System and method for restoring an optical disc signal

A restoration method, which restores a signal in which 3T is corrected by using a signal output from a slice that samples a signal optically picked up from an optical disc, a channel clock signal output from a phase locked loop that receives a signal output from the slice, and a signal output from a latch circuit that receives the signal output from the slice and the channel clock signal and outputs the signal output from the slice in synchronization with the channel clock signal, the method comprising:

• detecting a current length of a current pulse of the signal output from the latch circuit, a previous length of a previous pulse immediately before the current pulse, and a next length of a next pulse immediately after the current pulse, a leading phase, which indicates a difference between the channel clock signal and the signal output from the slice when the signal output from the slice is enabled, a trail phase, which indicates a difference between the signal output from the slice and the channel clock signal when the next pulse is enabled, and a previous phase, which indicates a difference between the signal output from the slice and the channel clock signal when the previous phase is enabled;
• determining whether the current length is less than 2T;
• selecting a two directional correction or a non-correction if the current length is less than 2T;
• and
• selecting a forward correction or a backward correction if the current length is equal to 2T, wherein the selection of one of the two directional correction and non-correction comprises:
• determining whether the current length is equal to 1T;
• selecting the non-correction if the current length is not equal to 1T;
• and
• selecting the non-correction when both the previous length and the next length are less than or equal to 3T, and selecting the two directional correction when both the previous length and the next length are greater than 3T, if the current length is equal to 1T.

A signal correction circuit for a signal received from an optical disk, the system comprising:

• an extension storage device for storing the signal output from a latch circuit in a predetermined storage device in response to a channel clock signal;
• a length measuring device for measuring lengths of a predetermined current pulse sourced from the extension storage device, a previous pulse that precedes the current pulse, and a next pulse that succeeds the current pulse, and to output a current length, a previous length, and a next length;
• a phase detector for measuring a phase difference between the channel clock signal and the signal output from a slice, the phase detector outputs a leading phase, a trail phase, and a previous phase;
• and
• an extension determiner, receiving and utilizing the lengths of the current pulse, the previous pulse, the next pulse, the leading phase, the trail phase, and the previous phase for selecting one of a non-correction, a two-directional correction, a forward correction, and a backward correction, wherein the non-correction is selected when both the previous length and the next length are less or equal to 3T.

A restoration method, which restores a signal in which 3T is corrected by using a signal output from a slice that samples a signal optically picked up from an optical disc, a channel clock signal output from a phase locked loop that receives a signal output from the slice, and a signal output from a latch circuit that receives the signal output from the slice and the channel clock signal and outputs the signal output from the slice in synchronization with the channel clock signal, the method comprising:

• measuring a current length of a current pulse of the signal output from the latch circuit, a previous length of a previous pulse immediately before the current pulse, and a next length of a next pulse immediately after the current pulse;
• detecting a leading phase, which indicates a difference between the channel clock signal and the signal output from the slice when the signal output from the slice is enabled, a trail phase, which indicates a difference between the signal output from the slice and the channel clock signal when the next pulse is enabled, and a previous phase, which indicates a difference between the signal output from the slice and the channel clock signal when the previous phase is enabled;
• and
• selecting one of a non-correction, a two-directional correction, a forward correction, and a backward correction, wherein the non-correction is selected when both the previous length and the next length are less or equal to 3T.