JP2006023495A - Map display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a map display device capable of displaying a map in a desired condition regardless of drawing sequence of each object constituting map data or drawing sequence of sections of the map. <P>SOLUTION: In the map display device, an image is formed by: taking map data out of a map data storing medium 51 and storing the map data in a data storing buffer 53; taking out, one by one, objects constituting background data, road data or the like stored in the data storing buffer 53; and writing the objects in an image forming area 55. Each pixel in the image forming area 55 is constituted of display color information and drawing priority, and the pixel in the image forming area 55 is updated only when the drawing priority of the objects is higher than the drawing priority of the pixel in the image forming area 55. When all the objects are processed and image formation is completed, the display color information in the image forming area 55 is transferred to a VRAM 57 to display a map on a display section. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

 The present invention relates to a map display technique applicable to a navigation device or the like.

As a map display method in a conventional navigation device or the like, map data (background data, road data, name data, etc.) is read from a map data storage medium such as a map disk, and based on a predetermined drawing order, for example, A background object is drawn using the background data, then a road object is drawn using the road data, and finally a name object is drawn using the name data to form a map image. And the formed map image was displayed on the display device (for example, refer to patent documents 1).
JP-A-6-331371 (FIG. 2 etc.)

  However, in the navigation apparatus using the conventional map display method as described above, for example, in order to make the map viewer aware of the entrance to the underground tunnel, only a specific road object is behind the building object (background object). I couldn't do that. Because, as described above, the map image formed so as to overlap in a predetermined order is composed only of color information, so when an object is added later, the object is necessarily brought to the forefront. This is because it will be drawn. Of course, a method of drawing by appropriately changing the drawing timing of the road object is also conceivable. However, however, it is not easy to derive an appropriate drawing timing in consideration of all the relations with other adjacent objects.

  In general, map data is managed by being divided into sections. For example, in the case of a method in which the next section is drawn after drawing one section, an object that spans adjacent sections is displayed. There was a problem that a part was overwritten. Specifically, as shown in the map image of FIG. 6A, after the map section 85 including the road object 81 is first drawn, the road section 81 is not included but the building object 83 is included. When drawing from the above, there is a possibility that the building object 83 is drawn so as to overlap the road object 81 (preferably FIG. 6B).

  The present invention has been made in view of such problems, and a map capable of displaying a map in a desired state regardless of the drawing order of each object constituting map data and the drawing order of map sections. An object is to provide a display device.

  The map display device according to claim 1, which has been made to solve the above-mentioned problem, obtains stored data from a map data storage medium in which data corresponding to each map object is stored. And a drawing priority holding means for holding a drawing priority determined for each type of map object, and a map image that draws each map object in order using the data acquired by the map data acquisition means to form a map image Forming means, and display means for displaying the map image formed by the map image forming means.

  The map image forming means holds the drawing priority for each pixel of the map image being formed, and when drawing the map object, obtains the drawing priority corresponding to the map object from the drawing priority holding means. The map object is compared with the drawing priority of the drawing destination pixel of the map object and the drawing priority obtained from the drawing priority holding means, and only when the drawing priority obtained from the drawing priority holding means is higher The pixel of the image is updated with the data of the map object, and the drawing priority held for each pixel is updated with the drawing priority acquired from the drawing priority holding means, and drawing priority is given only for a specific map object. Instead of the drawing priority held by the degree changing means, the designated drawing priority is used.

  Note that the drawing performed by the map image forming means does not mean that the drawing is actually visible to the user (that is, the drawing displayed on the display means), but inside the map (specifically, for example, on the memory). It means forming an image.

  According to such a map display device, since the drawing priority is held for each pixel of the map image being formed, a desired map image can be formed regardless of the order in which the map objects are drawn. it can. Therefore, for example, when only a specific road object is displayed behind the building object, if the drawing priority of the road object is specially lower than the drawing priority of the building object, the drawing order is conscious. It becomes possible easily. In addition, the above-described problem that a part of an object extending over adjacent sections is overwritten can be avoided because the overwriting presence / absence is controlled by the drawing priority set for each pixel.

  By the way, the drawing priority held by the drawing priority holding means may be fixed, but may be changed by the user's operation, traffic situation, time zone, map scale, etc. Good. That is, as in the map display device according to claim 2, it is preferable to further include a drawing priority changing unit that can change the drawing priority held by the drawing priority holding unit.

