OPTICAL PICKUP DEVICE EQUIPPED DUAL FOCUS PRISM

摘要

PURPOSE: An optical pickup device equipped a dual focus prism is provided to solve a difficulty in a processing of lens according to a formation of dual focus and a difficulty in a production of optical pickup device according to an arrangement of many optical elements. CONSTITUTION: An optical pickup device is equipped: a hologram element(10) to detect an optical signal by emitting laser lights and to convert an optical path of emitting lights and receiving lights; a dual focus prism(20) to compatibly play a DAD(digital audio disk) and a DVD(digital video disk) by separating a wave width with converting the optical path of laser lights emitted from the hologram element(10); and an objective lens(30) to collect laser lights passed the dual focus prism(20) on an optical disk. Thereby a minimum optical element and the easily produced optical pickup device are offered by compatibly playing the DAD and the DVD because a numerical aperture is controlled by irradiating lights on disks differed each other with a different exterior projectile angle.