Abstract: There is provided an optical recording medium having a phase-change recording layer formed based on a drastically new concept of making the content of Mn still higher than the prior art while using Sb as a main component. The optical recording medium has a recording layer composed of a plurality of elements, and the recording layer contains Sb, and also has an Mn content of more than 20 atomic % but not more than 40 atomic %, on condition that the total amount of all the elements composing the recording layer is 100 atomic %.

Abstract: In a data recording and readingout system in which data is recorded and readout, or is readout on, or from an optical recording medium 1 by irradiating a laser beam having a wavelength “?” via an objective lens of a numerical aperture “NA” onto said optical recording medium, while the optical recording medium contains a layered structure formed by sandwiching a dielectric layer 6 between a recording layer 7 and an optical absorption layer 5, with respect to the optical recording medium 1 arranged in such a manner that data recorded by a recorded mark train can be readout and the recorded mark train contains a recorded mark smaller than, or equal to a limit of resolution, the laser beam is irradiated via the objective lens and a solid immersion lens having a refractive index “n” which is positioned between the optical recording medium and the objective lens, so that the data is recorded and readout, or is readout with respect to the optical recording medium by a recorded mark train which contains a recorded ma

Abstract: Increase of jitter in a phase change optical recording medium is suppressed with no extreme decrease in the crystallization speed of the recording layer when the medium is overwritten at a high linear velocity. In addition, in a disk-shaped medium operated at a constant angular velocity, the overwriting is accomplished with the increase of jitter suppressed over the entire area of the medium. Provided is an optical recording method for recording a disk-shaped optical recording medium having a phase change recording layer which is rotated at a constant angular velocity, wherein amorphous recorded marks are formed in the recording layer. In this method, the minimum recorded mark is formed such that WL/ML incrementally or gradually decreases from the radially inner side to the radially outer side of the optical recording medium, when the minimum signal has a length of SL, and when the minimum recorded mark corresponding to said minimum signal has its maximum width of MW, EW is 0.

Abstract: An optical recording medium includes a substrate, a first recording layer formed on the substrate and containing an element selected from the group consisting of Si, Ge, C and Al as a primary component, and a second recording layer located in the vicinity of the first recording layer and containing Zn as a primary component, the optical recording medium being constituted to be irradiated by a laser beam projected onto the side opposite from the substrate and the total thickness of the first recording layer and the second recording layer being equal to or thinner than 30 nm. According to the thus constituted optical recording medium, it is possible to decrease a noise level and improve a C/N ratio in a reproduced signal.

Abstract: In an optical information medium having an information bearing surface having projections and depressions and/or capable of forming recorded marks, a functional layer is added. The information borne on the information bearing surface can be read by using reading light of a wavelength longer than 4NA·PL wherein PL is the minimum size of the projections and depressions or the recorded marks and NA is the numerical aperture of a reading optical system, setting the power of the reading light within such a range that the functional layer does not change its complex index of refraction, and irradiating the reading light to the information bearing surface constructed by the functional layer or to the information bearing surface through the functional layer or to the functional layer through the information bearing surface. The medium enables reading at a high resolution beyond the diffraction limit.

Abstract: In an optical information medium having an information bearing surface having projections and depressions and/or capable of forming recorded marks, a functional layer is added. The information borne on the information bearing surface can be read by using reading light of a wavelength longer than 4NA·PL wherein PL is the minimum size of the projections and depressions or the recorded marks and NA is the numerical aperture of a reading optical system, setting the power of the reading light within such a range that the functional layer does not change its complex index of refraction, and irradiating the reading light to the information bearing surface constructed by the functional layer or to the information bearing surface through the functional layer or to the functional layer through the information bearing surface. The medium enables reading at a high resolution beyond the diffraction limit.

