Recording and reproducing method for optical information recording medium and optical information recording medium

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.

An 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 irradiation of a laser beam, the recording thin film formed on a disk-shaped substrate including guide grooves having a groove depth d (nm), wherein

• the groove depth d, a wavelength λ1 (nm) of laser beam for forming a record mark on the recording thin film based on an information signal and a refractive index n1 of the substrate at the wavelength λ1 satisfy a relationship:
• 0.05×λ1/n1≦d;
• the groove depth d (nm), a wavelength λ2 (nm) of 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;
• a phase φ1 of light reflected from the record mark and a phase φ2 of light reflected from a non-record mark region with respect to laser beam at the wavelength λ2 satisfy a relationship:
• (2n+0.7)×π<φ2−φ1<(2n+1.3)×π,
• where n is an integer;
• and
• an amplitude intensity I1 of light reflected from the record mark in the optical information recording medium and an amplitude intensity I2 of light reflected from a non-record mark region with respect to incident laser beam at the wavelength λ2 (nm) satisfy a relationship:
• I1<I2.

An 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 irradiation of a laser beam on a disk-shaped substrate, wherein

• a phase φ1 of light reflected from a record mark in the optical information recording medium and a phase φ2 of light reflected from a non-record mark region with respect to a wavelength λ2 of the laser beam for reproducing a signal recorded on the optical information recording medium satisfy a relationship:
• (2n+0.7)×π<φ2−φ1<(2n+1.3)×π,
• where n is an integer;
• and
• an amplitude intensity I1 of light reflected from the record mark in the optical information recording medium and an amplitude intensity I2 of light reflected from the non-record mark region with respect to incident laser beam at the wavelength λ2 (nm) satisfy a relationship:
• I1<I2.