| 摘要 |
<p>With respect to a main beam, a side beam scans a position offset by about (1/4 + n)P or (3/4 + n)P in the radial direction of an optical disc and a difference signal is generated from a push-pull signal of a return beam of the side beam, thereby generating a track cross signal. Moreover, with respect to the main beam, the side beam scans a position offset by about (1/4 + n)P or (3/4 + n)P in the radial direction of an optical disc and with respect to the push-pull signal of the return beam of the main beam, a light reception result of a far side or near side of the return beam of the side beam is processed and calculated.</p> |
