| US 7,525,887 B2 | ||
| Playback signal processing apparatus and optical disc device | ||
| Youichi Ogura, Saijo (Japan); Toshihiko Takahashi, Kawachinagano (Japan); Kazutoshi Aida, Hirakata (Japan); and Kouji Okamoto, Ikeda (Japan) | ||
| Assigned to Matsushita Electric Industrial Co., Ltd., Osaka (Japan) | ||
| Filed on Jun. 21, 2004, as Appl. No. 10/871,062. | ||
| Claims priority of application No. 2003-176763 (JP), filed on Jun. 20, 2003. | ||
| Prior Publication US 2005/0018578 A1, Jan. 27, 2005 | ||
| Int. Cl. G11B 15/52 (2006.01) | ||
| U.S. Cl. 369—47.28 [369/47.19; 369/53.34; 369/59.2] | 34 Claims |
| 1. A playback signal processing apparatus including:
an over sampling phase synchronization unit for
converting a playback waveform which is obtained by reproducing a digital signal recorded on an information storage medium
with an information playback unit, into a multiple-bit discrete signal by using an over sampling clock that is synchronized
with a frequency N times (N: a multiple of 2, N≧2) as high as a frequency of a channel bit clock of the digital signal, and
generating, from the multiple-bit discrete signal, first, second, and third digital data which have different phases and are
synchronized with the frequency of the channel bit clock; and
a digital data demodulation unit having a first demodulation unit for demodulating the first digital data, and a second demodulation
unit for demodulating the second digital data or the third digital data.
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