  If this is the case, for example, in a traffic jam or at night, the priority of road objects is relatively increased to form a map image (an example of claims 3 and 4), or the map scale is large. In addition, it is possible to relatively lower the drawing priority of the building object (an example of claim 5), or to adjust the drawing priority according to the user's preference. The drawing priority holding means may hold a plurality of drawing priorities in a table format, and the drawing priority changing means may switch the table.

  Further, a program that functions as the map image forming means in the map display device according to any one of claims 1 to 5 as described in claim 6 is caused to be executed by a computer built in the map display device. It may be. In this case, for example, the program is recorded on a computer-readable recording medium such as a flexible disk, a magneto-optical disk, a CD-ROM, a hard disk, a ROM, and a RAM, and the program is stored in the computer as necessary. When loaded and activated, the computer can function as a map image forming unit of the map display device. Further, since the program can be distributed using a network or the like, it is easy to improve the function of the map display device.

  Embodiments to which the present invention is applied will be described below with reference to the drawings. The embodiments of the present invention are not limited to the following examples, and can take various forms as long as they belong to the technical scope of the present invention.

FIG. 1 is a block diagram showing a schematic configuration of a navigation device 20 in which the functions of the map display device of the present invention are incorporated.
The navigation device 20 is mounted on a vehicle, and a position detector 21 that detects the current position of the vehicle, an operation switch group 22 for inputting various instructions from a user, and various instructions as with the operation switch group 22 are input. A remote control terminal (hereinafter referred to as a remote control) 23a that is possible and separate from the navigation device 20, a remote control sensor 23b that inputs a signal from the remote control 23a, a packet communication network, etc. An external communication device 24 that performs communication, a map data input device 25 that inputs map data and the like from a map storage medium that records map data and various types of information, a display unit 26 that displays maps and various types of information, A voice output unit 27 for outputting various kinds of guide voices, a microphone 28 for outputting an electrical signal based on a voice uttered by a user, An in-vehicle LAN communication unit 30 for exchanging various information with other devices via the internal LAN, the above-described position detector 21, operation switch group 22, remote control sensor 23b, map data input device 25, microphone 28, in-vehicle LAN communication A control unit 29 that executes various processes according to input from the unit 30 and controls the display unit 26, the audio output unit 27, and the in-vehicle LAN communication unit 30 is provided.

  The position detector 21 receives a radio wave from a GPS (Global Positioning System) artificial satellite via a GPS antenna (not shown) and outputs a received signal, and a magnitude of rotational motion applied to the vehicle. A gyroscope 21b for detecting the distance, a distance sensor 21c for detecting a distance traveled from the longitudinal acceleration of the vehicle, and the like, and a geomagnetic sensor 21d for detecting the traveling direction from the geomagnetism. Then, based on the output signals from these sensors 21a to 21d, the control unit 29 calculates the position, direction, speed, etc. of the vehicle. Although there are various methods for obtaining the current position based on the output signal from the GPS receiver 21a, either a single positioning method or a relative positioning method may be used.

  The operation switch group 22 includes a touch panel configured integrally with the display surface of the display unit 26, mechanical key switches provided around the display unit 26, and the like. The touch panel and the display unit 26 are laminated and integrated. There are various types of touch panels such as a pressure-sensitive method, an electromagnetic induction method, a capacitance method, or a combination of these methods. It may be used.

The external communication device 24 acquires accident information, traffic jam information, and the like from the VICS information center via an optical beacon or a radio beacon installed on the roadside.
The map data input device 25 is a device for inputting various data stored in a map data storage medium (not shown). Map data storage media include map data (node data, link data, cost data, background data, road data, name data, mark data, intersection data, facility data, etc.), voice data for guidance, voice recognition data, etc. Is remembered.

  The display unit 26 is a color display device such as a liquid crystal display, an organic EL display, or a CRT, and any of them may be used. The display screen of the display unit 26 includes a mark indicating the current location identified from the current position of the vehicle detected by the position detector 21 and the map data input from the map data input device 25, a guidance route to the destination, and a name. Additional data such as landmarks and various facility marks can be displayed in an overlapping manner. Also, facility guides can be displayed.

The voice output unit 27 can output facility guides and various guidance voices input from the map data input device 25.
The microphone 28 outputs an electric signal (voice signal) based on the inputted voice to the control unit 29 when the user inputs (speaks) voice. The user can operate the navigation device 20 by inputting various sounds to the microphone 28.

