JPH07193747A - Picture display device - Google Patents

Abstract

PURPOSE:To simply synthesize parts of video signals obtained from plural video cameras as a picture without requiring a frame memory and to display the syntiaesized picture. CONSTITUTION:Plural television cameras 01 to 04 are successively delayed to start scanning by a frame scanning control circuit 7, a switch control circuit 8 synchronized with the circuit 7 successively switches the cameras 01 to 04 and a video waveform generating circuit 5 shapes video signals so as to synthesize parts of video signals obtained from plural TV cameras 01 to 04 as a picture and outputs the synthesized picture to a monitor 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display device, which does not require a frame memory and combines and displays a part of video signals from a plurality of video cameras on one screen.

[0002]

2. Description of the Related Art Conventionally, when the video signals from a plurality of video cameras are combined into one screen, as shown in FIG. 4, the video signals from the video cameras 01 to 04 are A / D converters corresponding to the respective cameras. After performing A / D conversion in 20 to 23, rearranging in the frame memory 3 and synthesizing into one screen, the D / A converter 4 restores the analog signal, and the video waveform generating circuit 5
Then, it was shaped into a video signal and output to the monitor 6 or the like.

[0003]

However, since the frame memory and the A / D and D / A converters described above are used, the system becomes large-scale and expensive, and a simpler method has been desired.

In view of the above problems, the present invention does not require a frame memory and simply displays a part of video signals from a plurality of video cameras by synthesizing the video on one screen.

[0005]

According to the present invention, a plurality of video cameras for outputting video signals, a frame scanning control circuit connected to these video cameras by control lines, and controlling a frame scanning start time thereof, Provided is an image display device including a switch for sequentially switching output signals from a video camera, a switch control circuit for controlling the switch, and a video waveform generation circuit for shaping a signal from the video camera switched by the switch into a video signal. It is a thing.

[0006]

EXAMPLES Next, examples of the present invention will be specifically described. FIG. 1 is a block diagram of an embodiment of the image forming apparatus of the present invention. In this embodiment, four video cameras 01-0
4 is sequentially delayed by the frame scanning control circuit 7 to start scanning. If you want to extract and combine areas at the same position on the screen with four video cameras, the delay time is 1 for video cameras 2, 3 and 4 with video camera 1 as the reference.
/ 2H, 1 / 2V, 1 / 2V + 1 / 2H. Here, 1H is the time required for horizontal scanning of one scanning line, and 1V is 1
This is the time required for vertical scanning of the field. The video output line 11 from each video camera is sequentially switched by the switch 9 and the switch control circuit 8, and the video waveform generation circuit 5 synthesizes one area of the video from each video camera into a video signal of one screen and displays it on the monitor 6. indicate. The switching timing of the switch 9 is 0 to 1/2 with reference to the video camera 1.
Video camera 1 and video camera 2 every 1 / 2H up to V
Output is switched, and the output of the video camera 3 and the video camera 4 is switched every 1 / 2H at 1 / 2V to 1V. The frame scanning control circuit, the switch control circuit, and the video waveform generation circuit are connected by the control line 10, and the timing of switching the switches and generating horizontal and vertical blanking is taken.