Abstract: The present invention relates to a method for processing a photoresist-coated board, a method for manufacturing a stamper for a recording medium and a method for manufacturing a recording medium which can form a fine raised and depressed pattern having a uniform width after development even in the case where a laser beam having a relatively long wavelength is used for forming pre-pits on a recording medium with high accuracy. A photoresist-coated board 108 is constituted by laminating a light absorption layer 108b and a photosensitive material layer 108c on a glass substrate 108a in this order and is exposed to a laser beam 102 by condensing the laser beam 102 onto the photosensitive material layer 108c, thereby forming a raised and depressed pattern corresponding to pre-pits on the the photosensitive material layer 108.

Abstract: The optical recording medium of the present invention is a phase change optical recording medium which can be used as a write once medium and which can be recorded at a high recording density. The optical recording medium of the present invention is adapted for recording such that, when the recording beam has a wavelength of ?, and objective lens of recording optical system has a numerical aperture of NA, minimum record marks formed are circular or ellipsoidal marks having a length of 0.4 ?/NA or less; and the medium is a write once medium wherein the recorded information can not be erased or rewritten at the minimum linear velocity used.

Abstract: A stamper with a sharp protrusion/depression pattern is obtained, and high precision information media can be produced using this stamper. A method of manufacturing a stamper comprises the steps of manufacturing a photoresist master 100 by laminating a light absorption layer 103 and a photoresist layer 104 on top of a substrate 102, and then forming an protrusion/depression pattern 106 in the photoresist layer 104 by forming and developing a latent image, providing Pd on the surface of the protrusion/depression pattern 106 as a preliminary treatment to conducting electroless plating onto the protrusion/depression pattern of the photoresist master 100, and forming a stamper 120 by forming a thin metal film 108 on top of the Pd-containing protrusion/depression pattern surface by using electroless plating, forming a Ni film 110 on top of this Ni thin film 108 using electroforming, and then removing the thin metal film 108 and the Ni film 110.

Abstract: An optical information recording medium which makes it possible to reduce the noise level, improve the C/N ratio and store record data for a long time period. An optical information recording medium has a recording layer formed on a substrate, for having a laser beam irradiated thereto for recording and reproduction of record data. The recording layer includes a first sub-recording film and a second sub-recording film. The first sub-recording film is formed of a first material containing Si as the main component. The second sub-recording film is formed of a second material containing Al as the main component and having Ti added thereto, and disposed in the vicinity of the first recording film. The laser beam is irradiated to the recording layer via a light transmitting layer formed in a manner covering the recording layer side.

Abstract: An optical information recording medium which makes it possible to reduce the noise level, improve the C/N ratio and store record data for a long time period. An optical information recording medium has a recording layer formed on a substrate, for having a laser beam irradiated thereto for recording and reproduction of record data. The recording layer includes a first sub-recording film and a second sub-recording film. The first sub-recording film is formed of a first material containing Si as the main component. The second sub-recording film is formed of a second material containing Al as the main component and having Cu added thereto, and disposed in the vicinity of the first recording film. The laser beam is irradiated to the recording layer via a light transmitting layer formed in a manner covering the recording layer side.

Abstract: An optical information recording medium which makes it possible to reduce the noise level and improve the C/N ratio. An optical information recording medium has a recording layer formed on a substrate, for having a laser beam irradiated thereto for recording and reproduction of record data. The recording layer includes a first sub-recording film and a second sub-recording film. The first sub-recording film is formed of a first material containing Si as the main component. The second sub-recording film is formed of a second material containing Zn as the main component and having Cu added thereto, and disposed in the vicinity of the first recording film. The laser beam is irradiated to the recording layer via a light transmitting layer formed in a manner covering the recording layer side.

Abstract: An optical information recording medium which is capable of performing high-density recording of record data, and storing the recorded data for a long time period such that the recorded data can be normally reproduced during the long time period. An optical information recording medium has a recording layer formed on a substrate, for having a laser beam irradiated thereto for recording and reproduction of record data. The recording layer includes a first sub-recording film and a second sub-recording film. The first sub-recording film is formed of a first material containing Si as the main component. The second sub-recording film is formed of a second material containing Cu as the main component and having Zn added thereto, and disposed in the vicinity of the first recording film.

