Patent application number | Description | Published |
20080279066 | METHOD FOR EVALUATING SIGNAL IN OPTICAL RECORDING AND READING AND METHOD FOR OPTICAL RECORDING AND READING - A signal quality evaluation method is provided that can objectively evaluate signal quality regardless of a PRML detection method used. The signal quality evaluation method is used when recording and reading is performed by irradiating a medium with a laser beam having a wavelength of λ through an objective lens having a numerical aperture of NA. In the signal quality evaluation method, information of the difference between an ideal signal recoded in the medium and a real signal obtained by irradiating the medium with the laser beam is statistically analyzed for each signal level of the ideal signal. The evaluation of the quality of the real signal is made using the statistics obtained by the statistical analysis. | 11-13-2008 |
20090016184 | METHOD FOR SETTING RECORDING POWER, MULTILAYER OPTICAL RECORDING MEDIUM, AND METHOD FOR RECORDING INFORMATION - A method for setting recording power of recording light, capable of an appropriate setting for a multilayer optical recording medium. The recording power of the recording light for an information recording layer of the multilayer optical recording medium to be irradiated with, is set by: evaluating an information recording layer to be evaluated for recording power when all the information recording layer(s) lying closer to a light incident surface than the information recording layer to be evaluated does is/are in a low transmittance state; evaluating the information recording layer to be evaluated for recording power when all the information recording layer(s) lying closer to the light incident surface than the information recording layer to be evaluated does is/are in a high transmittance state; and determining ground information for setting recording power, based on these values of the recording power. | 01-15-2009 |
20090016205 | Optical Recording Medium and Method for Reproducing Information From Optical Recording Medium - An optical recording medium includes a substrate, a first dielectric layer, a recording layer, a second dielectric layer, a super-resolution layer, and a third dielectric layer, which are provided in that order. The super-resolution layer is formed of a material configured such that voids are generated when the material is irradiated with DC light at a predetermined irradiation power for 1 to 300 seconds. Therefore, super-resolution reproduction can be made such that the irradiation power of a readout laser beam does not depend on the size of a recording mark. | 01-15-2009 |
20090067314 | OPTICAL READING METHOD AND OPTICAL READING SYSTEM - An optical reading system is provided to improve read signal quality with increasing its linear recording density. An optical recording medium in which the distance from a light incident surface to an information recording layer is less than 100 μm is irradiated with a laser beam through an objective lens and information stored in the information recording layer is read by means of a PRML detection method. At this time, the constraint length n in the PRML detection method is set to an integer which satisfies 0.5×(λ/NA)/(LV/f)−103-12-2009 | |
20090073862 | OPTICAL RECORDING DISC - It is an object of the present invention to provide an optical recording disc which can record data constituted by a recording mark train including recording marks and blank regions neighboring recording marks therein and reproduce the data therefrom in a desired manner even in the case where the lengths of a recording mark and a blank region between neighboring recording marks are shorter than the resolution limit and whose storage capacity can be markedly increased. | 03-19-2009 |
20090080320 | METHOD FOR EVALUATING READ SIGNAL - A method for evaluating a read signal obtained by irradiating a medium with a laser beam through an objective lens and reading data from the reflected laser beam by a PRML detection method is provided. The method includes: a sampling step of sampling the data obtained from the reflected laser beam at clock timings to obtain sampled values; and a step of, when a constraint length of a PR class in the PRML detection method is an even number, computing an intermediate sampled value for evaluation using at least adjacent two of the sampled values arranged in the order sampled at the clock timings. The provided method is an objective evaluation method when the PRML detection method is used, whereby the selection of a recording medium and a reading apparatus is facilitated. | 03-26-2009 |
20090122689 | OPTICAL READING METHOD AND OPTICAL READING SYSTEM - An optical reading method which suppresses variations in the reading quality of a low-reflection optical recording medium. The optical reading method is to read information from an optical recording medium by irradiating the medium with read laser light having a wavelength λ of 400 to 410 nm. In this method, an information recording layer of the optical recording medium is irradiated with the read laser light with an average read power P | 05-14-2009 |