The above operation will be described in more detail with reference to FIGS. 2 and 3. FIG. 2 shows areas a to d to be combined by the video cameras 1 to 4 and the combined result. The area of each of the regions a to d is 1/4 of the entire area. In the video camera 1, the horizontal scanning line in the area is set to a _n starting from a 0. The same applies to the video cameras 2, 3 and 4. The areas a to d are the same on the screen, that is, the starting points a _{0 to} d ₀ have the same coordinates. FIG. 3 shows the video outputs of four video cameras whose frame scanning has been delayed and started, and the outputs obtained by sequentially switching by the switch control circuit. FIG. 3A shows the case of 1V and FIG. 3B shows the case of 1H. As shown in FIG. 3 (a), the video cameras 2 to 4 are each 1 / th with respect to the video camera 1.
The frame operation is started with a delay of 2H, 1 / 2V, 1 / 2V + 1 / 2H. Since the area a is located near the center of the screen in FIG. 2, its video signal is present at 1/2 V near the center of one field period as shown in FIG. This one
When viewed at H, as shown in FIG. 3B, the horizontal scanning line a _n of the area a exists at 1/2 H near the center, and its end is just the start point of the horizontal scanning line b _n of the area b of the video camera 2. Connect to. Delay time of frame start of video camera 3 is 1
Since it is / 2V, the end of the region b is connected to the starting point of the region c just through the horizontal blanking period. Since the relationship between the areas b and c is the same as the relationship between the areas a and b, description thereof will be omitted. The image composition can be achieved by sequentially switching the signals of the video cameras 1 to 4 by the switch control circuit 8.
That is, first, the frame operation control circuit 7
When a certain period of time has passed after the start of the frame operation, the video waveform generation circuit 5 forms vertical blanking until the video camera 1 outputs the signal of the area a, and when the video camera 1 starts to operate the area a. , Switch control circuit 8
Then, the video signal of the video camera 1 is connected to the video waveform generating circuit 5 and video is output to the monitor 6 or the like. Then 1/2
After H, the switch control circuit 7 switches to the video signal of the video camera 2 and the video signal is output through the video waveform generation circuit 5. After that, the video waveform generation circuit 5 forms horizontal blanking, and the switch control circuit 8 causes the video camera 1
Switch to the video signal of. After that, the above operation is repeated to obtain a video output as shown in FIG. a ₀
After 1/2 V has passed, the switch control circuit 8 switches to the video signal of the video camera 3 and outputs the video through the video waveform generation circuit 5. After 1 / 2H, the switch control circuit 8 switches to the video signal of the video camera 4 and outputs the video through the video waveform generation circuit 5. After that, the above-described operations relating to the video cameras 1 and 2 are performed in the same manner for the video cameras 3 and 4, so that a partial area a to d of the video cameras 1 to 4 is combined into one screen as shown in FIG. Output is obtained. As shown in FIG. 3A, the video output at that time is a combination of areas a and b for 0 to 1/2 V and a combination of areas c and d for 1/2 V to 1 V. The state at 1H is as shown in FIG. 3B as described above.

In this embodiment, one monitor screen is 2 ×
The case of dividing into 2 and combining the images of 4 video cameras has been described, but 9 (3 × 3) or 16 (4)
For example, the video output of an integer squared number of video cameras (such as divided into × 4) can be combined into one screen or divided vertically or horizontally such as 1 × 2 or 1 × 3 and output. This can be easily realized by changing the delay time or the switch switching timing. Although the size of the video image of each video camera is the same, the size of the video image of each video camera in one screen can be changed by changing the switch switching timing in the switch control circuit 8.
Further, the case where the regions to be combined are located at the same position in each video camera has been described, but this can also be arbitrarily selected by changing the delay time at the start of frame scanning.

[0009]

As described above, according to the image display device of the present invention, a part of the video signals from a plurality of video cameras can be easily combined on one screen without using a frame memory. Can be displayed.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing, on a monitor screen, how a part of images from four video cameras are combined into one screen in the embodiment of the present invention.

FIG. 3 shows the video output of each video camera and the combined result.

FIG. 4 is a diagram showing an image display device for extracting a part of images from a plurality of conventional video cameras and combining them into one screen.

[Explanation of symbols]

 01, 02, 03, 04 Video camera 20, 21, 22, 23 A / D converter 3 Frame memory 4 D / A converter 5 Video waveform generation circuit 6 Monitor 7 Frame scanning control circuit 8 Switch control circuit 9 Switch 10 Control Line 11 Video output line

Claims (1)

[Claims] 1. A plurality of video cameras that output video signals, a frame scanning control circuit that is connected to these video cameras by a control line, and controls the frame scanning start time of the video cameras, and output signals from the video cameras sequentially. An image display device comprising a switch for switching, a switch control circuit for controlling the switch, and a video waveform generating circuit for shaping a signal from a video camera switched by the switch into a video signal.