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 information medium includes a disk-shaped substrate (100) having a center hole (101), an annular information recording area thereon, and an annular resin-based light-transmitting layer (102) thereon by which recording/reading laser beam is transmitted to the information recording area. The light-transmitting layer (102) terminates at a radially inner periphery which forms an annular raised rim (6). The rim is effective for protecting the light-transmitting layer from damages and dust adhesion, and when a plurality of such media are stacked, preventing the media from intimate contact.

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: 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: It is an object of the present invention to provide a method for determining a pattern for modulating the power of a laser beam which can determine a pattern for modulating the power of a laser beam so that data can be recorded in a write-once type optical recording medium with a laser beam having a low recording power at a high linear recording velocity.

Abstract: It is an object of the present invention is to provide an apparatus for discriminating an optical recording medium and a method for discriminating an optical recording medium which can reliably discriminate the kind of an optical recording medium even in the case where the optical recording medium to be discriminated is formed with periodical undulation in the circumferential direction thereof. The apparatus for discriminating an optical recording medium according to the present invention includes a first electrode 11, a second electrode 12, an alternate current signal generation circuit 13 for applying an alternate current A to the first electrode 11, a detection circuit 14 for detecting a level of an alternate current B appearing at the second electrode 12, and a control circuit 15 for controlling the operations of the alternate current signal generation circuit 13 and the detection circuit 14.

Abstract: The optical recording medium according to the present invention includes a recording layer, a second absorbing layer and a heat sink layer formed in order from an incident side for laser light, the second absorbing layer having an extinction coefficient k for a wavelength of the laser light that satisfies 0.06?k?1.0. In this case, a first absorbing layer is preferably formed on an incident side-surface of the recording layer for the laser light, the first absorbing layer having an extinction coefficient k for the wavelength of the laser light that satisfies 0.06?k?1.0. By doing so, even when recording at high density, it is possible to sufficiently improve the reproduction durability and to sufficiently reduce the cross-erasing.

Abstract: It is an object of the present invention to provide a method for recording data in an optical recording medium which can record data in a write-once type optical recording medium at a high linear recording velocity using a laser beam having a low recording power.

Abstract: It is an object of the present invention to provide a method for recording data in an optical recording medium which can record data in a write-once type optical recording medium at a high linear recording velocity using a laser beam whose recording power is set low.

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: It is an object of the present invention to provide a method for recording data in an optical recording medium which can form a recording mark having desired length and width in a write-once type optical recording medium. The method for recording data in an optical recording medium according to the present invention is constituted so as to project a laser beam whose power is modulated by a pulse train pattern onto an optical recording medium including a substrate, a first recording layer, a second recording layer and a light transmission layer 16 wherein a recording pulse of the pulse train pattern is divided into (n?1) divided pulses and the power of the laser beam is set to a recording power Pw at the peak of each of the divided pulses, set to a second bottom power Pb2 at a portion immediately after a last divided pulse and set to a first bottom power Pb1 at other intervals where Pb1 is higher than Pb2.

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: An optical information medium includes a disk-shaped substrate (100) having a center hole (101), an annular information recording area thereon, and an annular resin-based light-transmitting layer (102) thereon by which recording/reading laser beam is transmitted to the information recording area. The light-transmitting layer (102) terminates at a radially inner periphery which forms an annular raised rim (6). The rim is effective for protecting the light-transmitting layer from damages and dust adhesion, and when a plurality of such media are stacked, preventing the media from intimate contact.

Abstract: It is an object of the present invention is to provide an apparatus for discriminating an optical recording medium and a method for discriminating an optical recording medium which can quickly discriminate the kind of an optical recording medium. The apparatus for discriminating an optical recording medium according to the present invention includes a first electrode and a second electrode, an alternating current signal generation circuit for applying an alternating current A to the first electrode, a detection circuit for detecting the level of an alternating current B appearing at the second electrode, and a control circuit for controlling the operations of the alternating current signal generation circuit and the detection circuit, and a table provided in the control circuit.

Abstract: The optical recording medium of the invention comprises a recording layer and at least one mixed dielectric layer. The mixed dielectric layer contains cerium oxide and an additive compound. The additive compound is at least one compound selected from among aluminum oxide, chromium oxide, iron oxide, manganese oxide, niobium oxide, magnesium oxide, zinc oxide, titanium oxide, yttrium oxide, tantalum oxide, antimony oxide, zirconium oxide, bismuth oxide and magnesium fluoride. The optical recording medium has a high storage reliability and satisfactory recording/reading characteristics.

Abstract: It is an object of the present invention to provide an apparatus for discriminating an optical recording medium which can reliably discriminate the kind of an optical recording medium even in the case where the optical recording medium to be discriminated is warped and formed with periodical undulation in the circumferential direction thereof.

Abstract: It is an object of the present invention to provide an apparatus for discriminating an optical recording medium and a method for discriminating an optical recording medium which can reliably discriminate the kind of an optical recording medium even in the case where the optical recording medium to be discriminated is warped.

Abstract: An optical information medium having a light transmission layer obtained by curing a composition containing a urethane di(meth)acrylate (A) of the formula (I) and the other urethane di(meth)acrylate (B), and having a tensile elastic modulus of 600 to 1300 MPa at 25° C. and a light transmittance of 80% or more at wavelength of 400 nm (in the formula, R1=an alicyclic diisocyanate residue, R2=an alkylene group or an organic group containing a cycloalkyl group or ester bond, R3=H or methyl group.

Abstract: An optical information medium includes a disk-shaped substrate (100) having a center hole (101), an annular information recording area thereon, and an annular resin-based light-transmitting layer (102) thereon by which recording/reading laser beam is transmitted to the information recording area. The light-transmitting layer (102) terminates at a radially inner periphery which forms an annular raised rim (6). The rim is effective for protecting the light-transmitting layer from damages and dust adhesion, and when a plurality of such media are stacked, preventing the media from intimate contact.

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.