Patent ID: 8018799
Filing Date: 2011-09-13
Classification: G11B

Abstract:
1. An optical pickup device for recording/reproducing information to/from an optical recording media, the optical pickup device comprising: a first light emitting portion that emits a first light beam with a first wavelength; a second light emitting portion that emits a second light beam with a second wavelength; a third light emitting portion that emits a third light beam with a third wavelength; an adjusting element that controls the optical axis of the return light beam of said second light beam reflected by said optical recording media, where said adjusting element is a binary-blazed-type diffraction grating having a number p of steps, where p is not smaller than 4 and no more than 6; and a photo detector that receives said return light beams of said first light beam, said second light beam and said third light beam passing through said adjusting element; and wherein said first light emitting portion and said third light emitting portion are arranged in such a way that the optical axis of said first light beam and the optical axis of said third light beam approximately coincide with each other.