JPH07168524A - Navigation device - Google Patents

Abstract

PURPOSE:To provide a navigation device without the change of size of a displayed character and symbol even when a map is expanded/reduced and easy to visualize the character and symbol. CONSTITUTION:A signal operation processor 3 reads out road map information incorporated in the map data of a division to be displayed from a storage place for storing the road map information of an information storage device 4, and generates a road map for display, and reads out position coordinate information showing a display position on the map to be displayed related to the character and symbol incorporated in the map data of the division to be displayed and font information showing their forms, and writes the character and symbol shown by the font information on a position corresponding to the position coordinate information of the generated road map. Further, the position of a vehicle is calculated, and is displayed on a display device 5 together with the road map where the character and symbol are written.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle-mounted navigation device for displaying a current position of a vehicle, a road map, information necessary for traveling, and the like.

[0002]

2. Description of the Related Art A vehicle traveling guide device for detecting the current position of a vehicle, displaying it on a road map, and displaying information necessary for traveling is disclosed in, for example, Japanese Patent Application Laid-Open No. 57-169785. An "induction device" is known. This displays a mark indicating the position and the traveling direction of the vehicle in a predetermined direction on the display screen with a certain direction, and is displayed on the display screen as the vehicle travels. Then, in this, an apparatus adapted to move a map pattern is disclosed. In this device, in order to easily identify the current position of the vehicle on the map, the display map can be enlarged and reduced at a plurality of predetermined magnifications.

[0003]

In the device disclosed in this known example, the display map is represented as a set of dots (dots) on the screen, and when the display map is enlarged, the display screen is displayed. The corresponding display point of M rows and N columns is extracted from the data, and the display point is dispersed on the display screen to enlarge the display map.

By the way, in the map, not only road figures but also characters and symbols for representing place names and the like are described.

However, as described above, when the map is simply enlarged or reduced, the characters and symbols are also enlarged or reduced accordingly. Therefore, there is a problem that the size of the character / symbol changes, and the character / symbol becomes very difficult to read.

Further, when the map is enlarged and displayed due to the dispersion of the display points, there is a drawback that the displayed map is difficult to visually recognize.
Therefore, even if the display points are dispersed, the magnification of enlargement can be suppressed to such an extent that it can be visually recognized as a map display with the naked eye.

In the above-mentioned publicly known example, for example, the number of display points required to display a map at a scale of 1 / 250,000 is M rows N.
It is assumed that the row (M × N) is sufficient. Next, when this 1 / 250,000 scale map is displayed at a 1 / 50,000 scale (magnification of 5 times), the dispersion of the display points becomes large (that is, the area of the display points becomes 5 × 5 = 25 times). , The display map has poor visibility.

Therefore, in order to be able to enlarge and display at a scale of 1 / 50,000 (magnification of 5 times), the number of display points is reduced to 1 / 250,000.
The display map with good visibility cannot be obtained unless it is stored with the accuracy of 5 times as many as the map of 5 in 5M rows and 5N examples (5M × 5N pieces). That is, in order to display a map at a magnification of 5 times and a scale of 1 / 50,000, a storage capacity that is 25 times the storage capacity necessary to store the original map (scale of 1 / 50,000) is required. If the magnification of the enlarged map is 10 times, the storage capacity of 100 times that of the original map is required.

As described above, the conventional technique has a drawback that the storage capacity of map data becomes enormous when an enlarged view is required. If the amount of magnetic tape that stores map data increases, the read time for reading one map data will increase, and the amount of data handled as a vehicle travel guidance device will increase. ,
A large-capacity storage unit is required for the entire device, which is problematic in terms of cost.

The present invention has been made in view of the above-mentioned problems of the prior art. A first object of the present invention is that even if a map is enlarged or reduced, the size of displayed characters or symbols does not change, It is to obtain a navigation device in which characters and symbols are easily visible.

A second object of the present invention is to provide a large amount of map information including an enlarged map with a relatively small storage capacity without excessively increasing the storage capacity of the storage medium and the storage device in the navigation device. To obtain a memorable navigation device.

