JP2747283B2 - Navigation device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-vehicle navigation device for displaying a current position of a vehicle, a road map, information necessary for traveling, and the like. 2. Description of the Related Art Japanese Patent Application Laid-Open No. Sho 57-169785 discloses an automobile travel guide system which detects the current position of a vehicle, displays the current position on a road map, and displays information necessary for traveling. 2. Description of the Related Art A traveling guidance device for a vehicle is known. In this method, a mark indicating a position and a traveling direction of a vehicle is displayed at a predetermined position on a display screen in a fixed direction, and is displayed on the display screen as the vehicle travels. In this, an apparatus for moving a map pattern is disclosed. In this device, the display map can be enlarged and reduced at a plurality of predetermined magnifications in order to facilitate identification of the current position of the vehicle on the map. In the device disclosed in this known example, a display map is represented as a set of points (dots) on a screen, and when the display map is enlarged, the corresponding M lines are displayed from the display screen data. The display map is enlarged by extracting the display points in N columns and dispersing the display points on the display screen. At this time, when the map is enlarged and displayed by dispersing the display points, there is a disadvantage that the displayed map is difficult to visually recognize. Therefore, even if the display points are dispersed, the magnification of the enlargement can be suppressed to such an extent that it is sufficiently visible as a map display when viewed with the naked eye. In the above known example, for example, the number of display points required to display a map at a scale of 1 / 250,000 is M rows and N rows.
Assume that rows (M × N) were sufficient. Next, when the map at a scale of 1 / 250,000 is displayed at a scale of 1 / 50,000 (magnification: 5 times), the variance of the display points increases (that is, the area of the display points becomes 5 × 5 = 25 times). , The display map has poor visibility. Therefore, in order to enable the display to be enlarged at a scale of 1 / 50,000 (magnification: 5 times), the number of display points must be reduced to 1 / 250,000.
If the map is not stored with an accuracy of 25 times 5M rows and 5N examples (5M × 5N), a display map with good visibility cannot be obtained. That is, in order to display a map at a magnification of 1 / 50,000 at a magnification of 5 times, a storage capacity 25 times as large as that required to store the original map (1 / 250,000) is required. Assuming that the magnification of the enlarged map is 10 times, a storage capacity 100 times that of the original map is required. [0006] As described above, the conventional technique has a disadvantage that the storage capacity of map data becomes enormous when an enlarged view is required. When the amount of magnetic tape for storing map data increases, the reading time for reading one map data increases,
Further, since the amount of data handled as the vehicle travel guidance device becomes large, a large-capacity storage unit is required for the entire device, and there is a problem in cost. SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to increase the storage capacity of a navigation device and a storage device with a relatively small storage capacity without excessively increasing the storage capacity. An object of the present invention is to provide a navigation device capable of storing a large number of map information including drawings. In general, a navigation apparatus is configured to function only as a navigation apparatus, and cannot be used for other purposes. In particular, there was no one that enabled television reception. Therefore, conventionally, it was necessary to separately provide the television receiver and the navigation device. Another object of the present invention is to provide, in addition to a map display,
An object of the present invention is to provide a navigation device that can also display television. According to the present invention, there is provided a navigation apparatus having a function of displaying a map image, the signal for generating display data based on the map data. An arithmetic processing unit, a device for performing television reception, display of the display data, and
A display device capable of performing the television display,
The signal processing device has means for taking in map data, and means for creating display data based on the taken in map data, and the means for taking in the map data is provided on a map to be taken in. For each of the roads, a process is performed in which the position coordinate information of the division points obtained by dividing the respective roads within a range that can be linearly interpolated is sequentially taken from one end to the other end along each road and temporarily stored. Means for creating the display data
The position coordinate information included in the temporarily stored map data is read for each road, and the read position coordinate information is linearly interpolated between adjacent coordinates to form a line connecting division points in order. A navigation device is provided, wherein display data for forming and displaying a road is created, and processing for displaying the created display data on the display device is performed. According to another aspect of the present invention, there is provided a navigation apparatus having a function of displaying a map image, the signal for generating display data based on the map data. A navigation device is provided, comprising: an arithmetic processing device; a device for performing television reception; and a display device capable of displaying the display data and performing the television display. [0012] The means for taking in the map data includes:
For example, map data can be fetched from a storage medium mounted on an information storage device for reading data from the storage medium. As this storage medium, a storage medium that stores at least map data including road map information for each pre-divided map is used. For example, for each pre-divided map, the road map has a storage location for storing road map information indicating a road appearing in the map, and a storage location for storing character / symbol information. The storage location of the information includes, for each road that appears on the map,
The position coordinate information of the division point obtained by dividing each road within a range that can be linearly interpolated is sequentially stored along one road from one end to the other end for each road, and the storage location of the character / symbol information is A storage medium is used in which positional coordinate information indicating a display position on a map where the characters / symbols are to be displayed and font information indicating their shapes are stored. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows the overall configuration of a navigation device according to the present invention. In FIG. 1, a traveling distance detector 1 generates a pulse signal corresponding to, for example, a vehicle speed. 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 using geomagnetism. The signals detected from the traveling distance detector 1 and the traveling direction detector 2 are read into the signal processing unit 3. The signal processing unit 3 calculates the current running position of the vehicle by calculating these two signals. In addition, the signal processing unit 3 calculates the current traveling position and inputs map data corresponding to the current traveling position from the information storage device 4. As the information storage device 4, a cassette tape recorder is used.
