JPH05216405A - Map displaying method of on-vehicle navigator - Google Patents

Abstract

PURPOSE:To easily make roads and a target in a map image correspond to the actual roads and target while eliminating unnecessary rotation of the map image. CONSTITUTION:When a request to switch a display direction is made on a console panel 2 during a travel, a map image drawing part 13 draws a wide- range map image including the current place detected by a vehicle position detection part 3 on a 1st V-RAM 16 with a reference direction up while regarding the vehicle azimuth detected by the vehicle position detection part 3 at the point of time as the reference direction. Then, the vehicle position detection part 3 detects the current place and vehicle azimuth during the travel, an image segmentation part 14 segments the area of one screen centering the current position from the 1st V-RAM 16 with the reference direction up and draws it on a 2nd V-RAM 17, and a vehicle position mark drawing part 15 draws a vehicle position mark at the center of the 2nd V-RAM 17 in the direction indicated by the vehicle azimuth. Then the image on the 2nd V-RAM 17 while converted into a video signal is outputted to a CRT display device 4 to display the image on the screen.

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 for an in-vehicle navigator, and more particularly, to display a map image in which a vehicle position mark is superimposed on a map around the present location of a vehicle so that a predetermined direction is upward. The present invention relates to a map display method for an in-vehicle navigator.

[0002]

2. Description of the Related Art There is a vehicle-mounted navigator that guides a vehicle so that a driver can easily reach a desired destination. In this in-vehicle navigator, while traveling, the position and direction of the vehicle are detected, the map data around the vehicle position is read from the CD-ROM, the map image is drawn in the V-RAM, and the current position on the map image is equivalent. Where you want to
The vehicle position mark is overlaid and drawn in a direction corresponding to the direction of travel of the vehicle, and the image of the V-RAM is converted into a video signal while C
Output to RT display device and display on screen. Then, as the current position changes due to the movement of the vehicle, the vehicle position mark on the screen is moved, or the vehicle position mark is fixed at the center of the screen and the map is scrolled to constantly display the map around the vehicle position. Information is available at a glance.

The map stored in the CD-ROM is divided into areas of a longitude width and latitude width of appropriate sizes according to the scale level, and roads are represented by vertices (nodes) represented by coordinates of longitude and latitude. ) Is shown as a set. A part that connects two or more nodes is called a link.

In such a vehicle-mounted navigator, a method of displaying a map image on the screen is as shown in FIG. 9 in which the direction is fixed so that the north on the map image always faces the top of the screen during traveling. As shown in FIG. 10, there is a north-up mode in which the vehicle travels and a head-up mode in which the vehicle travels on the map image while rotating so that the traveling direction of the vehicle always faces the upper side of the screen. The navigator is displayed in only one mode, or in one of the two modes selected by the user.

[0005]

However, in the former case of the north-up mode, it is good if the vehicle is traveling to the north or a direction close to the north, but it is traveling to a direction other than north such as south, west or east. In this case, since the vehicle traveling direction on the screen and the actual vehicle traveling direction are significantly different, there is a problem that the map image is difficult to see and it is difficult to associate the roads and targets on the map image with the actual roads and targets. It was Also, in the latter head-up mode, when traveling on a straight road, the vehicle traveling direction on the screen matches the actual vehicle traveling direction, and the map image does not rotate, so the map image is easy to see. It becomes easy to associate roads and targets on the map image with actual roads and targets. However, as shown in FIG. 10, when traveling on a winding road such as a mountain road, the direction of the vehicle constantly changes. As a result, the map image on the screen constantly sways in the clockwise and counterclockwise directions, which makes it very difficult to see roads and targets on the map image.

In the latter head-up mode, the display direction of the map image is not changed until the vehicle direction changes by a predetermined constant angle (for example, 90 °) or more, and the vehicle direction changes by a predetermined constant angle or more. At that time, a simple head-up display that changes the display direction of the map image by a certain angle is also proposed, but since the vehicle direction changes repeatedly on the winding road, the display direction of the map image is changed. The frequent changes in unavoidable.

In view of the above, an object of the present invention is to provide a map display method for an in-vehicle navigator which makes it easy to associate a road or a target on the map image with an actual road or a target while eliminating unnecessary rotation of the map image. It is to be.

