| 摘要 |
A DVD-RAM disk reproduction apparatus for reducing an error during detection of ID data, which includes a first operational amplifier for obtaining a sum signal resulting from the addition of four picked-up signals picked up by divided-by-four photodiodes from a DVD-RAM disk having a header region and a recording region, second and third operational amplifiers for respectively obtaining two sum signals corresponding to the upper and lower regions of the header region resulting from the addition of the first and second picked-up signals and the third and fourth picked-up signals, respectively, a fourth operational amplifier for obtaining a difference signal between the two sum signals, a header region detector for detecting upper and lower header region signals corresponding to the upper header region and the lower header region based on the difference signal, and detecting a header region signal corresponding to a header region by logically summing the two detected signals, a first multiplexer for selecting one of the two sum signals obtained by the second and third operational amplifiers according to the upper header region signal, and a second multiplexer for selecting the sum signal selected by the first operational amplifier and the sum signal selected by the first multiplexer according to the header region signal, to thereby output the selected result to an equalizer. Thus, during detection of ID data in a header region, a difference signal between the picked-up four signals is not used, but a signal resulting from the addition of two signals among the picked-up signals according to the corresponding upper and lower regions of the header region is selectively used. Accordingly, ID data can be detected from a signal without deterioration, to thereby reduce an error and thus improve a detection margin.
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