Method and apparatus for controlling record and reproduction of optical record medium involving averaging servo error signals
View Patent ↗Disclosed is a method and apparatus for controlling the record and reproduction of optical record medium in which plural non-record regions having different phase are arranged between recordable data regions for the distinction in the shape of the data region. The method and apparatus performs the servo using focus error signal and tracking error signal averaged by the low pass filter at the header region of the optical disc. Especially, the tracking servo is performed by holding a fixed DC off-set value at the header region existing on the L/G switching or holding the tracking error value of the previous same track region. As a result, the exact header region is detected, the track sliding phenomenon is removed, and the tracking servo is stabilized, resulting in preventing the degeneration of the record and reproduction characteristics.
1. A method for controlling the servo operation of optical storage medium in which plural non-recordable regions having different phase are arranged between recordable data regions for the distinction in the shape of the data region, the method comprising:
detecting a non-recordable region;
averaging servo error signals that are generated by a light reflection signal from the optical storage medium;
selectively outputting the averaged servo error signal or a servo error signal prior to being averaged based on a result of the detecting step; and
performing servo operation using the selected servo error signal at a non-recordable region or recordable region of the optical storage medium.
2. The method of claim 1 , wherein said averaging step comprises a step of low pass filtering the servo error signal.
3. The method of claim 1 , wherein the servo error signal comprises a focus error signal and a tracking error.
4. The method of claim 1 , wherein the non-recordable region is a header region.
5. The method of claim 4 , wherein the header region is arranged within same track.
6. The method of claim 4 , wherein the header region is arranged between land track and groove track.
7. The method of claim 1 , wherein the outputting step outputs the averaged servo error signal when the non-recordable region is detected, and outputs the servo error signal prior to being averaged when the record region is detected.
8. The method of claim 7 , wherein the averaged servo error signal is outputted at the non-recordable region between land track and groove track.
9. An apparatus for controlling a servo operation of optical storage medium in which plural non-recordable regions having different phase are arranged between recordable data regions for the distinction in the shape of the data region, the apparatus comprising:
a detector to detect a non-recordable region;
an averaging unit to average servo error signals that are generated by a light reflection signal from the optical storage medium;
a selection unit to selectively output the averaged servo error signal or a servo error signal prior to being averaged based on a result of detecting step; and
a servo controller to control servo operation using the selected servo error signal at a non-recordable region or recordable region of the optical storage medium.
10. The apparatus of claim 9 , wherein said averaging unit comprises a low pass filter for filtering the servo error signal.
11. The apparatus of claim 9 , wherein the servo error signal comprises a focus error signal and a tracking error signal.
12. The apparatus of claim 9 , wherein the non-recordable region is a header region arranged within same track or between land track and groove track.
13. The apparatus of claim 12 , wherein the detector detects the header region based on an indication signal to indicate the header region.
14. The apparatus of claim 12 , wherein the indication signal is generated from a read channel 1 signal or a real channel 2 signal, the real channel 1 signal being obtained from sum signal of a photo detector, and read channel 2 signal being obtained from difference signal of the photo detector.
15. The apparatus of claim 9 , wherein the selection unit outputs the averaged servo error signal when the non-recordable region is detected, and outputs the servo error signal prior to being averaged when the recordable region is detected.