[0008]

According to the present invention, there is provided a map information storage means for storing map data, a means for detecting a current position and a vehicle direction of a vehicle while traveling, and a means for making a display direction change request. And the vehicle direction at the time when the display direction change request is issued while traveling, and using the map data stored in the map information storage means, the reference direction becomes the upward direction of the screen, And means for displaying a map image in which the vehicle position mark is superimposed on the map around the present location.

[0009]

According to the present invention, while the vehicle is traveling, the current direction and the vehicle direction of the vehicle are detected, and the map direction stored in the map information storage means is used to determine the vehicle direction at the time of the display direction change request as the reference direction. Then, the map image in which the vehicle position mark is superimposed on the map around the current position of the vehicle is displayed so that the reference direction is the upward direction of the screen. As a result, if a display direction change request is made after the vehicle has entered the straight road, the map image is displayed so that the vehicle traveling direction at that time is the upward direction of the screen. As long as the traveling direction indicated by the vehicle position mark on the map image matches the actual traveling direction of the vehicle, and the rotation of the map image does not occur, the map image is easy to see and the roads and objects on the map image are It can be easily compared with the target object, and even when traveling on the winding road, if the display direction change request is issued while the vehicle is traveling on the average course of the winding road, the vehicle traveling direction at that time will be displayed. Since the map image is displayed so as to face upward, the average course of the winding road on the map image will be the actual wine as long as you drive on the winding road. Consistent with average course of Ingu roads, it does not occur rotation of the map image, easy viewing the map image, so that can be easily compared with actual road and the desired product roads and the desired product in the map image.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an overall configuration diagram of an in-vehicle navigator embodying a route guidance method according to the present invention.

In the figure, reference numeral 1 is a CD-ROM serving as map data storage means, 2 is an operation panel, which is provided with a map search key, a display direction switching key and the like. 3 is a vehicle position detection unit that detects the vehicle direction and the vehicle position by self-contained navigation and outputs the vehicle direction data and the vehicle position data. 4 is a CRT display device that inputs a video signal and displays a map of the vehicle position on the screen. And so on.

Reference numeral 10 denotes a navigation controller having a microcomputer configuration, which displays a map image around the vehicle position on the screen of the CRT display device 4 together with a vehicle position mark and the like. Of these, 11 is a buffer memory for temporarily storing the map data read from the CD-ROM 1,
When the display direction switching key is pressed on the operation panel to issue a display direction switching request, the vehicle orientation data 2 output from the vehicle position detection unit 3 at that time is input.
A registration unit 13 for registering as reference direction data is a map image drawing unit, and a CD-ROM 1 for storing one map including the current position detected by the vehicle position detection unit and data around the map while traveling. From the buffer memory 11 to the buffer memory 11 described later, and the reference direction registered in the registration unit 12 is upward so that the first V-RAM described later includes map images of the same size as nine maps including the current location and its periphery. Is drawn (see FIGS. 4 and 5). Then, when the current position of the vehicle moves and the area of one screen including the current position in the center is about to deviate from the first V-RAM, one map including the current position detected by the vehicle position detection unit is displayed again. , The map data around the map is read from the CD-ROM 1 to the buffer memory 11, and the map image including the current position in the center is drawn in the first V-RAM so that the reference direction is upward.

Reference numeral 14 denotes a map image drawn in the first V-RAM, which includes the current position in the center and cuts out an area for one screen (see the hatched area in FIG. 4) with the reference direction facing upward, and stores it in the second V-RAM. It is an image cutout part to draw,
The central coordinate data on the first V-RAM is input from the map image drawing unit, and the cut-out range from the first V-RAM is determined based on the coordinate data and the vehicle position data input from the vehicle position detection unit. Reference numeral 15 is a vehicle position mark drawing unit, which inputs the vehicle direction data from the vehicle position detecting unit 3 and refers to the reference direction data registered in the registering unit 12 to refer to the one screen drawn in the second V-RAM. A vehicle position mark is drawn in the center of the map image in a direction corresponding to the vehicle traveling direction on the map image. Reference numeral 16 is a first V-RAM for storing a map image of a predetermined size which is drawn by the map image drawing unit such that the current position of the vehicle is upward and the reference direction is upward, and 17 is the first V by the image cutout unit.
-A second V-RAM for storing a one-screen map image cut out from the RAM. Reference numeral 18 denotes a video conversion unit that reads image data from the second V-RAM, converts it into a video signal, and outputs the video signal to the CRT display device 4.

