Abstract: An optical recording medium of the present invention includes a substrate (202), a protection plate (205), and a plurality of information layers (203) sandwiched between the substrate and the protection plate. An information signal is recorded as a length of a mark and a length of a space between two marks. The mark is formed when the information layer is irradiated by light received through the substrate. The information layers have a management region (206) recording a leading edge recording condition and a trailing edge recording condition. The leading edge recording condition is used to change a recording start position for forming a leading edge of the mark. The trailing edge recording condition is used to change a recording end position for forming a trailing edge of the mark. Each of the leading and trailing edge recording condition is depending on which information layer is recorded.

Abstract: A rewriteable type optical recording medium for recording information has an information recording area for recording information and a recording/reproduction condition recording area for recording at least one recording/reproduction condition to be used in a recording/reproduction apparatus and at least one set of apparatus information for identifying a recording/reproduction apparatus which uses the at least one recording/reproduction condition. A plurality of recording/reproduction conditions and a plurality of sets of apparatus information, each one the plurality of sets of apparatus information corresponding to one of the plurality of recording/reproduction conditions, can be recorded on the rewriteable type optical recording medium and overwritten on the rewriteable type optical recording medium.

Abstract: An optical information recording medium includes a plurality of recording layers, a reflectance of at least one of the plurality of the recording layers in a non-initialized state with respect to a light beam for initialization being smaller than a reflectance of the same in an initialized state with respect to the light beam for initialization. The recording layers are initialized by irradiating, among the plurality of recording layers, the recording layer positioned farther from a light beam irradiation side with the light beam prior to irradiating the recording layer positioned closer to the light beam irradiation side, so that the initialized recording layers have no initialization irregularities.

Abstract: An optical information recording medium according to the present invention includes at least one groove track and at least one land track allowing information to be recorded on or reproduced from the groove track and the land track, the groove track and the land track adjoining each other. The optical information recording medium further includes: an identification signal region including a pre-pit array, the pre-pit array indicating identification information concerning the groove track and the land track; and a servo control region disposed ahead of the identification signal region along the groove track and the land track, the servo control region including wobble pits positioned so as to shift to opposite sides of a center line of either the groove track or the land track.

Abstract: A rewriteable type optical recording medium for recording information has an information recording area for recording information and a recording/reproduction condition recording area for recording at least one recording/reproduction condition to be used in a recording/reproduction apparatus and time information representing a date on which the at least one recording/reproduction condition was recorded. A plurality of recording/reproduction conditions and a plurality of time information, each one the plurality of time information corresponding to one of the plurality of recording/reproduction conditions, can be recorded on the rewriteable type optical recording medium and overwritten on the rewriteable type optical recording medium.

Abstract: A rewriteable type optical recording medium for recording information has an information recording area for recording information and a recording/reproduction condition recording area for recording at least one recording/reproduction condition to be used in a recording/reproduction apparatus and at least one set of manufacturer information for identifying a manufacturer of a recording/reproduction apparatus which uses the at least one recording/reproduction condition. A plurality of recording/reproduction conditions and a plurality of sets of manufacturer information, each one the plurality of sets of manufacturer information corresponding to one of the plurality of recording/reproduction conditions, can be recorded on the rewriteable type optical recording medium and overwritten on the rewriteable type optical recording medium.

Abstract: An optical recording medium has a recording/reproduction conditions recording area for recording recording/reproduction conditions and recording/reproduction apparatus information identifying the recording/reproduction apparatus using the recording/reproduction conditions. When the optical recording medium is accessed in a recording/reproduction apparatus, the recording/reproduction conditions for the recording/reproduction apparatus are used. Therefore, recording or reproduction can be performed with use of optimum recording/reproduction apparatus information appropriate for the optical recording medium and for the recording/reproduction apparatus. When the optical recording medium is used for the first time, test recording is performed by using a test recording region provided in the optical recording medium, and the obtained recording/reproduction conditions are recorded.

Abstract: An optical recording medium has a recording/reproduction conditions recording area for recording recording/reproduction conditions and recording/reproduction apparatus information identifying the recording/reproduction apparatus using the recording/reproduction conditions. When the optical recording medium is accessed in a recording/reproduction apparatus, the recording/reproduction conditions for the recording/reproduction apparatus are used. Therefore, recording or reproduction can be performed with use of optimum recording/reproduction apparatus appropriate for the optical recording medium and for the recording/reproduction apparatus. When the optical recording medium is used for the first time, test recording is performed by using a test recording region provided in the optical recording medium, and the obtained recording/reproduction conditions are recorded.

