Tracking control apparatus of optical disc apparatus and method of same

A tracking control apparatus of an optical disc apparatus for performing reproduction and/or recording of a signal from a disc-like recording medium, comprising:

• a condensing means for condensing a light beam emitted from a light source toward the disc-like recording medium;
• a light receiving means for receiving the light beam reflected from the disc-like recording medium and outputting first and second received light detection signals from regions located on the two sides of the center of a signal track of the disc-like recording medium;
• a first computing means for calculating a first calculation signal based on the first received light detection signal detected by the light receiving means;
• a second computing means for calculating a second calculation signal based on the second received light detection signal detected by the light receiving means;
• a third computing means for calculating a tracking error signal based on the first calculation signal and the second calculation signal;
• a signal processing means for masking a half cycle of an off-track part of the tracking error signal at a time of transition from an off-track state to an on-track state immediately after high speed movement of the condensing means;
• and
• a tracking servo means for performing the tracking servo control of the condensing means by using the masked tracking error signal.

A tracking control apparatus of an optical disc apparatus for performing reproduction and/or recording of a signal from a disc-like recording medium, comprising:

• a condensing means for condensing a light beam emitted from a light source toward the disc-like recording medium;
• a light receiving means for receiving the light beam reflected from the disc-like recording medium and outputting first and second received light detection signals from regions located on the two sides of the center of a signal track of the disc-like recording medium;
• a first computing means for calculating a first calculation signal based on the first received light detection signal detected by the light receiving means, wherein the first computing means is a calculation circuit for detecting a peak of the first received light detection signal and subtracting a signal obtained by multiplying a first coefficient with the peak of the first received light detection signal to calculate the first calculation signal;
• a second computing means for calculating a second calculation signal based on the second received light detection signal detected by the light receiving means, wherein the second computing means is a calculation circuit for detecting a peak of the second received light detection signal and subtracting a signal obtained by multiplying a second coefficient with the peak of the second received light detection signal to calculating the second calculation signal;
• a third computing means for calculating a tracking error signal based on the first calculation signal and the second calculation signal;
• a signal processing means for masking a half cycle of an off-track part of the tracking error signal at a time of transition from an off-track state to an on-track state immediately after high speed movement of the condensing means;
• and
• a tracking servo means for performing the tracking servo control of the condensing means by using the masked tracking error signal.

A tracking control method of calculating a tracking error signal from first and second received light detection signals respectively detected from two side regions of a center of a track of a disc-like recording medium and using the tracking error signal for performing tracking servo control, said tracking control method including the steps of:

• detecting a peak of the first received light detection signal and subtracting a signal obtained by multiplying a first coefficient with the peak of the first received light detection signal to calculate a first calculation signal;
• detecting a peak of the second received light detection signal and subtracting a signal obtained by multiplying a second coefficient with the peak of the second received light detection signal to calculate a second calculation signal;
• calculating a tracking error signal by subtracting the second calculation signal from the first calculation signal;
• masking a half cycle of an off-track part of the tracking error signal at a time of an on-track state immediately after a sled high speed feed calculation;
• and
• performing the tracking servo control by using the masked tracking error signal.

A tracking control apparatus of an optical disc apparatus having at least one photodiode for outputting first and second received light detection signals from regions located on two sides of a center of a track of a disc-like recording medium, calculating a tracking error signal from said first and second received light detection signals, and performing tracking servo control by using the tracking error signal, said tracking control apparatus comprising:

• a first calculation circuit for detecting a peak of the first received light detection signal from the at least one photodiode and subtracting a signal obtained by multiplying a first coefficient with the peak from the first received light detection signal to calculate a first calculation signal;
• a second calculation circuit for detecting a peak of the second received light detection signal from the at least one photodiode and subtracting a signal obtained by multiplying a second coefficient with the peak from the second received light detection signal to calculate a second calculation signal;
• a third calculation circuit for subtracting the second calculation signal from the first calculation signal to calculate the tracking error signal;
• a signal processing circuit for masking a half cycle of an off-track part of the tracking error signal at a time of an on-track state immediately after a sled high speed feed calculation;
• and
• a tracking servo control circuit for performing the tracking servo control by using the masked tracking error signal.

A tracking control apparatus of an optical disc apparatus for performing reproduction and/or recording of a signal from a disc-like recording medium, comprising:

• an object lens for condensing a light beam emitted from a light source toward the disc-like recording medium;
• at least one photodiode for receiving the light beam reflected from the disc-like recording medium and outputting first and second received light detection signals from regions located on the two sides of the center of a signal track of the disc-like recording medium;
• a first calculation circuit for calculating a first calculation signal based on the first received light detection signal detected by the at least one photodiode;
• a second calculation circuit for calculating a second calculation signal based on the second received light detection signal detected by the at least one photodiode;
• a third calculation circuit for calculating a tracking error signal based on the first calculation signal and the second calculation signal;
• a signal processing circuit for masking a half cycle of an off-track part of the tracking error signal at a time of transition from an off-track state to an on-track state immediately after high speed movement of the object lens;
• and
• a tracking servo circuit for performing the tracking servo control of the object lens by using the masked tracking error signal.