The in-vehicle LAN communication unit 30 communicates with various devices (for example, an engine ECU (not shown)) connected to the in-vehicle LAN via the in-vehicle LAN.
The control unit 29 is configured around a well-known microcomputer including a CPU, ROM, RAM, SRAM, I / O, and a bus line connecting these components, and is based on a program stored in the ROM and RAM. Various processes. For example, the current position of the vehicle is calculated as a set of coordinates and traveling directions based on each detection signal from the position detector 21, and a map or the like near the current position read via the map data input device 25 is displayed on the display unit 26. The optimal route from the current position to the destination is calculated based on the processing to be performed, the map data stored in the map data input device 25, and the destination set according to the operation of the operation switch group 22 or the remote controller 23a. A process, a process of guiding the route by causing the display unit 26 to display the calculated route or outputting the sound as a voice to the voice output unit 27 is executed.

  Here, correspondence between each part of the navigation device 20 and the terms described in the claims is shown. The control unit 29 corresponds to a drawing priority holding unit, a map image forming unit, and a guide route calculation unit, the map data input device 25 corresponds to a map data acquisition unit, the display unit 26 corresponds to a display unit, and a group of operation switches. 23 and the remote controller 23a correspond to a drawing priority changing unit.

  Next, the object table 41 stored by the control unit 29 will be described using the table shown in FIG. The object table 41 includes an object type 43 (for example, a national road mark, a prefectural road mark, a facility name, etc.), an object classification 45 (for example, name data, road data, background data, etc.), a drawing priority 47 (for example, 1, 2, 3) and color information 49 (for example, blue, green, black, etc.). These pieces of information can be changed by the user operating the operation switch group 22 or the remote controller 23a.

  Next, a map image forming process which is a process characteristic of the navigation device 20 of the present embodiment among the processes executed by the control unit 29 will be described with reference to FIGS. 3 and 4. First, the outline of the map image forming process will be described using the schematic explanatory diagram of FIG. 3, and then the details of the map image forming process will be described using the flowchart of FIG. It should be noted that a description will be given of a destination setting process for setting a destination based on information input by a driver, a route guidance process for performing guidance based on a calculated route, and the like performed by a general navigation device. Omitted.

  As shown in the schematic explanatory diagram of FIG. 3, the map data is first extracted from the map data storage medium 51 and stored in the data storage buffer 53. At this time, it is acquired from the map data storage medium 51 and stored in units of map sections. Each stored map section is divided into background data, road data, and name data.

  Next, a map image is formed by taking out the objects constituting the background data and road data stored in the data storage buffer 53 one by one and writing them in the image forming area 55. Note that each pixel in the image forming area 55 includes display color information and drawing priority, and only when the drawing priority of the object is higher than the drawing priority of the corresponding pixel in the image forming area 55. The pixels in the image forming area 55 are updated with the display color information of the object and the drawing priority.

When all the objects are processed and the formation of the map image is completed, the display color information of the image forming area 55 is transferred to the VRAM 57 and the map is displayed on the display unit 26.
Next, the map image forming process will be described in detail with reference to the flowchart of FIG. The control unit 29 executes a map image forming process when a request for displaying a map on the display unit 26 is made. When the control unit 29 starts executing the map image forming process, map data is first extracted from the map data storage medium 51 via the map data input device 25 and stored in the data storage buffer 53 (S210). At this time, the map data is divided into map sections, and these are further divided and stored for each object classification (specifically, background data, road data, name data).

Next, data for one object is read from the specific map section of the data storage buffer 53 (S215).
Next, the drawing priority 47 corresponding to the object type 43 of the object read in S215 is acquired from the object table 41 (S220).

Next, the color information 49 corresponding to the object type 43 of the object read in S215 is acquired from the object table 41 (S225).
Next, object data (pixel set) is generated by adding the drawing priority 47 acquired in S220 to the color information 49 acquired in S225 (S230).

  Next, the drawing priority is changed only for a specific object (S235). This is to change the drawing priority in the object data generated in S230 for an object for which a drawing priority different from the drawing priority 47 of the object table 41 is to be set.

  Next, the drawing priority 47 of the object data is compared with each drawing priority of the pixel to be written in the image forming area, and only the pixel to be drawn having a higher drawing priority 47 of the object data is used as the object data. Update (S240). In this update, both display color information and drawing priority are updated.

Next, the process branches depending on whether or not all objects in the specific map section of the data storage buffer 53 have been processed (drawing as described in terms of claims) (S245). If all objects have been processed, the process proceeds to S250. If all objects have not been processed, the process returns to S215.