20090122693 | OPTICAL RECORDING MEDIUM - An optical recording medium of improved recording and reading characteristics, having both a read-only information recording layer and an information recording layer. The optical recording medium includes information recording layers capable of recording and reading by irradiation of laser light having a wavelength λ of 400 to 410 nm through an optical system having a numerical aperture NA of 0.8 to 0.9. In this medium, the information recording layers include at least a read-only information layer having information recorded in advance and an information recording layer different from the read-only information recording layer, the read-only information recording layer being capable of information recording of write-once type or rewritable type. The read-only information recording layer is stacked closest to a light incident surface of the laser light. | 05-14-2009 |
20090135711 | INFORMATION READOUT METHOD FOR NON MASK LAYER TYPE OPTICAL INFORMATION MEDIUM - An information readout method for an optical information medium comprising an information recording layer having pits or recorded marks representative of information data involves the step of irradiating a laser beam to the information recording layer through an objective lens for providing readings of the pits or recorded marks. When the laser beam has a wavelength λ of 400 to 410 nm, the objective lens has a numerical aperture NA of 0.70 to 0.85, and the pits or recorded marks have a minimum size P | 05-28-2009 |
20090141609 | MULTI-LAYERED OPTICAL RECORDING MEDIUM AND METHOD FOR OPTICAL RECORDING AND READING - A multi-layered optical recording medium is provided of which the manufacturing costs is significantly reduced. The multi-layered optical recording medium has multiple information recording layers and at least two layers of the information recording layers have the same medium-side address information. This configuration allows for reducing the types of master stampers and thus reducing manufacturing costs. | 06-04-2009 |
20100034067 | INFORMATION RECORDING METHOD AND INFORMATION RECORDING APPARATUS - Information is recorded on a multi-layered optical recording medium by irradiating it with a laser beam. The recording medium can form a first information recording layer that is the farthest from a light incident surface, a second information recording layer that is the second farthest from the light incident surface, and at least one third information recording layer that is located closer to the light incident surface than the second information recording layer is. At this time, if all the information recording layers other than the first information recording layer are either blank or have been completely recorded, then information is recorded on the first information recording layer. This allows for stabilizing the energy of a recording laser beam during recording and thereby providing improved recording quality. | 02-11-2010 |
20100039911 | INFORMATION RECORDING METHOD AND INFORMATION RECORDING APPARATUS - A recording method for irradiating a multi-layered optical recording medium with a laser beam to record information thereon. The optical recording medium can form a first information recording layer that is the farthest from a light incident surface, a second information recording layer that is the second farthest from the light incident surface, and at least one third information recording layer that is located closer to the light incident surface than the second information recording layer is. The method is to record information on the second information recording layer when all the information recording layers other than the second information recording layer are either blank or have been completely recorded. This allows for realizing high-quality information recording in consideration of adherence of foreign matters or occurrence of scratches. | 02-18-2010 |
20100074084 | OPTICAL RECORDING MEDIUM AND METHOD FOR REPRODUCING THE SAME - An optical recording medium which includes three or more information layers and has a higher stack density of information layers than before in the direction of thickness while reducing crosstalk during reproduction, and a method for reading the optical recording medium are provided. The optical recording medium has a three-layer structure which includes a substrate, a first information layer, a first spacer layer, a second information layer, a second spacer layer, a third information layer, and a cover layer thinner than the substrate, with these layers being stacked in that order over the substrate, wherein the following Equation (I) is satisfied: | 03-25-2010 |
20100097913 | INFORMATION RECORDING METHOD AND INFORMATION RECORDING APPARATUS - An information recording method for a multi-layered optical recording medium that can form information recording layers in 3 layers or more. When all the information recording layers are blank, the information recording layer that is the closest to the light incident surface is irradiated with a laser beam to start recording. High quality information recording is thus implemented in consideration of adherence of foreign matters and occurrence of scratches. | 04-22-2010 |
20100260026 | MULTILAYER OPTICAL DISC - In a multi-layer optical disc, having three ( | 10-14-2010 |