Abstract: An optical information recording medium which is capable of performing high-density recording of record data, and storing the recorded data for a long time period such that the recorded data can be normally reproduced during the long time period. An optical information recording medium has a recording layer formed on a substrate, for having a laser beam irradiated thereto for recording and reproduction of record data. The recording layer includes a first sub-recording film and a second sub-recording film. The first sub-recording film is formed of a first material containing Si as the main component. The second sub-recording film is formed of a second material containing Cu as the main component and having Au added thereto, and disposed in the vicinity of the first recording film.

Abstract: An optical information recording medium which makes it possible to reduce the noise level, improve the C/N ratio and store record data for a long time period. An optical information recording medium has a recording layer formed on a substrate, for having a laser beam irradiated thereto for recording and reproduction of record data. The recording layer includes a first sub-recording film and a second sub-recording film. The first sub-recording film is formed of a first material containing Si as the main component. The second sub-recording film is formed of a second material containing Al as the main component and having Au added thereto, and disposed in the vicinity of the first recording film. The laser beam is irradiated to the recording layer via a light transmitting layer formed in a manner covering the recording layer side.

Abstract: An optical information recording medium which is capable of performing high-density recording of record data, and storing the recorded data for a long time period such that the recorded data can be normally reproduced during the long time period. An optical information recording medium has a recording layer formed on a substrate, for having a laser beam irradiated thereto for recording and reproduction of record data. The recording layer includes a first sub-recording film and a second sub-recording film. The first sub-recording film is formed of a first material containing Si as the main component. The second sub-recording film is formed of a second material containing Cu as the main component and having Mg added thereto, and disposed in the vicinity of the first recording film.

Abstract: A stamper with a sharp uneven pattern and a favorable surface state is obtained. A photoresist master 100 is manufactured by forming a light absorption layer 103 and a photoresist layer 104, in that order, on top of a substrate 102, and then forming an uneven pattern 106 in the photoresist layer 104 by forming and developing a latent image, a Ni thin film 108 is formed on top of the uneven pattern 106 of the photoresist master 100 using either a sputtering method or a vapor deposition method, a Ni film 110 is formed on top of the Ni thin film 108, and then the Ni thin film 108 and the Ni film 110 are separated from the photoresist master 100 to form a stamper 120.

Abstract: It is an object of the present invention to provide an optical recording medium that is suitable for recording information therein at a high velocity. An optical recording medium according to the present invention includes a recording layer formed of a phase change material and capable of recording data therein at a linear recording velocity equal to or higher than 10 m/sec, wherein Rtop satisfies the condition that it is larger than {11?(V/5)} and smaller than {22?(2V/5)}, where Rtop (%) is a reflectivity of the crystal phase change material forming the recording layer and V (m/sec) is a target linear recording velocity. According to the present invention, since modulation (MOD) of 50% or more can be ensured, it is possible to effectively suppress the degradation of jitter caused by recording data at a high linear recording velocity equal to or higher than 10 m/sec.

Abstract: An optical information recording medium which is capable of performing high-density recording of record data, and storing the recorded data for a long time period such that the recorded data can be normally reproduced during the long time period. An optical information recording medium has a recording layer formed on a substrate, for having a laser beam irradiated thereto for recording and reproduction of record data. The recording layer includes a first sub-recording film and a second sub-recording film. The first sub-recording film is formed of a first material containing Si as the main component. The second sub-recording film is formed of a second material containing Cu as the main component and having Si added thereto, and disposed in the vicinity of the first recording film.

Abstract: An optical information recording medium which makes it possible to reduce the noise level and improve the C/N ratio. An optical information recording medium has a recording layer formed on a substrate, for having a laser beam irradiated thereto for recording and reproducing record data. The recording layer includes a first sub-recording film and a second sub-recording film. The first sub-recording film is formed of a first material containing Si as a main component. The second sub-recording film is formed of a second material containing Zn as a main component and having Al added thereto, and disposed in the vicinity of the first recording film. The laser beam is irradiated to the recording layer via a light transmitting layer formed in a manner covering the recording layer.