Adaptive sync protection method in digital reproduction systems and apparatus therefor

A sync protection apparatus in a digital reproduction system which adaptively protect a sync signal being reference of processing a digital reproduction signal reproduced via a recording medium from the varied reproduction characteristics of a channel, the apparatus comprising:

• a sync detection unit for detecting sync data from the digital reproduction signal and outputting a sync detection signal and a sync signal;
• a reference value generation unit for storing data format information of the recording medium and a sync detection reference number for a presently read first data section of the recording medium, and generating the sync detection reference number with respect to the following first data section of the recording medium by using a sync missing number and an error-sync generation number obtained in said first data section;
• a counter unit for counting a predetermined sync block term from a point of time corresponding to a sync detection prediction position, and outputting a counted value;
• a sync prediction/error detection unit for determining a sync detection prediction position for said presently read first data section using the sync detection signal applied from said sync detection unit and the sync detection reference number stored in said reference value generation unit, detecting error-sync and sync missing in said presently read first data section based on the counted value supplied from said counter unit and said sync detection signal, and outputting an error-sync generation number and a sync missing number to said reference value generation unit;
• and
• a control unit for controlling said counter unit to execute a counting operation from a point of time corresponding to the sync detection prediction position determined by said sync prediction/error detection unit, and controlling said sync detection unit to generate the sync signal according to the counted value outputted from said counter unit after the sync detection prediction position for said presently read first data section is determined.