Disc driving device and wobble information detection method

A disc driving device for recording and/or reproducing a disc-shaped recording medium, having a land and/or a groove formed thereon in a circling fashion for operating as a recording track, said recording track meandering depending on a wobble signal, comprising:

• wobble signal reproducing means for reproducing said wobble signal from said disc-shaped recording medium, said wobble signal containing a first digital information MSK modulated using a carrier signal of a predetermined frequency and using a sinusoidal signal of a frequency different from the frequency of said carrier signal and a second digital information modulated onto said carrier signal by adding even harmonics signals to said carrier signal and by changing the polarity of said harmonics signals according to said second digital information (HMW modulated);
• MSK demodulation means for demodulating said wobble signal to retrieve said first digital information from said wobble signal;
• and
• HMW demodulation means for demodulating said wobble signal to retrieve said second digital information from said wobble signal;
• said MSK demodulating means including an MSK synchronization signal generating unit for generating said carrier signal and data clocks of said first digital information, from the wobble signal reproduced from said disc-shaped recording medium;
• an MSK multiplication unit for multiplying said wobble signal reproduced from said disc-shaped recording medium with the generated carrier signal;
• an MSK integrating unit for integrating an output signal from said multiplication unit at each delayed clock corresponding to the data clock of said first digital information delayed a predetermined time;
• and
• an MSK verification unit for verifying the sign of said first digital information based on an output value of said integrating unit at an end edge of said data clock;
• said HMW demodulating means including
• an HMW synchronization signal generating unit for generating said even harmonics signal and data clocks of said second digital information, from the wobble signal reproduced from said disc-shaped recording medium;
• an HMW multiplication unit for multiplying said wobble signal reproduced from said disc-shaped recording medium with the generated even harmonics signal;
• an HMW integrating unit for integrating an output signal from said multiplication unit at each delayed clock of said second digital information;
• and
• an HMW verification unit for verifying the sign of said second digital information based on an output value of said integrating unit at an end edge of said data clock of said second digital information.

A wobble information detection method for detecting the wobble information modulated into said wobble signal, from a disc-shaped recording medium, having a land and/or a groove formed thereon in a circling fashion for operating as a recording track, said recording track meandering depending on a wobble signal, comprising:

• reproducing said wobble signal from said disc-shaped recording medium, said wobble signal containing digital information modulated onto a sinusoidal carrier signal by adding even harmonics signals to said sinusoidal carrier signal and by changing the polarity of said harmonics signals according to said digital information (HMW modulated);
• generating said even harmonics signals and data clocks of said digital information from the wobble signal reproduced from said disc-shaped recording medium;
• multiplying said wobble signal with the reproduced even harmonics signals;
• integrating the signals obtained on multiplication every data clock;
• and
• verifying the sign of said digital information based on an integrated value at an end edge of said data clocks.

A wobble information detection method for detecting the information modulated into a wobble signal, from a disc-shaped recording medium, having a land and/or a groove formed thereon in a circling fashion for operating as a recording track, said recording track meandering depending on a wobble signal, comprising:

• reproducing said wobble signal from said disc-shaped recording medium, said wobble signal containing a first digital information MSK modulated using a carrier signal of a predetermined frequency and using a sinusoidal signal of a frequency different from the frequency of said carrier signal and a second digital information modulated onto said carrier signal by adding even harmonics signals to said carrier signal and by changing the polarity of said harmonics signals according to said second digital information (HMW modulated);
• generating data clocks of said first digital information and said carrier signal from the wobble signal reproduced from said disc-shaped recording medium, multiplying the generated carrier signal with the wobble signal reproduced from said disc-shaped recording medium, integrating the multiplied signal at each delayed clock obtained on delaying the data clocks of said first digital information a predetermined time, and detecting the first digital information based on an integrated output value at an end edge of said delayed clock;
• generating data clocks of said second digital information and said even harmonics signal from the wobble signal reproduced from said disc-shaped recording medium, multiplying the generated even harmonics signal with the wobble signal reproduced from said disc-shaped recording medium, integrating the multiplied signal every data clock of said second digital information, and detecting the second digital information based on an integrated output value at an end edge of said data clock of said second information.