Storage means such as M and a magnetic disk are also conceivable. And
The signal processing unit 3 compares the current travel position with the information in the information storage device 4 and displays the map data and the accurate current travel on the map data on the screen of a display device 5 composed of a Cathode Ray Tube (CRT). The position and the display at the same time. The input device 6 is an input device for controlling the operation of the signal processing unit 3. Next, the configuration of the signal processing unit 3 will be described in detail with reference to FIG. The signal processing unit 3 receives signals from the traveling distance detector 1, the traveling direction detector 2, and the input device 6, respectively, and calculates the current position of the vehicle. Then, the map data corresponding to the current position is read out 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, 32. The microprocessor 31 performs arithmetic processing of the current position and controls 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. Processing unit 312
Performs waveform shaping processing so that the microprocessor 31 can easily perform arithmetic processing on signals from the traveling distance detector 1 and the traveling direction detector 2. The interface 313 is a circuit for controlling the microprocessor 32 with the microprocessor 31. The microprocessor 32 operates according to a program stored in a read only memory (ROM) 321. Read / write memory (RAM 322 temporarily stores stack memory data, map data, and the like of microprocessor 32. Input / output circuit 3
Reference numeral 23 searches for map data such as reproduction, fast-forward, and rewind 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. The reproduction and editing of the map data such as temporary storage are performed. The video RAM 324 is a read / write memory for storing display data for one display map. Video R
The display data written in the AM 324 is displayed on the display device 5 by a video display generator (VDG) 325. In this embodiment, the television antenna 7, the television tuner 33, and the demodulation circuit 331 are provided. By switching the switching circuit 314 to the television receiving side by the microprocessor 31, television reception is also possible. The display device 5 includes a deflection circuit 501, a video amplification circuit 502, a CRT
503. With the navigation device having such a configuration,
When a map as shown in FIG. 3 is displayed on the display device 5, map data such as characters and symbols in FIG. 3 and map data of a road map are stored on a recording medium such as a magnetic tape 11 shown in FIG. Then, as in 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 contents to be stored. First, the character / symbol information recording unit 112 will be described. As shown in FIG. 5, the data format of the character / symbol information recording unit 112 is such that, for one character, the character is a main scale map (map data that is always displayed. The position corresponding to the indicated map (1 / 250,000 scale map) is recorded at the head of the stored character as the main scale position information section 112A of the X and Y coordinates of the main scale diagram in FIG. 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. Such stored information such as characters and symbols is called font information. Then, the cassette deck 5 searches for a predetermined map number, and the read data such as characters and symbols are stored in the video RAM 32 corresponding to the position information of the data.
4 is written to a predetermined location. This way,
The size of the characters is not changed when the displayed image is enlarged or reduced. In addition, if the same number of characters are always displayed on the enlarged and reduced display screens, the display screen when the display is reduced becomes very difficult to see.
In 2A, discrimination information for displaying each character / symbol information 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, and FIG.
