JP2001159533A - Navigation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a navigation device capable of improving easiness to see displayed map information. SOLUTION: When executing display of a map image corresponding to the periphery of the own car, a connected-road determination part 20 determines a second road connected to a first road where a vehicle is traveling. A one-way traffic information plotting part 24 converts one-way traffic information corresponding to the first and second roads into a display state based on the determination result, and converts one-way traffic information corresponding to another third road into a non-display state, to thereby produce plot data corresponding to the one-way traffic information. Respective plot data of the map image and the one-way traffic information are combined by an image combining part 18, and the combined image is displayed on the screen of a display device 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a navigation device for displaying map information around a vehicle position including one-way information.

[0002]

2. Description of the Related Art In general, an in-vehicle navigation device detects a current position of a vehicle, reads map data near the current position from a data storage medium such as a CD or DVD, and displays the data on a screen. Also, a vehicle position mark indicating the vehicle position is displayed on the screen, and the map data in the vicinity is scrolled according to the progress of the vehicle around the vehicle position mark, so that the map information around the vehicle position is always known. It has become. Also, in most recent navigation devices, if there is a one-way road within the display range of the map image, an arrow or the like indicating the traveling direction of the one-way road (hereinafter, this will be referred to as "one-way information"). Is displayed. FIG.
FIG. 7 is a diagram showing a display example of one-way information in a conventional navigation device. In FIG. 10, an arrow displayed near the entrance of each road corresponds to one-way information indicating the traveling direction of the one-way road, and the display of such one-way information allows the user to enter the own vehicle. The possible roads can be grasped.

[0003]

By the way, in the above-mentioned conventional navigation device, one-way information is displayed for all one-way roads existing within the display range of the map image. For this reason, when a large number of one-way roads exist within the display range of the map image, a large number of one-way information is displayed on the screen, and the display becomes complicated, making it difficult to see other map information. There was a problem. For example, in places where many roads are dense, such as in the city center, there are often many one-way roads,
As in the display example shown in FIG. 10 described above, a large number of one-way information is displayed in the map image. As described above, if the display becomes complicated due to a large number of one-way information, it is necessary to easily and visually grasp map information that is really necessary for the user, such as information on one-way roads around the position of the vehicle and other map information. Becomes difficult.

[0004] The present invention has been made in view of such a point, and an object of the present invention is to provide a navigation device which can improve the visibility of displayed map information.

[0005]

In order to solve the above-mentioned problems, in the navigation apparatus of the present invention, map information drawing data is generated by the map drawing means based on the map information stored in the map information storage means. When a map image including one-way information is displayed on the screen by the display unit based on the drawing data, the above-described map drawing unit uses the second map connected to the first road on which the vehicle is traveling. The road is determined by the connection road determination unit, and based on the determination result, the one-way information drawing unit sets the one-way information corresponding to the first and second roads to the display state, and the other third road is displayed. The corresponding one-way information is set to the non-display state, and the drawing data corresponding to the one-way information is generated.
As described above, the one-way information corresponding to the first road on which the vehicle is traveling and the second road connected to this road is selectively displayed, so that all the roads on the map image are displayed. It is possible to prevent the display from becoming complicated as in the case where one-way information is displayed, and to improve the visibility of the map information.

[0006] The one-way information drawing means described above comprises:
It is desirable to set the drawing position of the drawing data of the one-way information corresponding to the second road to a position near one end of the second road and close to the first road. By setting the drawing position of the drawing data of the one-way information at such a position, it is determined whether the vehicle can enter the second road only by looking at the periphery of the map image corresponding to the first road. The judgment can be made easily.

The one-way information drawing means described above includes
It is desirable to generate the one-way information drawing data in different colors depending on whether the entrance portion of the second road is connected to the first road or the exit portion is connected to the first road. In this way, by coloring the drawing data of the one-way information, the one-way information can be visually and easily recognized.

