Recording and reproducing method for optical information recording medium and optical information recording medium
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsKen'ichi Nagata, Noboru Yamada, Nobuo Akahira, Kenichi Nishiuchi
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Abstract
Tracking control is carried out by a push-pull method or by mechanical feed at the time of recording signals, and tracking control is carried out by a phase difference tracking method at the time of reproduction. Thus, a phase change type optical disk which enables phase difference reproduction and is erasable may be realized. In a phase change type optical disk having a phase difference reproduction structure, servo mechanism at the time of reproducing signals may be stably controlled by causing the reflectance of a blank portion to be higher than the reflectance of a recording mark portion.
Claims12
A method for recording and reproducing information on an optical information recording medium, comprising the steps of:
- irradiating an optical information recording medium with a laser beam based on an information signal, the optical information recording medium comprising at least a recording thin film that effects a phase change between an amorphous state and a crystalline state by the irradiation of the laser beam, the recording thin film formed on a disk-shaped substrate including guide grooves;
- thereby recording a desired signal by forming a record mark on the recording thin film while applying a tracking servo mechanism with a tracking error signal obtained from the guide grooves of the substrate;
- and
- irradiating the optical information recording medium where the record mark is formed on the recording thin film with laser beam;
- thereby reproducing a signal while applying a tracking servo mechanism based on a tracking error signal obtained from the record mark;
- wherein a groove depth d (nm) of the guide groove, a wavelength λ1 (nm) of the laser beam for recording and a refractive index n1 of the substrate at the wavelength λ1 satisfy a relationship:
- 0.05×λ1/n1≦d;
- a groove depth d (nm) of the guide groove, a wavelength λ2 (nm) of the laser beam for reproducing the record mark formed on the recording thin film and a refractive index n2 of the substrate at the wavelength λ2 satisfy a relationship:
- d≦0.09×λ2/n2;
- and
- the wavelength λ2 and the wavelength λ1 satisfy a relationship:
- λ1≦λ2.
A method for recording and reproducing information on an optical information recording medium comprising the steps of:
- irradiating an optical information recording medium with a laser beam based on an information signal while rotating a substrate and moving a laser beam irradiation portion so that an interval between recorded signals in a radial direction is constant, the optical information recording medium comprising at least a recording thin film that effects a phase change between an amorphous state and a crystalline state by the irradiation of the laser beam, the recording thin film formed on a disk-shaped substrate including a specular recording region;
- thereby effecting the phase change to form a record mark on the recording thin film to record desired signals at a constant interval in the radial direction;
- and
- irradiating the optical information recording medium where the record mark is formed on the recording thin film with laser beam;
- thereby reproducing a signal while applying a tracking servo mechanism based on a tracking error signal obtained from the record marks;
- wherein
- a value of a wavelength of the laser beam for reproducing a signal recorded on the recording thin film is 630 nm to 670 nm,
- an interval between the recorded signal tracks in the radial direction is 0.74 μm,
- a linear density of recorded signals is 0.267 μm/bit, and
- a modulation system of the signal is 8/16, RLL (2,10).
A method for recording and reproducing information on an optical information recording medium, comprising the steps of:
- irradiating an optical information recording medium with a laser beam based on an information signal, the optical information recording medium comprising at least a recording thin film that effects a phase change between an amorphous state and a crystalline state by the irradiation of the laser beam, the recording thin film formed on a disk-shaped substrate including guide grooves;
- thereby recording a desired signal by forming a record mark on the recording thin film while applying a tracking servo mechanism with a tracking error signal obtained from the guide grooves of the substrate;
- and
- irradiating the optical information recording medium where the record mark is formed on the recording thin film with laser beam;
- thereby reproducing a signal while applying a tracking servo mechanism based on a tracking error signal obtained from the record mark;
- wherein when a phase φ1 of light reflected from the record mark on the optical information recording medium and a phase φ2 of light reflected from a non-record mark region between the record marks with respect to a wavelength λ2 of incident laser beam for reproduction satisfy a relationship:
- (2n+0.5)×π<φ2−φ1<(2n+1)×π,
- where n is an integer, a signal is recorded between the grooves of the substrate;
- and
- when the following relationship is satisfied:
- (2n+1)×π<φ2−φ1<(2n+1.5)×π,
- where n is an integer, a signal is recorded on the grooves of the substrate.
Dependencies are inferred from the claim text.