20100296377 | METHOD OF EVALUATING CHARACTERISTICS OF MULTILAYER OPTICAL RECORDING MEDIUM - A multilayer optical recording medium having three or more information recording layers is irradiated with a laser beam, and a first signal obtained from the reflected laser beam is subjected to a frequency filter. A second signal obtained by filtration through a high-pass filter is used to evaluate the characteristics of the multilayer optical recording medium. In this manner, even in a multilayer optical recording medium having three or more information recording layers, the influence of the variation of the thickness and material of the information recording layers and the influence of the variation of the thickness of a spacer layer can be clearly determined and evaluated. | 11-25-2010 |
20110076436 | OPTICAL RECORDING MEDIUM AND METHOD FOR MANUFACTURING THE SAME - An optical recording medium having three or more information recording layers reduces crosstalk caused by multi-reflected beams and improves signal quality. In the optical recording medium having three or more information recording layers, the refractive index of a plurality of intermediate layers disposed between adjacent information recording layers is greater than the refractive index of a cover layer disposed between a light incident surface and an information recording layer being the closest from the light incident surface. | 03-31-2011 |
20110128833 | OPTICAL DRIVE DEVICE - An optical drive apparatus that reproduces an optical disk having a land and a groove, the optical drive apparatus including a first tracking-error-signal generating unit that generates a first tracking error signal by using a DPD method, a second tracking-error-signal generating unit that generates a second tracking error signal by using a DPP method, a tracking servo unit that controls the optical system, and a determining unit that determines that an irradiation point of an optical beam is in a non-recorded area. The tracking servo unit switches over to a control based on the second tracking error signal in response to a result of determination by the determining unit during performing a control based on the first tracking error signal. | 06-02-2011 |
20110205867 | OPTICAL RECORDING MEDIUM, AND SERIES OF OPTICAL RECORDING MEDIA - In a multilayer optical recording medium, it is an object to suppress generation of crosstalk while reducing an interlayer distance of recording and reading layers. In an optical recording medium including three or more recording and reading layers, a first distance, and a second distance greater than the first distance by 3 μm or more are alternately defined as interlayer distances of recording and reading layers. | 08-25-2011 |
20110205868 | OPTICAL RECORDING MEDIUM AND OPTICAL RECORDING-READING METHOD - Efficient recording and reading are achieved in an optical recording medium including servo layers and recording and reading layers. The optical recording medium includes: a first servo layer having a projection and a depression for tracking control that are formed in a first spiral direction; a second servo layer having a projection and a depression for tracking control that are formed in a second spiral direction opposite to the first spiral direction; and a plurality of recording and reading layers having a flat structure with no projection and depression for tracking control. Information is recorded on each of the plurality of recording and reading layers while tracking control is performed using the first servo layer or the second servo layer. | 08-25-2011 |
20110205869 | OPTICAL RECORDING-READING METHOD AND OPTICAL RECORDING MEDIUM - An optical recording and reading method is provided in which the information necessary for recording and reading layers is quickly acquired to reduce the seek time during reading and recording. The optical recording and reading method is used for an optical recording medium that includes a plurality of recording and reading layers and a servo layer. Information is recorded on or read from the recording and reading layers by irradiating them with a recording and reading beam while the servo layer is irradiated with a servo beam to perform tracking control. When information is recorded on the recording and reading layers, control information necessary for subsequent recording and reading to be performed on the recording and reading layers is recorded on the servo layer | 08-25-2011 |
20110205870 | OPTICAL RECORDING MEDIUM AND OPTICAL RECORDING-READING METHOD - An optical recording medium including recording and reading layers and a servo layer increases the recording capacity thereof. In the optical recording medium including the plurality of recording and reading layers and the servo layer, the servo layer has a groove and a land that can be used to perform tracking control with a long-wavelength servo beam. Information is recorded on the recording and reading layers with a recording and reading beam having a wavelength shorter than the wavelength of the servo beam. Recording marks are formed on the recording and reading layers while both the groove and land are tracked. | 08-25-2011 |
20110205881 | SERIES OF OPTICAL RECORDING MEDIA - A series of optical recording media is provided to reduce a burden on an optical pickup by introducing a standardized idea among a plurality of optical recording media. In the series of optical recording media, optical recording media are of a plurality of types, each optical recording medium including a plurality of planar recording and reading layers with no projections and depressions for tracking control, and a servo layer with projections and depressions for tracking control. The plurality of optical recording media have different numbers of stacked recording and reading layers, and the positions of the servo layers with respect to the corresponding light incident surfaces are standardized among the plurality of optical recording media. | 08-25-2011 |