[0008] Further, a search target road determining means for determining whether or not the first road is a target of the route search is further provided, and the one-way information drawing means makes the first road a target of the route search. In this case, it is desirable to enable the above-described drawing operation for putting the one-way information corresponding to the third road in a non-display state. Some roads that are not targeted for route search are not targeted for the map matching process, and when the vehicle is running on such a road, the vehicle position must be accurately detected. May not be possible, so that the one-way information corresponding to the third road is hidden only when the first road is the target of the route search, and otherwise, all the roads (the By setting the one-way information corresponding to the first to third roads to the display state, even when the vehicle position cannot be accurately detected,
One-way information around the own vehicle can be reliably grasped.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A navigation device according to an embodiment of the present invention will be described below with reference to the drawings.

(1) Overall Configuration of Navigation Apparatus FIG. 1 is a diagram showing the overall configuration of a vehicle-mounted navigation apparatus according to an embodiment to which the present invention is applied. The navigation device shown in FIG. 1 includes a navigation controller 1 for controlling the whole, a DVD 2 on which various map data necessary for map display, route search, and the like are recorded, and a disk reading device 3 for reading the map data recorded on the DVD 2. A remote control (remote control) unit 4 as an operation unit for the user to input various instructions; a GPS receiver 5 for detecting a position and a direction of the vehicle; and an autonomous navigation sensor 6
And a display device 7 for displaying a map image, a guidance route, a vehicle position mark, and the like superimposed on the map image.

The above-mentioned disk reader 3 can load one or a plurality of DVDs 2 and reads map data from any one of the DVDs 2 under the control of the navigation controller 1. The loaded disk is not necessarily a DVD, but may be a CD.
Alternatively, both a DVD and a CD may be selectively loaded.

The remote control unit 4 includes a search key for giving a route search instruction, a route guidance mode key used for setting a route guidance mode, a destination input key, left / right / up / down cursor keys, a map scale / enlargement key, and a display screen. Various operation keys such as a setting key for fixing the item at the upper cursor position are provided, and an infrared signal corresponding to the operation state of the key is transmitted to the navigation controller 1.

The GPS receiver 5 receives radio waves transmitted from a plurality of GPS satellites, performs three-dimensional positioning processing or two-dimensional positioning processing, and calculates the absolute position and direction of the vehicle (the vehicle direction is the current Is calculated based on the own vehicle position and the own vehicle position one sampling time ΔT before), and these are output together with the positioning time. The autonomous navigation sensor 6 includes an angle sensor such as a vibrating gyroscope that detects the vehicle rotation angle as a relative direction, and a distance sensor that outputs one pulse every predetermined traveling distance. Detect orientation.

The display device 7 displays a map image around the own vehicle together with a departure mark, a destination mark, etc., based on the image data output from the navigation controller 1, and displays a guidance route on this map. Or

(2) Detailed Contents of Map Data Next, detailed contents of map data recorded on the DVD 2 will be described. The map data recorded on the DVD 2 is in units of rectangular figures separated by predetermined longitude and latitude, and the map data of each figure is specified by specifying a figure number and can be read out. It becomes possible. The map data for each map includes a drawing unit composed of various data necessary for map display, a road unit composed of data necessary for various processes such as map matching, route search, and route guidance, and an intersection. Intersection unit composed of detailed data such as.

In the above-mentioned road unit, a line connecting a certain intersection on the road and another adjacent intersection is called a link, and an intersection connecting two or more links is called a node. FIG. 2 is a diagram showing the contents of various tables included in the road unit. As shown in FIG. 2, the road unit includes a unit header for identifying a road unit, a connection node table storing detailed data of all nodes, and a node table indicating a storage position of the connection node table. And a link table storing detailed data of a link specified by two adjacent nodes.

FIG. 3 is a diagram showing the detailed contents of various tables included in the road unit. As shown in FIG. 3A, the node table includes node records # 0, # 1,... Corresponding to all the nodes included in the target leaf.
Is stored. Each node record is #
Node numbers are given in order from 0, and indicate the storage position of the connection node table corresponding to each node.

