| 摘要 |
<p>An objective lens (20) and an optical scanning device (30, 20, 50) provided with such a lens are described, of which lens both surfaces (22, 23), viewed from the object side, are concave, while the focal length is considerably smaller than its thickness (d) of along the axis and the surface (23) at the image side is aspherical. When using this objective lens, the scanning device may be very compact.</p> |
