JP2805684B2 - Map data display method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a map data display method for reading and displaying selected map data from a recording medium on which map data corresponding to a plurality of scales are recorded.

[0002]

2. Description of the Related Art A navigation system reads, for example, map data recorded on a CD-ROM as a recording medium, detects position information such as a vehicle speed and a traveling direction through a hardware device mounted on a vehicle, and detects such information. Are synthesized and displayed on the display device. Various methods for obtaining information on the current position using the above hardware device have been studied and implemented.

A map viewed through hardware such as this navigation system has only a display resolution that depends on hardware. Therefore, the relationship between the range that can be simultaneously viewed on one screen and the object that can be expressed within this range is considerably limited.

[0004] On the other hand, a user requires a map resolution suitable for the purpose of the map. In order to respond to this request, simply changing the scale and displaying it is possible, for example, by recording detailed map data from the beginning on a recording medium and devising the hardware side for display. However, in order to respond to the higher demands of users, it is necessary to respond on the software side. A map viewed through hardware in consideration of the necessity of software has a plurality of sets of map data describing the same area corresponding to the range of a range displayed on one screen. Having a plurality of sets of map data in this way is called map hierarchy. There are a plurality of types of map scales corresponding to this map hierarchy.

When displaying a map of a certain area, it is necessary to indicate which scale level the currently displayed map is displaying in a hierarchical map. Several methods have been proposed to indicate this scale level hierarchy.

[0006] The first method is to reduce the scale level of the map data from the scale data of the scale level for overlooking the wider area to the hierarchical level of the map data in which the narrow area is described in detail, while the coarse description is recorded on the recording medium. In this method, the display is treated as relative and displayed on the screen. For example, if a layer above a certain layer is displayed with a certain layer as a boundary, “wide area” is displayed on the screen, and if a layer below this layer is displayed, “detail” is displayed on the screen. indicate.

In the second method, an error message is simply displayed unless the scale specified by the operation exists without displaying the scale level (hierarchy level) displaying the map data on the screen. There is something.

[0008] In the third method, a dedicated display device is provided outside the screen, and the hierarchy of the map being displayed is highlighted and displayed. In the dedicated display device shown in FIG. 6, for example, a CD-ROM currently used has six layers out of a maximum of 30 scale-level layers, and the display device displays the current display in these six layers. You can indicate where the hierarchy level is. In this way, the number of layers fixed by hardware is displayed.

[0009]

However, in the first and second methods described above, it is not possible to know exactly where the current layer is among all the layers of the recording medium.
Further, it is difficult to perform operations such as moving the hierarchy one or more steps or jumping directly to the selected hierarchy from the current hierarchy.

In the third method, the number of layers that can be displayed is limited because dedicated hardware is used.

However, a CD-R for recording map data
There are various types of CD-ROMs, such as OMs, which have many layers and inexpensive ones which have only a few layers. When the current hierarchy is indicated in correspondence with all of these various CD-ROMs, each CD-ROM is stored in the fixed unit.
If the hierarchical level bar indicating the hierarchical level is provided in consideration of the maximum number of hierarchical levels in, an area of the hierarchical level bar that is not used is generated and is wasted.

Actually, as shown in FIG. 6, the maximum number of layers is determined to be 30 layers by setting the format as described above. CD-RO having only six layers, for example, even if the fixed unit has 30 layers as hardware
When the current layer of M is shown, only the area A from the bottom to the sixth layer is used, and there are also 24 layers whose unused level bar is indicated by area B. In the display of layers by such a fixed unit, the compatibility of the CD-ROM is impaired because it is necessary to define the number of layers at the scale level in addition to the format. Therefore, the present invention has been made in view of such circumstances, and the display compatibility of the information is not impaired in a flexible manner when displaying information recorded on each recording medium. It is an object of the present invention to provide a map data display method capable of displaying the read information as described above.

[0013]

According to the present invention, there is provided a map data display method for reading and displaying map data from a recording medium on which map data corresponding to a plurality of scales is recorded. The above-described problem is solved by arranging symbols that are display elements in the order of the plurality of types of scale ratios of the map data recorded on a medium.

Here, in the map data display method, a symbol is displayed two-dimensionally on a display screen by controlling display of data through a data processing means for processing read information by a graphic display means. . In the map data display method, the position of the selected symbol is moved to clearly display the position of the hierarchy selected in this display, and the selected symbol is highlighted to be distinguished from other symbols. This highlight display can be moved like a cursor. With this display, the user knows the relative positions of the symbols in the hierarchy on the recording medium. Note that the cursor movement of the highlighted display is performed, for example, in accordance with a key operation whether the user operation of the scale level selection key is operated in a direction of raising or lowering the scale level hierarchy. Can be.

