Optical recording method and medium
AssigneeTDK Corporation
InventorsHiroyasu Inoue, Hajime Utsunomiya, Tatsuya Kato, Hiroshi Shingai
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Abstract
When information is recorded in an optical recording medium having a recording layer by irradiating a laser beam thereto through an optical system, the recording is carried out under the conditions: λ/NA≦680 nm and n·Tw≦22 ns wherein the laser beam has a wavelength λ, the optical system includes an objective lens having a numerical aperture NA, the window margin is Tw, and a signal length corresponding to the shortest recorded mark is n·Tw. The method provides for a high transfer rate and minimizes the jitter.
Claims13
An optical recording method for recording information in an optical recording medium having a recording layer by irradiating a laser beam thereto through an optical system, wherein
- provided that the laser beam has a wavelength λ, the optical system includes an objective lens having a numerical aperture NA, the window margin is Tw, and a signal length corresponding to the shortest recorded mark is n·Tw, the recording is carried out under the conditions:
- λ/NA≦680 nm, andn·Tw≦22 ns.
An optical recording medium comprising a phase change recording layer represented by an atomic ratio composition:
- (RaTebSbc)1-xMx
- wherein R denotes rare earth elements, Te is tellurium, Sb is antimony, and M denotes constituent elements excluding R, Te and Sb, and letters a, b, c and x satisfy:
- a+b+c=1,
- a>0,
- 0.4≦c≦0.95,
- a/b≦1.2,
- a/c≦0.7, and
- 0≦x≦0.1.
An optical recording medium comprising a phase change recording layer, a dielectric layer, and a reflective layer stacked in the described order as viewed from the incident side of a recording laser beam, wherein
- the reflective layer has a thermal conductivity KR of at least 100 W/mK, and the dielectric layer disposed between the recording layer and the reflective layer has a thermal conductivity K2D of at least 1 W/mK.
An optical recording medium comprising a light-transmitting substrate, a dielectric layer, and a phase change recording layer stacked in the order from closer to remoter one as viewed from the incident side of a recording laser beam, wherein
- the dielectric layer disposed between the substrate and the recording layer includes at least two dielectric sublayers, of which two dielectric sublayers having different thermal conductivity are contiguous to each other,
- one of the two dielectric sublayers which is disposed close to the recording layer has a thermal conductivity KC, and the other of the two dielectric sublayers which is disposed remote from the recording layer has a thermal conductivity KD wherein KC<KD.
Dependencies are inferred from the claim text.