JPS602977A - Map display on vehicle - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an in-vehicle map display device that displays a map on a display section installed inside a vehicle.

BACKGROUND ART Conventionally, devices that display maps on a cathode ray tube display device inside a car have been announced. However, since the map is displayed in a fixed manner, these systems have the disadvantage that if the current driving point crosses the border of the displayed map, the surrounding map around the current point cannot be viewed. Another disadvantage is that changing the contents of the map while driving requires manual operation, which is dangerous.

The present invention has been made in order to eliminate the drawbacks of the conventional ones.The present invention calculates the current location where the car is currently located using the current location calculation means, and displays a part of the map pattern using the display area control means. By controlling the display means so that the current location becomes a fixed point on the screen, the contents of the displayed map will automatically change as the car moves so that it is centered around the current location. The object of the present invention is to provide an in-vehicle map display device that can be used to display images.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is an overall configuration diagram of an on-vehicle map display device according to an embodiment of the present invention. In the figure, 1 is a geomagnetic direction sensor attached to the car, 2 is a distance sensor that measures the distance traveled, and 3 is an initial setting key 17 from the outputs of both sensors 1 and 2.
This calculation means calculates the displacement from the point set by , and determines the current location where the car is currently located. Reference numeral 5 indicates a control means for outputting a display area designation signal for specifying the image display area of the video memory 4 storing the map pattern based on the calculation result of the calculation means 3; A cathode ray tube monitor device 7 serving as a display means uses a part of the video memory 4 that stores the images as a display area.
A display area control means 40 is configured to determine the display area so that the current location becomes a fixed point on the screen by the above-mentioned two means 5 and 6.

Figure 2 shows the geomagnetic direction sensor 1 shown in Figure 1. Distance sensor 2.
Current location calculation means 3. The electrical connections of the control means 5 parts are shown. In the figure, 1.2 is the same as 1.2 in FIG. 8 is an A/D converter that converts the analog output of the geomagnetic direction sensor 1 into a digital signal. The part 13 in the figure is a microcomputer, which automatically starts a program when the power is turned on, and the input circuit 9. CPUI O, ME%'J 11. It has an output circuit 12. The microcomputer 13 is connected to the current location calculation means 3. This corresponds to the control means 50 portion.

FIG. 3 shows the electrical connections of the display processing means 6 portion of the video memory 41 in FIG. 1, and I4 corresponds to the display processing means 6 portion. Note that 4 in the figure is the same as the video memory 4 in FIG. 1, and has a memory capacity that is sufficiently larger than the memory capacity equivalent to one screen. Reference numeral 15 in the figure is a so-called graph ink display controller, which is used for control to display one character and one figure on a rusk scanning type CRT.
It is a known SI and has the following functions and is open to the public.

This graph ink display controller 15 is configured so that the size and position of the display area in the video memory 4 are determined by a parallel external signal A supplied from the microcomputer 13. Therefore, only a part of the video memory 4 can be displayed, and this state is shown in FIG.

In FIG. 4, 4 is a video memory that stores map patterns, and 20 is a display area, which corresponds to one screen. The position of this display area 2o on the video memory 4 is determined by specifying the display start address point B and display size in FIG. 4 from the input A in FIG. 3, and thereby the display area 20 is specified. Ru.

Returning to Figure 3 again, 16 is a parallel-to-serial conversion register,
This outputs a display disclosure address B which is a video output specifying the display area 2o of the video memory 4, and thereby the display area 20 is displayed as one screen. In addition, a, b
, d are interface lines connecting each block, and C is a synchronization signal output from the graphic display controller 15.

Next, the operation of the apparatus of this embodiment will be explained with reference to FIG. FIG. 5 is a flowchart showing a program stored in the memory 11 of the microcomputer 13.

When the power is turned on to the microcomputer 13, the program starts operating, and the microcomputer 13 issues a signal to specify the size of the display area 20, which corresponds to a part of the video memory 4 that stores the map pattern. A to the graph ink display controller 15. At this time, first, the size of the display area 20 in FIG. 4 is specified (step 31). Next, the initial setting point (X, Y) is set using the initial setting key 17 (step 32).

