JPS5974789A - Television conference device - Google Patents

Abstract

PURPOSE:To eliminate the disturbance of reproduced pictures, by keeping the synchronizing signal of a transmitted video signal at a fixed level when a all- participant shooting mode is switched to a closeup shooting mode and vice versa. CONSTITUTION:When all participants of a conference is photographed, cameras 1 and 2 are externally genlocked by synchronizing signals A and B having difference phases which are produced from an external genlock signal generating circuit 5. These camera video outputs and the vertical blanking signal lack a vertical synchronizing signal, and a synchronizing signal G is superposed 10 on a synthetic video signal to be delivered through a terminal 11 as a video signal H. While a video signal C photographed with closeup is sent to a video processing circuit 9 from a camera 1, and a closeup-shooted video signal F is delivered from the circuit 9 to be superposed on a reference vertical synchronizing signal G. Thus a closeup video output H is transmitted. In such a way, the signal G is kept at a fixed level regardless of mode switching. Thus no disturbance is produced to the reproduced pictures.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a video conferencing device that allows a plurality of people at two separate locations to hold a conference at the same time, that is, a video and audio transmission path. The present invention relates to video equipment in which images of people, documents, etc. are played back on each other's television receivers via a TV receiver, and audio is played back from each other's loudspeaker.

Prior Art This type of conference device is equipped with a plurality of cameras that take pictures of all conference participants, and a camera that takes close-ups of a specific number of conference participants. It was used only for this purpose, and it was difficult to use both cameras for reasons that will be explained later.By preparing two cameras and compositing the images obtained by these cameras, it is possible to display a large number of people on one screen. Think about projecting it on the screen. If these two cameras are of the same type as described above to take pictures of all the participants, each camera can take full control of the images, extract the vertical center of the images, and combine them to create a single image. It is necessary to obtain a video signal to be transmitted. To do this, both cameras must be externally genlocked with different synchronization signals; h! l
l.

The external genlock signals are those whose phases are shifted with respect to the reference synchronization signal of the screen after one synthesis, that is, the video signal sent to the ground. Since the transmitted image for close-up photography is a single screen of only that camera, the external genlock signal used has the same phase as the reference synchronization signal of the transmitted video signal. Therefore, during the aforementioned multi-person composite shooting and close-up shooting.

The phase relationship of the external genlock signals used will be different. Therefore, if you try to use one camera for all-person shooting and close-up shooting, the phase of the synchronization signal will be different in both cases.

When the video signal is sent through a band compression transmission line that thins out and samples the synchronization signal, the situation changes from the all-person shooting state to the close-up shooting state.

Or, when switching to the opposite, one image was distorted and not very useful. As a result, a dedicated camera must be provided for each purpose, making the system more complex.

OBJECTS OF THE INVENTION The present invention provides a method for switching the synchronization signal of the output video (m number) from the time of shooting all the members to the time of close-up shooting.

Moreover, even in the opposite case, the purpose is to eliminate the image disturbances that occur in the past. Further, the present invention provides all means that enable colorization of a composite image when all the members are photographed.

Summary of the Invention In order to achieve the above object, the video conferencing device of the present invention has a plurality of six devices that can be arranged to separately photograph all participants in a conference, and can generate all output video signals without including a vertical synchronization signal. A camera, a reference synchronization signal generation circuit that generates a reference vertical synchronization signal, and a control circuit that selectively generates control signals representing the first and second operation modes and determines all operation modes of the camera.

