OPTICAL INFORMATION RECORDING CARRIER

摘要

PURPOSE:To increase the S/N of a reproduced signal for an optical information recording carrier, by detecting the information track with the diffraction of light and the tracking truck in the form of a variation of the reflectance or transmissivity of light. CONSTITUTION:An information pit 18 is provided on a certain track 20. A track 17 for meandering tracking has a certain frequency with the >=0.1mum amplitude to the track 20 formed by the pit 18 and also has a track pitch of <=1/2 track pitch of the track 20. The track 17 has a different reflectance or transmissivity from other parts. The high frequency component of a reproduced information signal is detected by the diffraction caused by the pit 18. While the low-frequency component is the signal that is detected mainly as a difference of the reflectance or the transmissivity caused by the track 17.