FIG. 2 is a flow chart showing the navigation processing of the navigation controller 10, FIG. 3 is an explanatory view of the road condition around the traveling path of the vehicle, and FIGS. 4 and 5 are first VRs, respectively.
Explanatory drawing which shows the example of the map image stored in AM16, FIG.
8 is an explanatory diagram of a screen display example of the CRT display device 4, which will be described below with reference to these figures.

It is assumed that each data of the vehicle position and the vehicle azimuth immediately before the power-off last time is internally registered in the vehicle position detecting section 3 in advance. When the power supply of the set is turned on before starting traveling, the reference direction data indicating north is initialized in the registration unit 12 (step 101 in FIG. 2). The map image drawing unit 13 inputs the vehicle position data from the vehicle position detecting unit 3, and from the CD-ROM 1 all the data of one map including the current position (see point A in FIG. 3) and the map around the map. The read buffer memory 11 stores the first
A map image of the same size as the nine maps is drawn in the V-RAM 16 so as to include the current location and its periphery so that the reference direction (north) registered in the registration unit 12 is upward and the current location is in the center. (Step 102, see FIG. 4). The map image drawing unit 13 outputs the coordinate data of the center of the map image drawn in the first V-RAM 16 to the image cutting unit 14.

Then, the image cut-out unit 14 uses the coordinate data input from the map image drawing unit 13 and the vehicle position data input from the vehicle position detection unit 3 to generate the first V-RAM1.
An area for one screen (refer to the hatched area in FIG. 4) is cut out from 6 and the current position is included in the center and the reference direction is facing upward, and is drawn in the second V-RAM 17 (step 10).
3). Then, the vehicle position mark drawing unit 15 inputs the vehicle direction data from the vehicle position detecting unit 3 and refers to the reference direction data registered in the registering unit 12 to refer to the second V-RAM 17
A vehicle position mark is drawn in the center of the one-screen map image drawn in (1) in the direction corresponding to the vehicle traveling direction on the map image (step 104). The image data stored in the second V-RAM 17 is output to the video conversion unit 18, converted into a video signal by the video conversion unit 18, and output to the CRT display device 4. The CRT display device 4 displays a map on the screen based on the input video signal (step 105).

As a result, the map image around the departure place is displayed on the screen with the north facing upward, and the vehicle position mark is displayed in the center of the screen in the direction corresponding to the vehicle direction (FIG. 6 (1)). reference).

When the vehicle starts traveling, a predetermined unit distance (for example, 1
Each time the vehicle travels, the vehicle position and the vehicle direction are sequentially detected by the vehicle position detection unit 3, and the vehicle position data is output to the map image drawing unit 13 and the image cutting unit 14, and
The vehicle direction data is registered in the registration unit 12 and the vehicle position mark drawing unit 1.
5 is output. However, the registration unit 12 does not rewrite the reference direction data during registration unless the display direction switching key is pressed on the operation panel 2.

The map image drawing unit 13 inputs the vehicle position data, and when the vehicle position indicated by the vehicle position data changes (YES in step 106), the current first V-RAM 16 is present.
In the map image drawn in Fig. 1, the area corresponding to one screen with the current position indicated by the vehicle position data as the center and the reference direction facing upward deviates from the map image of the first V-RAM16. Is rewritten (step 107), and if not necessary, the map image is not rewritten, the coordinate data of the center of the image is output to the image cutout unit 14 (step 110), and when rewriting is necessary, A single map including the current location and data of maps around the map are all read from the CD-ROM 1 and stored in the buffer memory 11, and the first V-RAM 16
A map image having the same size as the nine maps including the current position and its periphery is drawn so that the reference direction (north) registered in the registration unit 12 is upward and the current position is in the center (step 103). ). Then, the map image drawing unit 13 outputs the coordinate data of the center of the map image drawn this time to the first V-RAM 16 to the image cutting unit 14.

