Video/audio information transmission system

A video/audio information service system comprising:

• a center including a plurality of video and audio files, and a central processing unit for controlling the files;
• a plurality of subscriber units, each subscriber unit including TV receiver means, converter means for converting an analog baseband signal into a standard TV signal for application to said receiver means, and terminal controller means for generating a calling signal and a request;
• a plurality of subcenters each accommodating thereto a plurality of said subscriber units, each of said subcenters including therein a character generator means for generating character information for said TV receiver means corresponding to character information inputted from said subscriber units, change-over switch means for changing over said video/audio information and said character information, said change-over switch means being coupled to said character generator means, a plurality of video/audio buffer memories coupled to said change-over switch means, said exchange means coupled to said video/audio buffer memories for communicating with said associated subscriber units;
• first transmission path means for connecting said center and said subcenter respectively to transmit said video/audio information in an analog based band signal form, said character generator means in each subcenter being provided for diminishing traffic of said first transmission path means between said center and subcenters;
• and
• second transmission path means for connecting said subcenter and said subscriber units respectively to transmit said video/audio information and said character information in an analog baseband signal form, said central processing unit controlling said video and audio files in accordance with requests from said subscriber units via said subcenters, and
• wherein said subcenter includes picture system means having a frame memory, a video change-over unit coupled to said frame memory, a video output unit coupled to said video change-over unit and said character generator means coupled to said video change-over unit, audio system means having an audio change-over unit, said audio buffer memory coupled to said audio change-over unit and an audio output unit coupled to said audio change-over unit, control system means having a multi-frequency receiver and a microcomputer coupled to said multi-frequency receiver, said audio buffer memory and said character generator means, and said exchange means having an exchanger coupled to said audio and video output units and end office units coupled to said exchanger.