The connection node table is shown in FIG.
For each of the existing nodes, a. Normalized longitude / latitude b. An intersection node flag indicating whether or not this node is an intersection node, an adjacent node flag indicating whether or not this is a node at a boundary with another figure leaf, and whether or not a link has branched at this node. If so, a “node attribute flag” including, for example, branch road information indicating whether the shape of the branch corresponds to a T-junction or a Y-junction; c. "The number of connected nodes" indicating the number of nodes forming the other end of each link when there is a link having this node as one end of the link; d. No right turn or U
If there are traffic restrictions such as turn prohibition, the "number of traffic restrictions", e. Connection node records for the number of links indicating the link number of each link having this node at one end; f. A traffic regulation record indicating the specific content of the traffic regulation corresponding to the number of the traffic regulations, if any, g. If this node is a node at a boundary with another figure leaf, an “adjacent node record” indicating the position of the connection node table of the corresponding node of the neighboring figure leaf, h. If this node is an intersection node, the storage location and size of the corresponding intersection record in the intersection unit are included.

Further, as shown in FIG. 3C, the link table includes a plurality of link records in the order of link numbers corresponding to all the links included in the target figure. Each of these link records: a. A link ID, which is a code assigned to each link mainly for displaying a search route, b. Node number 1 and node number 2 identifying the two nodes located at both ends of the link; c. Link distance d. Cost of traveling on this link e. Various road attribute flags including attribute information of the road associated with this link (whether there is one-way traffic, whether this road is subject to search processing, etc.), f. A road type flag indicating the type of road such as whether the actual road corresponding to this link is an expressway or a general road, and the width of the road such as how many meters the road is; g. A number assigned to the road corresponding to this link is included.

(3) Details of Navigation Controller
Configuration and Operation Next, a detailed configuration of the navigation controller 1 shown in FIG. 1 will be described. The navigation controller 1 includes a data buffer 10, a map reading control unit 12, a map drawing unit 14, a VRAM 16, and an image synthesizing unit 18 for displaying a predetermined map image or the like on the display device 7, and calculating the position of the vehicle and performing map matching. A vehicle position calculation unit 30, a route search processing unit 32, a guidance route drawing unit 34, a mark image drawing unit 36 for performing processing, a route search process, and a route guidance process and displaying a result thereof; A remote control unit 60 for displaying a screen and transmitting an operation instruction from the remote control unit 4 to each unit, a cursor position calculation unit 62, and an operation screen generation unit 64 are provided.

The data buffer 10 is for temporarily storing map data read from the DVD 2 by the disk reading device 3. Map reading control unit 12
When the vehicle position is calculated by the vehicle position calculation unit 30, a request to read map data in a predetermined range including the vehicle position is sent to the disk reading device 3, and the map data necessary for map display is read from the DVD 2. Data buffer 1
Store to 0. For example, map data corresponding to four sheets including the own vehicle position is read and stored in the data buffer 10.

FIG. 4 is a diagram conceptually illustrating map data stored in the data buffer 10. In FIG. 4, each of the areas A to D is a data buffer 10
4 shows a map image created based on the map data corresponding to the four sheets stored in. The area P is
This is a predetermined area centered on the own vehicle position G. In an actual display, a map image corresponding to the area P is displayed on the display device 7.
Will be displayed on the screen. As described above, when the own vehicle travels and the own vehicle position G moves, the area P moves accordingly, thereby scrolling the screen. Further, when the area P moves with the movement of the own vehicle position G, map data corresponding to a new figure is read out according to the own vehicle position G and stored in the data buffer 10.

The map drawing section 14 creates drawing data necessary for displaying a map image around the position of the vehicle based on the map data stored in the data buffer 10. The drawing data created by the map drawing unit 14 is a VRA
It is stored in M16 and read out by the image synthesizing unit 18. The image combining unit 18 combines the drawing data read from the VRAM 16 and the image data output from each of the mark image drawing unit 36 and the operation screen generating unit 64 to perform image combining. The image combined by the image combining unit 18 is displayed on the screen of the display device 7.

