Patent ID: 6611492
Filing Date: 2003-08-26
Classification: G11B

Abstract:
An optical recording medium in which information signals are recorded and/or reproduced along a recording track, wherein the recording density is made to be higher than that in a standardized pre-existing optical recording medium despite the fact that the modulation/demodulation system for information signals recorded and/or reproduced on or from said recording track is made to be the same as that for said standardized pre-existing optical recording medium, and whereinif the track pitch of said recording track is Tp, the shortest recording mark period in recording on said recording track is Mc, the wavelength of a light beam used in recording and/or reproducing said recording track is &lgr;, and the numerical aperture of the objective lens is NA, the following relation (1) to (3) X=Tp/(&lgr;/NA)â€ƒâ€ƒ(1) Y=Mc/(&lgr;/NA)â€ƒâ€ƒ(2) Y>2.9118X2âˆ’5.5422X+3.19â€ƒâ€ƒ(3).