, it is possible that the building is not displayed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a map display method and apparatus suitable for a route guidance apparatus such as a navigation apparatus for guiding a vehicle along a preset route.

[0002]

2. Description of the Related Art A prior art which guides or controls a vehicle such as an automobile running on a road so as to travel at an appropriate speed in accordance with the degree of abruptness when entering a curved road is disclosed in, for example, Japanese Patent Application Laid-Open No. Hei 4 -236699. However, with such prior art, it is not possible for the driver of the vehicle to easily understand the route guidance required when changing the traveling direction at an intersection in an urban area or the like.

[0003] Conventionally, in a navigation device mounted on a vehicle for performing route guidance, route guidance at an intersection or the like is performed by image display. Generally, a method of enlarging and showing a two-dimensional map near an intersection is used.
If the three-dimensional display of the intersection as shown in FIG. 8 is performed, a display close to the situation of the intersection that the driver actually sees with the naked eye can be obtained, and the situation of the intersection can be grasped instantaneously. However, when the intersection 1, the traveling road 2, the road 3 to be the course, and the other roads 4 and 5 are related, and the display from the traveling road 2 to the road 3 to be the course by the route guidance 6 is performed, With only the display, the difference from the actual scenery becomes large and it is difficult to grasp the situation of the intersection. Building 7, which is a landmark related to intersection 1 from the road map data,
By extracting 8 and displaying it as a three-dimensional image in accordance with the three-dimensional display of the road, it is possible to provide guidance while the intersection 1 is actually visible to the naked eye.

[0004]

If the route guidance of the intersection 1 is performed on the guidance screen of the three-dimensional display including the buildings 7 and 8 as shown in FIG. 8, it is considered that a display that is easy for the vehicle driver to understand is possible. However, as shown in FIG. 8, there is a building 7 serving as a landmark in front of the road 3 serving as a course, and the road 3 serving as a course is displayed by displaying the building 7.
May be obstructed and cannot be seen. Such a display is similar to the state of the intersection 1 that the driver actually sees, but when the driving direction is to be changed from the traveling road 2 to the road 3 which is the course according to the route guidance 6, the traveling direction is determined. Since the situation of the road 3 cannot be grasped, there is a possibility that anxiety may remain.

[0005] In addition, as shown in FIG. 8, only a three-dimensional display guide image including the buildings 7 and 8 can provide easy-to-understand route guidance to a driver who can only see the screen for a short time. Have difficulty.

An object of the present invention is to display a three-dimensional map,
An object of the present invention is to provide a map display method and apparatus capable of preventing a display from being disturbed by a building.

[0007]

SUMMARY OF THE INVENTION According to the present invention, when a map including a three-dimensional building is displayed on display means based on map data, the map is displayed in a display form in which a part of the building can be seen behind. Is a map display method characterized by the following.

Further, according to the present invention, when a map including a three-dimensional building is displayed on the display means based on the map data, the map is displayed in a display form such that the back of a part of the building can be seen according to the vehicle position. Is a map display method characterized by the following.

Further, the present invention is characterized in that, when a map including a three-dimensional building is displayed on the display means based on the map data, the map is displayed in a display form in which the back of the building on the near side of the path can be seen. This is a map display method.

Further, according to the present invention, when a map including a three-dimensional building is displayed on the display means based on the map data, the map is displayed in a display form such that the back of the building existing in front of the center of the display image can be seen. This is a map display method characterized in that:

[0011] Further, the present invention, when displaying a map including a three-dimensional building on the display means based on the map data, as a display form such that the back of a part of the building can be seen based on the positional relationship between the route and the building. Is displayed on the map.

Further, according to the present invention, when a map including a three-dimensional building is displayed on the display means based on the map data, some of the buildings are not displayed three-dimensionally from the three-dimensional display so as to be displayed behind the building. This is a map display method characterized in that a map is displayed as a display form in which the image can be viewed.

According to the present invention, when a map including a three-dimensional building is displayed on the display means based on the map data, a part of the building is displayed translucently and the map is displayed as a display form in which the back of the building can be seen. And a map display method.

According to the present invention, when a map including a three-dimensional building is displayed on the display means based on the map data, a part of the building is displayed in a wire frame shape, and the map is displayed in a display form in which the back of the building can be seen. This is a map display method characterized by displaying.