Further, the map drawing section 14 of the present embodiment determines whether each road included in the map image is included in the map image in accordance with whether or not the road on which the vehicle is traveling (first road) is a target of the route search. In order to selectively display the corresponding one-way information, a connection road determining unit 20, a search target road determining unit 22, and a one-way information drawing unit 24 are included.

The connection road judging section 20 includes a data buffer 1
The first road on which the own vehicle is traveling is specified based on the map data stored in the first vehicle and the own vehicle position and the traveling direction obtained by the vehicle position calculation unit 30, and the road connected to the first road is specified. (The second road) is extracted. Here, the first and second roads in the present embodiment will be specifically described.

FIG. 5 is a diagram for explaining the first and second roads. In FIG. 5, links corresponding to each road are represented by “straight lines”, and nodes connecting the links are represented by “「 ”. In FIG. 5, it is assumed that the own vehicle is traveling toward the node N1, as indicated by the own vehicle position G. At this time, if the vehicle keeps going straight without making a course change by turning right or left,
It can be seen that the light passes through the nodes N1, N2, N3 and N4 in order. As described above, the road (in the example shown in FIG. 5, nodes N1, N2, Roads identified by N3 and N4)
In the present embodiment, it is referred to as “first road”. Also, in FIG. 5, the link L1 connected to the nodes N1 to N4
Roads corresponding to links connected to the first road, such as L8, are referred to as "second roads" in the present embodiment. In the present embodiment, roads other than the first and second roads described above are referred to as “third roads”.

As described above, the connection road determination unit 20 specifies the node corresponding to the above-mentioned first road based on the own vehicle position and the traveling direction obtained by the vehicle position calculation unit 30, and The second road is extracted by examining the link connected to the node corresponding to the road.

The search target road determination unit 22 determines whether or not the road on which the vehicle is currently traveling (first road) is a search target when performing a route search. Specifically, whether or not the vehicle is a search target of the route search can be determined by checking a road attribute flag (see FIG. 3) of the link corresponding to the road on which the vehicle is currently traveling. Also,
When the road on which the vehicle is currently traveling is the target of the route search, the search target road determination unit 22 determines only the first and second roads as one-way information. Outputs an instruction to be displayed, and if the road on which the vehicle is currently traveling is not a route search target, the first, second,
An instruction is output so that all of the third roads are displayed as one-way information. In the present embodiment, the search target road determination unit 22 is described as being provided in the map drawing unit 14, but the location where the search target road determination unit 22 is provided is not limited to this. For example, it may be provided in the route search processing unit 32, or may be provided as one functional block in the navigation controller 1.

The one-way information drawing unit 24 creates drawing data for displaying one-way information based on the determination result by the connection road determination unit 20 and the instruction given from the search target road determination unit 22. Specifically, when the one-way information drawing unit 24 is instructed by the search target road determination unit 22 to display only the first and second roads, the one-way information drawing unit 24 outputs the first and second roads. The road attribute of the vehicle is checked, and drawing data indicating that the road is a one-way road is generated. Specifically, as described above, whether or not each road is a one-way road can be determined by checking the road attribute flag (see FIG. 3) of the link corresponding to the road. The one-way information drawing unit 24 of the present embodiment sets the drawing position of the drawing data of the one-way information corresponding to the second road near one end of the second road and close to the first road. It shall be set to the position specified. In addition, the one-way information drawing unit 24 is configured such that when the second road is a one-way road, the case where the entrance is connected to the first road and the case where the exit is connected to the first road. Thus, the one-way information is created in different colors. A specific display example of the one-way information will be described later.

The search target road determination unit 22 sends the first,
When an instruction is given to display all of the second and third roads as one-way information display targets, the one-way information drawing unit 24
Examines the road attributes of the links corresponding to all the roads, and creates drawing data indicating that to be a one-way road. A specific display example will be described later.

