JPS6149577A - Television conference device - Google Patents

Abstract

PURPOSE:To adjust automatically phases of subcarriers of plural cameras by synchronizing the phase of the reproduced subcarrier from the camera with that of a reference subcarrier generated in a TV conference device. CONSTITUTION:Phases of output subcarriers of cameras 1 and 2 are compared with the phase of the output subcarrier of a reference synchronizing signal generating circuit 12 by phase synchronizing circuits 10 and 11. If a subcarrier signal whose phase lags behind the phase of the output subcarrier of the camera 1 and a subcarrier signal whose phase leads the phase of the output subcarrier of the camera 2 are outputted from circuits 10 and 11 respectively as the result, these outputs are supplied as external synchronizing signals of subcarrier generating circuits of cameras 1 and 2 through camera external synchronizing signal generating circuits 15 and 16, and circuits 10 and 11 change phases of output subcarriers of cameras 1 and 2 and the reference subcarrier so that phases of subcarriers of cameras 1 and 2 coincide with each other automatically.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a video conference device that performs conference communication with a remote location. In particular, it is suitable for synchronization devices that automatically match the subcarrier phases of multiple cameras with the reference subcarrier phases generated inside the video conferencing device.

It is related to Here, a video conference device is used to transmit images of people, documents, and other objects to each other's television receiver via a video and audio transmission path when multiple people hold a conference at two separate locations. This refers to a device that is configured to reproduce audio and other sounds from the other party's public address system.

[Conventional technology]

Video conferencing equipment uses multiple cameras, so it is necessary to match the phases of these subcarriers. To do this, a subcarrier phase measuring device is used to manually adjust the subcarrier phase. I was going there.

[Problem that the invention seeks to solve]

However, since this kind of adjustment is usually done as an initial adjustment when setting up the camera, it is common for phase differences to occur between the subcarriers of multiple cameras due to aging, changes in temperature, etc. Become. Therefore, there is a drawback that manual readjustment is required each time a phase difference occurs.

The present invention solves this problem and aims to provide a device that does not require manual re-adjustment of the sub-primary transmission phase.

[Means for solving problems]

The present invention provides a means for synthesizing video signals taken by a plurality of cameras, a means for transmitting the synthesized video signals by the means to a corresponding device at a remote location, and a means for transmitting the video signals synthesized by the means to a corresponding device at a remote location. A video conference device comprising means for displaying a video signal, further comprising means for generating one reference subcarrier, and further comprising means for reproducing the subcarrier of the camera for each of the plurality of cameras; The camera is characterized by comprising means for comparing the phase of the output subcarrier and the reference subcarrier, and means for negative feedback connecting the phase control signal obtained from the output of this means to the subcarrier generation circuit of the corresponding camera. shall be.

[Effect]

The present invention relates to the phase of a subcarrier reproduced by a plurality of corresponding subcarrier reproduction means from color burst signals of respective video signals from a plurality of cameras, and the phase of a reference subcarrier generated by a reference subcarrier generation means. The subcarriers of multiple cameras are automatically phase synchronized by comparing the signals using their corresponding phase synchronization means and connecting the phase control signal obtained by the output with negative feedback to the subcarrier generation circuit of the corresponding camera. be able to.

〔Example〕

Embodiments of the present invention will be described with reference to the drawings.

The figure is a block diagram of a video conference device according to an embodiment of the present invention. In the figure, video signals captured by cameras 1 and 2 are each connected to a video distribution circuit 3.4. One of the two outputs of the video distribution circuit 3.4 is connected to the video switching circuit 5, and the other to the subcarrier regeneration circuit 8.9.

A control signal from a control circuit 6 is connected to a control input of the video switching circuit 5. The two video signals are switched and a composite video signal is generated and connected to the line terminal 7.

A subcarrier reproducing circuit 8.9 reproduces a continuous wave subcarrier based on the color burst signal of each human input video signal.