[0012]

In order to achieve the above first object, according to the first aspect of the present invention, in a navigation device displaying a map and a vehicle position, at least road map information and characters / symbols are displayed. A storage medium for storing map data including information for each of the divided maps, an information storage device for reading the map data from the storage medium, and a display device capable of displaying at least the position of the map and the vehicle. And a signal arithmetic processing unit for performing arithmetic processing of the current position of the vehicle, processing of map data and processing of display data, and the storage medium appears on the map for each of the previously divided maps. It has a storage location for storing road map information indicating a road and a storage location for storing character / symbol information.
In the storage location of the symbol information, position coordinate information indicating the display position on the map where each character / symbol is to be displayed and font information indicating their shape are stored. A means for reading road map information contained in the map data of the section to be displayed from the storage location of the road map information via the storage device, and generating a road map for display, and the information storage device. hand,
From the storage location of the character / symbol information, the position coordinate information indicating the display position on the map where the characters / symbols should be displayed, which are included in the map data of the section to be displayed, and their shapes are displayed. A means for reading out the font information to represent and writing a character / symbol in a form represented by the font information at a position corresponding to the position coordinate information of the generated road map; and a means for calculating the position of the vehicle. There is provided a navigation device comprising: a road map in which the characters / symbols are written; and means for displaying the calculated vehicle position on the display device.

In order to achieve the first and second objects, according to the second aspect of the present invention, in addition to the first aspect, an instruction is input to the signal processing device. Further comprising an input device for, the means for generating the road map, according to the instructions input from the input device,
A means for generating a road map by enlarging or reducing is further provided, and, in the storage location of the road map information, for each road appearing on the map, a division point obtained by dividing each road within a range where linear interpolation can be performed is performed. The position coordinate information is sequentially stored for each road from one end to the other end along each road, and means for generating a road map for the display is
From the storage location of the road map information, the position coordinate information included in the map data to be displayed is read for each road in the order stored, and the adjacent coordinates of the read position coordinate information are linearly interpolated. Thus, a navigation device is provided, wherein a line connecting the division points in order is formed, and a road map is generated using the information of the line as data indicating a road.

[0014]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the overall structure of a navigation device according to the present invention.

In the figure, the traveling distance detector 1 generates a pulse signal according to the vehicle speed, for example. The traveling direction detector 2 is a detector for detecting the traveling direction of the vehicle, and is, for example, a magnetic sensor that detects the traveling direction by utilizing the geomagnetism. The signals detected by the traveling distance detector 1 and the traveling direction detector 2 are read by the signal arithmetic processing unit 3.

The signal arithmetic processing unit 3 calculates the present traveling position of the vehicle by arithmetically processing these two signals. Further, the signal processing unit 3 calculates the current traveling position and inputs the map data corresponding to the current traveling position from the information storage device 4. A cassette tape recorder is used as the information storage device 4, but RA
Storage means such as M and a magnetic disk are also conceivable. And
The signal processing unit 3 compares the current traveling position with the information stored in the information storage device 4, and simultaneously displays the map data and the accurate current traveling position on the map data on the screen of the display device 5 which is a CRT. To do.

The input device 6 is an input device for controlling the operation of the signal arithmetic processing device 3.

Next, the configuration of the signal arithmetic processing unit 3 will be described in detail with reference to FIG.

The signal arithmetic processing unit 3 inputs signals from the traveling distance detector 1, the traveling direction detector 2 and the input unit 6, respectively, and calculates the current position of the vehicle. Then, the map data corresponding to the current position is read from the information storage device 4 and displayed on the display device 2. In FIG. 2, a television antenna 7 is provided so that the display device 5 can be used as a television.

Next, the configuration of the signal processing unit 3 will be described.

The signal processing unit 3 is controlled by two microprocessors 31 and 32. The microprocessor 31 performs arithmetic processing of the current position and control of the entire system, and the microprocessor 32 performs map data processing and map display.

The input / output circuit 311 reads a signal from the input device 6 such as a keyboard. Processor 312
Performs waveform shaping processing so that the signals from the traveling distance detector 1 and the traveling direction detector 2 can be easily processed by the microprocessor 31. The interface 313 is a circuit for controlling the microprocessor 32 by the microprocessor 31.

The microprocessor 32 operates according to a program stored in a read only memory (ROM) 321. A read / write memory (RAM 322 is for temporarily storing stack memory data, map data, etc. of the microprocessor 32. Input / output circuit 3
Reference numeral 23 is a map data search for reproducing, fast-forwarding, and rewinding operations of the information storage device (cassette / deck in this embodiment) 4, and converts serial map data from the cassette deck 4 into parallel data. , Reproduce and edit map data such as temporarily storing it.

