Information recording carrier and method of reproducing the same
View Patent ↗An information recording carrier according to one embodiment has minute pattern including plural grooves or lands formed to be substantially in parallel and adjacent each other and comprises a supporting body having the minute pattern, a recording layer formed on the minute pattern formed on the supporting layer and a light transmission layer formed on the recording layer. The minute pattern is formed under a relation of P<λ/NA, where a pitch of each groove or land is P, a wavelength of a laser beam is λ and a numerical aperture of an objective lens is NA. The plural grooves or lands have at least a wobbling region and data is recorded wobblingly in the wobbling region by frequency shift modulation. A phase relation between a high frequency portion and a low frequency portion composing the frequency shift modulation is ±(π/20.5) to ±(π/0.75). The data is also recorded wobblingly in the wobbling region by bi-phase modulation.
1. An information recording carrier having minute pattern including plural grooves or lands formed to be substantially in parallel and adjacent each other, comprising:
a supporting body having the minute pattern;
a recording layer formed on the minute pattern formed on the supporting body; and
a light transmission layer formed on the recording layer,
wherein when a pitch of each groove or land is P, a wavelength of a laser beam is λ and a numerical aperture of an objective lens is NA, the minute pattern is formed under a relation of P<λ/NA,
wherein the plural grooves or lands have at least a wobbling region and data is recorded wobblingly in the wobbling region by frequency shift modulation,
wherein a phase relation between the high frequency portion and the low frequency portion composing the frequency shift modulation is ±(π/20.5) to ±(π/0.75), and
wherein said data is also recorded wobblingly in the wobbling region by bi-phase modulation.
2. A method of reproducing an information recording carrier as recited in claim 1 , comprising:
irradiating the laser light on the recording layer through the light transmission layer in such a way that the laser light tracks the grooves or lands therebeneath;
detecting the laser light reflected by the recording layer; and
recognizing the frequencies that are used in frequency shift modulation through the detected laser light.