Optical disc device and tracking controlling method therefor

1. An optical disc apparatus comprising:

a circuit receiving a tracking error signal while controlling tracking servo control, the tracking error signal indicating a position error with respect to a track of a light beam spot focused on an optical disc, to find the difference between a peak value and a bottom value of said tracking error signal; and

a circuit for comparing the difference between said peak and bottom values with a preset reference value to detect a tracking-off based on the result of comparison.

2. An optical disc apparatus comprising:

a circuit receiving a tracking error signal indicating a position error with respect to a track of a light beam focused on an optical disc to find the difference a peak value and a bottom value of said tracking error signal;

a circuit for comparing the difference between said peak and bottom values with a preset reference value to detect a tracking-off based on the of comparison; and

a circuit for managing control for discontinuing tracking servo control in case said tracking-off persists for a preset time duration.

3. An optical disc apparatus for managing tracking position control for a light beam spot with respect to a track arranged on a disc as an optical information recording medium to effect information recording and/or replaying, comprising:

a tracking error detection circuit for detecting a tracking error signal while controlling tracking servo control, the tracking error signal indicating a position error of said light beam spot with respect to said track;

a detection circuit for receiving said tracking error signal output from said tracking error detection circuit to detect the peak and the bottom values of said tracking error signal;

a difference circuit for finding the difference between said peak value and the bottom value from said detection circuit; and

a comparator for comparing an output voltage of said difference circuit with a preset reference level to activate a tracking-off signal in case of an output level of said difference circuit exceeding said reference level.

4. An optical disc apparatus for managing tracking position control for a light beam spot with respect to a track arranged on a disc as an optical information recording medium to effect information recording and/or replaying, comprising:

a tracking error detection circuit for detecting and outputting a tracking error signal while controlling tracking servo control, the tracking error signal indicating a position error of said light beam spot with respect to said track;

an analog-to-digital converter circuit for sampling an analog time-continuous tracking error signal, output from said tracking error detection circuit, converting the sampled signal to a digital signal and outputting the resulting digital signal;

a peak/bottom detection circuit for detecting a peak value and a bottom value of sampled digital signal sequence output from said analog-to-digital converter circuit for a preset time period;

a subtractor for finding the difference between the peak and the bottom values from said peak/bottom detection circuit; and

a comparator for comparing an output value of said subtractor with a preset reference value to activate a tracking-off signal in case of an output level of said subtractor exceeding said reference voltage.

5. An optical disc apparatus for managing tracking position control for a light beam spot with respect to a track arranged on a disc as an optical information recording medium to effect information recording and/or replaying comprising:

a tracking detection circuit for detecting a tracking error signal indicating a position error of said light beam snot with respect to said track;

a detection circuit for receiving said tracking error signal output from said tracking error detection circuit to detect the peak and the bottom values of said error signal;

a difference circuit for finding the difference between said peak value and the bottom value from said detection circuit;

a comparator for comparing an output voltage of said difference circuit with preset reference level to activate a tracking-off signal in case of an output level of said difference circuit exceeding said reference level;

a tracking actuator for driving-controlling the position of said light beam spot with respect to said track;

a tracking servo circuit supplied with said tracking actuator based on said tracking error signal output from said tracking error detection circuit to control the driving of said tracking actuator based on said tracking error signal; and

a monitor circuit for monitoring said off-track-center signal and for managing control for halting said tracking actuator by said tracking servo circuit in case of detection of an activated state of said off-track-center signal continuing for a preset time.

6. An optical disc apparatus for managing tracking position control for a light beam spot with respect to a track arranged on a disc as an optical information recording medium to effect information recording and/or replaying comprising:

a tracking, error detection circuit for detecting and outputting a tracking error signal while controlling tracking servo control the tracking error signal indicating a position error of said light beam spot with respect to said track;

an analog-to-digital converter circuit for sampling an analog time-continuous tracking error signal, output from said tracking error detection circuit, converting the sampled signal to a digital signal and outputting the resulting digital signal;

a peak/bottom detection circuit for detecting a peak value and a bottom value of sampled digital signal sequence output from said analog to-digital converter circuit for a preset time period;

a subtractor for finding the difference between the peak and the bottom values from said peak/bottom detection circuit;

a comparator for comparing an output value of said subtractor with a preset reference value to activate a tracking off signal in case of an output level of said subtractor exceeding said reference voltage;

a tracking actuator for driving-controlling the position of said light beam spot with respect to said track;

a tracking servo circuit supplied with said tracking error signal output from said tracking error detection circuit to control the driving of said tracking actuator based on said tracking error signal; and

a monitor circuit for monitoring said off-track-center signal and for managing control for halting said tracking actuator by said tracking servo circuit in case of detection of an activated state of said off-track-center signal continuing for a preset time.

7. A tracking controlling method for an optical disc apparatus comprising:

finding the difference between a peak value and a bottom value of a tracking error signal while controlling tracking servo control, the tracking error signal indicating a position error of a light beam spot focused on an optical disc with respect to a track; and

comparing a difference signal between said peak and bottom values with a preset reference value to detect a tracking-off based on the results of comparison.

8. A tracking controlling method for an optical disc apparatus comprising:

finding the difference between a peak value and a bottom value of a tracking error signal indicating a position error of a light beam spot focused on an optical disc with respect to a track;

comparing a difference signa 1 between said peak and bottom values with a preset reference value to detect a tracking-off based on the results of comparison; and

managing control for halting the tracking servo control in case of said tracking-off continuing for a preset time duration.