OPTICAL PICKUP AND OPTICAL DISK DRIVE

摘要

PROBLEM TO BE SOLVED: To provide an optical pickup with which recording operation by a light source of one wavelength is made possible by making the utilization efficiency of another optical system higher than the utilization efficiency of an optical system which is the basis of design with the optical system designed to make a condenser lens and an objective lens common for two wavelengths by using two light sources varying in the wavelengths and an optical disk drive. SOLUTION: The optical system commonly using the objective lens 4 and the condenser lens 2 by using a hologram unit 1 for a DVD of 650 nm in wavelength and a hologram unit 20 for a CD of 780 nm in wavelength is mounted with a means 6 for separating and synthesizing the diversion light of the DVD and the diversion light of the CD and is inserted with a lens means 10 between the separating and synthesizing means 6 and the hologram unit 1 for the DVD, by which the utilization efficiency of the CD side optical system of 780 nm in wavelength may be made higher than the utilization efficiency of the DVD side optical system of 650 nm in wavelength.