| 摘要 |
<p>In an optical disc drive, adapted for forming a label on the label side 14 of a recordable optical disc 10, a determination of the rotation angle a is provided, so that the marking of the label side 14 can be synchronized upon. The method to determine the rotation angle a is based upon one or two of the signals 17', 18', 19' generated by the Hall-effect elements 17, 18, 19 which are normally present in an optical disc drive and are used to generate the tacho signal 24. Advantageously, the actual relationship between rotation angle a and the amplitude of these signals is recorded in a calibration procedure, so as to allow for a higher precision of the rotation angle a determined. This calibration procedure may be performed in the factory or by the user, and may not require any additional ad-hoc equipment if a synchronization pattern present in an optical disc is used.</p> |
