OPTICAL RECORDING MEDIUM AND PLAYING DEVICE THEREFOR

摘要

PURPOSE:To increase the recording density of an optical recording medium by making the interval between each track group composed of a plurality of tracks larger than the pitch of the tracks and performing tracking servo by using signals reproduced from both end tracks of each group. CONSTITUTION:The track pitch of this optical disk 1 is made smaller than the spot diameter of the reading beam of an optical pickup and the track gap between each group of tracks is made larger than the optical cut-off wavelength of the optical pickup and the track pitch of the recording medium. Three read- out optical beams reflected from the surface of the optical disk 1 are made incident to a half mirror 5 through an objective lens 6. Then the three beams are introduced to a photodetector 7 by means of the mirror 5 and converted into electric signals. The electric signals are outputted as reproduced signals 1-3 through a cross talk elimination circuit 10.