RECORDING STATE DETECTING DEVICE AND INFORMATION RECORDER AND REPRODUCER PROVIDED WITH THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a recording state detecting device for detecting a recording state to be adapted to a channel when information which is recorded with high density is reproduced through the use of a viterbi detector. SOLUTION: A reproducing signal read from a disk unit is corrected to have a specified channel characteristic by a band limit filter and an equalizer and, then, read by an A/D converter by the timing of a synchronous clock which is generated by a PLL circuit as a digital signal Xi. The signal Xi is inputted to a viterbi detector 1 so as to obtain a viterbi detection output signal. The viterbi detection output is inputted to a reference level judging unit 2 and an error calculating circuit 3. The error calculating circuit calculates a difference Ei between the digital signal Xi and the viterbi detection output and outputs it to a recording state detecting circuit 4. The circuit 4 detects amplitude or an amplitude level and asymmetry through the use of the output of the reference level judging unit 2 and output detecting information.