In response to the control sequence, a reference vertical synchronization signal and an external Kenlock signal for controlling all cameras are formed, and each external control signal is outputted so that each camera can output all video signals with a predetermined phase relationship in the first operation mode. External genlock signal generation that makes the phase difference of the genlock signals different and completely determines the phase of the external genlock signal so that one of the cameras outputs a video signal in a period corresponding to the phase of the reference synchronization signal in the second operation mode. a vertical blanking signal generating means for generating a vertical blanking signal obtained by adding a VC color burst signal and a predetermined position Iw of a vertical period from a reference vertical synchronizing signal and a color subcarrier; and a first operation of the control signal. In mode, outputs a colored composite video signal of all conference participants from each output video signal of the camera and the vertical blanking signal,
In addition, there is also a video processing circuit that outputs a video signal representing a close-up image from a selected one of the cameras when the control signal is in the second operation mode, and a reference synchronization signal is superimposed on the output of this video processing circuit. It is fully equipped with a synchronizing signal superimposition circuit.

Embodiment of the Invention FIG. 1 shows a block circuit diagram of a television conference apparatus according to an embodiment of the invention, and FIGS. 2 and 3 are small waveform diagrams for explaining the circuit operation of the first embodiment.

The circuit shown in Fig. 1 shows the case where two cameras 1 and 2 are used, and 04, which is a reference synchronization signal generation circuit that generates a synchronization signal to be used as a 3μ reference vertical synchronization signal, converts the transmitted video into a conference mode, i.e. This is the control circuit for controlling the switching of the operation mode between photographing all conference participants and close-up photographing. The control signal obtained from the control circuit 4 is applied to an external genlock signal generation circuit 5 which generates an external genlock signal from the reference synchronization signal, and controls the cameras 1 and 2 to perform external genlock using synchronization signals having different phase relationships. Further, the reference synchronization signal is given to the vertical blanking signal generation circuit 6, and becomes a signal for performing vertical blanking of the composite video signal when photographing all the members. 7 is a color subcarrier generation circuit, which supplies a color burst adding circuit 8vc color subcarrier.

In conjunction with the vertical blanking signal, a color burst can be planted during the vertical blanking period. 9 is an image processing circuit; camera 1. 2 and the output of the color burst adding circuit 8 are given.

A predetermined video signal output is extracted depending on the operation mode of the control signal for full-body photography and close-up photography. This signal is superimposed with a synchronizing signal inputted from the reference JtJI signal generating circuit 3 in a synchronizing signal superimposing circuit 1 ( ) and outputted from a line terminal IJ.

Next, the operation of the circuit shown in FIG. 1 when all conference participants are photographed will be explained in detail with reference to FIG. 2. Figure 2 shows the first
The waveform at point A-I-] in the figure is shown. When photographing all members, the synchronization signals A shown in FIG.
, B has an external genlock. In other words, in the video output of camera 1.2, the digits C and I in Figure 2 are shifted by a predetermined amount g with respect to each other and with respect to the reference vertical synchronization signal.
It has become very popular. These camera outputs and vertical blanking (E in FIG. 2, which is number n) are connected to the video processing circuit 9.
At , the signals are sequentially switched at l/-1 based on the control signal from the control circuit 4, and the result and (at . F in Fig. 2, which is a composite video signal of the predetermined intercostal space and the vertical blanking signal, is output.By the way, since both the camera video output and the vertical blanking signal lack the vertical synchronization signal, , in the synchronization signal superimposition circuit 10, the synchronization signal G fully synthesized video signal shown in FIG.
:1 superimposed on FVc in FIG. 2 is sent from the A-line terminal 11 to the transmission path as a predetermined signal, H in FIG.

Next I/Ch close-up photographing a↓The circuit operation shown in Fig. 1 will be explained using the waveform sound shown in Fig. 3. FIG. 3 shows the waveforms of points A, C, F" to l (all 7J<0 in this case, 0: from the external genlock signal generation circuit 5 in FIG. 1). is the reference synchronization signal generation circuit 3
F) A signal in FIG. 3, which is a signal having the same phase as G in FIG. 3 required by the reference image quotient synchronization signal, is output and given to the camera l. Camera 1 outputs C in Figure 3, which includes a close-up shot of δ. The image processing circuit 91 is loaded and outputs the video signal 1' in FIG. 3, which is a close-up photographed video signal. This signal VC is multiplied by G in Figure 3, which is the reference vertical synchronization number 1d, in the 5 circuit 10, and is output from the terminal 11 as signal 11 in Figure 3, which is the close-up video output of the PJT rectangle, and is sent out to fl and filter. . .