Then, the image cutout unit 14 uses the coordinate data input from the map image drawing unit 13 and the vehicle position data input from the vehicle position detection unit 3 to generate the first V-RAM1.
From 6, the area for one screen is cut out with the current position in the center and the reference direction facing upward, and is drawn in the second V-RAM 17 (step 103). Subsequently, the vehicle position mark drawing unit 15 inputs the vehicle direction data from the vehicle position detecting unit 3 and refers to the reference direction data registered in the registering unit 12 to refer to the one screen drawn in the second V-RAM 17. A vehicle position mark is drawn in the center of the map image in a direction corresponding to the vehicle traveling direction on the map image (step 104).
As a result, on the screen, the map image scrolls by the unit distance with the upper part facing north.

Thereafter, the same processing is repeated every time the vehicle moves by a unit distance, and the map image on the screen is moved in accordance with the movement of the vehicle (the vehicle position mark is displayed in the center of the screen). Allows the driver to see map information around the current location.

By the way, although it is good for the vehicle to travel northward after departure, as shown in FIG. 3, when the vehicle travels along the straight road RD ₁ extending to the southeast, the vehicle on the screen is The traveling direction is downward right, making it difficult to see the map image and making it difficult to compare roads and targets on the map image with actual roads and targets (see FIG. 6 (2)).

In this case, the driver presses the display direction switching key on the operation panel 2 to issue a display direction switching request.
Then, the registration unit 12 inputs the vehicle azimuth data output from the vehicle position detection unit 3 at that time and rewrites and registers it as reference direction data (southeast) (step 108,
109). Next, the map image drawing unit 13 uses the vehicle position data output from the vehicle position detecting unit 3 at that time to read one map including the current location from the CD-ROM 1 and data of maps around the map. Are all stored in the read buffer memory 11, and the first V-RAM 16
A map image having the same size as that of the nine maps is drawn so that the reference direction (southeast) registered in the registration unit 12 is upward and the current position is in the center (step 102). , See FIG. 5). Then, the map image drawing unit 13 outputs the coordinate data of the center of the map image drawn this time to the first V-RAM 16 to the image cutting unit 14.

Then, the image cutout unit 14 uses the coordinate data input from the map image drawing unit 13 and the vehicle position data input from the vehicle position detection unit 3 to generate the first V-RAM1.
From 6, the area for one screen is cut out with the current position in the center and the reference direction facing upward, and is drawn in the second V-RAM 17 (step 103). Subsequently, the vehicle position mark drawing unit 15 inputs the vehicle direction data from the vehicle position detecting unit 3 and refers to the reference direction data registered in the registering unit 12 to refer to the one screen drawn in the second V-RAM 17. A vehicle position mark is drawn in the center of the map image in a direction corresponding to the vehicle traveling direction on the map image (step 104).
The image drawn in the second V-RAM 17 is the image conversion unit 18
Is converted into a video signal and output to the CRT display device 4. The CRT display device 4 displays a map on the screen based on the input video signal (step 105).

Thereafter, each time the vehicle travels for a certain distance and the vehicle position indicated by the vehicle position data input from the vehicle position detection unit 3 changes, the image cutout unit 14 causes the image cutting unit 14 to perform the first V-RAM.
A second V-RAM that cuts out a map image of the area for one screen centered on the current location from 16 with the southeast facing upward.
17 and the vehicle position mark drawing unit 15 displays the second VR
A vehicle position mark is drawn in the center of the map image drawn on the AM 17 in a direction corresponding to the vehicle traveling direction on the map image (steps 106, 107, 103, 104).

As a result, the screen is switched to a map image with the southeast direction facing upward, and then as the vehicle runs,
The map image on the screen moves with the upper side facing southeast (see FIG. 6 (3) and FIG. 7 (1)). Therefore, the traveling direction of the vehicle on the screen is the same as the traveling direction of the actual vehicle, and it becomes easy to compare the road and the target on the map image with the actual road and the target.

After that, when the vehicle turns around at the intersection CP ₁ in FIG. 3 and tries to enter the winding road RD ₂ which, on the average, runs in the northeast direction, the vehicle traveling direction on the screen is as it is. Since it is significantly different from the actual traveling direction of the vehicle, the map image becomes difficult to see (see FIG. 7 (2)). Therefore, for example, when the vehicle comes near the point B facing the northeast direction before entering the winding road (see FIG. 3), the display direction switching key of the operation panel 2 is pressed again to issue the display direction switching request.

