Abstract: A magneto-optical recording medium includes a substrate and a reproducing layer and a recording layer provided on the substrate. A recording magnetic domain is provided in the recording layer by heating the recording layer by irradiation with light and applying a recording magnetic field to the recording layer in such a manner that information is recorded in the recording layer. The recording layer is a magnetic film having magnetic anisotropy in a direction perpendicular to the film surface, and the magnetic film holds the recording magnetic domain formed therein. The magneto-optical recording medium further comprises a intermediate layer and a reproducing aid layer between the reproducing layer and the recording layer. Saturated magnetization of the reproducing aid layer increases with an increase in the temperature of the reproducing aid layer.

Abstract: An optical disc cutting apparatus capable of suppressing an unnecessary deflection component and unnecessary light intensity variation component and manufacturing a optical disc suitable for a high definition, high precision and high density optical disc.

Abstract: A magneto-optical recording medium includes a substrate and a reproducing layer and a recording layer provided on the substrate. A recording magnetic domain is provided in the recording layer by heating the recording layer by irradiation with light and applying a recording magnetic field to the recording layer in such a manner that information is recorded in the recording layer. The recording layer is a magnetic film having magnetic anisotropy in a direction perpendicular to the film surface, and the magnetic film holds the recording magnetic domain formed therein. The magneto-optical recording medium further comprises a intermediate layer and a reproducing aid layer between the reproducing layer and the recording layer. Saturated magnetization of the reproducing aid layer increases with an increase in the temperature of the reproducing aid layer.

Abstract: A process for producing an optical disk master, comprises the steps of forming a photoresist layer on a glass master, cutting the photoresist layer by projecting light beam onto the glass master having the photoresist layer thereon to expose the photoresist layer to light, developing the photoresist layer after the cutting step to form a hollow portion corresponding to the light-exposed portion, and carrying out an ion treatment by projecting ions onto the developed photoresist layer to decrease the thickness of the photoresist layer at the developed hollow portion to reach the prescribed depth by the ion-treatment.

Abstract: A magneto-optical recording medium includes at least a readout magnetic film and a recording magnetic film on a substrate, wherein information is recorded onto the recording magnetic film through magnetization of the recording magnetic film thereby forming domains therein, by a heating caused by irradiation of a recording light and application of a recording magnetic field, and the recorded information is read out through irradiation of a readout light thereby copying magnetization of the domains in the recording magnetic film to the readout magnetic film. The recording magnetic film is a perpendicular magnetic film in which the formed domains are retained The readout magnetic film Is a perpendicular magnetic film having a magnetic characteristic in which domains formed therein shrink The readout magnetic film contains no domains formed therein at a timing except for a readout operation to have a unidirectional magnetization.

Abstract: A magneto-optical recording medium comprises: a readout magnetic film which is perpendicular magneto-anisotropy in a temperature range higher than room temperature and less than a second temperature Tsw2, and is in-plane magneto-anisotropy in a temperature range equal to or more than the second temperature Tsw2; an intermediate magnetic film which is in-plane magneto-anisotropy in a temperature range higher than the room temperature; and a recording magnetic film which is perpendicular magneto-anisotropy for holding recording magnetic domains. When the coercive force of the readout magnetic film is Hc, the exchange coupled force between the readout magnetic film and the recording magnetic film is Hs, and the readout magnetic field is Hr, in a temperature range equal to or higher than room temperature and less than a first temperature Tsw1 which is higher than room temperature and is lower than the second temperature Tsw2, a first relation .vertline.Hr.vertline.>.vertline.Hs+Hc.vertline.

Abstract: A high quality magneto-optical disk which has the protective coating being excellent in the lubricity, the property of sliding and a long-term reliability includes a UV-ray resin composition comprising photo polymerizable prepolymer, photo polymerization initiator and organic compound having a side chain of fluoroalkyl group or unsaturated aliphatic alkyl group in the end of each molecule. The UV-ray setting resin comprising photo polymerization prepolymer at 30-80 parts by weight; photo polymerization initiator at 10-40 parts by weight; and organic polysiloxane at 0.1-10 parts by weight per 100 parts by weight of (meth-)acrylic ester is applied to approximately 10 .mu.m on the reflection layer 14 by the spincoat method and irradiating the UV-ray (illuminance: 600 mW/cm.sup.2, quantity of light: 800 mJ/cm.sup.2) at room temperature, thus forming the protective coating.

Abstract: In one embodiment, the magneto-optical recording medium of the present invention has a recording layer structure including at least a readout magnetic film, a control magnetic film, and a recording magnetic film. The readout magnetic film is a perpendicular magneto-anisotropy film at a temperature in a predetermined range. The control magnetic film provided between the readout magnetic film and the recording magnetic film has a prescribed structure so as to assume a perpendicular magneto-anisotropy film at a temperature in a predetermined range and an in-plane magneto-anisotropy film at a temperature in a range other than the predetermined range.