The diagram is a recording state diagram of the position coordinate information of each point O, P, Q, R in FIG. First, the map number N is searched on the cassette deck 4, 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 ), Q (x ₃ ,
y ₃ ), R (x ₄ , y ₄ ),..., the position coordinates on the road map are sequentially read. Then, by performing linear interpolation in the order of the read position coordinate information, the sixth
A road map of OPQR is drawn as shown in the figure. By doing so, the road map OPQ
In FIG. 6, four pieces of position information are necessary to draw R. By using such a linear interpolation method,
The number of data required to display a road on a map can be significantly reduced. A method of determining the division points divided within the range in which the linear interpolation can be performed will be described with reference to FIG. The arc ACB in FIG. 10 is a road map. With point A on the road map as a reference point, point B is slid along the road map. At this time, a parallel line L1 having a distance D with a chord AB (straight line L) formed between points A and B
Is assumed. Then, the parallel line L1 and the road map (arc ACB) may intersect with the slide of the point B. The point C at the intersection is 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 that can be obtained by linear interpolation. Next, by repeatedly performing the same operation as above with the point C as a reference point, the division points divided within a range in which 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-mentioned method, for example, there is a method of determining the radius of curvature of a road. The above is described in more detail with reference to FIG. FIG. 9 shows the road map of FIG. 3 displayed by the above-described linear interpolation. First, cassette deck 5
Then, position coordinates a1 to a13 are sequentially read, and linear interpolation is performed between two points of these position coordinates. Next, by reading the position coordinates b1 to b11, finally reading the position coordinates E1 to E5, and linearly interpolating the position coordinates, 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 stored as the position coordinates of the division points within the range that can be linearly interpolated as in the present invention, the number of position coordinate points is 44 as shown in FIG. There is no problem in the visibility of the map information when FIG. 9 is compared. According to this embodiment, the storage capacity can be greatly reduced for one road map, and the time for reading map data can be reduced. In the above description, characters and symbols are used as font information and the position coordinates of division points within a range in which a road map can be linearly interpolated. It may be recorded. Next, as described above, the navigation device according to the present invention enlarges / reduces the map 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 into 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 location 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). Is done. Therefore, when enlarging a part of the road map shown in FIG. 8, the area to be enlarged (the area Z in FIG. 8) and the magnification (10 times) on the display screen are designated by the input device 6. As a method of specifying the area, a cursor is fixed to a point on the display screen, and the map is enlarged around the point. Then, map data falling within the specified area is selected from the magnetic tape 11 and read. The position coordinates of the read map data are enlarged at the designated magnification, and the character / symbol information is written into 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 an accuracy that can be sufficiently displayed by linear interpolation, a map with a smaller scale than this stored information is displayed with higher accuracy. It is easy to do. In the above, when displaying an enlarged view,
The map data of the portion to be enlarged is read from the magnetic tape 11 again. Therefore, as another method for enlarging and displaying the map, if the original road information is recorded in the read / write memory 322 with an accuracy that allows the display to be enlarged, it is not necessary to search for the magnetic tape again. In this case, a portion to be enlarged and displayed can be selected from the original map information recorded in the read / write memory 322 and displayed as it is. As an effect of such an embodiment, an arbitrary place can be instantaneously enlarged, and a delay time required for displaying an enlarged view, that is, a time for reading again can be eliminated. 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, or the video display generator 325 may be provided with such a device. A function may be added. As described above, according to the present invention, the storage capacity required for storing map data can be reduced.
As a result, an enlarged map can be displayed without increasing the storage capacity, and a television display can be performed, so that the usability and usefulness of the navigator device can be further improved.

BRIEF DESCRIPTION OF THE 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 the navigation device. FIG. 3 is a diagram illustrating 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 illustrating an example of a data format of characters, symbols, and the like 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 on a scale of 1 / 250,000. FIG. 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 Signs] 1 ... Driving distance detector, 2 ... Progress direction detector, 3 ... Signal processing unit, 4 ... Cassette deck, 5 ... Display device, 6
... Input device, 11 ... Magnetic tape

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Takanori Shibata 2520, Oaza Takaba, Katsuta-shi, Ibaraki Hitachi, Ltd. Sawa Plant (56) References JP-A-57-152100 (JP, A) JP-A Sho 58-201433 (JP, A) JP-A-58-100178 (JP, A) JP-A-57-4562 (JP, A) JP-A-54-102891 (JP, A) JP-A-59-9693 (JP, A) A) Japanese Utility Model Application 58-195821 (JP, U) Japanese Utility Model Application 57-196318 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) G01C 21/00 G09B 29/00

Claims (1)

(57) [Claims] In a navigation device having a function of displaying a map image, a signal processing device for creating display data based on map data, a device for receiving television, a display of the display data, and the television A display device capable of performing display, wherein the signal arithmetic processing device has means for taking in map data, and means for creating display data based on the taken in map data; Means for taking in, for each road appearing on the map to be taken, the position coordinate information of a division point obtained by dividing each road within a range that can be linearly interpolated along each road from one end to the other end for each road. Means for sequentially taking in, temporarily storing, and generating the display data, Display data for reading the position coordinate information included in the data for each road, linearly interpolating adjacent coordinates of the read position coordinate information to form a line connecting division points in order, and displaying the road. And a processing for displaying the created display data on the display device.