OPTICAL SYSTEM FOR OPTICAL PICK-UP, OPTICAL HEAD, OPTICAL DISC DEVICE, OBJECTIVE LENS, ANTI-REFLECTIVE COATING AND MANUFACTURING METHOD OF OPTICAL PARTS FOR OPTICAL PICK-UP AND ANTI-REFLECTIVE COATING

摘要

An optical pickup system for reading information of three kinds of optical recording media. The optical pickup system has a wavelength selective filter that includes an outer area for shielding one light beam of light beams having three kinds of wavelengths and an inner area for allowing all the light beams to pass through. The optical pickup system also has an objective lens that focuses each light beam having passed through the wavelength selective filter on each light recording medium. An optical head and an optical disk apparatus have the optical pickup system.