Patent ID: 7190643

Claim:
A land pre-pit address demodulating device for use in an optical disc recording apparatus which irradiates a DVD-R/RW disc with a laser beam, the optical disc recording apparatus switching a power of the laser beam between first and second intensities so as to generate an amorphous region with the laser beam of the first intensity and a recrystallized region with the laser beam of the second intensity, thereby recording information to the DVD-R/RW disc, the land pre-pit address demodulating device detecting land pre-pit address information from the laser beam reflected by the DVD-R/RW disc, the device comprising: a generation section for generating a tracking error signal from the reflected laser beam; a first reference potential section for supplying a first reference potential lower than a potential of the tracking error signal; a laser intensity indicating section for indicating whether the reflected laser beam from which the tracking error signal is generated is of the first intensity or the second intensity; an RF residual component removing section for removing an RF residual component from the tracking error signal by muting the tracking error signal with the first reference potential during a period in which the tracking error signal is generated from the reflected laser beam of the first intensity; and a land pre-pit address signal detection section for comparing the tracking error signal from which the RF residual component has been removed to a second reference potential and detecting a land pre-pit address signal.