Patent ID: 7920458

Claim:
An optical recording medium comprising: a substrate light absorbing and heat generating parts each of which absorbs light and generates heat, and recording parts, wherein the light absorbing and heat generating parts are formed in any one of a single layer and a multi-layer and comprise one selected from the group consisting of phase-change materials, semiconductor materials, low-melting point metallic materials, inter-metallic compounds, and oxide materials, wherein the light absorbing and heat generating parts and the recording parts are formed on or above the substrate, and each of the recording parts is separately formed between two recording tracks, and wherein when the wavelength of a beam used for recording and reproducing is represented by λ, and the numerical aperture of the object lens is represented by NA, the track pitch that is a period of the separated recording parts in the radius direction of the optical recording medium has a value of λ/2NA or less, and the width of the each of the separated recording parts is 0.6 times to 0.9 times the track pitch.