Further, according to the present invention, when a map including a three-dimensional building is displayed on the display means based on the map data, the map is displayed so that the traveling direction of the vehicle is directed upward, and a part of the building is displayed behind the building. This is a map display method characterized in that a map is displayed in such a display form that the user can see the image.

According to the present invention, when a map including a three-dimensional building is displayed on the display means based on the map data, display of a part of the three-dimensional building is prohibited so that the back of the building can be seen. A map display method characterized by displaying a map.

Further, according to the present invention, in a display mode in which the back of the part of the building can be seen, display of a three-dimensional building is prohibited, the building is displayed translucently, and the building is displayed in a wire frame. Or any of the above.

According to the present invention, when a map including a three-dimensional building is displayed on the display means based on the map data, the control means controls the map to be displayed in a display form in which the back of some buildings can be seen. It is a map display device characterized by having.

Further, according to the present invention, when a map including a three-dimensional building is displayed on the display means based on the map data, the map is displayed in a display form in which the back of a part of the building can be seen according to the vehicle position. A map display device comprising a control means for controlling the map display device.

Further, according to the present invention, when a map including a three-dimensional building is displayed on the display means based on the map data, the control is performed such that the map is displayed in a display form in which the back of the building on the near side of the path can be seen. A map display device comprising means.

Further, according to the present invention, when a map including a three-dimensional building is displayed on the display means based on the map data, the map is displayed in a display form such that the back of the building existing in front of the display image can be seen. A map display device comprising control means for controlling the map display.

Further, according to the present invention, when a map including a three-dimensional building is displayed on the display means based on the map data, the map is displayed in a display form such that a part of the building can be seen behind based on the positional relationship between the road and the building. Is a map display device having control means for controlling so as to display.

Also, according to the present invention, when a map including a three-dimensional building is displayed on the display means based on the map data, some of the buildings are not displayed three-dimensionally from the three-dimensional display so as to be displayed behind the building. A map display device comprising a control unit for controlling a map to be displayed as a display mode in which a map can be viewed.

Further, according to the present invention, when a map including a three-dimensional building is displayed on the display means based on the map data, a part of the building is displayed in a translucent manner so that the back of the building can be seen. Is a map display device having control means for controlling so as to display.

Further, according to the present invention, when a map including a three-dimensional building is displayed on the display means based on the map data, a part of the building is displayed in a wire frame shape, and the map is displayed in a display form in which the back of the building can be seen. A map display device comprising a control unit for controlling display.

According to the present invention, regardless of the display at the time of route guidance, during map display, the back of the building is made translucent so that the back can be seen, or a wire frame shape can be used to make the back visible. . This makes it possible to see behind the building during map display.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a schematic overall configuration of a navigation device as an embodiment of the present invention by (a), and shows an example of a route guidance display at an intersection as a guide point ( Shown in b).

An input device 11 for inputting a departure point, a destination point, etc., where the vehicle travels, is searched in a navigation device 10 which is a route guidance device shown in FIG. 1 (a), and a route between the input points is searched. And a map database 13 storing road data of the route searched by the route searching unit 12. Guide image forming means 1
4 forms an image for guiding the vehicle so that the vehicle can travel along the route searched by the route searching means 12. When the vehicle is traveling halfway along a road, a two-dimensional road map is displayed according to an appropriately selected scale.

At a guide point such as an intersection set in advance, a guide image based on three-dimensional display is formed. In order to form a three-dimensional guide image, landmark extraction means 15
Extracts landmarks around the guide point from the map database 13. The landmark includes a public office indicated by a symbol on a map, a public service facility such as a hospital or a school, a gas station, a convenience store, a bank, and the like. In a memory 16 composed of a semiconductor or the like, image data formed in advance according to the type of building is stored. Guide image forming means 14
Forms a three-dimensional display image of a road in accordance with road data read from the map database 13 in order to perform three-dimensional display of a guide point, and displays a building corresponding to a landmark extracted by the landmark extracting means 15. The image is read from the memory 16 and added. Guide image forming means 14
The three-dimensional guide image of the guide point formed by
The display change means 17 determines whether or not a state in which the course is blocked by a mark building has occurred. When the course is blocked, the display mode of the building serving as the mark is changed, and the display is changed to a state in which the course can be seen. The changed display image is displayed as an image by display means 18 such as a CRT or an LCD.

