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Hideki Hirata, Tokyo JP

Hideki Hirata, Tokyo JP

Patent application numberDescriptionPublished
20080239934Optical recording medium and recording film material - An optical recording medium is provided which includes two or more information layers in which an Sb-based eutectic material is used as the material for a recording film of a translucent information layer. There is also provided a recording film material for the optical recording medium. The translucent information layer is configured to include a recording film formed of a phase change material Sb10-02-2008
20080310279Rewritable phase-change optical recording medium - A rewritable phase-change optical recording medium is provided, which includes a substrate, a first information layer, a spacer layer, a second information layer, and a cover layer. The second information layer includes a recording film containing Sb as a main component and V or V and In as second components. When an amorphous mark formed in the recording film is irradiated with a reproduction beam, crystallization of the amorphous mark occurs only in a central portion in the width direction of the amorphous mark. The width direction is orthogonal to the scanning direction of the laser beam. The recording film is formed of a material that exhibits a change in degree of modulation of 5% or less when recorded information is repeatedly reproduced. The change in degree of modulation is a change from when the number of times of reproduction is 100,000 to when it is 400,000.12-18-2008
20110205867OPTICAL RECORDING MEDIUM, AND SERIES OF OPTICAL RECORDING MEDIA - In a multilayer optical recording medium, it is an object to suppress generation of crosstalk while reducing an interlayer distance of recording and reading layers. In an optical recording medium including three or more recording and reading layers, a first distance, and a second distance greater than the first distance by 3 μm or more are alternately defined as interlayer distances of recording and reading layers.08-25-2011
20110205868OPTICAL RECORDING MEDIUM AND OPTICAL RECORDING-READING METHOD - Efficient recording and reading are achieved in an optical recording medium including servo layers and recording and reading layers. The optical recording medium includes: a first servo layer having a projection and a depression for tracking control that are formed in a first spiral direction; a second servo layer having a projection and a depression for tracking control that are formed in a second spiral direction opposite to the first spiral direction; and a plurality of recording and reading layers having a flat structure with no projection and depression for tracking control. Information is recorded on each of the plurality of recording and reading layers while tracking control is performed using the first servo layer or the second servo layer.08-25-2011
20110205869OPTICAL RECORDING-READING METHOD AND OPTICAL RECORDING MEDIUM - An optical recording and reading method is provided in which the information necessary for recording and reading layers is quickly acquired to reduce the seek time during reading and recording. The optical recording and reading method is used for an optical recording medium that includes a plurality of recording and reading layers and a servo layer. Information is recorded on or read from the recording and reading layers by irradiating them with a recording and reading beam while the servo layer is irradiated with a servo beam to perform tracking control. When information is recorded on the recording and reading layers, control information necessary for subsequent recording and reading to be performed on the recording and reading layers is recorded on the servo layer 08-25-2011
20110205870OPTICAL RECORDING MEDIUM AND OPTICAL RECORDING-READING METHOD - An optical recording medium including recording and reading layers and a servo layer increases the recording capacity thereof. In the optical recording medium including the plurality of recording and reading layers and the servo layer, the servo layer has a groove and a land that can be used to perform tracking control with a long-wavelength servo beam. Information is recorded on the recording and reading layers with a recording and reading beam having a wavelength shorter than the wavelength of the servo beam. Recording marks are formed on the recording and reading layers while both the groove and land are tracked.08-25-2011
20110205881SERIES OF OPTICAL RECORDING MEDIA - A series of optical recording media is provided to reduce a burden on an optical pickup by introducing a standardized idea among a plurality of optical recording media. In the series of optical recording media, optical recording media are of a plurality of types, each optical recording medium including a plurality of planar recording and reading layers with no projections and depressions for tracking control, and a servo layer with projections and depressions for tracking control. The plurality of optical recording media have different numbers of stacked recording and reading layers, and the positions of the servo layers with respect to the corresponding light incident surfaces are standardized among the plurality of optical recording media.08-25-2011
20110205882SERIES OF OPTICAL RECORDING MEDIA - A series of optical recording media is provided to reduce a burden on an optical pickup by introducing a standardized idea among a plurality of optical recording media. In the series of optical recording media, optical recording media are of a plurality of types, each optical recording medium including a plurality of planar recording and reading layers with no projections and depressions for tracking control, and a servo layer with projections and depressions for tracking control. The plurality of optical recording media have different numbers of stacked recording and reading layers. The plurality of optical recording media have different numbers of stacked recording and reading layers. The positions of the servo layers from the corresponding light incident surfaces are standardized among the plurality of optical recording media. The position of at least one recording and reading layer from the corresponding light incident surface is standardized among the plurality of optical recording media.08-25-2011

Patent applications by Hideki Hirata, Tokyo JP