Detecting radius of optically writable label side of optical disc at which marking have not been written

摘要

A method of an embodiment of the invention rotates an optical disc having an optically writable label side. The optical disc is radially scanned with a laser incident to the optically writable label side, from a first edge of the optical disc to a second edge of the optical disc. While the laser is radially scanned from the first edge to the second edge of the optical disc, a first radius at which markings have not been written to the optically writable label side of the optical disc, next to a second radius at which markings have been written to the optically writable label side of the optical disc, is detected.