A lens device which can be used as an objective lens in an optical pickup apparatus includes an objective lens provided along a light path facing a disc and having a predetermined effective diameter, and light controlling means provided along the light path for controlling the light in an intermediate...http://www.google.es/patents/US5822135?utm_source=gb-gplus-sharePatente US5822135 - Lens device including a light controlling mechanism and an optical pickup apparatus using a lens device
Lens device including a light controlling mechanism and an optical pickup ...
