Patent ID: 7193936

Claim:
A wobble information detection method for an optical recording medium having synchronizing information recorded at predetermined intervals along a track of said optical recording medium, said track being formed with a wobble which is phase modulated to record information in a plurality of sections including at least one reference wobble section which expresses a predetermined one of two different binary values and a plurality of successive unit data sections constituting a data wobble sequence, each of said unit data sections expressing one of said binary values, wherein said method comprises steps of: performing playback of said optical recording medium to obtain a wobble signal from said wobble of said track; operating on said wobble signal to generate a synchronizing signal that is synchronized with said wobble signal; sampling said wobble signal, using said synchronizing signal, to perform synchronous detection and thereby obtain successive sample values of said wobble signal; detecting said synchronizing information, based on said sample values; defining a series of phase integration intervals, occurring at respective timings determined based on said synchronizing information; initializing a phase integration value to zero immediately prior to a phase integration interval within said reference wobble section in said wobble signal and successively incrementing said phase integration value by sample values which are obtained during said phase integration interval, to obtain a reference phase integration value; storing said reference phase integration value; initializing said phase integration value to zero immediately prior to each of respective phase integration intervals within said unit data sections of said data wobble sequence and successively incrementing said phase integration value by sample values which are derived during said each phase integration interval, to thereby obtain a phase integration value corresponding to said each unit data section; for each said unit data section, comparing a polarity of said corresponding phase integration value with a polarity of said reference phase integration value1; and judging a binary value expressed by said each unit data section, based upon results of said comparison.