The navigation device 10 includes a current position detecting means 19 for detecting the current position of the vehicle. The current position detecting means 19 can detect the current position of the vehicle as an absolute position based on latitude and longitude, for example, based on an output from a GPS receiver. The position is estimated by dead reckoning based on the change in the traveling direction of the vehicle and the traveling direction detected by a gyro sensor or the like, or is calculated by a correction process of performing map matching on the position of a road in the map database 13. The current position can also be detected. When the current position approaches the guide point to a predetermined distance, the control means 20 displays a guide image by three-dimensional display for each guide point.

The navigation device 10 also includes a display control means 21, an angle detection means 22, a speed guidance means 23, and acoustic data 24 such as music and voice. Details of these operations will be described later. The sound information read from the sound data 24 is reproduced as a sound or music signal by the sound reproducing means 25 and converted into sound guidance for the vehicle by the speaker 26.

FIG. 1B shows an example of a guide image 30 of an intersection formed by the guide image forming means 14 of FIG. At an intersection 31 which is a guide point, a traveling road 32, a road 33 which is a course, and other roads 34 and 35 intersect. Buildings 37 and 38 serving as landmarks are displayed around the intersection 31 based on the landmarks extracted by the landmark extracting means 15 in FIG. However, since the building 37 indicated by the broken line is displayed so as to block the road 33 as the course, the display changing means 17 in FIG. 1A changes the building 37 so as not to be displayed. Thereby, when the vehicle turns from the running road 32 to the road 33 to be the course according to the route guidance 36, it is possible to see in advance the situation where the vehicle has turned.

FIG. 2 shows the operation of the navigation device 10 of FIG. The operation starts from step a1. In step a2, the departure point and the destination point are input to the input means 11. In step a3, a route search by the route search means 12 is performed. When the vehicle starts running in step a4, the current position is detected by the current position detecting means 19 in step a5. In step a6, it is determined whether the current position is approaching the guide point. If it is determined that the vehicle is approaching the predetermined distance, the step a
At 7, the guidance image forming means 14 forms a guidance image. In step a8, the display changing means 17 determines whether or not a building exists before the course.
When it is determined that the building exists, the display mode of the building is changed in step a9. When it is determined that there is no building in front of the course, or after the display mode of the building has been changed, an image for guidance is displayed by the display means 18 in step a10, and the process returns to step a5. Step a
If it is determined in step 6 that the vehicle is not approaching the guide point, it is determined in step all whether the vehicle has reached the destination point. Step a if not reached
Return to 5. When it is determined that it has reached, the operation is ended in step a12.

In the embodiment shown in FIG. 1, although the display of the building 37, which is a landmark on the near side of the road 33, is changed so as not to be displayed, the display state and the non-display state are alternately performed. The building 37 can be repeatedly displayed blinking. The blinking display allows both the building 37 serving as a mark and the road 33 serving as a route to be displayed, so that more easily understandable route guidance can be performed.

FIG. 3 shows a guide image according to still another embodiment of the present invention. In the present embodiment, portions corresponding to the guide image 30 of FIG. 1B are denoted by the same reference numerals, and redundant description will be omitted. Guide image 40a shown in FIG.
Then, the building 47 displayed in front of the building 33 to be the course
a is displayed in a wire frame shape. By displaying in the form of a wire frame, it is possible to simultaneously display the presence of the building 47a and the prospect of the road 33 which is the course. FIG. 3B shows, as a guide image 40b, a building 47b serving as a mark that blocks the road 33 serving as a route in a translucent manner, and the presence of the building 47b serving as a mark and the road 33 serving as a route.
Can be obtained in conjunction with the outlook.

