| 摘要 |
PURPOSE:To increase an error detecting and correcting capacity by outputting blank information when a blank detecting device and the blank information are present and being equipped with a switching device and a decoder to output code information when they are absent. CONSTITUTION:At a blank detecting device 1, a detecting device 4 extracts a synchronizing signal from the code information of a block form, resets a block address detecting device 5 and a symbol counter 6 and obtains the synchronization of a block unit. The detecting device 5 resets a block address signal, the counter 6 generates a symbol address signal and both signals determine the symbol position in a track. Further, the identification signal of tracks A and B is added and a symbol position is determined. Since the address, in which the blank information exists, is determined by an action mode, the detecting device 7 detects the coincidence of the code and the address, in which both pieces of blank information exist, by an action mode signal. After the information, in which the blank information exists in the code information, is set wholly to the correct blank information value, decoding 3 is executed, therefore, the erroneous detection and the correcting capacity can be directed to the information excluding the blank information and the erroneous detection and correcting capacity of the information can be increased.
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