The feature of the present invention is the subcarrier phase synchronization portion surrounded by a dashed line. That is, the reproduction side general transmission waves are respectively connected to the next stage phase synchronization circuits 10 and 11. In addition to the above inputs, the base 4ζ subcarrier generated by the reference synchronization signal generation circuit 12 is input to the phase synchronization circuit 10.11 via the subcarrier distribution circuit 13. The phase synchronization circuit 10.11 compares the phase of the reference subcarrier and the reproduced subcarrier from the camera, detects the lead or lag of the subcarrier phase from each camera with respect to the reference subcarrier phase, and determines the phase of the reference subcarrier. Generate subcarriers in phase synchronization. The reference synchronization signal generation circuit 12 generates a reference synchronization signal in addition to the reference subcarrier, and this reference synchronization signal is connected to each camera external synchronization signal generation circuit 15 and 16 via the synchronization signal distribution circuit 14. be done.

The camera external synchronization signal generation circuit 15.16 uses the subcarrier from the phase synchronization circuit 10.11 and the synchronization signal distribution circuit 14.
Each camera external synchronization signal is generated based on the reference synchronization signal from the reference synchronization signal generation circuit 12 connected via the camera. Camera external synchronization signal generation circuit 15.1
The camera external synchronization signal generated in step 6 is connected to the subcarrier generation circuit of camera 1.2, and external synchronization is applied to each camera.

The operation of the video conference device configured in this way will be explained. In the figure, the subcarrier phase of the output of camera 1.2 and the subcarrier phase of the output of reference synchronization signal generation circuit 12 are compared by phase synchronization circuit 10.11.

Now, suppose that the subcarrier phase of the output of camera 1 is leading with respect to the reference subcarrier, and the subcarrier phase of the output of camera 2 is lagging with respect to the subcarrier.

As a result of the comparison, the phase synchronization circuit 1O outputs a subcarrier whose phase is delayed from the subcarrier phase of the output of camera 1, and the phase synchronization circuit 11 outputs a subcarrier whose phase is ahead of the subcarrier phase of the output of camera 2. The carrier wave is outputted and supplied as an external synchronization signal to the subcarrier generation circuit of the camera 1.2 via the respective camera external synchronization signal generation circuit 15.16. The phase synchronization circuit 10 delays the subcarrier phase of the camera external synchronization signal until the subcarrier phase of the output of the camera 1 matches the reference subcarrier phase, and the phase synchronization circuit 11 delays the subcarrier phase of the output of the camera 2. The subcarrier phase in the camera external synchronization signal is advanced until the subcarrier phase of and the reference subcarrier phase match. In this way, phase adjustment can be performed automatically, rather than manually, so that the phases of the subcarriers of cameras 1 and 2 match. Also,
According to the present invention, it is possible to implement a camera in which the subcarrier phase adjustment of the camera is fixed and cannot be preadjusted.

Although a video conference device using two cameras has been described above, it can be similarly implemented using three or more cameras.

〔Effect of the invention〕

As described above, the present invention is configured such that the phase of the reproduced subcarrier from the camera matches the phase of the reference subcarrier generated inside the video conference device and is synchronized in the phase synchronization circuit. This has the excellent effect of automating subcarrier adjustment for multiple cameras.

[Brief explanation of drawings]

The figure is a block diagram of a video conference device according to an embodiment of the present invention. 1.2...Camera, 3.4...Video distribution circuit, 5.
...Video switching circuit, 6...Control circuit, 7...Line terminal, 8.9...Subcarrier regeneration circuit, 10.11...
Phase synchronization circuit, 12... Reference synchronization signal generation circuit, 13
... Subcarrier distribution circuit, 14... Synchronization signal distribution circuit, 15.16... Camera external synchronization signal generation circuit.

Claims (1)

[Claims] (1) A means for synthesizing video signals captured by multiple cameras, a means for transmitting the video signals synthesized by this means to a corresponding device at a remote location, and an image arriving from the corresponding device at a remote location. a means for displaying a signal; further comprising means for generating one reference subcarrier, and further comprising means for reproducing the subcarrier of the camera for each of the plurality of cameras; It is characterized by comprising means for comparing the phase of the output subcarrier and the reference subcarrier, and means for negative feedback connecting the phase control signal obtained from the output of this means to the subcarrier generation circuit of the corresponding camera. video conferencing equipment.