When switching to this shooting mode, the phase of the 7-C external genlock (i4) that also serves as camera 1 changes significantly after nU, and its output 11 center ξ signal also shifts.However, The synchronization signal (1) of the video signal to be sent out does not change before or after this operation, that is, the reference vertical synchronization signal shown in FIG. 3G regardless of the mode switching.

As a result, the video 1st female signal (C transmission) was transmitted via a band compression transmission line that thinned out and sampled the synchronization signal (even when the shooting mode was switched to 4), the playback image + C disturbance occurred when the shooting mode was switched. Also, the color burst adding circuit 8 was used to add a color burst to the vertical blanking signal.

This makes it possible to colorize the composite image of all 44 shots. That is, at this time, the color burst in the center of the output of camera 1 and 2 is
．． 2, and is generated within 1 meter of the color burst of 1 vertical blanking section.

Effects of the Invention As described above, if the present invention is implemented, it is possible to superimpose a certain synchronization signal at the time of video transmission and inject a color burst into the vertical blanking signal, so that even when passing through a band compression transmission line, it is possible to capture images of all members. The camera can also be used as a camera for close-up photography, and it is also possible to colorize a composite image when everyone is photographed.

Incidentally, in the above-mentioned embodiment, the case where there are two cameras in r is explained, but in reality, an arbitrary number of cameras are used in 1c, and the same operation is performed for them.

In addition to the color burst in the vertical blanking section,
It is generated including the color burst within the video section, and all a
It is also possible to find it.

[Brief explanation of the drawing]

FIG. 1 is a block circuit diagram of an embodiment of the video conference device of the present invention, FIG. 2 is a waveform diagram for fully explaining one of the operating modes of the circuit in FIG. 1, and FIG. FIG. 3 is a waveform diagram for explaining the other operation mode of the circuit. 1. Work 2...Camera, 3...Reference synchronization signal generation circuit, 4...Control circuit, 5...External genlock signal generation C=J path, 6...Vertical blanking signal generation circuit ,
7... Both conveyance V generation circuit, 8... Color burst addition circuit, 9... Signal processing circuit, 10... Synchronization 1B No. M (tatami circuit), 11... Output terminal. [□ Agent Patent Attorney Kuri IT, 1 Spring 716jj1
-,,,i1 2nd ward 3 Figure

Claims (1)

[Scope of Claims] A plurality of cameras that are arranged to separately photograph all conference participants and generate all output video signals excluding vertical synchronization signals, and a reference synchronization signal generation that generates all reference vertical synchronization signals. a control circuit for selectively generating a control signal indicative of a first and second operating mode to determine an operating mode of the camera; Controls external genlock signals for all formations. In the first operation mode, each of the cameras makes the phase difference of each external genlock signal different in order to output a video signal with a predetermined phase relationship, and in the second operation mode, one of the cameras outputs a video signal with a predetermined phase relationship. an external genlock signal generation circuit that determines the phase of an external genlock signal to output the entire video signal during a period corresponding to the phase of the reference vertical synchronization signal; a subcarrier generation circuit that generates a color subcarrier; and a subcarrier generation circuit that generates a color subcarrier; vertical blanking signal generating means for generating a vertical blanking signal in which a color burst signal is added to a predetermined position in a vertical period from a color subcarrier; and each output video signal of the camera in operation mode 2 and 1 of the control signal; and said vertical blanking signal to output a colorized composite video signal of all conference participants, and a close-up from a selected one of said cameras during a second operating mode of said control signal. 1. A television conference device comprising: a video processing circuit that outputs all video signals representing a video conference; and a synchronization signal review circuit that superimposes and adds the reference vertical synchronization signal to the output of the video processing circuit.