According to the map data display method of the present invention, the scale of a symbol is changed by software in accordance with the number of scales recorded on the recording medium in a predetermined area as a symbol display area. Are arranged in the order of the scale, the symbols of the selected scale are displayed separately from the other symbols, and the map data of the scale corresponding to the selected symbols of the scale are displayed. Further, by operating the scale level selection key like a cursor, the hierarchy of the scale level is moved up or down, and the map data of the scale corresponding to the scale level is displayed.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a map data display method according to the present invention will be described with reference to the drawings.

The map data display method according to the present invention will be described with reference to the schematic functional block configuration shown in FIG. Here, the map data is an optical disk, for example, a CD, which can have a large amount of digital data.
-Written in the ROM 10.

The map data display method is a data reading unit 11 which is a data reading unit for reading information recorded on a recording medium, and a data processing unit for performing a process based on the information from the data reading unit 11. The data processing unit 12, a graphic control unit 13 as display control means for controlling display data from the data processing unit 12, and a display device 14 as display means for displaying an output signal from the graphic control unit 13. Make up.

The operation based on this circuit configuration is as described below. Digital data recorded on the CD-ROM 10 shown in FIG. 1 is supplied to a data processing unit 12 via a data reading unit 11. The data reading section 11 is generally constituted by an optical pickup 11a and a signal processing circuit 11b. The optical pickup 11a includes an MPU (micro processing unit:
It is driven according to a control signal from the MPU 12a and moves to a target position. The target position is irradiated with laser light, and the return light reflected by the CD-ROM 10 is converted into an electric signal and supplied to the signal processing circuit 11b. The information read in this way is sent from the signal processing circuit 11b to the MPU 12a in the data processing unit 12.

The data processing unit 12 includes an MPU 12a for controlling the map data display device, a RAM 12b for temporarily storing read information, and a ROM 12c for storing data processing procedures for creating image data. It consists of:

The MPU 12a stores input information in the RAM 1
2b for writing. Also, R
The AM 12b is read again in response to a read signal from the MPU 12b. The MPU 12b supplies a control signal to the ROM 12c and, for example, a control processing program for a display operation according to the map data display method is written therein, and thus the MPU 12b creates display data according to the processing program.
In addition, the ROM 12c stores the overall control procedure of the map data display method.

The program of the ROM 12c and the MPU
The map data read from the CD-ROM 10 under the control of 12a and subjected to data processing necessary for displaying the map is sent to the graphic control unit 13. The graphic controller 13 includes a GDC (graphic display controller: hereinafter abbreviated as GDC) 13a and a V-RAM (video RAM: abbreviated as V-RAM) 13b. The map data supplied to the graphic control unit 13 is sent to the V-RAM 13b under the control of the GDC 13a, where the map data is temporarily stored. By storing the map data in the V-RAM 13b in this manner, the display on the display device 14 can be performed more easily.

Information such as read image data is displayed on a two-dimensional display screen of the display device 14 in response to an operation of an operation unit (not shown).

In this map data display method, various kinds of information are read after starting the map data display method or after exchanging the CD-ROM 10. At this time, the map data display method is, for example, the TO-
The area C (table of contents: hereinafter abbreviated as TOC) is read. This TOC information records the total number of scales of a plurality of types of maps written on the recording medium. The total number of scales of this map is stored in the RAM 12b as Nmax.

The total number of map scales Nmax stored in the RAM 12b is used as data of a screen display program built in the ROM 12c. The MPU 12a arithmetically processes parameters for displaying a so-called "scale bar" indicating the level of the scale according to the screen display program in a preset area. In the map data display method, the scale level corresponding to the currently displayed scale is highlighted so that the scale level indicated by the actual scale bar can be easily visually recognized. For the purpose of this highlight display, the currently displayed scale level, that is, the selected scale level is represented by using a variable n.

In the map data display method, the map data display at the start of the operation displays, for example, the widest area.
Here, the value of the variable n is larger at a scale level that can display a wider area. For this reason, the initial value of the variable n is set to Nmax. After displaying the initial screen, the user changes the variable n by, for example, moving up or down a scale level selection key for selecting a scale level on the operation panel. Thus C
While displaying the total number of scales included in the D-ROM 10,
If the scale level being displayed can be known in response to the operation of the scale level selection key, the operability of the user can be significantly improved.

The procedure for displaying the hierarchy of the map data, that is, the scale level, will be described with reference to the flowchart shown in FIG. FIG. 1 is referred to as needed. Displaying the scale level is part of a routine for displaying map data. Start the map data display method and start CD
-Set the ROM 10.

