| US 7,539,092 B2 | ||
| Optical disk playback apparatus and decoder determining text information | ||
| Koichi Abe, Aichi (Japan) | ||
| Assigned to Sanyo Electric Co., Ltd., Osaka (Japan) | ||
| Filed on May 16, 2005, as Appl. No. 11/129,575. | ||
| Claims priority of application No. 2004-146166 (JP), filed on May 17, 2004; and application No. 2004-151476 (JP), filed on May 21, 2004. | ||
| Prior Publication US 2005/0264859 A1, Dec. 01, 2005 | ||
| Int. Cl. G11B 7/00 (2006.01) | ||
| U.S. Cl. 369—47.1 | 9 Claims |
| 1. An optical disk playback apparatus which reads out sub-code information recorded in advance from a lead-in area of a CD
standard optical disk, and decodes into and playbacks TEXT information according to a CD-TEXT standard from R-W channel data
of the sub-code information, the playback apparatus comprising:
a decoder that decodes into the TEXT information from the R-W channel of the sub-code information read out from the lead-in
area and determines whether the TEXT information is present based on a result of decoding the R-W channel data into the TEXT
information, in parallel with being decoded into TOC information from Q channel data of the sub-code information read out,
wherein the TEXT information is formed from a plurality of packs that each comprises header information, a TEXT content, and
an error detection code, and
wherein the decoder, each time part of the R-W channel data for one of the packs is read out, performs error detection based
on the error detection code included in the one pack, in parallel with reading out the Q channel data from the lead-in area,
and
the decoder determines that the TEXT information is present if the number of times when normal is above a predetermined reference
value in results of the error detection for a predetermined number of packs, and that the TEXT information is nonexistent
if the number of times when normal is not above the predetermined reference value.
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