| 摘要 |
<p>PROBLEM TO BE SOLVED: To secure compatibility of a magnetic tape by detecting the recording density of the data recorded on a magnetic tape based on an output waveform of a part corresponding to a mark pattern in a regenerative waveform. SOLUTION: A BPF 521 transmits only a frequency component of all 1 of the mark pattern recorded at the regular recording density through. The BPF 52N passed only the frequency component of all 1 recorded in a density N times the regular one. The output of the BPF 52i (i=1-N) is supplied to a corresponding comparator 53i, and the output of the corresponding BPF 32i is compared with a reference voltage Vref, and when a signal output exists in the BPF 52i, a detection signal showing that the recording density is regular 1 times is outputted to a corresponding output terminal 54i. The detection signal is outputted to a signal line as a recording density switch control signal. Thus, the recording density of a magnetic tape device at a read mode time is set automatically based on the recording density switch control signal.</p> |
