Defect signal detecting apparatus for optical recording/reproducing apparatus and defect signal detecting method thereof

A defect signal detecting method for an optical recording/reproducing apparatus, comprising:

• detecting a highest amplitude among input signals during a maximum value detection period as a maximum value based on a reference maximum value;
• detecting a lowest amplitude among the input signals during a minimum value detection period as a minimum value based on a reference minimum value;
• calculating an amount δ of asymmetry using a detected maximum value ILmax and a detected minimum value ILmin of a signal IL that has a maximum periodicity among the input signals, and using a detected maximum value ISmax and a detected minimum value ISmin of a signal IS that has a minimum periodicity among the input signals;
• and
• determining whether there is a defect among the input signals, using the maximum value, the minimum value and the amount δ of asymmetry,
• wherein the defect determining unit determines a defect signal and outputs a corresponding blank signal if a ratio of the maximum value to the minimum value is higher than 1+Δ−δ, or lower than 1−Δ−δ,
• where Δ is a margin of the ratio of the maximum value to the minimum value.

A defect signal detecting apparatus for an optical recording/reproducing apparatus, the apparatus comprising:

• a maximum value detecting unit for detecting a highest amplitude among input signals during a maximum value detection period as a maximum value based on a reference maximum value;
• a minimum value detecting unit for detecting a lowest amplitude among the input signals during a minimum value detection period as a minimum value based on a reference minimum value;
• an asymmetry detecting unit for calculating an amount of asymmetry based on the input signals;
• and
• a defect determining unit for determining whether there is a defect in the input signals, using the maximum value, the minimum value and the amount of asymmetry,
• wherein the defect determining unit determines a defect signal and outputs a corresponding blank signal if a ratio of the maximum value to the minimum value is higher than 1+Δ−δ, or lower than 1−Δ−δ,
• where Δ is a margin of the ratio of the maximum value to the minimum value.

A defect signal detecting method for an optical recording/reproducing apparatus, the method comprising:

• detecting a highest amplitude among input signals during a maximum value detection period as a maximum value based on a reference maximum value;
• detecting a lowest amplitude among the input signals during a minimum value detection period as a minimum value based on a reference minimum value;
• calculating an amount of asymmetry based on the input signals;
• and
• determining whether there is a defect among the input signals, using the maximum value, the minimum value and the amount of asymmetry,
• wherein the defect determining unit determines a defect signal and outputs a corresponding blank signal if a ratio of the maximum value to the minimum value is higher than 1+Δ−δ, or lower than 1−Δ−δ,
• where Δ is a margin of the ratio of the maximum value to the minimum value.