Patent attributes
An optical recording medium of improved recording and reading characteristics, having both a read-only information recording layer and an information recording layer. The optical recording medium includes information recording layers capable of recording and reading by irradiation of laser light having a wavelength λ of 400 to 410 nm through an optical system having a numerical aperture NA of 0.8 to 0.9. In this medium, the information recording layers include at least a read-only information layer having information recorded in advance and an information recording layer different from the read-only information recording layer, the read-only information recording layer being capable of information recording of write-once type or rewritable type. The read-only information recording layer is stacked closest to a light incident surface of the laser light.
