Abstract: A multi-level optical recording medium according to the present invention is a multi-level optical recording medium (1) which is capable of recording record data according to multi-level recording that defines light reflection ratios of recording portions (12) into multiple levels by switching the irradiation amount of a recording laser beam between multiple levels, wherein light reflection ratio information enabling identification of a light reflection ratio dynamic range within which respective light reflection ratios of the recording portions (12) should be included is readably recorded.

Abstract: It is an object of the present invention to provide a multilevel optical recording medium in which influence of variation in characteristics of a recording layer in a plane of the recording layer on reproduced data can be corrected The multilevel optical recording medium according to the present invention includes at least a recording layer 12 and is constituted so that data can be recorded therein in a multilevel manner by controlling a state of the recording layer 12 among multiple stages and the multilevel optical recording medium according to the present invention is characterized in that a plurality of calibration signals are stored in the recording layer 12.

Abstract: A reproduction method for a multi-level optical recording medium according to the present invention rotates an optical recording medium, on which recording data has been recorded according to a multi-level recording method which sets several levels for light reflectivity of virtual recording cells, emits a reproduction laser beam towards the optical recording medium, and reproduces the recording data based on an electric signal generated in accordance with a received level of reflected light, the method setting the emission power of the reproduction laser beam in a range of 1.0 mW to 2.5 mW inclusive when the optical recording medium is rotated at a linear velocity in a range of 9 m/s to 25 m/s inclusive. By doing so, it is possible to improve the read accuracy for recording data while suppressing the reproduction deterioration of the optical recording medium to a level where deterioration effectively does not occur.

Abstract: On a recording layer (12) of a disc-shaped optical recording medium (10), a plurality of virtual recording cells (40) are assumed contiguously in a spiral or concentric fashion in a groove (16). The irradiation time of the laser beam is modulated in five stages or more for each of the virtual recording cells (40) in response to information to be recorded, thereby forming recording marks (48A to 48G) of different sizes in five stages or more. The optical reflectivity of the virtual recording cell (40) is modulated in multi-stages to thereby vary the reflection level of a reading laser beam for reading operations in five stages or more. The length of the virtual recording cells (40) in the rotational direction of the disc is set to be equal to that of an arc having the same center angle with respect to the center of the disc.

Abstract: An optical recording medium can be recorded at a high linear velocity of at least 10 m/s while maintaining an excellent light stability and favorable reflectance. A recording medium is constructed of a recording layer on a substrate, the recording layer including a first dye with a maximum absorption wavelength in a thin-film state of 450 nm to 620 nm inclusive as a first dye and being formed so as to include a second dye with an extinction coefficient of at least 0.5 for a recording wavelength. In this case, it is preferable for the second dye to have a maximum absorption wavelength of 620 nm to 750 nm inclusive in a thin-film state.

Abstract: Virtual recording cells are assumed within a groove on a recording layer of an optical recording medium. Recording marks with five or more different sizes are formed on each of the virtual recording cells by means of modulating the irradiation time of the laser beam in five levels or more in correspondence to the information to be recorded. The reflectance of the virtual recording cells modulates in many levels and the reflection level of the readout laser beam during regeneration is modulated in five levels or more.

Abstract: An optical recording medium can be recorded at a high linear velocity of at least 10 m/s while maintaining an excellent light stability and favorable reflectance. A recording medium is constructed of a recording layer on a substrate, the recording layer including a first dye with a maximum absorption wavelength in a thin-film state of 450 nm to 620 nm inclusive as a first dye and being formed so as to include a second dye with an extinction coefficient of at least 0.5 for a recording wavelength. In this case, it is preferable for the second dye to have a maximum absorption wavelength of 620 nm to 750 nm inclusive in a thin-film state.

