OPTICAL ELEMENT AND OPTICAL HEAD DEVICE USING IT, AND OPTICAL INFORMATION DEVICE USING THIS OPTICAL HEAD DEVICE, AND COMPUTER, OPTICAL DISK PLAYER, CAR NAVIGATION SYSTEM, OPTICAL DISK RECORDER AND OPTICAL DISK SERVER USING THIS OPTICAL INFORMATION DEVICE

摘要

To record to and reproduce from a conventional optical disk such as CD and DVD by using an optical head device provided with an object lens having a large numerical aperture (NA), for recording onto and reproducing from a high-density optical disk. An optical element (8) for converting the wave front of a second optical beam (32) is provided between first and second laser light sources and an object lens (18), with the optical element (8) and the object lens (18) integrally fixed with each other.