| 摘要 |
PURPOSE:To make clear the starting position of data for each sub-block and to simplify the constitution of a synchronism detecting citcuit, by varying the synchronous mode for each sub-block. CONSTITUTION:An input terminal 20 supplies a serious data which is reproduced out of a magnetic tape and received the wave form shaping. For a shift register 21 of 30 bits, the synchronous informations S1 and S2 are selected through a gate and then the video information is fed to an ROM by 14 bits to perform an adverse conversion of a code 8-10. For the synchronous detection, the probability for pseudo detection is greatly reduced since the collation is carried out over 34 bits. Furthermore it is easy to distinguish the head from the middle of a block since the S1 is different from the S2. In such a way, it is easy to simplify the constitution of a synchronism detecting circuit by varying the informations S1 and S2 of two sub-block in a block. |