Abstract: The invention provides an optical recording medium having excellent weatherability and a process for producing the same. The optical recording medium is provided with an organic dye layer, a reflecting layer and a protective layer in this order on a light-transmittable substrate. The organic dye layer contains an organic solvent in an amount of 2% to 15% by weight based on the organic dye. A solution, prepared by dissolving an organic dye in an organic solvent, is applied onto the light-transmittable substrate by a spin coating method to form an organic dye layer. A reflecting layer is formed on the organic dye layer without performing a drying treatment of the organic solvent in the organic dye layer, followed by forming the protective layer on the reflecting layer. The result is an optical recording medium containing an organic solvent in an organic dye layer in an amount of 2% to 15% by weight based on an organic dye.

Abstract: It is an object of the present invention to provide a multilevel optical recording medium in which influence of variation in characteristics of a recording layer in a plane of the recording layer on reproduced data can be corrected. The multilevel optical recording medium according to the present invention includes at least a recording layer 12 and is constituted so that data can be recorded therein in a multilevel manner by controlling a state of the recording layer 12 among multiple stages and the multilevel optical recording medium according to the present invention is characterized in that a plurality of calibration signals are stored in the recording layer 12.

Abstract: A reproduction method for a multi-level optical recording medium according to the present invention rotates an optical recording medium, on which recording data has been recorded according to a multi-level recording method which sets several levels for light reflectivity of virtual recording cells, emits a reproduction laser beam towards the optical recording medium, and reproduces the recording data based on an electric signal generated in accordance with a received level of reflected light, the method setting the emission power of the reproduction laser beam in a range of 1.0 mW to 2.5 mW inclusive when the optical recording medium is rotated at a linear velocity in a range of 9 m/s to 25 m/s inclusive. By doing so, it is possible to improve the read accuracy for recording data while suppressing the reproduction deterioration of the optical recording medium to a level where deterioration effectively does not occur.

Abstract: An optical recording medium is provided with a recording layer and a reflecting film on an optically transparent substrate. The principal component of the recording layer is a dye. Virtual recording cells are assumed within grooves on the recording layer and recording marks with five different levels or more of increasing size are formed on each of the virtual recording cells by modulating the irradiation time of the laser beam in five levels or more in correspondence to the information to be recorded. The reflectance of the virtual recording cells modulates in many levels and the reflection level of the reading laser beam during regeneration is changed in five levels or more. The optically transparent substrate is made of a plastic with a glass transition point (Tg) of 160° C. or less. The reflecting film is a metal with a coefficient of thermal conductivity of 300 k/W·m−1·K−1 or more and a film thickness of 50 nm or more.

Abstract: A multi-level optical recording medium according to the present invention is a multi-level optical recording medium (1) which is capable of recording record data according to multi-level recording that defines light reflection ratios of recording portions (12) into multiple levels by switching the irradiation amount of a recording laser beam between multiple levels, wherein light reflection ratio information enabling identification of a light reflection ratio dynamic range within which respective light reflection ratios of the recording portions (12) should be included is readably recorded.

Abstract: The irradiation time and/or the irradiation power of a laser beam is varied to perform multi-level recording on a recording layer in five stages or more. On the recording layer 12 of an optical recording medium 10, defined contiguously are virtual recording cells 40 within a groove 16 along tracks arranged at track pitches of 1 to 1.5 &mgr;m. The time and/or the irradiation irradiation power of the laser beam is modulated in five stages or more corresponding to the information to be recorded on each of the virtual recording cells 40 in order to form recording marks 48A-48G having five stages or more of different sizes and/or optical transmittance. The overall optical reflectivity of each of the virtual recording cells 40 is modulated in multi-stages to vary in five stages or more the entire reflectivity level of the reading laser beam used upon reading in the virtual recording cell including the outside of the recording mark.

Abstract: The present invention relates to a method for cutting a photoresist-coated glass board used for fabricating a stamper for an optical recording medium and the method includes steps of intermittently projecting a first laser beam onto the photoresist-coated glass board and intermittently projecting a second laser beam in synchronism with blocking the first laser beam onto the photoresist-coated glass board, thereby continuously and spirally forming an exposed region. According to the present invention, it is possible to obtain a high aperture ratio and suppress fluctuation of a local groove parameter at a land pre-pit portion.

