Buffer memory dispersion type video/audio transmission system
First Claim
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1. A buffer memory dispersion type video/audio transmission system comprising:
- a plurality of subscriber terminal units each including a telephone set and/or a keyboard, a video-audio receiver, and a converter for converting a video signal and an audio signal transmitted in a base band to a standard television signal;
a center including a group of audio files for storing audio information and a group of video files for storing video information, and a central processing unit responsive to a requesting command received from said subscriber terminal units for fetching specific video and/or audio information from said files and for transmitting the fetched information in time division multiplex form;
a plurality of sub-centers each accommodating thereto a plurality of said subscriber terminal units and each including a plurality of video and audio buffer memories for temporarily storing specific video information and specific audio information received from said center in time division multiplex form, a D/A converter for digital to analog converting the information of said audio buffer memory, a modulator for modulating a carrier wave by the audio information, and exchange means for combining outputs of said D/A converter and said modulator and for connecting said sub-center to a subscriber terminal lunit requesting information; and
a first transmission line connecting said sub-centers in common to said center and a plurality of second transmission lines connecting the respective sub-centers to a respective subscriber terminal unit, the length of said second transmission lines being shorter than the length of said first transmission line, said first transmission line enabling transmission in time division multiplex form and said second transmission lines enabling transmission in base band form.
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Abstract
A video/audio transmission system for sending video and audio information from video and audio files of a center to a subscriber through a subscriber'"'"'s junction line is disclosed in which at least one subcenter having a video/audio buffer memory, an exchange and the like is disposed near to the subscriber to reduce the number of repeaters arranged on the subscribers junction line, and in which the video and audio information is transmitted from the center to the sub-center in a time division multiplex fashion to reduce the number of transmission lines between the center and the sub-center.
204 Citations
5 Claims
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1. A buffer memory dispersion type video/audio transmission system comprising:
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a plurality of subscriber terminal units each including a telephone set and/or a keyboard, a video-audio receiver, and a converter for converting a video signal and an audio signal transmitted in a base band to a standard television signal; a center including a group of audio files for storing audio information and a group of video files for storing video information, and a central processing unit responsive to a requesting command received from said subscriber terminal units for fetching specific video and/or audio information from said files and for transmitting the fetched information in time division multiplex form; a plurality of sub-centers each accommodating thereto a plurality of said subscriber terminal units and each including a plurality of video and audio buffer memories for temporarily storing specific video information and specific audio information received from said center in time division multiplex form, a D/A converter for digital to analog converting the information of said audio buffer memory, a modulator for modulating a carrier wave by the audio information, and exchange means for combining outputs of said D/A converter and said modulator and for connecting said sub-center to a subscriber terminal lunit requesting information; and a first transmission line connecting said sub-centers in common to said center and a plurality of second transmission lines connecting the respective sub-centers to a respective subscriber terminal unit, the length of said second transmission lines being shorter than the length of said first transmission line, said first transmission line enabling transmission in time division multiplex form and said second transmission lines enabling transmission in base band form. - View Dependent Claims (2, 3, 4, 5)
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Specification