Samsung Electronics Co., Ltd.

Takao Sugawara

Jun Taek Lee

Yong-kyu Byun

Jun Yeop Lee

An information reproducing apparatus which reproduces information recorded on a medium includes an asymmetry correction circuit configured to correct an asymmetry of a signal read from a medium. The apparatus also includes a first high pass filter installed before the asymmetry correction circuit and configured to remove noise in the signal by a first cut-off frequency. The apparatus also includes a second high pass filter installed after the asymmetry correction circuit and configured to remove the noise in the signal by a second cut-off frequency, wherein the second cut-off frequency is higher than the first cut-off frequency.

Information reproducing apparatus

A Post-Viterbi processor generates a plurality of candidate codewords based on a plurality of dominant error patterns for a particular communication channel. The Post-Viterbi processor selects one among the candidate codewords as a corrected codeword upon determining that the candidate codeword is error free.

Post viterbi error correction apparatus and related methods

A disk writing apparatus includes: a temperature sensor sensing an ambient temperature of a disk; a sync mark generator generating a sync mark having a pattern when a writing temperature indicating an ambient temperature at which data is written on the disk is sensed, wherein the pattern of the sync mark corresponds to the sensed writing temperature; a writing controller outputting the writing temperature sensed by the temperature sensor to the sync mark generator; a multiplexer adding the sync mark generated by the sync mark generator to the data; and a writing unit writing the data to which the sync mark is added on the disk. Accordingly, error rates when data is written and when data is reproduced can be improved by optimally compensating for the disk writing temperature and the disk reproducing temperature using parameters of devices of an hard disk drive.

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Kanagawa-ken, Japan

Takao Sugawara