High speed forward sense sampling in optical drives using placed data patterns

摘要

An approach is described that allows an optical disc drive to accurately verify the power level of irradiation beam power levels associated a write strategy used in high speed, high density optical disc media formats using a front monitor diode with a relatively slow rise time and/or relative slow fall time compared to the clock cycle speed of the write strategy signal. A portion of encoded data to be written to an optical disc media may be overwritten to include a predetermined data pattern. During write strategy processing of the data, the predetermined data pattern is replaced with a constant write strategy power level. The constant write strategy output placed within the write strategy signal may control the optical disc drive laser to emit a constant irradiation beam for a duration sufficiently long to allow the front monitor diode to obtain an accurate measure of the irradiation beam power level.