Abstract: An optical information recording medium according to the present invention includes at least one groove track and at least one land track allowing information to be recorded on or reproduced from the groove track and the land track, the groove track and the land track adjoining each other.

Abstract: The present invention relates to an optical information recording medium including a disk-shaped transparent substrate and a recording layer for recording, reproducing or erasing information by irradiation of laser light, the recording layer being formed over the substrate. The recording layer of the present invention includes information tracks including groove tracks and land tracks that are formed alternately in a radial direction of the disk. The information tracks comprise information recording regions and address regions interposed between the information recording regions, the information recording regions and the address regions being arranged along the tracking direction of the laser light.

Abstract: A method of manufacturing an optical information recording medium comprising the steps of: forming a plurality of component thin films on a substrate or on a sample at a predetermined film-forming speed and within a predetermined film-forming time in sequence; measuring spectral reflectance of the multilayer thin film formed on the substrate or on the sample; comparing the measured value of the spectral reflectance and the standard value of the spectral reflectance to detect the difference between them; compensating at least one of the film-forming speed and the film-forming time based on the detected difference; and forming a plurality of thin films based on the compensated film-forming speed and with the compensated film-forming time. Consequently, a thickness of each component thin film of the optical information recording medium can be measured easily and production loss in measuring a film-forming speed can be decreased.

Abstract: On a substrate, a recording layer which reversibly transforms between two states with different optical properties--a crystalline phase and an amorphous phase--by the irradiation of a laser beam, a first and a second dielectric layer on the bottom and the top surfaces of the recording layer, and a third dielectric layer on one surface of the first or the second dielectric layers and on the opposite side with respect to the recording layer are successively laminated, thus preparing an optical information recording medium. The third dielectric layer has a smaller coefficient of thermal expansion than the first and the second dielectric layers, so that the thermal deformation of the first and the second dielectric layers is reduced and the mass transfer of the recording layer is controlled. As a result, the overwrite cycle characteristics of the optical information recording medium are excellent.

Abstract: On one surface of a disk substrate, a first dielectric layer, a thin recording layer, a second dielectric layer and a reflecting layer are cumulatively formed. The second dielectric layer is thinner than the first dielectric layer and is 35-70 nm thick. The reflecting layer is 70-120 nm thick. The total thickness of the four layers is 250-430 nm. The compressive stress of the layers is offset by tensile stress generated by an overcoat resin protective layer, formed on the reflecting layer. A method of using the optical recording medium applies the MCAV (Modified Constant Angular Velocity) recording method which records information by changing recording frequencies in accordance with linear velocity. The linear velocity is 5-12 m/s. A ratio of an inner circumference recording pulse width to an outer circumference recording pulse width is 1.2 or more.

Abstract: On one surface of a disk substrate, a first dielectric layer, a thin recording layer, a second dielectric layer and a reflecting layer are cumulatively formed. The second dielectric layer is thinner than the first dielectric layer and is 35-70 nm thick. The reflecting layer is 70-120 nm thick. The total thickness of the four layers is 250-430 nm. The compressire stress of the layers is offset by tensile stress generated by an overcoat resin protective layer, formed on the reflecting layer. A method of using the optical recording medium applies the MCAV (Modified Constant Angular Velocity) recording method which records information by changing recording frequencies in accordance with linear velocity. The linear velocity is 5-12 m/s. A ratio of an inner circumference recording pulse width to an outer circumference recording pulse width is 1.2 or more.

Abstract: In a record medium wherein information is recorded and/or erased by changing the optical state thermally by the irradiation with a laser beam or the like, a protection layer made from a material having a larger thermal conductivity than adjacent protection layers is used to decrease the temperature difference between the center and edges of a record mark on recording and/or erasing with a laser beam. By using the material having a larger thermal conductivity, the heat due to the irradiation with a laser beam or the like is diffused not only to the periphery of the substrate, but also to the plane of the substrate surely. Therefore, the temperature difference between the center and the edges in a mark on irradiation with the laser beam is decreased, and the recording/erasing characteristics and the power margin for erasing can be improved.

Abstract: A phase change type information storage disk in which a reflective layer is formed of an alloy thin film comprising as a main component any one of Ni--Cr, Cr or Ti and a metal having a larger malleability than said main component, being easy to be initialized and strong to thermal shock.

Abstract: In an optical information recording medium, a protective layer containing a material not reacting with an active layer is disposed, and the composition ratio of this protective layer is designed so as to increase the amount of the material not reacting with the active layer near the border contacting with the active layer, so that degradation of the active layer is prevented. In this construction, the stability is maintained after repetition of recording and erasing cycles over 1 million times.