Optical data readout with two beams on three tracks

Abstract

The present invention provides a data readout apparatus and method using optical beams by which high data-recording density for optical recording media and high transfer rate for regenerated data can be realized. The data readout method of the present invention comprises the steps of: making a first optical beam incident on an optical recording medium in a manner such that in three successive tracks n-1, n, and n+1, n being an integer of two or more, on the recording medium, the center of the beam spot of the first optical beam lies, in a transverse direction of the tracks, between the boundary point of tracks n-1 and n and the center of track n-1; making a second optical beam incident on the optical recording medium in a manner such that the center of the beam spot of the second optical beam lies, in the transverse direction of the tracks, between the boundary point of tracks n+1 and n and the center of track n+1; detecting reflected beams of the first and second optical beams from the optical recording medium; and regenerating data recorded on the three tracks in accordance with levels of the detected reflected beams. According to this, data sequences recorded on three successive tracks can be regenerated simultaneously by using two optical beams; thus, even if the track pitch is narrowed, it is possible to detect signals without the influence of crosstalk, and the data transfer rate can be increased. The apparatus for implementing this method allows simpler circuit arrangement.