The CD-ROM set in step S10
10. Digital data is read from 10.

In step S11, the TOC information written in the CD-ROM 10 is also read out and written in the RAM 12b. In this step, the CD-ROM 10
Is read as Nmax, and the process proceeds to step S12.

In step S12, the scale level at which the image is initially displayed is represented by using a variable Ninit. For example, the variable Ninit is set to Nmax, which is the total number of layers. Also,
The initial screen is displayed through a screen display routine (not shown) by substituting the value of Ninit into a variable n indicating the hierarchy to be actually displayed.

Next, in step S13, the subsequent display operation is changed depending on whether or not the scale level selection key is pressed. If the operation of pressing the scale level selection key has not been performed (No), the process returns to step S13. Also,
If the operation of pressing the scale level selection key has been performed (Yes), the process proceeds to step S14. In step S13, the scale level selection key may be interrupted in response to a pressing operation, and the process may proceed to step S14.

In step S14, it is determined whether or not the user's operation of the scale level selection key has been operated in the direction of raising or lowering the scale level hierarchy. This operation is performed by moving the above-mentioned highlight display like a cursor. If it is determined that the operation has been performed in a direction to raise the displayed hierarchy, the process proceeds to step S15. On the other hand, if it is determined that the operation has been performed to lower the displayed hierarchy, the process proceeds to step S17.

In step S15, it is determined whether or not the value of the variable n before raising the hierarchy is smaller than the total number Nmax. When the value of the variable n is a large value equal to or greater than the total number Nmax, for example, control is performed so as to display the maximum displayable wide area, and the display and the scale level display are not changed at all and the process proceeds to step S13. return. If the value of the variable n is smaller than the total number Nmax, step S
Proceed to 16.

In step S16, the value of the variable n is incremented by one.
Subroutine S
Proceed to UB.

In the step S17 in which the displayed hierarchy is lowered, the value of the variable n before lowering the hierarchy is set to CD-
If the value is smaller than the lowermost layer (n = 1) of the ROM 10, for example, control is performed so that the most detailed map data is displayed on the CD-ROM 10 being displayed.
The process returns to step S13 without making any change in the display and the scale level display. If the value of the variable n is larger than 1, the process proceeds to step S18.

In step S18, the value of the variable n is set to -1.
Subroutine S
Proceed to UB.

The subroutine SUB includes the changed variable n
The display is changed according to the value of. In response to this display change, the highlight display position in the scale level display is changed and displayed, and the map data at the scale level corresponding to the value of the variable n is displayed. When the display is completed, the process returns to step S13 and waits until the next scale level selection key is operated.

FIG. 3 shows an example in which a scale level is displayed on the display screen. The display screen 15 shown in FIG. 3 has an area 16 secured in advance at the lower right of the screen. In this area 16, symbols are displayed as display elements corresponding to the number of layers recorded on the CD-ROM 10. CD-RO currently reading according to the map data display method
It is easy to see that M10 has eight scale levels. In the mode for displaying the position of this hierarchy, the hierarchy S3, which is two levels higher than the lowest hierarchy currently highlighted, is selected, or the hierarchy to be selected is displayed as a cursor. With this display, it is possible to visually and easily determine the relative position in the eight layers as described above. Further, when the specific scale of the scale level of the lowest hierarchy is known, for example, the scale of the above-mentioned hierarchy S3 can also be known.

The procedure for controlling the symbol display in this map data display method will be described with reference to the flowchart shown in FIG. In order to explain these symbol display controls, reference is made to the schematic diagram shown in FIG.

The symbol display area in this map data display method is set in advance. This display area is the display area 20 shown in FIG. In this display area 20, a so-called scale level bar indicating a hierarchy is displayed.

At the same time as the start of the display process, the process proceeds to step S20, where the total number Nmax of scale levels recorded on the CD-ROM 10 is read. The scale level bar used for this hierarchical display is one unit (hereinafter referred to as a unit)
Treat as

In step S20, the total number N of layers read
The pitch P between each unit is calculated from max. In this calculation, the total length of one of the hierarchically displayed areas shown in FIG.
And Also, a width 21 from the upper end 20a of the hierarchical display area 20 of the CD-ROM 10 being reproduced to the unit of the highest hierarchical level, that is, the level unit displaying the widest area.
Is set at the upper end margin MU. Similarly, the lower margin MD is set to the width 22 from the lower end 20b of the hierarchical display area 20 to the lowest level, that is, the unit of the level that displays the most detailed area.