The vehicle position calculating section 30 calculates the position of the own vehicle based on the data detected by the GPS receiver 5 and the autonomous navigation sensor 6, and when the calculated position of the own vehicle is not on the road in the map data. Performs a map matching process for correcting the own vehicle position. The route search processing unit 32 searches for a traveling route that connects a preset destination and departure place under predetermined conditions. For example, under various conditions such as the shortest distance and the shortest time, a guidance route with the lowest cost is set. As a typical route search method, the Dijkstra method and the horizontal search method are known. Guide route drawing unit 34
Draws the guidance route set by the route search processing unit 32 on the map image. Mark image drawing unit 36
Generates a vehicle position mark at the own vehicle position after the map matching processing, or generates a cursor mark having a predetermined shape.

The data buffer 10 corresponds to the map information storage means, the map drawing section 14 corresponds to the map drawing means, the image synthesizing section 18 and the display device 7 correspond to the display means. Further, the connecting road determining unit 20 corresponds to the connecting road determining unit, the one-way information drawing unit 24 corresponds to the one-way information drawing unit, and the search target road determining unit 22 corresponds to the search target road determining unit.

The entire navigation device and the navigation controller 1 have the above-described configuration. Next, the operation will be described. FIG. 6 is a flowchart showing an operation procedure of the navigation device when displaying one-way information on a map image. In the present embodiment, the description will be made on the assumption that the route guidance operation is not performed.

The connection road determination unit 20 includes a vehicle position calculation unit 3
The first road (own vehicle path) is specified based on the own vehicle position and the traveling direction obtained by 0 and the map data stored in the data buffer 10 (step 100). Specifically, as described with reference to FIG. 5 described above, the connection road determination unit 20 specifies the node that is scheduled to pass when the own vehicle keeps going straight without changing the course, and Identify the road.

Next, the connection road judging section 20 executes Step 1
The road (second road) connected to the first road specified in 00 is extracted (step 101). Specifically, the connection road determination unit 20 extracts the second road by examining the link connected to the node corresponding to the first road, as described in FIG. 5 described above.

In parallel with the above-described processing by the connection road determination unit 20, the search target road determination unit 22 is a search target when a route (first road) on which the vehicle is traveling performs a route search. It is determined whether or not it is (Step 102). When the first road is a search target of the route search, the search target road determination unit 22 sends the first traffic information
And an instruction to output only the second road as a display target of one-way information. The one-way information drawing unit 24 that has received the instruction creates drawing data for displaying one-way information on the first and second roads (step 10).
3).

More specifically, since the node corresponding to the first road is specified by the connection road determining unit 20, the one-way information drawing unit 24 generates a link connecting the nodes corresponding to the first road. The road attributes of the data buffer 1
0, and the drawing data of one-way information on the first road is created based on the contents of the road attribute. Similarly, the link corresponding to the second road is also connected to the connection road determination unit 2.
0, the one-way information drawing unit 2
4 reads the road attributes of the links related to the second road from the data buffer 10 and creates drawing data of one-way information related to the second road based on the contents of the road attributes. The one-way information drawing data created by the one-way information drawing unit 24 is temporarily stored in the VRAM 1.
6 is read out by the image synthesizing unit 18 and displayed on the display device 7.

FIG. 7 is a diagram showing a display example of one-way information when the first road is a search target of a route search. In FIG. 7, it is assumed that the own vehicle is moving in the direction from the bottom to the top in the drawing as indicated by the own vehicle position mark 200. In FIG. 7, a road 210 extending in the vertical direction near the center of the drawing corresponds to a road on which the vehicle is traveling, that is, a first road,
Arrow images 220 and 230 correspond to one-way information. In the present embodiment, when the first road is a search target of the route search, as shown in FIG. 7, one-way information on the first road and the second road connected to the first road are provided. Since only one-way information on the third road having low importance as information is not displayed, it is possible to improve the visibility of the display image.

The arrow images 220 and 230 indicating one-way information corresponding to the second road, as shown in FIG.
Since it is drawn near one end of the second road and close to the first road, the user only needs to look at the periphery of the map image corresponding to the first road, and the second road is drawn. Can be easily determined whether or not the vehicle can enter. In particular, by displaying the minimum number of one-way information necessary for making such a determination, the visibility of map information other than the one-way information can be further improved.