In S250, the process branches depending on whether or not all the sections stored in the data storage buffer 53 have been processed. If all map sections have been processed, this process (map image forming process) is terminated. If all map sections have not been processed, the process returns to S215.

  Since the navigation device 20 is configured and operates as described above, conventionally, as shown in the map image of FIG. 5A, all the name objects can only be displayed in front of the building object. As in the map image shown in FIG. 5B, it is possible to easily display only a specific object (name object 73) behind the specific object (building object 71). In addition, the above-described problem that a part of an object extending over adjacent sections is overwritten (see FIG. 6A) is avoided because overwriting is controlled by the drawing priority set for each pixel. be able to. That is, according to the navigation device 20 of the embodiment, it is possible to display a map in a desired state regardless of the drawing order of the objects constituting the map data and the drawing order of the map sections.

Other embodiments will be described below.
In the above embodiment, the drawing priority 47 can be changed by the user operating the operation switch group 22 or the remote controller 23a. However, the control unit 29 can change the drawing priority 47 according to the congestion on the guidance route. The drawing priority 47 may be changed. Specifically, for example, the drawing priority 47 of the object of the guidance route or the traffic road may be relatively increased in a traffic jam.

  Further, the control unit 29 may change the drawing priority 47 according to the current time. Specifically, for example, in the evening or at night, the drawing priority 47 of the object of the guide route or the congested road may be relatively increased so that the guide route is most easily recognized.

  Further, the control unit 29 may change the drawing priority 47 according to the map scale. Specifically, for example, when the map scale is large, the drawing priority 47 of the building object or the name object may be relatively lowered.

  If it becomes like these, the visibility of the map displayed on the display part 26 will improve.

The block diagram which shows schematic structure of the navigation apparatus of an Example. It is a table | surface for demonstrating an object table. It is a schematic explanatory drawing for demonstrating map image formation processing. It is a flowchart for demonstrating map image formation processing. It is a map image for demonstrating the effect of the navigation apparatus of a present Example. It is a map image for demonstrating the problem of the conventional navigation apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 20 ... Navigation apparatus, 21 ... Position detector, 21a ... GPS receiver, 21b ... Gyroscope, 21c ... Distance sensor, 21d ... Geomagnetic sensor, 22 ... Operation switch group, 23a ... Remote control, 23b ... Remote control sensor, 24 ... External Communication device 25 ... Map data input device 26 ... Display unit 27 ... Audio output unit 28 ... Microphone 29 ... Control unit 30 ... In-vehicle LAN communication unit 41 ... Object table 43 ... Object type 45 ... Object Classification: 47 ... Drawing priority, 49 ... Color information, 51 ... Map data storage medium, 53 ... Data storage buffer, 55 ... Image forming area, 57 ... VRAM.

Claims (6)

Map data acquisition means for acquiring the stored data from a map data storage medium storing data corresponding to each map object;
Drawing priority holding means for holding drawing priority determined for each type of the map object;
Map image forming means for drawing each map object in order using the data acquired by the map data acquiring means to form a map image;
Display means for displaying the map image formed by the map image forming means;
With
The map image forming means includes:
A drawing priority is held for each pixel of the map image being formed, and when drawing the map object, a drawing priority corresponding to the map object is acquired from the drawing priority holding means, and the map object The drawing priority of the drawing destination pixel is compared with the drawing priority acquired from the drawing priority holding unit, and only when the drawing priority acquired from the drawing priority holding unit is higher, the map The pixel of the image is updated with the data of the map object, and the drawing priority held for each pixel is updated with the drawing priority acquired from the drawing priority holding means.
Only for a specific map object, using the designated drawing priority instead of the drawing priority held by the drawing priority changing means,
A map display device characterized by the above. The map display device according to claim 1,
The map display device further comprises a drawing priority changing unit capable of changing the drawing priority held by the drawing priority holding unit. The map display device according to claim 2,
The drawing priority changing unit changes the drawing priority held by the drawing priority holding unit according to a traffic congestion state on the map image formed by the map image forming unit. Display device. The map display device according to claim 2,
The map display device, wherein the drawing priority changing means changes the drawing priority held by the drawing priority holding means according to a current time. The map display device according to claim 2,
The drawing priority changing unit changes the drawing priority held by the drawing priority holding unit according to a scale of the map image to be formed by the map image forming unit. .   The program for functioning a computer as the said map image formation means of the map display apparatus in any one of Claims 1-5.