| 摘要 |
PURPOSE: To obtain an optical information recording medium for making recording, reproducing and erasing of information in both of the groove parts and between the grooves of a substrate by irradiation with a laser beam and a recording and reproducing method. CONSTITUTION: This optical recording medium is constituted by successively laminating a dielectric layer, phase transition type recording layer, dielectric layer and material reflection layer on a transparent substrate 1 formed with the grooves. Both of the parts on the grooves and between the grooves are used as recording regions and the recording, erasing and reproducing of the information are made by irradiation with the laser beam of a wavelength of <=700nm. The width of the grooves is specified to 0.1 to 0.7μm, the spacing between the grooves to 0.1 to 0.7μm and the depth (d) of the grooves to λ/7n<d<λ/5n (where, λ: the wavelength of the irradiating light, n: refractive index of the substrate, d: the depth of the grooves). The reflectivity of the reflected light from the unrecorded regions and the reflected light from the recorded regions defined as follows and the phase difference of the reflected light from the unrecorded regions and the recorded regions are specified. |