In FIG. 7, an arrow image 220 represented by a white arrow is one-way information representing that the own vehicle can enter the second road. It is displayed with a color such as blue. Also,
In FIG. 7, an arrow image 230 represented by a black arrow is one-way information representing that the vehicle cannot enter the second road, and in an actual display, for example, a color such as red. Is displayed. As described above, in the present embodiment, the color of the arrow image indicating the one-way information corresponding to the second road is determined according to whether or not the own vehicle can enter. Can be easily grasped visually. Note that the color added to the arrow images 220 and 230 indicating one-way information is not limited to blue or red as described above, and may be another color.

If the road on which the vehicle is traveling is not a search target of the route search, a negative determination is made in step 102 described above. , And instructs all roads (first, second, and third roads) to be displayed as one-way information. The one-way information drawing unit 24 receiving the instruction,
The road attributes of the links corresponding to all roads stored in the data buffer 10 are read, and drawing data for displaying one-way information on all roads is created based on the contents (step 104).

FIG. 8 is a diagram showing a display example of one-way information when the road (first road) on which the vehicle is traveling is not a search target of the route search. In FIG. 8, it is assumed that the own vehicle is traveling on a road that is not a search target, as indicated by the own vehicle position mark 200. Further, in FIG. 8, a large number of black arrow images displayed correspond to one-way information. As described above, when the road on which the vehicle is traveling is not the target road for the route search, one-way information is displayed for all roads as in the related art.

Step 103 or step 1 described above
When the process of Step 04 is performed, the connection road determination unit 20 determines whether or not the course of the own vehicle has been changed to a road different from the first road identified in Step 100 (Step 105). If the course of the own vehicle has been changed, an affirmative determination is made in step 105, and the connection road determination unit 20
Returns to step 100, and repeats the operation after the operation of specifying the own vehicle course (first road) corresponding to the current position and the traveling direction of the own vehicle.

If the course of the own vehicle has not been changed, a negative determination is made in the above-described step 105, and the connection road determination unit 20 determines whether the map stored in the data buffer 10 as the own vehicle moves. It is determined whether the data (map data corresponding to the leaf to be displayed) has been changed (step 106). If the map data stored in the data buffer 10 has not been changed, the process returns to step 105, and the connection road determination unit 20 repeats the operation after determining whether or not the course of the own vehicle has been changed. If the map data stored in the data buffer 10 has been changed, an affirmative determination is made in step 106 described above, and the connection road determination unit 20 returns to step 100 and performs an operation for identifying the first road. Repeat the operation.

As described above, the navigation device according to the present embodiment, when displaying a map image corresponding to the vicinity of the vehicle,
The connection road determination unit 20 determines the second road connected to the first road on which the vehicle is traveling. Based on the determination result, the one-way information drawing unit 24 determines the first and second roads.
The one-way information corresponding to the third road is displayed, and the other one-way information corresponding to the third road is not displayed, so that the drawing data corresponding to the one-way information is generated. One-way information corresponding to all the roads on the map image is displayed to prevent the display from becoming complicated,
The visibility of the map information can be improved. In particular,
In the present embodiment, when the drawing data of the one-way information corresponding to the second road is generated, the drawing position is set to a position near one end of the second road and close to the first road. Therefore, it is possible to easily determine whether or not the vehicle can enter the second road only by looking at the periphery of the map image corresponding to the first road. Drawing data in which blue is added to the corresponding one-way information when the entrance of the road is connected to the first road, and red is added when the exit is connected to the first road. Is generated, so that one-way information can be easily visually recognized.

