Patent ID: 7983134
Filing Date: 2011-07-19
Classification: G11B

Abstract:
1. A method for recording/reproducing data, the method comprising: splitting light diffracted or reflected from a recording medium into a main beam and first and second sub beams using a diffraction element, the main beam and the first and second sub beams having no interference from each other, the main beam not being diffracted, and the first and second sub beams being diffracted into different directions from each other based on the main beam; detecting the main beam and the first and second sub beams; and controlling a position of the diffraction element based on at least one of a detected position and light capacity of the detected beams, wherein the first sub beam is diffracted by diffraction grating located on an upper part of a left side of the diffraction element and a lower part of a right side of the diffraction element, and the second sub beam is diffracted by diffraction grating located on a lower part of the left side of the diffraction element and an upper part of the right side of the diffraction element.