FIG. 4 shows a display operation of a guide image performed by the display control means 18 in the navigation device 10 shown in FIG. 1A as still another embodiment of the present invention. The operation is started from step b1 and step b6
Steps a1 to a shown in FIG.
The operation is the same as the operation of each step up to 6. When it is determined in step b6 that the vehicle is approaching the guide point to a predetermined distance, in step b7, a guide image of three-dimensional display at a plurality of points along a route including an intersection, which is a guide point, is displayed as a guide image. It is formed by the forming means 14. In step b8, the formed guidance images at a plurality of points are displayed by switching at a speed higher than the actual traveling speed, and the driver of the vehicle is informed of the road condition ahead of the turn.
In step b9, the current position of the vehicle is detected by the current position detecting means 19, and it is determined in step b10 whether or not the vehicle has reached a display end position set as a predetermined distance before the guide point, for example. If it has not reached, the process returns to step b8, and the sequential display of the guidance image is repeated. When it is determined in step b10 that the vehicle has reached the display end position, the process returns to step b5, and the route guidance along the road 33 serving as the course is continued. In step b6,
When it is determined that the vehicle is not approaching the guide point, the process proceeds to step b11. Similar to step a11 shown in FIG. 2, if the vehicle reaches the destination, the operation ends in step b12. Return.

By such a repetitive display, for example, when turning at an intersection, especially at an intersection that passes for the first time, it is not possible to know what the turning point is, but it is possible to see in advance the road ahead. It is expected that danger can be predicted.

FIG. 5 shows the sound data 2 shown in FIG. 1B as an operation of route guidance according to still another embodiment of the present invention.
The operation using No. 4 will be described. Step c1 to step c7
The operations up to are the same as the operations of the respective steps from step a1 to step a7 in FIG. In step c8, the landmark extracting means 15 shown in FIG. 1A determines the type of the building serving as a guide point landmark from the landmark symbol. In step c9, the control unit 20 in FIG. 1A selects the acoustic data corresponding to the type of the building extracted by the landmark extracting unit 15 from the acoustic data 24 stored in advance. The acoustic data includes, for example, audio guidance for a building serving as a landmark and music strongly associated with the building. For example, if the landmark building is running a large amount of advertising that uses commercial songs, such as in a convenience store, playing such commercial songs will provide audible information and will be easy to understand. Guidance can be provided. If the landmark building is a pachinko parlor, by playing music that is often played in the shop, easy-to-understand guidance based on auditory association is possible.

If it is determined in step c6 that the vehicle is not approaching the guide point, it is determined in step c11 whether or not the vehicle has reached the destination. If not, the flow returns to step c5. Step c12
The point at which the operation is ended in step a11 in FIG.
Step a12 and step b11, step b12
The operation is the same as that described above.

FIG. 6 shows a route guide according to still another embodiment of the present invention, in front of a guide point such as an intersection.
An example in which guidance is provided to change the traveling speed according to the angle at which the traveling direction is changed will be described. At the intersection 51, the roads 53a and 53b, which are the courses from the running road 52, and the other roads 5
4, 55 and 56 branch. Roads 53a and 5 to be the course
3b is different from the angle required for changing the course from the running road 52. The angle β when turning on the road 53b, which is a course, is smaller than the angle α when turning on the road 53b, which is a course, and the angle of change in direction is steep. Therefore, it is necessary to greatly reduce the speed.

FIG. 7 shows an operation for providing guidance for decreasing the speed according to the angle as shown in FIG. The control means 20 of FIG. 1A starts the operation from step d1, and in step d2, the angle detecting means 22 obtains the angle to the turning road from the map of the intersection in the map database 13 by the angle detecting means 22. In step d3, it is compared with a predetermined reference angle, for example, 90 °, to determine whether or not the turning angle is steep. If it is determined that it is sudden, step d4
Then, the speed guide means 23 is caused to perform a speed guide that greatly reduces the speed. In step d3, the angle is 9
If it is greater than 0 ° and it is determined that it is not steep,
In step d5, guidance that slightly reduces the speed
This is performed by the speed guiding means 23. Speed guidance means 23
Gives an instruction to reduce the speed to guide image forming means 1
4 and the display means 18 by the guide image forming means 14.
When the speed guidance image is displayed in step d6, the operation is terminated in step d6. Note that the speed control of the vehicle may be directly performed.

