Patent ID: 6449231
Filing Date: 2002-09-10
Classification: G11B

Abstract:
A storage unit for optically reproducing information from an optical recording medium of a type having a control track and a data track said control track and said data track having mutually different recording densities, said storage unit comprising: reproducing means for reproducing information from the optical recording medium;control means for switching a frequency of a read clock which is used when reproducing the control information and data from the optical recording medium depending on whether the control information is reproduced from the control track or the data is reproduced from the data track; wherein said control track includes a first data part prerecorded with control information having medium information peculiar to the optical disk using embossed pits, and a first identification part for identifying a recording track of said first data part using embossed pits; and said data track includes a second data part recorded with the data recorded by an optical means, and a second identification part for identifying the recording track of said data part of said data track using embossed pits.