Patent ID: 7626900

Claim:
An optical pickup configured to irradiate a laser beam emitted from a photoemission element onto a disk-like recording medium through an objective lens, the optical pickup comprising: a diffraction element configured to split the laser beam emitted from the photoemission element into a main beam, a pair of first sub-beams, and a pair of second sub-beams, the diffraction element including a first region configured to split a portion of the laser beam emitted from the photoemission element that is incident on the first region into the main beam and the pair of first sub-beams, the diffraction element including a second region configured to split a portion of the laser beam that is incident on the second region into the main beam and the pair of second sub-beams, the diffraction element being arranged in the optical pickup such that the pair of first sub-beams form a pair of first sub-beam spots on a recording surface of the disk-like recording medium and the pair of second sub-beams form a pair of second sub-beam spots on the recording surface of the disk-like recording medium such that: D =(2 n −1)× P /2 wherein D is a distance between a spot center of one of the pair of first sub-beam spots and a spot center of one of the pair of second sub-beam spots, the one of the pair of first sub-beam spots and the one of the pair of second sub-beam spots being spaced in a substantially radial direction of the disk-like recording medium, n is a natural number, and P is a track pitch of the disk-like recording medium.