JPS6439892A - Video tex with sound - Google Patents

Abstract

PURPOSE:To improve the quality of information by changing-over a picture and sound switching circuit with receiving sound end detecting information in a center side and sending the next picture data with a picture transmittable condition. CONSTITUTION:When A sound information are ended, the silence of a constant period is detected by a silence detector 18 to have a threshold which is enough smaller than a sound and enough larger than line noise and it is decided as A sound information ending and transmitted to a control device 1 as a sound ending code. The control device 1 changes-over a picture and sound changing- over switch 10 to a high-speed MODEM 6 side and executes the preparation of the next receiving of picture information. The sound ending code is sent to the control device 1 of the center side by a route 1. The control device 1 recognizes that a terminal side decides the A sound information ending, changes-over a picture and sound changing-over switch 17 to a high-speed MO DEM 14 side and sends the next B screen information to the terminal side by a route 2. Then, an operator can listen to a B sound simultaneously with a B picture in the same way as the case of an A picture. Thus, picture information and sound information can be automatically received continuously.