The video RAM 324 is a read / write memory that stores display data for one display map. Video R
The display data written in the AM 324 is displayed on the display device 5 by the video display generator (VDG) 325.

In this embodiment, the television antenna 7, the television tuner 33, and the demodulation circuit 331 are provided, and television reception can be performed by switching the switching circuit 314 to the television receiving side by the microprocessor 31. The display device 5 includes a deflection circuit 501, a video amplification circuit 502, and a CRT.
503.

In the navigation device having such a configuration,
When a map as shown in FIG. 3 is displayed on the display device 5, the map data such as characters and symbols shown in FIG. 3 and the map data for the road map are recorded on a recording medium such as the magnetic tape 11 shown in FIG. Then, like the map number recording unit 111, the character / symbol information recording unit 112, and the road map information recording unit 113, the area is divided and recorded according to the stored contents.

First, the character / symbol information recording section 112 will be described. The data format of the character / symbol information recording unit 112 is, as shown in FIG. 5, for one character, that character is a main scale map (map data that is always displayed. In this embodiment, it is shown in FIG. Which position on the map (scale of 1 / 250,000 shown) corresponds to the main scale position information section 112A of the X and Y coordinates of the main scale map of FIG. 8 is recorded at the beginning of the stored character. Then, after the main scale position information section 112A, character / dot position information such as characters / symbols is recorded in the character information recording section 112B, similarly to the output of the character generator. Memory information such as characters and symbols is called font information.

Therefore, the cassette deck 5 searches for a predetermined map number, and the read data such as characters and symbols corresponds to the position information of the data in the video RAM 32.
4 is written in place. This way,
The size of characters does not change as the display image is enlarged or reduced. If the same number of characters are always displayed on the enlarged and reduced display screens, the reduced scale display screen becomes very difficult to see, so the main scale position information section 11
In 2A, discrimination information of whether each character / symbol information is displayed in an enlarged view or a reduced view is recorded.

Next, the road map recording unit 113 will be described.

FIG. 6 is an explanatory diagram of linear interpolation,
The figure is a recording state diagram of the position coordinate information of each point O, P, Q, and R in FIG. First, the cassette deck 4 is searched for the map number N, and then the position coordinate information on the road map is read. That is, the position coordinate information O (x ₁ , y ₁ ) is read, and then the position coordinate information P (x ₂ , y ₂ ) and Q (x ₃ ,
y ₃ ), R (x ₄ , y ₄ ), ... In this order, the respective position coordinates on the road map are read in sequence. Then, by performing linear interpolation in the order of the read position coordinate information, the sixth
The O / P / Q / R road map as shown in the figure is drawn.

In this way, the road map O / P / Q /
The number of pieces of position information required to draw R is four in FIG. By using such a linear interpolation method,
The number of data required to display roads on the map can be greatly reduced.

A method of determining the division points divided in the range where the linear interpolation can be performed will be described with reference to FIG.

The arc ACB in FIG. 10 is a road map. The point A on this road map is set as a reference point, and the point B is slid along the road map. At this time, a string AB (straight line L) formed between points A and B and a parallel line L1 having a distance D
Suppose Then, as the point B slides, the parallel line L1 and the road map (arc ACB) may cross each other. The point C at this intersection is defined as a division point divided within a range in which linear interpolation can be performed. Then, the reference point A and the division point C are connected. This straight line (broken line) AC is a road map formed by linear interpolation. Next, by using the point C as a reference point and repeating the same operation as described above, the division points divided within the range where linear interpolation can be performed are determined.

The accuracy of the map created by the above method is determined by the distance D between the parallel line L1 and the chord AB (straight line L). In addition to the above method, for example, there is a determination method based on the radius of curvature of the road. The above will be described in more detail with reference to FIG.

FIG. 9 shows the road map of FIG. 3 displayed by the above-mentioned linear interpolation. First, cassette deck 5
The position coordinates a1 to a13 are sequentially read in and linear interpolation is performed between two points of these position coordinates. Next, the position coordinates b1 to b11 are read, finally the position coordinates E1 to E5 are read, and linear interpolation of these position coordinates is performed, whereby a road map as shown in FIG. 9 is completed.

