Abstract: It is an object of the present invention to provide a method of recording information to an optical recording medium that is suited to achieving high data transfer rates. The optical recording medium according to the present invention comprises a method of recording information to an optical recording medium where information is recorded by forming on the optical recording medium a plurality of recording marks selected from a group consisting of several types of recording marks with different lengths each corresponding to n times (n is a natural number) the clock frequency T, wherein: taking Tr to be the transition time required for a laser beam to rise and Tf to be the transition time required for the laser beam to fall, said recording marks are formed using a laser beam made up of a number of pulses given by nT/(Tr+Tf) or less.

Abstract: An optical recording medium and a method for testing that optical recording medium are provided, which can prevent degradation of a reproduction signal in the case where the optical recording medium is stored at a high temperature for a long time, which enables stable recording and reproduction of data before and after the high-temperature storage, and which can achieve high-speed recording and increase of recording density. In the optical recording medium, a reproduction signal output of a recording mark after high-temperature storage that is formed in a recording layer after the optical recording medium is stored at a storage temperature t in a range from 60° C. to 90° C. for at least 50?(4/3)(t?60) hours is 0.9 times or more a reproduction signal output of a recording mark before the high-temperature storage that has the same bit length as the recording mark after the high-temperature storage and is formed before the above high-temperature storage.

Abstract: The optical recording medium is an optical recording medium having at least one information layer including a recording film, characterized in that the recording film is formed by a phase change material including at least Sb, Ge and Mg as main components.

Abstract: An information recording method enables the precise formation of a recording mark on a recording layer having a high light transmittance such as an L1 layer of a double-layered optical recording medium. The information recording method uses the following recording strategy. A laser beam is pulse-modulated so as to create a pulse series including a write pulse of a recording power and a cooling pulse of a base power. Data to be recorded is modulated to have a length of a recording mark along a track of the recording layer. At the same time, the length of the recording mark is made to correspond to an integral multiple nT of T where T is one clock cycle. An nT recording mark corresponding to nT is recorded by using the same number of write pulses and cooling pulses when n is 4 or larger. Moreover, an average width AveTc for a single cooling pulse width Tc is set to satisfy: 1.0<AveTc/T<1.6 and a total pulse width SumTc of the used cooling pulses is set to satisfy: 0.5?SumTc/nT?0.8.

Abstract: An optical recording medium is provided which enables overwriting at high speeds or the value of (?/NA)/V being 70 or less (where ? is the wavelength of the laser beam, NA is the numerical aperture of the objective lens, and V is the overwrite linear speed), and which also enables overwriting at high speeds even in a next-generation optical recording system typified by a blu-ray disc. The recording layer of the optical recording medium is predominantly composed of at least Sb and Mg.

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 an information layer having a recording film. The recording film contains Sb of 79 atomic % to 95 atomic % and Ge of 5 atomic % to 21 atomic % as main components, and is formed of a phase change material which does not contain the elements in the sixteenth group of the periodic table.

Abstract: In an optical recording medium including at least one information layer having a recording film formed of a phase change material mainly containing a binary alloy, the binary alloy is an alloy in which a compound phase or an ordered alloy phase does not appear in a thermal equilibrium phase diagram thereof

Abstract: A method of recording data on a double-layer optical recording medium having a recording layer with high light transmittance is provided. A laser beam is modulated to emit a pulse series of laser including a write pulse of a write power and a cooling pulse of a bottom power, so as to encode and write data to be recorded as recording marks of a length nT along a track of the recording layer, where n is an integer and T is one clock cycle. An nT recording mark is formed using (n-1) write pulse(s), and when forming a recording mark of 4 T or longer, a cooling pulse with a pulse width of 0.8 T to 2 T is inserted before the last write pulse. Recording marks are thereby accurately formed without heat interference between consecutive recording marks and cross erase between recording marks of adjacent tracks.

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: An optical recoding medium including a plurality of information layers laminated on a substrate 11 through an intermediate layer 12, at least one of the information layers other than the most distant information layer from a light incidence plane of a laser beam having a fourth dielectric film 31, a reflection film 32, a third dielectric film 33, a recording film 34, a second dielectric film 35, a first dielectric film 36 and a radiation film 37, and the fourth dielectric film 31 and the third dielectric film 33 containing zirconium oxide as a main component

Abstract: An optical recording medium including a recording layer 23 having a phase transition material and a light transmitting layer 13 on a substrate 11, a laser beam being irradiated on the recording layer 23 through the light transmitting layer 13 so that data can be recorded and recorded data can be erased, wherein at least three dielectric layers 24, 25 and 26 containing, as main components, different dielectric materials from each other are formed between the recording layer 23 and the light transmitting layer 13.

Abstract: The present invention relates to a method of recording information to an optical recording medium that can reduce the influence from heat caused when neighboring recording marks are formed and can prevent cross-talk and cross-erase of information. According to the present invention, when forming recording marks in the optical recording medium by projecting a pulse-modulated laser beam thereonto, since the recording powers of a top pulse and a last pulse are set to Pw2 lower than the recording power Pw1 of any of intermediate pulses-and the width Tcl of a cooling pulse is set to be equal to or wider than 1.0 T wider than the width of a pulse of the recording power, it is possible to improve cooling efficiency when recording marks are formed, thereby decreasing thermal interference between recording marks and achieve high density recording and high data transfer rate.

Abstract: A method for recording data in an optical recording disc including a substrate and a recording layer formed on the substrate and containing a phase change material as a primary component is constituted so that data can be recorded therein and data recorded therein can be erased by projecting thereonto at a high linear velocity equal to or higher than a predetermined linear velocity a laser beam whose power is modulated in accordance with a pulse train pattern including a plurality of kinds of unit pulse train patterns each having at least recording pulses whose levels are set to a recording power and bottom pulses whose levels are set to a bottom power onto the recording layer and forming a plurality of recording marks having different lengths in the recording layer, wherein among the plurality of kinds of unit pulse train patterns used for forming recording marks having different lengths those other than the unit pulse train pattern used for forming the shortest recording mark are determined so that they inc

Abstract: A method for recording data in an optical recording disc including a substrate and a recording layer formed on the substrate and containing a phase change material as a primary component is constituted so that data can be recorded therein and data recorded therein can be erased by projecting a laser beam thereonto at a high linear velocity equal to or higher than a predetermined linear velocity by a laser beam whose power is modulated in accordance with a pulse train pattern including a unit pulse train pattern having at least recording pulses whose levels are set to a recording power and bottom pulses whose levels are set to a bottom power onto the recording layer and forming at least one recording mark in the recording layer, wherein the unit pulse train pattern for forming one recording mark includes after a last recording pulse included therein a bottom pulse whose pulse width is determined in accordance with a width of the last pulse included therein.

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: It is an object of the present invention to provide a method of recording information to an optical recording medium that is suited to achieving high data transfer rates.

Abstract: It is an object of the present invention to provide a method of recording information to an optical recording medium that is suited to achieving high data transfer rates.

Abstract: It is an object of the present invention to provide a method of recording information to an optical recording medium that is suited to achieving high data transfer rates.