According to the above-described embodiment, a three-dimensional guide image of a building serving as a landmark is displayed together with a road at a guide point, and an image of a building on the near side of the vehicle path is displayed so that the rear path can be seen. Since the mode is changed to the mode, the prospect of the course can be easily provided. For example, when an intersection is used as a guide point, even if you do not know what the destination of the direction change will be at the intersection you pass for the first time, you can see the route after the route change in advance, so danger prediction etc. It becomes possible. Further, since the image of the building on the near side of the route of the vehicle is not displayed, the visibility of the route can be easily obtained. Further, since the image of the building on the front side of the route of the vehicle is blinkingly displayed, it is possible to easily confirm the intersection to be changed in route based on the presence of the building serving as a landmark, and to easily obtain the prospect after the route is changed. Further, since the image of the building on the front side of the vehicle is displayed in the form of a wire frame, the outline of the building is displayed, but the course behind the building can be displayed at the same time. The landmark building can be easily recognized from the wireframe-shaped outer shape, the guide point is displayed in an easily recognizable manner, and the prospect after the course change can be given. In addition, since the image of the building on the front side of the path of the vehicle is displayed translucently, the shape and position of the building serving as a mark can be easily seen, and the visibility of the path behind the building can be given.

Further, when the vehicle approaches the guide point to a predetermined distance, the guidance images at a plurality of points along the route passing through the guide point are displayed repeatedly and sequentially, so that the driver can see the vehicle according to the route to be traveled. The situation can be shown first. As a result, it is possible to perform an image training on the danger prediction and the situation, and to provide an easy-to-understand route guidance for an unknown guide point. Further, since the acoustic information is reproduced in relation to the type of the building serving as the landmark at the guide point, the building to be rerouted is specified by the acoustic information, and the route guidance can be easily understood. In addition, when changing the course of a vehicle at a guidance point, a guidance display that detects the change angle and makes the traveling speed of the vehicle appropriate is displayed, so that it is a safe and easy-to-understand route even when traveling at unknown guidance points Guidance can be provided.

As described above, according to the above-described embodiment, at guide points such as intersections, three-dimensional display of buildings serving as landmarks is performed together with roads, and buildings on the near side of the course are changed so that the course can be seen. Therefore, route guidance that is easy for the driver to understand can be provided. Even if the guidance point is an intersection that you pass for the first time, and you do not know what the route changed to, it is possible to know the route in advance, so you can expect to be able to predict danger This allows the vehicle to travel with confidence.
Also, since the building on the front side of the vehicle's path is not displayed,
You can surely see the course. In addition, since the building on the near side of the path of the vehicle is blinked, both the building serving as the mark and the path can be seen, so that easy-to-understand route guidance can be performed. Further, since the image of the building on the front side of the route is displayed in the form of a wire frame, both the shape of the building serving as a mark and the route can be seen, and the route guidance can be easily understood. Further, since the building on the near side of the path of the vehicle is displayed translucently, the building serving as the mark and the path can be seen at the same time, and easy-to-understand route guidance can be performed. Furthermore, when approaching the guide point to a predetermined distance, guidance display is performed with multiple images along the route including the guide point, so that the state of the course change can be seen in advance, and easy-to-understand route guidance can be repeated and viewed. In addition, it becomes a risk prediction or an image training of the situation, and can provide easy-to-understand route guidance. Further, it is easy to identify a building which is a landmark by acoustic information related to a type of a building which is a landmark of a guide point, for example, music or voice, and it is possible to surely change a course. Furthermore, guidance at an appropriate speed is performed at the guide point in accordance with the degree of the steepness of the angle at which the course is changed, so that the course can be changed safely and the possibility of making a mistake in the course can be reduced.

[0045]

According to the present invention, irrespective of the display at the time of route guidance, the back of the building can be made translucent so that the back of the building can be seen, or made into a wire frame shape so that the back can be seen during map display. To This makes it possible to see behind the building during map display.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic electrical configuration of an embodiment of the present invention and a diagram showing an example of a guide image.

FIG. 2 is a flowchart showing an operation of the navigation device 10 of FIG.

FIG. 3 is a diagram showing an example of a guide image according to another embodiment of the present invention.

FIG. 4 is a flowchart showing an operation of still another embodiment of the present invention.

FIG. 5 is a flowchart showing an operation of still another embodiment of the present invention.

FIG. 6 is a schematic diagram showing a concept of speed guidance in still another embodiment of the present invention.