When the road map of FIG. 3 is recorded as a set of display points as in the prior art, about 350 position coordinate information must be recorded as the number of display points required for display. However, when it is stored as the position coordinates of the division points in the range where linear interpolation can be performed as in the present invention, as is clear from FIG. 9, the number of position coordinate points is sufficient, and in addition, as shown in FIG. There is no problem in the visibility of the map information when comparing FIG.

According to this embodiment, the storage capacity for one road map can be greatly reduced, and the time required to read the map data can be shortened.

In the above description, the characters / symbols, etc. are used as font information, and the position coordinates of the dividing points in the range where linear interpolation can be performed on the road map are used. May be recorded.

Next, as described above, the navigation device according to the present invention enlarges / reduces the map by using the recorded map data. Therefore, this operation will be described below.

First, in FIG. 2, the map data recorded as described above is read by the cassette deck 4. At this time, the road map information is read after the character / symbol information and written in the read / write memory 322. The position coordinate information of the road map information written in the read / write memory 322 is linearly interpolated by the microprocessor 32 and written in a predetermined place in the video RAM 324 as a set of straight lines.

As described above, the map data written in the video RAM 324 is controlled by the video display generator 325 and displayed on the display device 5 as a road map as shown in FIG. 8 (characters and symbols are omitted). To be done.

Therefore, when enlarging a part of the road map shown in FIG. 8, the area to be enlarged on the display screen (area Z in FIG. 8) and the magnification (10 times) are designated by the input device 6. As a method of designating this area, the cursor is fixed to one point on the display screen, and the map is enlarged centering on that one point. Then, map data within the range of this designated area is selected from the magnetic tape 11 and read.

The position coordinates of the read map data are magnified by the designated magnification, and the character / symbol information is written in the video RAM 324 and displayed by the video display generator 325 by the same operation as described above. Here, if the original road information, that is, the map with the largest scale (Fig. 9) is recorded with sufficient accuracy for linear interpolation, a map with a smaller scale than this stored information is displayed with high accuracy. It's easy to do.

In the above, when displaying an enlarged view,
The map data of the portion to be enlarged is read again from the magnetic tape 11. Therefore, as another method of enlarging and displaying the map, if the original road information is recorded in the read / write memory 322 with an accuracy capable of enlarging and displaying, it is not necessary to search the magnetic tape again. In this case, it is possible to select a portion to be enlarged and displayed from the original map information recorded in the read / write memory 322 and display it as it is. As an effect of such an embodiment, it is possible to instantly enlarge any place and eliminate the delay time required for displaying the enlarged view, that is, the time for re-reading.

In the above-described embodiment, the microprocessor 32 is provided with the function of linear interpolation. However, a device for performing linear interpolation may be provided separately from the microprocessor 32, and the video display generator 325 may be provided with such a device. You may add a function.

[0047]

As described above, according to the present invention, the road map information and the character / symbol information attached thereto are independently stored, and the character / symbol is written separately from the road.
Even if the display of the road is enlarged or reduced, the character size is not changed accordingly. Therefore, it is possible to prevent the visibility of the characters / symbols from being deteriorated due to the enlargement / reduction of the map. In addition, if it is configured to record the discrimination information of whether to display each character / symbol information in an enlarged view or a reduced view, if the same number of characters are always displayed on the enlarged and reduced display screens, It is possible to prevent the display screen when it is reduced from becoming very difficult to see.

Further, according to the present invention, it is possible to reduce the storage capacity required for storing map data, which makes it possible to display an enlarged map without increasing the storage capacity. The usability and usefulness as a device can be further improved.

[Brief description of drawings]

FIG. 1 is a diagram illustrating an outline of a navigation device according to the present invention.

FIG. 2 is a block diagram showing a basic configuration of a navigation device.

FIG. 3 is a diagram showing an example of a map displayed on a display device.

FIG. 4 is a diagram showing an example of a map data format recorded on a magnetic tape.

FIG. 5 is a diagram showing an example of a data format of characters, symbols, etc. recorded on a magnetic tape.

FIG. 6 is an explanatory diagram of linear interpolation.

FIG. 7 is a diagram showing an example of a data format of a road map recorded on a magnetic tape.

FIG. 8 is a diagram showing an example of a normally displayed map at a scale of 1 / 250,000.

