| 摘要 |
PURPOSE:To decrease the eccentricity by providing a glass substrate having a light transmitting property, on an information recording part of a disk-shaped recording medium for recording and reproducing optically or magneto-optically an information signal, and also forming a resin having a center hole, on its center part. CONSTITUTION:A glass substrate 5 having a light transmitting property is provided on the part for forming a recording layer 4, also the periphery of a center hole 6 of a disk is made of a resin 7, the center hole 6 which is smaller than a standard is formed, and the center hole 6 is worked and formed with a high accuracy so as to suppress very small the eccentric quantity based on the center of a series of information or an open groove which has been formed spirally or in a shape of a concentric circle. In this way, a disk which is excellent in the workability against the eccentricity and scarcely has the eccentricity is obtained. |