Then, in the same manner as described above, the registration unit 12 inputs the vehicle azimuth data output from the vehicle position detection unit 3 at that time, and rewrites and registers it as the reference direction data (northeast) (steps 108 and 109). ). Next, the map image drawing unit 13 uses the vehicle position data output from the vehicle position detecting unit 3 at that time to read the CD-ROM.
From 1 to one map including the current location and all map data around the map are read out and stored in the buffer memory 11, and the first V-RAM 16 includes the current location and its periphery, which is the same area as nine maps. Sano's map image,
The reference direction (northeast) registered in the registration unit 12 is upward,
Draw so that the current location is in the center (step 10)
2). Then, the map image drawing unit 13 uses the first V-RAM 1
The coordinate data at the center of the map image drawn this time is output to the image cutout unit 6 in FIG.

Then, the image cutout unit 14 uses the coordinate data input from the map image drawing unit 13 and the vehicle position data input from the vehicle position detection unit 3 to generate the first V-RAM1.
From 6, the area for one screen is cut out with the current position in the center and the reference direction facing upward, and is drawn in the second V-RAM 17 (step 103). Subsequently, the vehicle position mark drawing unit 15 inputs the vehicle direction data from the vehicle position detecting unit 3 and refers to the reference direction data registered in the registering unit 12 to refer to the one screen drawn in the second V-RAM 17. A vehicle position mark is drawn in the center of the map image in a direction corresponding to the vehicle traveling direction on the map image (step 104).
The image drawn in the second V-RAM 17 is the image conversion unit 18
Is converted into a video signal and output to the CRT display device 4. The CRT display device 4 displays a map on the screen based on the input video signal (step 105).

Thereafter, each time the vehicle travels for a certain distance and the vehicle position indicated by the vehicle position data output from the vehicle position detection unit 3 changes, the image clipping unit 14 causes the first V-RA to move.
Cut out a map image of one screen area centered on the current location from M16 with the northeast facing upward and cut out the second V-RA
Draw on M17, and the vehicle position mark drawing unit 15 displays the second V-
At the center of the map image drawn in the RAM 17, a vehicle position mark is drawn in a direction corresponding to the vehicle traveling direction on the map image (steps 106, 107, 103, 10).
4).

As a result, after the screen is switched to the map image with the northeast direction facing upward, as the vehicle travels,
The map image on the screen moves with the top facing northeast (see FIGS. 7 (3) and 8 (1)). Therefore, while traveling on the winding road RD ₂ , the vehicle traveling direction on the screen changes frequently, but the average vehicle traveling direction remains upward, and the road or target on the map image is changed to the actual road or target. It becomes easier to compare.

With respect to this point, in the conventional display in the head-up mode, the map image on the screen is frequently rotated while traveling on the winding road, which makes it very difficult to see the road and the target on the map image. It is difficult to compare with the target.

The vehicle exits the winding road RD ₂ ,
When turning into a road RD ₃ which is straight at the intersection CP ₂ of FIG. 3 and extends straight to the southeast (see FIG. 8 (2)), the display direction switching key of the operation panel 2 is pressed again to display. Issue a direction change request.

Then, in the same manner as described above, the registration unit 12 inputs the vehicle direction data output from the vehicle position detection unit 3 at that time, and rewrites and registers it as the reference direction data (southeast) (steps 108, 109). ). Next, the map image drawing unit 13 uses the vehicle position data output from the vehicle position detecting unit 3 at that time to read the CD-ROM.
From 1 to one map including the current location and all map data around the map are read out and stored in the buffer memory 11, and the first V-RAM 16 includes the current location and its periphery, which is the same area as nine maps. Sano's map image,
The reference direction (southeast) registered in the registration unit 12 is upward,
Draw so that the current location is in the center (step 10)
2). Then, the map image drawing unit 13 uses the first V-RAM 1
The coordinate data at the center of the map image drawn this time is output to the image cutout unit 6 in FIG.

