| 摘要 |
PURPOSE:To secure an accurate reading for the head part of the next data by utilizing the general monostable multivibrator in addition to the double-trigger type monstable multivibrator in case the extra pulse is applied in the section in which the address mark is detected. CONSTITUTION:When the input data is supplied, double-trigger type monostable multivibrator 1 operates and then changes after a fixed time. Then the signal enters general monostable multivibrator 2 which operates at the front edge of the pulse of circuit 1 and also produces the pulse of a fixed duration. In case the extra pulse emerges near the middle of the blank section, circuit 2 is actuated to delete the extra pulse through the NAND circuit to circuit 3. As a result, the address mark can be detected with no effect of the extra pulse, thus ensuring an accurate reading for the head part of the next data. |
