Recording method, recording device and information recording medium
AssigneePanasonic Corporation
InventorsKiyotaka Ito, Yasumori Hino, Naoyasu Miyagawa, Atsushi Nakamura
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Abstract
A writing method according to the present invention is a method for writing a data sequence as a combination of marks and spaces on an information recording medium by condensing a laser beam through a lens. The writing method is characterized in that a cooling pulse for recording a mark that is even shorter than the limit of optical resolution of the laser beam and another cooling pulse for recording a mark that is still longer than the limit of the optical resolution of the laser beam are applied under mutually different conditions.
Claims8
A method for writing a data sequence as a combination of marks and spaces on an information recording medium by condensing a laser beam through a lens,
- wherein a cooling pulse for recording a mark that is even shorter than the limit of optical resolution of the laser beam and another cooling pulse for recording a mark that is still longer than the limit of the optical resolution of the laser beam are applied under mutually different conditions, and
- wherein if a mark length is P, the wavelength of the laser beam is λ and the numerical aperture of the lens is NA,
- the mark that is shorter than the limit of the optical resolution of the laser beam satisfies P≦λ/4NA, and
- the mark that is still longer than the limit of the optical resolution of the laser beam satisfies P>λ/4NA, and
- wherein the width of the cooling pulse for recording the mark that satisfies P≦λ/4NA is set to be equal to zero, and
- wherein the width of the cooling pulse for recording the mark that satisfies P>λ/4NA is set to be not equal to zero.
-3. (canceled)
A device for writing a data sequence as a combination of marks and spaces on an information recording medium, the device comprising an optical head section including a lens that condenses a laser beam and a control section for controlling the pulse shape of a write signal,
- wherein the control section makes a condition for applying a cooling pulse to record a mark that is even shorter than the limit of optical resolution of the laser beam different from a condition for applying another cooling pulse to record a mark that is still longer than the limit of the optical resolution of the laser beam, and
- wherein if a mark length is P, the wavelength of the laser beam is λ and the numerical aperture of the lens is NA,
- the mark that is shorter than the limit of the optical resolution of the laser beam satisfies P≦λ/4NA, and
- the mark that is still longer than the limit of the optical resolution of the laser beam satisfies P>λ/4NA, and
- wherein the control section sets the width of the cooling pulse for recording the mark that satisfies P≦λ/4NA to be equal to zero, and also sets the width of the cooling pulse for recording the mark that satisfies P>λ/4NA to be not equal to zero.
-7. (canceled)
An information recording medium on which a data sequence is written as a combination of marks and spaces by being irradiated with a laser beam that has been condensed through a lens,
- wherein the recording medium has a disc information area on which stored is a writing condition that is defined so that a cooling pulse for recording a mark that is even shorter than the limit of optical resolution of the laser beam and another cooling pulse for recording a mark that is still longer than the limit of the optical resolution of the laser beam are applied under mutually different conditions, and
- wherein if a mark length is P, the wavelength of the laser beam is λ and the numerical aperture of the lens is NA,
- the mark that is shorter than the limit of the optical resolution of the laser beam satisfies P≦λ/4NA, and
- the mark that is still longer than the limit of the optical resolution of the laser beam satisfies P>λ/4NA, and wherein the writing condition is defined so that the width of the cooling pulse for recording the mark that satisfies P≦λ/4NA is set to be equal to zero and that the width of the cooling pulse for recording the mark that satisfies P>λ/4NA is set to be not equal to zero.
Dependencies are inferred from the claim text.