Patent ID: 7142497
Filing Date: 2006-11-28
Classification: G02F,G11B

Abstract:
1. An optical pickup which performs at least one of recording, reproduction and deletion of information onto an optical recording medium, said pickup comprising: a light source of a wavelength λ a light source of a wavelength λ a light source of a wavelength λ an object lens which condenses a light from the light source onto the optical recording medium, where: a phase plate which transforms a light in each of a blue wavelength zone and a red wavelength zone into a light in an approximately circular polarization state, wherein at least two of an aperture switching device, a phase correction device and the phase plate are formed integrally, wherein an electro-optic device is employed to form integrally said phase plate with the phase correction device, and the aperture switching device is formed on a surface of the phase correction device or a surface of the phase plate.