Abstract: An optical recording medium in which a high recording density is to be realized as compatibility with respect to a pre-existing optical recording medium is kept. A wobbling groove 5 is formed on a disc substrate 1. The modulation/demodulation system for the wobbling signals recorded on the wobbling groove 5 and that for information signals recorded and/or reproduced on or from the recording track are made to be the same as the modulation/demodulation system for a standardized pre-existing optical recording medium. Moreover, if the track pitch of kept recording track is Tp, the shortest recording mark period in recording on kept recording track is Mc, the wavelength of a light beam used in recording and/or reproducing kept recording track is &lgr;, and the numerical aperture of the objective lens is NA, the following relation (1) to (3) X=Tp/(&lgr;/NA)  (1) Y=Mc/(&lgr;/NA)  (2) Y>2.9118X2−5.5422X+3.19  (3) are met.

Abstract: An optical recording medium which can provide a wobbling signal at a sufficiently high level even if the track pitch is reduced to enhance the recording density. The recording medium can attain a practically adequate recording-reproducing characteristic such as jitter characteristic. The medium has a wobbling groove that has a depth falling within the range of &lgr;/2.90 n to &lgr;/2.15 n. Here, &lgr; is the wavelength of a light beam applied to record and reproduce signals and n is the refractive index of the substrate of the optical recording medium. The ratio of the width Wg of the wobbling groove to the track pitch Tp (Wg/Tp) falls within the range of 25.0% to 45.5%.

Abstract: The mark length of each of pits forming together the pit train is made shorter than that of each of pits for a to-be-written signal normalized at the predetermined bit interval T. Also, the mark length of a shortest one of the pits forming together the pit train is set to 64.8 to 80.0% of the shortest mark length for the to-be-written signal normalized at the predetermined bit interval T.

Abstract: An optical recording medium which can provide a wobbling signal at a sufficiently high level even if the track pitch is reduced to enhance the recording density. The recording medium can attain a practically adequate recording-reproducing characteristic such as jitter characteristic. The medium has a wobbling groove that has a depth falling within the range of ë/2.90n to ë/2.15n. Here, ë is the wavelength of a light beam applied to record and reproduce signals and n is the refractive index of the substrate of the optical recording medium. The ratio of the width Wg of the wobbling groove to the track pitch Tp (Wg/Tp) falls within the range of 25.0% to 45.5%.

Abstract: An optical recording medium in which a high recording density is to be realized as compatibility with respect to a pre-existing optical recording medium is kept. A wobbling groove 5 is formed on a disc substrate 1. The modulation/demodulation system for the wobbling signals recorded on the wobbling groove 5 and that for information signals recorded and/or reproduced on or from the recording track are made to be the same as the modulation/demodulation system for a standardized pre-existing optical recording medium.