Abstract: A data recording method of modulating the power of a laser beam in accordance with a pulse pattern, projecting the laser beam onto a write-once type optical recording medium to form a record mark and recording data in the write-once type optical recording medium, wherein the pulse pattern is constituted by a pattern in which the power of the laser beam is set to a recording power Pw within a first period and a second period and the power of the laser beam is set to an intermediate power Pm lower than the recording power Pw within a third period provided between the first period and the second period, the length of the first period and the levels of the recording power Pw and the intermediate power Pw being set to satisfy 1.7T≦ttop2 and 1.4≦Pw/Pm where T is a length corresponding to one cycle of a reference pulse and ttop2 is the length of the first period.

Abstract: An optical recording medium has at least a substrate, and a recording layer arranged on the substrate. The recording layer contains at least a first dye (main component) which has a maximum absorption wavelength in a range of 450 to 600 nm, and a second dye which has a maximum absorption wavelength in a range of 600 to 750 nm. A content of the second dye in the recording layer is adjusted so that an attenuation coefficient &agr; of the recording layer with respect to a light of a wavelength 655 nm, and an attenuation coefficient &bgr; of the recording layer with respect to a light of a wavelength 670 nm can simultaneously satisfy conditions represented by the following equations (1) to (3): (1) 0.03≦&agr;, (2) 0.03≦&bgr;, (3) 0.7≦(&agr;/&bgr;)≦1.05.

Abstract: An optical recording medium (10) is adapted such that information is recorded by forming recording marks on a recording layer (12) that covers grooves (16) of an optical transparent substrate (14). In the recording layer (16), contiguously defined along a feed direction S of irradiation are virtual recording cells (40) which have a given unit length in the feed direction S of irradiation along the groove 16 and a given unit width in the direction orthogonal thereto. In addition, the groove width W is set so that 0.20×(&lgr;/NA)<W<0.50×(&lgr;/NA), where &lgr; is the wavelength of a laser beam to be irradiated with and NA is the numerical aperture of the objective lens for the laser beam in a irradiation optical system. The irradiation time is set in five stages or more to radiate the laser beam, thereby making it possible to record information in multi-levels.

Abstract: An optical recording medium can be recorded at a high linear velocity of at least 10 m/s while maintaining an excellent light stability and favorable reflectance. A recording medium is constructed of a recording layer on a substrate, the recording layer including a first dye with a maximum absorption wavelength in a thin-film state of 450 nm to 620 nm inclusive as a first dye and being formed so as to include a second dye with an extinction coefficient of at least 0.5 for a recording wavelength. In this case, it is preferable for the second dye to have a maximum absorption wavelength of 620 nm to 750 nm inclusive in a thin-film state.

Abstract: There are provided a spin coating method and an apparatus for forming a thin film having a uniform thickness on a substrate at a low cost in a process for manufacturing semiconductors, optical disks and the like. A coating solution is dropped onto the surface of a substrate (2) to be coated, mounted on a horizontal turn table (3) through a discharge nozzle (4) and the substrate is turned to form a thin film. After the coating solution is dropped through the nozzle, a stand-by nozzle tip (4a) is soaked and held in a nozzle soaking solution (10) having a composition near or equivalent to that of the coating solution. The crystal deposition of the solute is suppressed. Inter alia, the present invention is useful when a solution containing a solute having high crystallizability is coated.

Abstract: The irradiation time and/or the irradiation power of a laser beam is varied to perform multi-level recording on a recording layer in five stages or more. On the recording layer 12 of an optical recording medium 10, defined contiguously are virtual recording cells 40 within a groove 16 along tracks arranged at track pitches of 1 to 1.5 &mgr;m. The time and/or the irradiation irradiation power of the laser beam is modulated in five stages or more corresponding to the information to be recorded on each of the virtual recording cells 40 in order to form recording marks 48A-48G having five stages or more of different sizes and/or optical transmittance. The overall optical reflectivity of each of the virtual recording cells 40 is modulated in multi-stages to vary in five stages or more the entire reflectivity level of the reading laser beam used upon reading in the virtual recording cell including the outside of the recording mark.