| 摘要 |
<p>PURPOSE:To realize a satisfactory tracking control over the whole area of a track by switching two converting means composed in assigning two or more code words to one information word by means of a pilot signal frequency and superimposing the pilot signal frequency. CONSTITUTION:Tables 30 and 32 for converting codes to convert the information word with 8 bits to the code words with 10 bits are composed of, for example, ROMs. According to the frequency of a pilot signal, a switch 46 is changed over, the conversion tables 30 and 32 are switched, and then, the frequency of the pilot signal is superimposed on the code work with 10 bits in an output terminal 44. At the time of reproducing, for example, when a reproducing head 50 traces a track D, a crosstalk f2 from a track C and a crosstalk f4 from a track E are extracted, and tracking error information is obtained over the whole area of the track. Thus, over the whole area of the recording area, the satisfactory tracking can be executed.</p> |
