Patent ID: 7277545

Claim:
A data scrambler for a high density optical recording and/or reproducing apparatus using an optical disc, the data scrambler comprising: a random data generator which generates random data having a random data generation cycle based on a result obtained by multiplying at least a size of a first data frame by a result obtained by dividing a data amount of two tracks in an outermost circumference of the optical disc by a size of a second data frame, wherein the random data generator comprises: serially arranged registers, which shift-store n bits and generate the random data, and use a total of n values as initial values, including a first initial value and register values, which are supplied in each 4K times left-shifting of the first initial value, a first serial logic circuit having a plurality of logic gates, which exclusive-ORs outputs of a first group of the registers which correspond to a number of effective branches with a predetermined branch value, and feedbacks the random data to a least significant register, wherein the data scrambler further comprises a second logic circuit which scrambles outputs of a second group of registers and input data and outputs scrambled data in units of bytes to the recording and/or reproducing apparatus.