An optical information recording and reproducing device.

摘要

An optical information recording and reproducing device is provided. The device includes a light source for emitting a light beam, a first diffraction element for splitting the light beam into at least three diffracted beams, an optical system guiding the diffracted beams to a recording medium, and a second diffraction element including at least one division line and a diffraction surface from which the diffracted beams are diffracted. The diffraction surface is divided into at least two regions by the division line or lines. One of the division lines is at a predetermined angle against the direction of a track on the recording medium, and the regions split each of the diffracted beams into at least two parts to diffract the parts in different directions. The device also includes an optical detecting element for detecting the light beams diffracted with the second diffraction element. <IMAGE>