OPTICAL RECORDING MEDIUM AND ITS PRODUCTION

摘要

PURPOSE:To widen the degree of freedom in designing a reader and to provide a sufficient yield of non-defective articles by using smoothly surfaced parts and diffraction grating relief surface parts as data bits and forming a high- refractive index film on the surface formed with these patterns. CONSTITUTION:An optical recording medium 10 is constituted by forming the patterns of the smoothly surfaced 2 parts and the diffraction grating relief surface 3 parts in the patterns corresponding to recording data on a light transparent substrate 1 and forming the high-refractive index film 4 having the refractive index higher than the refractive index of the material of the substrate 1 over the entire surface of these patterned parts. Laser light 5 is refracted by the refractive index (n) of the high-refractive index film 4 and is emitted as transmitted refraction light 6 at an angle theta1 from the surface 2 parts when the light 5 is projected at an incident angle theta to the medium 10. On the other hand,the incident light 5 at the angle theta on the surface 3 formed with the diffraction grating relief generates transmitted refraction light 6 at the angle theta1 and transmitted diffraction light 7 transmitted and diffracted at a specific angle alpha. The data is read by detecting the difference in quantities of the above- mentioned light.