It is apparent that the number of pitches P between the units is represented by Nmax -1 based on the total number of layers Nmax. Therefore, the effective length obtained by subtracting the margin is (Nmax
-1) By dividing, the pitch P can be obtained by the following equation: P = {L− (MU + MD)} / (Nmax−1) (1) The process proceeds to step S21 to find this pitch P.

In step S21, a unit size h shown in FIG. 5 is obtained from the pitch P in the effective length. The unit size h is preferably at least smaller than the pitch P (h <P).

For example, the unit size h is set to h = P / 2 (2) to represent the width of the unit. This unit size h
Is set and the process proceeds to step S22.

In step S22, the display area 2 is determined based on the parameters determined in steps S20 and S21.
The drawing data for unit display indicating each layer is created in 0. As shown in FIG. 5, for example, drawing data from the lowest unit 1 to the highest unit Nmax is created in the display area 20, and after the creation is completed, the process proceeds to step S23.

In step S23, the unit 21 corresponding to the scale specified by the scale level selection key is obtained from the above-described procedure.

In step S24, data for highlighting is added to the drawing data of the unit specified in step S23.

In step S25, the drawing data created by the above-described procedure is stored in, for example, the V-RAM 1 shown in FIG.
3b to perform drawing processing. Also, the V-RAM 13
The data from b is supplied to the display device 14 and displayed.

The drawing data is output to the display device 14, and the procedure of the display processing is completed.

With this configuration, it is possible to visually and instantaneously determine the relative scale level of the scale level of the displayed map in the total number of the recording media used. This makes it easy to make significant scale level changes. If the scale of the highest or lowest level of this scale level is clear, the absolute scale level can also be known.

Further, the display of the so-called scale bar can be displayed in the display area in response to the change in the number of units. As a result, when a fixed unit using hardware is used, an unnecessary display area generated for maintaining compatibility of the information in displaying information can be eliminated, and the scale of the recording medium can be effectively displayed as a symbol. . In other words, the screen can be effectively used, and even if the recording medium is changed, the number of scale factors and the displayed scale level can be immediately known in a flexible manner.

[0053]

As is apparent from the above description, according to the map data display method of the present invention, a map for reading and displaying map data from a recording medium on which map data corresponding to a plurality of scales is recorded. In the data display method, symbols as display elements are arranged in the order of the plurality of scale scales of the map data recorded on the recording medium, and map data corresponding to the selected scale symbol is displayed. In addition, by displaying the above-mentioned symbols separately from other symbols, it is possible to determine where the scale level of the displayed map is as a relative scale level in the total number of the recording media used. It is visually instantaneous and makes it easy to make significant scale level changes. Also, when the scale of the highest or lowest level of the scale level is clear, the absolute scale level can be known. That is, it is easy to proceed to the hierarchical level of the information requested by the user when searching for the target place, and it is possible to efficiently perform operations such as searching.

When the operation of changing the scale is performed, the user moves the scale of the map data corresponding to the symbol of the scale displayed differently by the scale level operation key in the direction of raising or lowering the cursor. The operation can be carried out lightly while visually confirming the absolute position and relative position of the map data in the whole scale of the scale level. Improve efficiency.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic block configuration of a map data display method.

FIG. 2 is a flowchart illustrating a procedure for changing the display of a scale level using the schematic block configuration shown in FIG. 1;

FIG. 3 is a schematic diagram illustrating an example of a display screen when display control is performed according to the flowchart illustrated in FIG. 2;

FIG. 4 is a flowchart illustrating a procedure for displaying a unit indicating a hierarchy in software in a preset display area.

FIG. 5 is a schematic diagram showing a relationship between parameters necessary for displaying a unit indicating a layer by software in a display area set in advance in accordance with the procedure shown in FIG. 3;

FIG. 6 is a schematic diagram showing an example of a conventional scale level display by a fixed unit configured by hardware.

[Explanation of symbols]

 10 CD-ROM 11 Data reading unit 12 Data processing unit 13 ... Graphic control unit 14 Display device

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G09B 29/00 G01C 21/00 G08G 1/0969

Claims (3)

(57) [Claims] 1. A map data display method for reading and displaying map data from a recording medium on which map data corresponding to a plurality of scales is recorded, wherein the plurality of scales of the map data recorded on the recording medium are provided. Arranging a plurality of symbols as display elements in the order of the scale of the scale, and displaying map data of the corresponding scale by selecting one of the scales displayed by the symbols. Map data display method. 2. The map data display method according to claim 1, wherein the symbol of the selected scale is displayed separately from other symbols. 3. The map data display method according to claim 1, wherein the user operates the scale level selection key to increase or decrease the scale of the scale displayed by the symbol.