Then, the image cutout unit 14 uses the coordinate data input from the map image drawing unit 13 and the vehicle position data input from the vehicle position detection unit 3 to generate the first V-RAM1.
From 6, the area for one screen is cut out with the current position in the center and the reference direction facing upward, and is drawn in the second V-RAM 17 (step 103). Subsequently, the vehicle position mark drawing unit 15 inputs the vehicle direction data from the vehicle position detecting unit 3 and refers to the reference direction data registered in the registering unit 12 to refer to the one screen drawn in the second V-RAM 17. A vehicle position mark is drawn in the center of the map image in a direction corresponding to the vehicle traveling direction on the map image (step 104).
The image drawn in the second V-RAM 17 is the image conversion unit 18
Is converted into a video signal and output to the CRT display device 4. The CRT display device 4 displays a map on the screen based on the input video signal (step 105).

Thereafter, every time the vehicle travels for a certain distance and the vehicle position indicated by the vehicle position data output from the vehicle position detection unit 3 changes, the image cutout unit 14 causes the first V-RA to move.
Cut out a map image of one screen area centered on the current location from M16 with the northeast facing upward and cut out the second V-RA
Draw on M17, and the vehicle position mark drawing unit 15 displays the second V-
At the center of the map image drawn in the RAM 17, a vehicle position mark is drawn in a direction corresponding to the vehicle traveling direction on the map image (steps 106, 107, 103, 10).
4).

As a result, after the screen is switched to the map image with the southeast direction facing upward, as the vehicle travels,
The map image on the screen moves with the top facing southeast (see Fig. 8 (3)). Therefore, the traveling direction of the vehicle on the screen is the same as the traveling direction of the actual vehicle, and the road or target on the map image can be easily compared with the actual road or target.

[0038]

As described above, according to the present invention, while the vehicle is traveling, the vehicle direction at the time when the display direction change request is made by using the map data stored in the map information storage means while detecting the current position and the vehicle direction of the vehicle. Is set as a reference direction, and the reference direction is directed upwards on the screen, and a map image in which the vehicle position mark is superimposed on the map around the vehicle's current position is displayed. When the display direction change request is issued, the map image is displayed so that the vehicle traveling direction at that time is the upward direction of the screen, and thereafter, as long as the vehicle travels on the straight road, the progress indicated by the vehicle position mark on the map image is displayed. Since the direction matches the vehicle traveling direction on the actual road and the map image does not rotate, the map image is easy to see and the roads and objects on the map image can be easily compared with the actual roads and objects. , Wai Even when traveling on the loading road,
If a display direction change request is issued while the vehicle is traveling on an average road on a winding road, the map image is displayed so that the vehicle traveling direction at that time is the upward direction of the screen. As long as you drive on the winding road, the average path of the winding road on the map image matches the average path of the actual winding road, and the rotation of the map image does not occur, so the map image is easy to see and It will be possible to easily compare the roads and objects of interest with the actual roads and objects of interest.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an in-vehicle navigator embodying a map display method according to the present invention.

FIG. 2 is a flowchart showing map display processing of a navigation controller.

FIG. 3 is an explanatory diagram of road conditions around a traveling path of a vehicle.

FIG. 4 is an explanatory diagram showing an example of a map image drawn in a first V-RAM.

FIG. 5 is an explanatory diagram showing another example of the map image drawn in the first V-RAM.

FIG. 6 is an explanatory diagram showing a screen display example of a CRT display device.

FIG. 7 is an explanatory diagram showing a screen display example of a CRT display device.

FIG. 8 is an explanatory diagram showing a screen display example of a CRT display device.

FIG. 9 is an explanatory diagram showing a screen display example in the north-up mode.

FIG. 10 is an explanatory diagram showing a screen display example in a head-up mode.

[Explanation of symbols]

 1 CD-ROM 2 Operation panel 3 Vehicle position detection unit 4 CRT display device 10 Navigation controller 12 Registration unit 13 Map image drawing unit 14 Image cutout unit 15 Vehicle position mark drawing unit 16 First V-RAM 17 Second V-RAM 18 Video conversion Department

Claims (1)

[Claims] 1. A predetermined map image in which a vehicle position mark is superimposed on a map around the current position of a vehicle by using the map data stored in the map information storage means while detecting the current position and the vehicle direction of the vehicle while traveling. In the map display method of the in-vehicle navigator that is displayed so that the direction is upward, if there is a display direction change request during traveling, the vehicle direction at that time is set as the reference direction, and the reference direction becomes the upward direction of the screen. In this way, a map image in which the vehicle position mark is superimposed on the map around the current location of the vehicle is displayed, and a map display method for an in-vehicle navigator.