Title:
DATA REPRODUCING DEVICE
Document Type and Number:
Japanese Patent JP3536993
Kind Code:
B2
Abstract:
PURPOSE: To correctly obtain a multivalued signal code value even when local fluctuation exists by generating a threshold value from an envelope waveform based on a voltage value corresponding to a nonzero point, a zero point estimated from a processing object signal temporarily detected beforehand and detecting the multivalued signal code value.
CONSTITUTION: A regenerative multivalued processing object signal S11 such as ternary, etc., through an A/D converter 56, a DC offset canceling HPF 57 and an equivalent circuit 58 is detected by a temporary detection part 12 in an envelope forming circuit 11. Then, an envelope extraction circuit 13 extracts the envelope waveform S11A based on a maximum voltage value for a sample point estimated as a nonzero and a voltage of an immediate before the sample point for a zero sample point. A detection circuit 59, according to the waveform S11A, decides a detection threshold value to detect the multivalued signal code value. By such a constitution, the multivalued signal code value is detected without erroneous detection even when local amplitude fluctuation exists, and an excellent musical sound is outputted through a speaker 63.
Inventors:
Hirasaka, Hisakado
Application Number:
JP18394594A
Publication Date:
June 14, 2004
Filing Date:
July 13, 1994
Export Citation:
Assignee:
SONY CORP
International Classes:
G11B20/10; G11B20/00; H03H15/00; H03H17/00; H03H21/00; H03M1/08; H03M5/18; H03M13/00; H04B3/04; (IPC1-7): G11B20/10