The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention. For example, in the embodiment described above,
When the road on which the vehicle is traveling (the first road) is not a search target of the route search, one-way information is displayed for all roads, but a predetermined range based on the position of the vehicle is used. One-way information may be displayed only for roads entering the area. FIG. 9 is a diagram showing a modification of the display of one-way information when the road on which the vehicle is traveling is not a search target of the route search. As shown in FIG. 9, for example, if one-way information is displayed only for a road within a radius of 100 m from the position of the host vehicle, the display of the one-way information is not performed even if the first road is not a search target of the route search. The complexity can be reduced. The predetermined range based on the vehicle position may be arbitrarily set, for example, within a predetermined rectangular range, in addition to the case where the predetermined range is set within a predetermined radius as described above. it can. The size of the region set as the predetermined range may be set in consideration of, for example, the detection accuracy of the vehicle position.

In the above-described embodiment, a case has been described in which one-way information is displayed when route guidance is not performed. However, the present invention can be applied when route guidance is performed. In this case,
Since the route search processing unit 32 finds a guide route according to the preset destination and departure place, this guide route is set as the first road, and one-way information on the first and second roads is displayed. What should I do?

Further, in the above-described embodiment, traffic information such as one-way information is read from the DVD 2 in advance, and is used. Various types of traffic information, such as VICS information sent from a traffic information center (VICS center) and traffic information obtained via the Internet, may be acquired from outside the vehicle and used.

[0049]

As described above, according to the present invention, one-way information corresponding to the first road on which the vehicle is traveling and the second road connected to this road is selectively displayed. Prevents the display from becoming complicated as in the case where one-way information corresponding to all roads on the map image is displayed,
The visibility of the map information can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an overall configuration of a vehicle-mounted navigation device according to an embodiment.

FIG. 2 is a diagram showing the contents of various tables included in a road unit.

FIG. 3 is a diagram showing detailed contents of various tables included in a road unit.

FIG. 4 is a diagram conceptually illustrating map data stored in a data buffer.

FIG. 5 is a diagram illustrating first and second roads.

FIG. 6 is a flowchart showing an operation procedure of the navigation device when displaying one-way information on a map image.

FIG. 7 is a diagram illustrating a display example of one-way information when a road on which the own vehicle is traveling is a search target of a route search;

FIG. 8 is a diagram illustrating a display example of one-way information when a road on which the own vehicle is traveling is not a search target of a route search;

FIG. 9 is a diagram showing a modification of the display of one-way information when the road on which the vehicle is traveling is not a search target of the route search.

FIG. 10 is a diagram showing a display example of one-way information in a conventional navigation device.

[Description of Signs] 1 Navigation controller 7 Display device 10 Data buffer 12 Map readout control unit 14 Map drawing unit 16 VRAM 18 Image synthesis unit 20 Connection road determination unit 22 Search target road determination unit 24 One-way information drawing unit 30 Vehicle position calculation Unit 32 route search processing unit 34 guidance route drawing unit 36 mark image drawing unit

Claims (4)

[Claims] 1. A map information storage means for storing map information necessary for displaying a map image, a map drawing means for generating drawing data of the map image based on the map information, and one of a map drawing means based on the drawing data. A navigation device having display means for displaying the map information including traffic information on a screen, wherein the map drawing means determines a second road connected to the first road on which the vehicle is traveling. Determining means, based on a determination result by the connecting road determining means, displaying the one-way information corresponding to the first and second roads, and displaying the one-way information corresponding to the other third roads A non-display state, and a one-way information drawing means for generating drawing data corresponding to the one-way information. 2. The one-way information drawing unit according to claim 1, wherein the one-way information drawing means sets a drawing position of the one-way information drawing data corresponding to the second road near one end of the second road. The navigation device is set at a position close to the first road. 3. The one-way information drawing means according to claim 2, wherein the one-way information drawing means determines whether an entrance portion of the second road is connected to the first road or an exit portion is connected to the first road. A navigation device for generating drawing data of the one-way information by differentiating colors according to different colors. 4. The one-way information drawing unit according to claim 1, further comprising a search target road determination unit that determines whether the first road is a target of a route search. Is a navigation device that, when the first road is a target of a route search, activates a drawing operation for hiding the one-way information corresponding to the third road.