LENS DEVICE AND AN OPTICAL PICKUP APPARATUS USING THE LENS DEVICE

摘要

The lens device includes an objective lens (200) focusing light into a focal zone, and having a set effective diameter. A light controlling device (100) is provided in a light path of the lens, for preventing the light in an intermediate axial region of the light path from reaching the focal zone. The intermediate axial region is located between a near axial region, that includes a centre of the light path and a far axial region, located radially outward from the intermediate region. The light controlling device permits the light in the near and far regions of the light path, to reach the focal zone. The light controlling device blocks the light in the intermediate region of the light path.