POLARIZING ADAPTIVE-TYPE OBJECTIVE LENS AND OPTICAL PICKUP DEVICE USING OBJECTIVE LENS

摘要

PURPOSE: A polarizing adaptive-type objective lens is provided to automatically control the number of apertures according to a polarized direction of an optical beam, thereby exactly accessing different kinds of optical disks. CONSTITUTION: A polarizing adaptive-type objective lens(13) comprises a lens portion(13A) where a polarizing material film(13B) is applied in an edge area of an incident surface of an optical beam. The polarizing material film(13B) selectively passes the optical beam along a polarized direction. If the polarizing material film(13B) is made of material particles for absorbing a linear polarized optical beam, the polarizing material film(13B) absorbs the linear polarized optical beam such that the optical beam cannot reach an optical disk, while passing the linear polarized optical beam toward the disk via the lens portion(13A). The lens portion(13A) condenses the optical beam on the first information recording surface if the optical beam is incident over an entire incident surface.