公开(公告)号：US3752908A

公开(公告)日：1973-08-14

申请号：US3752908D

申请日：1972-06-28

Applicant: KMS IND INC

Inventor： BOENKE C ,  REIMINK R ,  JACKSON J

IPC: H04N7/14

CPC classification number: H04N7/147

Abstract: A central station including a computer is connected via a multichannel CATV cable to a plurality of remote terminal stations. Some of the channels are reserved for commercial television programs. However, a predetermined number of forward television channels are reserved for private television programs which may be generated either at the central station and transmitted on these forward channels to selected terminal stations under the control of the computer, or else a private TV program may be originated at one of the remote terminals, transmitted via the cable on a return television channel thereof to the central station, and then retransmitted from the central station via the cable on a forward television channel thereof to selected remote terminal stations under the control of the computer. Each terminal station contains an audio input means, such as a microphone and an audio transmitter, for permitting a return audio or speech signal to be inserted at the central station upon the audio subcarrier of television signal which is being received by the other remote terminal stations. For a given television channel, all terminal stations use the same audio return channel, thereby communicating in a party line mode. In one embodiment, the return audio carriers for the private television channels are generated at each terminal station and the audio interaction is provided by a novel audio insertion unit using a phase locked loop which does not require demodulation and remodulation of the video signal. In another embodiment of the invention, the audio carriers for the return audio channels are generated at the central station and transmitted to the terminals for modulation by the respective return audio inputs.

Abstract translation: 包括计算机的中央站通过多路CATV电缆连接到多个远程终端站。 一些渠道是为商业电视节目预留。 然而，预定数量的前向电视频道被保留用于私人电视节目，其可以在中央台产生并且在这些前向频道上发送到在计算机的控制下的所选终端站，或者可以发起专用电视节目 在其中一个远程终端上，通过电缆在其返回电视频道上传送到中心站，然后经由其前向电视频道上的电缆从计算机的控制下通过电缆重传到所选择的远程终端站。 每个终端包含诸如麦克风和音频发送器的音频输入装置，用于允许在由其他远程终端站接收的电视信号的音频副载波上的中央站插入返回音频或语音信号 。 对于给定的电视频道，所有终端站使用相同的音频返回信道，从而以派对线路模式进行通信。 在一个实施例中，用于专用电视频道的返回音频载波在每个终端站处产生，并且音频交互由使用不需要解调和重新调制视频信号的锁相环的新颖音频插入单元提供。 在本发明的另一个实施例中，用于返回音频信道的音频载波在中心站处产生并被发送到终端以进行相应的返回音频输入的调制。