| 摘要 |
<p>In an objective lens (1) shared by various kinds of optical disks using different wavelengths, damage due to collision between the disk and lens is avoided. A protective member (1b) is provided in the entire periphery or in a part of the periphery of a protective protrusion (1p) of the objective lens (1). The protective member (1b) may replace the protective protrusion (1p).</p> |
