| 摘要 |
<p>PURPOSE:To improve the read precision of a controller by operating the deviation of stop pulse timing between different frequencies of the induction voltage of a coil in accordance with counted values of counters and correcting counted values of counters with corresponding correction values based on this deviation. CONSTITUTION:At the time of measuring the cursor position, the voltage induced in a coil 2 is shaped to two stop pulses 18 and 20 by band-pass filters 10 and 12 different in frequency pass band, and they are supplied to counters 14 and 16 prepared for band-pass filters 10 and 12 respectively. The difference between clock pulse counted values of counters 14 and 16 indicates a phase deviation d between stop pulses 18 and 20 outputted from two band-pass filters 10 and 12, and a correction value corresponding to this deviation is called from a memory, and counted values of counters 14 and 16 are corrected with this correction value. Thus, the read precision is improved.</p> |
