Patent ID: 7724630

Claim:
An optical disc device capable of reproducing a two-wavelength two-layer disc configured by a first recording layer corresponding to a laser light of a first wavelength and a second recording layer corresponding to a laser light of a second wavelength longer than the first wavelength, the second and first recording layers being arranged from a laser light entering side in that order, and the first recording layer being not optically detected when the laser light of the second wavelength is used, the optical disc device comprising: a first detecting means for detecting the number of recording layers arranged in an optical disc by irradiating the laser light of the first wavelength onto the optical disc loaded on the optical disc device; a second detecting means for detecting the number of recording layers arranged in the optical disc by irradiating the laser light of the second wavelength onto the optical disc; a first demodulating means for performing a demodulation process according to a first data format responding to the laser light of the first wavelength; a second demodulating means for performing a demodulation process according to a second data format responding to the laser light of the second wavelength; a first determining means for determining whether or not a signal obtained by irradiating the laser light of the first wavelength to the recording layer of the optical disc that appears first when seen from the laser light entering side is demodulatable with the first demodulating means; a second determining means for determining whether or not the signal obtained by irradiating the laser light of the first wavelength to the recording layer of the optical disc that appears first when seen from the laser light entering side is demodulatable with the second demodulating means; and a disc determining means for determining the disc loaded on the optical disc device as the two-wavelength two-layer disc when two recording layers are detected by the first detecting means, one recording layer is detected by the second detecting means, the signal is determined as not demodulatable with the first demodulating means by the first determining means, and the signal is determined as demodulatable with the second demodulating means by the second determining means.