FIG. 7 is a flowchart for performing the speed guidance shown in FIG. 6;

FIG. 8 is a diagram showing an image of a three-dimensional display of an intersection according to a base technology underlying the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Navigation apparatus 12 Route search means 13 Map database 14 Guidance image formation means 15 Landmark extraction means 16 Memory 17 Display change means 18 Display means 19 Current position detection means 20 Control means 21 Display control means 22 Angle detection means 23 Speed guidance means 24 Acoustic data 30, 40a, 40b Guide images 31, 51 Intersections 32, 52 Roads 33, 53a, 53b running Roads 34, 35, 54, 55 Routes other roads 36 Route guidance 37, 38, 47a, 47b Buildings

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G09B 29/10 G09B 29/10 A

Claims (19)

[Claims] 1. A map display method comprising: when displaying a map including a three-dimensional building on a display means based on map data, displaying the map in a display form in which the back of some of the buildings can be seen. 2. When displaying a map including a three-dimensional building on the display means based on the map data, the map is displayed in a display form in which the back of some of the buildings can be seen according to the vehicle position. Map display method. 3. A map display method comprising: when displaying a map including a three-dimensional building on a display means based on map data, displaying the map in a display form such that the back of the building on the front side of the path can be seen. . 4. When displaying a map including a three-dimensional building on the display means based on the map data, displaying the map in a display form such that the back of the building existing in front of the center of the display image can be seen. Characteristic map display method. 5. When displaying a map including a three-dimensional building on the display means based on the map data, the map is displayed in a display form such that a part of the building can be seen behind based on the positional relationship between the route and the building. A map display method characterized in that: 6. When displaying a map including a three-dimensional building on the display means based on the map data, a display in which a part of the building is not displayed three-dimensionally from the three-dimensional display so that the back of the building is visible. A map display method characterized by displaying a map as a form. 7. When displaying a map including a three-dimensional building on the display means based on the map data, displaying a part of the building in a translucent manner and displaying the map in a display form in which the back of the building is visible. Characteristic map display method. 8. When displaying a map including a three-dimensional building on the display means based on the map data, displaying a part of the building in a wire frame shape and displaying the map as a display form in which the back of the building can be seen. A map display method characterized by the following. 9. When displaying a map including a three-dimensional building on the display means based on the map data, the map is displayed so that the traveling direction of the vehicle is upward, and the back of a part of the building is visible. A map display method characterized in that the map is displayed as a simple display form. 10. When a map including a three-dimensional building is displayed on the display means based on the map data, the display of a part of the three-dimensional building is prohibited and the map is displayed in a display form in which the back of the building can be seen. And a map display method. 11. The display form in which the back of the part of the building can be seen is any of prohibiting the display of a three-dimensional building, displaying the building translucently, and displaying the building in a wire frame. 11. The map display method according to claim 9, wherein: 12. When displaying a map including a three-dimensional building on the display means based on the map data, a control means is provided for controlling the map to be displayed in a display form in which the back of some buildings can be seen. A map display device characterized by the above-mentioned. 13. When displaying a map including a three-dimensional building on the display means based on the map data, control is performed such that the map is displayed in a display form in which the back of a part of the building can be seen according to the vehicle position. A map display device comprising control means. 14. When a map including a three-dimensional building is displayed on the display means based on the map data, a control means is provided for controlling the map to be displayed in a display form in which the back of the building on the near side of the path can be seen. A map display device, characterized in that: 15. When displaying a map including a three-dimensional building on the display means based on the map data, the map is displayed in a display form in which the back of the building existing on the near side from the center of the display image can be seen. A map display device having control means for controlling. 16. When displaying a map including a three-dimensional building on the display means based on the map data, the map is displayed in a display form such that a part of the building can be seen behind based on the positional relationship between the road and the building. A map display device having control means for performing control as described above. 17. When displaying a map including a three-dimensional building on the display means based on the map data, a display in which a part of the building is not displayed in a three-dimensional manner from the three-dimensional display so that the back of the building is visible. A map display device comprising a control unit for controlling a mode to display a map. 18. When displaying a map including a three-dimensional building on the display means based on the map data, a part of the building is displayed translucently, and the map is displayed in a display form such that the back of the building can be seen. A map display device having control means for performing control as described above. 19. When displaying a map including a three-dimensional building on the display means based on the map data, a part of the building is displayed in a wire frame shape, and the map is displayed as a display form in which the back of the building can be seen. A map display device comprising a control means for controlling the map display.