9 is a diagram showing an example of a map in which a part of the map of FIG. 8 is enlarged and displayed by linear interpolation.

FIG. 10 is a diagram illustrating a linear interpolation method.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Odometer, 2 ... Travel direction detector, 3 ... Signal processing unit, 4 ... Cassette deck, 5 ... Display unit, 6
… Input device, 11… Magnetic tape

Front page continuation (72) Inventor Takanori Shibata 2520 Takaba, Katsuta City, Ibaraki Prefecture Inside the Sawa Plant, Hitachi, Ltd.

Claims (7)

[Claims] 1. A navigation device for displaying a map and a position of a vehicle, comprising: a storage medium for storing map data including at least road map information and character / symbol information for each pre-divided map; An information storage device for reading out map data, a display device capable of displaying at least the position of a map and a vehicle, and a signal operation for calculating a current position of a vehicle, processing map data, and processing display data. A storage device for storing road map information indicating a road appearing on the map, and a memory for storing character / symbol information. And a location indicating the display position on the map where each character / symbol should be displayed in the storage location of the above-mentioned character / symbol information. The sign information and font information representing their shapes are stored, and the signal processing unit stores the roads included in the map data of the section to be displayed from the storage location of the road map information via the information storage device. A means for reading the map information and generating a road map for display, and a character included in the map data of the section to be displayed from the storage location of the character / symbol information via the information storage device. Positions corresponding to the position coordinate information of the generated road map by reading out the position coordinate information indicating the display position of the symbols on the map where they are to be displayed and the font information indicating their shape. , A means for writing characters / symbols in the form represented by the font information, a means for calculating the position of the vehicle, a road map in which the characters / symbols are written, and the calculated vehicle Location and navigation device, characterized in that it comprises a means for displaying on the display device. 2. The navigation device according to claim 1, further comprising an input device for inputting an instruction to the signal processing unit. 3. The means for generating the road map according to claim 2, according to an instruction input from the input device.
A navigation device further comprising means for enlarging or reducing to generate a road map. 4. The position coordinate information of the division points obtained by dividing each road shown in the map within a range where linear interpolation is possible, in the storage location of the road map information according to claim 3. In addition, the means for generating the road map for display, which are sequentially stored from one end to the other end along each road, include the position coordinates included in the map data to be displayed from the storage location of the road map information. Information is read for each road in the order in which they are stored, and adjacent coordinates of the read position coordinate information are linearly interpolated to form a line that connects the division points in order, and the information of the line is used for the road. A navigation device characterized by generating a road map as the data to be shown. 5. The signal processing unit according to claim 4, further comprising a read / write memory for storing display data for one display map, and the means for generating a road map for the display is the road map. In the read / write memory, and the character / symbol writing means writes the font information in a corresponding position of the road map written in the read / write memory. 6. The character / symbol information for each character / symbol information is displayed in an enlarged view or a reduced view in the storage location of the character / symbol information according to claim 3, 4 or 5. The navigation device further stores determination information for determining whether to perform. 7. A navigation device for reading out map data from a mounted storage medium and displaying the position of a map and a vehicle, an information storage device for reading out map data from the mounted storage medium, and at least a map and The information storage device is equipped with a display device capable of displaying the position of the vehicle, and a signal processing device for processing the current position of the vehicle, processing map data, and processing display data. As storage media, map data including at least road map information indicating roads appearing on the map and character / symbol information included in the map is stored for each pre-mapped map, and the road map information is stored in each map. It has a memory location for storing and a memory location for storing the character / symbol information. As the character / symbol information,
The one in which the position coordinate information indicating the display position on the map where the symbol is to be displayed and the font information indicating the shape thereof are stored is used, and the signal calculation processing device uses the information storage device to store the road map. A means for reading road map information contained in the map data of the section to be displayed from the storage location of the information and generating a road map for display, and the character / symbol information of the character / symbol information via the information storage device. From the storage location, the position coordinate information indicating the display position on the map where the characters / symbols should be displayed and the font information indicating their shape, which are included in the map data of the section to be displayed, are read. A means for writing a character / symbol in the form represented by the font information at a position corresponding to the position coordinate information of the generated road map, and a position of the vehicle are calculated. And a means for displaying the calculated position of the vehicle on the display device.