摘要 |
<p>The present invention relates to a master disk used as a matrix for manufacturing a stamper by transferring, which is used for reproducing an optical disk, the master disk according to the present invention is provided with an appointed number of calibration tracks formed at an appointed pitch symmetrically relative to the center of guide tracks in the area including a position corresponding to an edge portion of a center hole of the stamper, whereby the center hole of the stamper can be easily formed concentrically with the guide tracks of the master disk and the tolerance of diameter of the center hole or the eccentricity between the center of the center hole and the center of the guide track can be easily measured.</p> |