OPTICAL PICKUP DEVICE AND OBJECTIVE LENS FOR OPTICAL PICKUP DEVICE

摘要

PURPOSE: An optical pickup device and an objective lens for the optical pickup device are provided to supply the optical pickup device, a recording and reproducing device, an optical element and a recording and reproducing method for recording and/or reproducing different types of optical information recording mediums by using rays having at least two different wavelengths with one pickup device. CONSTITUTION: An optical pickup device for reproducing or recording information from and onto an optical information recording medium is composed of a first light source for emitting a first light flux having a first wavelength; a second light source for emitting a second light flux having a second wavelength different from the first wavelength; a converging optical system having an optical axis; a diffractive portion; and a photo detector(30). The diffractive portion generates diffracted rays of n-th more than the diffracted rays of other n-th of the first light flux passing through the diffractive portion and of the second light flux passing through the diffractive portion, wherein n stands for an integer other than zero.