Patent ID: 7055082

Claim:
An information recording and reproducing apparatus comprising: first means for scrambling user data in response to address information to get scramble-resultant data; second means for adding first error correction code data and second error correction code data to the scramble-resultant data and the address information to get addition-resultant data placed in error correction blocks; third means for recording the addition-resultant data on a recording medium for every error correction block; fourth means for reproducing recorded data from a recording medium to get reproduced data for every error correction block; fifth means for correcting errors in the reproduced data in response to first error correction code data and second error correction code data contained in the reproduced data to get correction-resultant data for every error correction block; sixth means for extracting all pieces of address information from the correction-resultant data for every error correction block; seventh means for subjecting all the address information pieces extracted by the sixth means to error checks to decide whether at least one of all the address information pieces is correct and whether all the address information pieces are erroneous; eighth means for, when the seventh means decides that at least one of all the address information pieces is correct, setting a descramble initial value in response to the correct address information piece; ninth means for, when the seventh means decides that all the address information pieces are erroneous, estimating a correct address information piece from an address information piece associated with a previous error correction block and setting the descramble initial value in response to the estimated correct address information piece; and tenth means for descrambling the correction-resultant data in response to the descramble initial value set by one of the eighth means and the ninth means for every error correction block.