| 摘要 |
<p>PROBLEM TO BE SOLVED: To enable optimum synchronizing protection without increasing the possibility of the misidentified detection of a pit queue being the same alignment as a synchronizing pattern by performing magnifying control on the width of a detection window when the number of times of successive nondetection of a detecting synchronizing signal. SOLUTION: When the synchronizing signal of the output of a synchronizing signal detection 21 is not detected, an window protection 24 transmits that effect to a number-of-undetected-times counter 25 to perform the counting of number-of-undetected-times. Then, also in detection, the window protection 24 transmits it to the counter 25, and transmits the counted value of the counter 25 to an window width determination 26 at each time, compares the set value of a number-of-undetected-times prepared in a determination reference table 27 with the counted number of the output of the counter 25, and if both coincide, it supplies detection window width information corresponding to that number of undetected times to a detection window generation 29 to perform the control for generating a detection window having the above width. Then, the detection window having the changed width is outputted to the window protection 24.</p> |
