Patent ID: 6331966
Filing Date: 2001-12-18
Classification: G11B

Abstract:
An optical storage apparatus comprising:a recording unit for recording data to a recording layer of an optical storage medium having at least a recording layer to record data and a reproducing layer to reproduce the data recorded in said recording layer on a board at a recording density smaller than a beam diameter of a laser beam;a reproducing unit for reproducing the data recorded in the recording layer of said optical storage medium at a recording density smaller than said beam diameter by setting a combination of a reproducing magnetic field and a reproducing laser power which are necessary for reproduction to best values; anda calibration processing unit for measuring a reproducible state by performing the reproducing operation of said optical storage medium by said reproducing unit while changing said reproducing magnetic field and said reproducing laser power, thereby determining a set of the best values of the reproducing magnetic field and the reproducing laser power which are used in said reproducing unit on the basis of the reproducing magnetic field or the reproducing laser power at the time when said reproducible state is obtained,wherein said calibration processing unit determines the best values of said reproducing magnetic field and said reproducing laser power every predetermined zone of said optical storage medium and stores and holds said best values into a memory.