JPH0647966U - Map display - Google Patents

Abstract

(57) [Abstract] [Purpose] By making the display accuracy different depending on the degree of the load on the control device, it is possible to ensure the speed of the processing and the detail of the data. [Constitution] The vector data is converted into image data according to the degree of load on the central processing unit 1, and the road map information for 9 screens is transferred to the 9 screen buffer memory 6 at the time of start-up or at the present time of the vehicle. When the position is modified or when the screen is enlarged or reduced, etc., the load is heavy. , When other load is small, for example, road width, background drawing,
Drawing detailed information such as drawing service information is set as a parameter.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a map display device, and relates to a map display device having different display accuracy according to the degree of load of a control device.

[0002]

[Prior art]

 The vehicle-mounted navigation device that calculates the current position according to the running of the vehicle displays the calculated current position information on a road map read from a map storage medium on a display device such as a CRT in an overlapping manner. However, the road map is scrolled according to the movement of the vehicle, so that the vehicle relatively runs on the map.

The road map information is stored as vector data, and when it is displayed on a display device, it is converted into image data by painting the background surface pattern, drawing the road width, character data, and the like. It

[0004]

[Problems to be solved by the device]

 By the way, when scrolling the map, it is necessary to first read the surrounding map together with the target map, but in all cases image processing such as filling the surface pattern and width of the road is performed. Promptly responds to situations such as when the map of the vehicle cannot be displayed because it cannot keep up with the movement of the vehicle, when a map other than the current position of the vehicle is displayed, and when switching between expanding and contracting the map becomes slow. It was a bad system because it could not be used.

[0005]

[Means for Solving the Problems]

 The main feature of the present invention is that the conversion of vector data into image data changes the display accuracy according to the degree of load on the control device. We have realized a map display device that can selectively use detailed data processing and quick processing depending on the situation.

[0006]

【Example】

 FIG. 1 shows an embodiment of a map display device according to the present invention. FIG. 1 is an overall configuration diagram of a vehicle-mounted navigation device, FIG. 2 is an explanatory diagram of drawing, FIG. 3 is an explanatory diagram of input parameters, and FIG. 4 is a main routine. 5 is a flowchart of the subroutine.

The central processing unit 1 is connected with a position detection sensor 2, a keyboard 3, a map storage medium 4, a display control unit 5, a 9 screen buffer memory 6, and a drawing memory 7, and the display control unit 5 is connected to the display control unit 5. A display 8 is connected to.

Road map information is recorded in the map storage medium 4 as vector data. Then, in order to scroll the map, as shown in FIG. 2, a total of 9 screens for 8 screens around the map screen of the section including the current position of the vehicle detected by the data from the position detection sensor 2 are centered. It is necessary that a map of image data for the screen is in the 9-screen buffer memory 6, and a necessary part of the 9-screen buffer memory 6 is cut out and transferred to the display control device 5. That is, the road map information in the map storage medium 4 is read by the central processing unit 1, and detailed data such as road width, background drawing, and service information drawing are drawn on the drawing memory 7 to form image data. After being converted to, the data is transferred to the 9-screen buffer memory 6. The degree of fineness of this image data is determined according to the degree of load on the central processing unit 1. That is, when the road map information for 9 screens is transferred to the 9 screen buffer memory 6, when starting up, when correcting the current position of the vehicle, when enlarging or reducing the screen, a large load is applied to the central processing unit 1. Since the processing speed will be slow, for example, only the basic data of the minimum necessary such as drawing the road with a line will be drawn, and the width of the road, background drawing, service Drawing information, etc. Drawing fine data. The degree of this fineness is set by the input parameters as shown in FIG. In FIG. 3, 1-byte data is shown. When each bit is "1", the item is drawn, and when it is "0", the item is not drawn. Then, necessary data is selected from the map data based on this parameter and drawn in the drawing memory 7.

Next, the operation procedure will be described based on the flowcharts shown in FIGS. 4 and 5. First, in the main routine of FIG. 4, first, is the current position of the vehicle detected based on the data from the position detection sensor 2? Or, if a position is input by operating the keyboard 3 when correcting the position, it is checked whether there are 9 screen maps required for position display in the 9-screen buffer memory 6, and then it is necessary to draw the map. When it is not necessary, the current load state is checked, and when it is necessary, the process moves to the subroutine of FIG. 5 and the current load state is checked after drawing. When the load is large, it is out of the main routine. When it is small, it is judged whether the map in the 9-screen buffer memory 6 is a simple map. The map of the memory 6 is transferred to the drawing memory 7, and then the process moves to the subroutine of FIG. 5 to return to the original position of the 9-screen buffer memory 6 after drawing.

In the subroutine of FIG. 5, first, it is determined whether or not redrawing is necessary. When redrawing is necessary, items that were not drawn previously are set as parameters, and the map is set according to the input parameters. After drawing, the process returns to the main routine, and when redrawing is not necessary, it is determined whether the power is on or the enlargement / reduction is performed. When the power is turned on or when enlarging / reducing, a simple map item is set as a parameter, for example, among the items shown in Fig. 3, the minimum required 0-bit "draw basic road with line" is drawn. Set only the item of “”, draw a map according to the entered parameters, and then return to the main routine to determine whether it is the time of turning on the power, or the time of position correction when not enlarging / reducing. When not correcting the position, set all the detailed map items such as the items shown in Fig. 3 in the parameter, draw the map according to the input parameters, and then return to the main routine. It is determined whether or not it is outside the area of the screen buffer memory 6. When the position is outside the area of the 9-screen buffer memory 6, the parameter of the intermediate map, for example, the 6th bit “Background, filling width road” of the items shown in FIG. Therefore, the items except this 6th bit item are set, the map is drawn according to the input parameters, and then the process returns to the main routine, and the position is within the area of the 9-screen buffer memory 6. In this case, the detailed map item is set in the parameter, the map is drawn according to the input parameter, and then the process returns to the main routine.

By repeating the above operation, the detailed map or the simple map is selected according to the degree of the load, and the speed of the process is improved and the detail of the data is secured.

[0012]

[Effect of device]

 As will be apparent from the above description, according to the present invention, the central processing unit performs processing by selecting a detailed map or a simple map according to the degree of load, so that the processing speed can be increased depending on the situation. At the same time, the detail of the data can be secured.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram of a vehicle-mounted navigation device showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram of input parameters for map drawing.

FIG. 3 is a schematic explanatory diagram of map drawing.

FIG. 4 is a flowchart of a main routine.

FIG. 5 is a flowchart of a subroutine.

[Explanation of symbols]

 1 Central Processing Unit 2 Position Detection Sensor 3 Keyboard 4 Map Storage Medium 6 9 Screen Buffer Memory 7 Drawing Memory 8 Display

Claims (1)

[Scope of utility model registration request] 1. A map storage medium for storing map information as vector data, a control device for converting vector data read from the map storage medium into image data, and a display device for displaying the map information under the control of the control device. A map display device comprising: a map display device, wherein the control device performs conversion of vector data into image data simply when the load on the control device is large and in detail when the load is small. .