If you specify the initial setting point (X, Y), cpuio.

The memory 11 performs the calculation process Ad=F (X, Y) (step 3.3). Here, Ad corresponds to the display start point address B of the display area 20 in FIG. Also F
(X, Y) are functions of X and Y for converting the X and Y coordinates of the initial setting point into a display area start address for setting the display area 20 in the center of FIG. 4.

When this arithmetic processing result is given to the graphic display controller 5 via the signal A, the display area start address B in FIG. Become.

Next, when the car starts running, the CPU 10 receives the geomagnetic component ΔU in the longitudinal direction of the vehicle body and the component ΔV in the perpendicular direction to the vehicle body from the geomagnetic azimuth sensor via the A/D comparator 8 and the input circuit 9. Direction θ−t a n”Δ■
/ΔU is calculated, and further, the distance displacement ΔS from the initial setting point (X, Y) set by the initial setting key 17 is input from the distance sensor 2 via the input circuit 9 (step 34).

Next, the X-axis direction component ΔX and Y-axis direction component ΔY of the distance displacement ΔS from the initial setting point (X, Y) are calculated by ΔX=Δ5−cos θ ΔY−ΔS −5in θ (step 35).

Then, the current travel point is determined as X←Y+ΔX Y←Y+ΔY (step 36), and the process returns to step 33 in FIG. Returning to step 33, the calculation Ad=F (X, Y) is performed in the same way as above, and the start address B of the display area is updated.

Graph ink display controller 15
When sent via signal A, the current driving location is set to be in the center of the image.

By repeating the above steps, a map image centered on the current driving location is always displayed even if the car moves.

In the above embodiment, when the current driving point is set to be at the center of the image, if the current driving point is drawn at the center of the image, it is also possible to display the past driving trajectory.

In addition, in the above embodiment, the start address B of the display area is changed so that the current driving point is in the center of the image, but by changing the function of Ad-p (X, Y), the current driving point is placed in the image display area. It is also possible to replace it with a function that can be any fixed point within.

Furthermore, in the above embodiment, a case has been described in which a video memory is provided in which a map pattern is recorded, but the map information can be coded and stored in a ROM (read-on memory), and the microcomputer operates. The same operation can be performed by executing the program and storing the map pattern in the video memory.

As described above, according to the present invention, the current location calculating means determines the current location where the car is currently located, and the display area control means causes the displaying device for displaying a part of the map pattern to be set so that the current location is on the screen. Since the control is set to a fixed point, the contents of the displayed map will automatically change around the current driving point even when the car is driving, so there is no need to manually change the map as in the past. This has the effect of providing a very convenient in-vehicle map display device that is completely free of nuisance or danger.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of an in-vehicle map display device according to an embodiment of the present invention, FIGS. 2 and 3 are diagrams showing its electrical connections, and FIG. 4 is a diagram showing its video memory and display area. FIG. 5 is a diagram showing the flowchart. ■...Direction 1 sensor, 2...Distance sensor, 3...Current point calculation means, 4...Video memory, 7...Display means (CRT monitor device), 40...Display area control means. In the drawings, the same reference numerals indicate the same or equivalent parts. Agent Masuo Oiwa Figure 4 Figure 5

Claims (1)

[Claims] +11 Current location calculation means for determining the current location of the vehicle based on the output of a direction and distance sensor installed in the vehicle, and a portion of the map pattern stored in the video memory. What is claimed is: 1. A vehicle-mounted map display device comprising: display means for displaying the current location as a display area; and display area control means for determining the display area so that the current location is a fixed point on the screen. (2) The in-vehicle map display device according to claim 1, wherein the display area control means determines the display area so that the current location is at the center of the screen. (3) The display area control means controls the display means so that the current location is drawn for a predetermined period and the travel trajectory of the vehicle is displayed. The in-vehicle map display device according to item 2.