MAGNETO OPTICAL RECORDING MEDIUM

• Main Authors: TAWARA YOSHIO, SHIMIZU YOSHIMASA, TOKUNAGA KATSUSHI, KANEKO HIDEO, NOMURA TADAO
• Format: Patent
• Language: English
• Published: 05.06.1992
• Subjects: INFORMATION STORAGE; INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORDCARRIER AND TRANSDUCER; PHYSICS

PURPOSE:To improve recording sensitivity and durability by forming a first dielectric film, a recording film, a second dielectric film and a reflecting film sequentially on a substrate and by specifying the refractive index of the first dielectric film and a difference between the refractive indexes of the first dielectric film and the substrate respectively. CONSTITUTION:A first dielectric film, a recording film, a second dielectric film and a reflecting film are formed sequentially on a substrate so as to construct a four-layer structure, and the refractive index of the first dielectric film is made to be 1.4 through 1.8, while a difference between the refractive indexes of the first dielectric film and the substrate is made to be 0.35 or below. As the result, the reflectivity of light on an interface between the first dielectric film and the substrate is about zero and an enhance effect is dependent on multiple reflection on the second dielectric film laid between the recording film and the reflecting film. The reflective index thereof can be selected arbitrarily, and the optimum film thickness of the dielectric film becomes large when the film of which the refractive index is 1.8 or below is used. Consequently, a heat insulation effect between the recording film and the reflecting film becomes large and further the optimum film thickness of the recording film can be made small. According to this constitution, recording sensitivity and durability can be improved.