| 摘要 |
PURPOSE:To establish early economically a videotex network on a nation-wide scale by constituting the network with an information center transmitting a videotex signal in terms of a TV signal, picture converting centers provide at each prescribed zone and the existing TV broadcast network. CONSTITUTION:The information center 10 inputs videotex (VTX) information from an input device 14 or an external data base 15 to a processor 11 and stores the information to a file 12 with prescribed processing. The VTX is extracted from the file 12, superimposed on the TV signal by transmitters 13A, 13B and inserted thereto, and distributed and transmitted to picture information centers 30A, 30B provided at each prescribed zone via a TV broadcast network 20A and an artificial satellite 20B. The centers 30A, 30B receive the TV signal by receivers 33A, 33B, extract and separate the VTX signal, convert 31 the picture and store the signal to a file 32. Each terminal 50 requests the VTX to the centers 30A, 30B via a telephone line 40A or CATV networks 40B, 40C and obtains the desired VTX information stored in the file 32. |
