| 摘要 |
PURPOSE:To eliminate the uneven coating in the stage of forming a coating layer so that the coating layer is made uniform and to improve the uniformity of performance as a recording medium by expanding an annular groove at the skirt part of the aperture in such a manner that the angle between the surface of a substrate and the skirt part of the aperture on the outside peripheral side of the annular groove attains >=100 deg.. CONSTITUTION:The aperture end on the outside peripheral side of the annular groove provided nearer the inside peripheral side than the recording region 11 of the substrate 13 for the information recording medium 1 is formed to a curved surface or the groove 12 is expanded at the skirt part of the aperture on the outside peripheral side in such a manner that the angle between the surface of the substrate 13 and the skirt part of the aperture on the outside peripheral side of the groove 12 attains >=100 deg.. The distance of the coating liquid is thereby obviated and the uniformity of the coating layer to be formed is improved. |
