US 6,333,902 B1 · Method for generating land/groove switching signal from POLG type disc and apparatus therefor

Abstract

A method for generating a land/groove (L/G) switching signal from pits on a land/groove (POLG) type disc and an apparatus therefor. In the method for generating an L/G switching signal from pits on a POLG type disc having tracks with wobbles, in which header information is recorded in sectors of each track, the header information including physical identification data (PID) and a peak header and a bottom header distinguished by envelopes of the peak header signal and the bottom header signal and both the peak and bottom header signals having phases according to lands or grooves, the phases of the peak header signal and the bottom header signal are compared to determine a track switching point and the sequence of sectors is determined using the physical identification data of the disc. Then, the number of sectors included in each track is counted based on the number of wobble signal cycles reproduced from the disc, to determine a track switching point and a land/groove (L/G) switching signal is generated corresponding to the results of these steps. Therefore, a L/G switching point is accurately determined using the continuity of the PID and the number of wobbles signal cycles so that precise tracking control can be achieved.

Claims30

Dependent claims

A method for generating a land/groove switching signal from pits on a land/groove type disc having tracks with wobbles, in which header information is recorded in sectors of each track, the header information including physical identification data and a peak header and a bottom header distinguished by envelopes of a peak header signal and a bottom header signal, both the peak and bottom header signals having phases corresponding to lands or grooves, comprising the steps of:

(a) comparing the phases of the peak header signal and the bottom header signal to determine a track switching point;
(b) determining a sequence of sectors using the physical identification data of the disc;
(c) counting a number of sectors included in each track based on a number of wobble signal cycles reproduced from the disc to determine the track switching point;
and
(d) generating a land/groove switching signal according to the comparison in the step (a), the sequence of sectors determined in the step (b) and the number of sectors counted in the step (c).

2 more elements

An apparatus to generate a land/groove switching signal from pits on a land/groove type disc having lands and grooves, in which data is recorded in a sector having a header information region and a data region which are distinguished by envelopes of a recorded data signal, the apparatus comprising:

a header envelope extractor to extract a header region signal including a peak header signal indicating a peak header region and a bottom header signal indicating a bottom header region from a radio frequency signal extracted from the disc;
a header window signal generator to generate a header window signal indicating an effective region of the header information based on wobble signals of the radio frequency signal;
a header region information extractor and physical identification data reproducer to determine the effective header region signal using the header window signal to reproduce the effective header region signal and physical identification data;
a phase comparator to compare phases of the peak header signal and the bottom header signal of the effective header region signal to generate a first determination signal;
a continuity determiner to determine whether the physical identification data has continuity to generate a second determination signal;
a down counter to count the header window signal cycles to generate a third determination signal;
and
a land/groove switching signal generator to generate a land/groove switching signal according to the first through third determination signals.

5 more elements

(a) comparing the phases of the peak header signal and the bottom header signal to determine a land/groove switching point;
(b) checking three bits of the physical identification data to determine if these bits consecutively represent a second to last sector of a current track, a last sector of the current track and a first sector of a next track to determine the land/groove switching point;
and
(c) down-counting the number of sectors included in each track based on the number of wobble signal cycles reproduced from the disc to determine the land/groove switching point;
and
(d) generating said land/groove switching signal according to the comparison of operation (a), the sequence of sectors determined in operation (b), and the number of sectors counted in operation (c).

3 more elements

Dependencies are inferred from the claim text.

Method for generating land/groove switching signal from POLG type disc and apparatus therefor

Life of this patent

Method for generating land/groove switching signal from POLG type disc and apparatus therefor

Life of this patent

Abstract

Claims30