20110205882 | SERIES OF OPTICAL RECORDING MEDIA - A series of optical recording media is provided to reduce a burden on an optical pickup by introducing a standardized idea among a plurality of optical recording media. In the series of optical recording media, optical recording media are of a plurality of types, each optical recording medium including a plurality of planar recording and reading layers with no projections and depressions for tracking control, and a servo layer with projections and depressions for tracking control. The plurality of optical recording media have different numbers of stacked recording and reading layers. The plurality of optical recording media have different numbers of stacked recording and reading layers. The positions of the servo layers from the corresponding light incident surfaces are standardized among the plurality of optical recording media. The position of at least one recording and reading layer from the corresponding light incident surface is standardized among the plurality of optical recording media. | 08-25-2011 |
20120069727 | METHOD FOR EVALUATING READ SIGNAL - A method for evaluating a read signal obtained by irradiating a medium with a laser beam through an objective lens and reading data from the reflected laser beam by a PRML detection method is provided. The method includes: a sampling step of sampling the data obtained from the reflected laser beam at clock timings to obtain sampled values; and a step of, when a constraint length of a PR class in the PRML detection method is an even number, computing an intermediate sampled value for evaluation using at least adjacent two of the sampled values arranged in the order sampled at the clock timings. The provided method is an objective evaluation method when the PRML detection method is used, whereby the selection of a recording medium and a reading apparatus is facilitated. | 03-22-2012 |
20120102509 | MULTILAYER OPTICAL RECORDING MEDIUM - The multilayer optical recording medium with six or more recording and reading layers disposed one above the other has at least two or more recording and reading layer groups. The recording and reading layer groups each include a plurality of recording and reading layers successively disposed one above the other. The reflectance of each of the recording and reading layers in a stacked state decreases in the order from a front side near a light incident surface toward a back side far from the light incident surface. A recording and reading layer nearest the front side among the recording and reading layers in the recording and reading layer group nearer the back side has a reflectance in a stacked state higher than that of a recording and reading layer nearest the back side among the recording and reading layers in the recording and reading layer group nearer the front side. | 04-26-2012 |
20120102510 | MULTILAYER OPTICAL RECORDING MEDIUM - Simple design of a multilayer optical recording medium is achieved while suppressing interlayer crosstalk and confocal crosstalk in the multilayer optical recording medium. Simple recording and reading control by a recording and reading unit is also achieved. The multilayer optical recording medium includes at least three or more recording and reading layers deposited one above the other with intermediate layers interposed therebetween, and information can be read by light irradiation from the layers. The intermediate layers have film thicknesses of two types or less, and all the recording and reading layers except the recording and reading layer farthest from a light incident surface have substantially the same optical constant. | 04-26-2012 |
20120102511 | MULTILAYER OPTICAL RECORDING MEDIUM - The multilayer optical recording medium with at least four or more recording and reading layers disposed one above the other has at least two or more recording and reading layer groups each including the recording and reading layers successively disposed one above the other. In adjacent recording and reading layer groups with an intermediate layer interposed therebetween, a recording and reading layer nearest a front side in the recording and reading layer group nearer a back side is higher than the higher value of the reflectances in a stacked state of two recording and reading layers nearest the back side in the recording and reading layer group nearer the front side. | 04-26-2012 |
20120201110 | OPTICAL RECORDING AND READING METHOD, OPTICAL RECORDING AND READING APPARATUS, OPTICAL RECORDING MEDIUM, AND METHOD FOR PRODUCING AN OPTICAL RECORDING MEDIUM - An optical recording medium includes a recording and reading layer that is previously staked or formed afterward and has no concavo-convex pattern for tracking control, and a servo layer in which a concavo-convex pattern or a groove for tracking control is formed. Information can be recorded in the recording and reading layer while tracking is performed using the servo layer. | 08-09-2012 |
20120201118 | MULTILAYER OPTICAL RECORDING MEDIUM - An object of the present invention is to increase the number of stacked layers in a multilayer optical recording medium while simplifying the design of the multilayer optical recording medium. | 08-09-2012 |
20120230174 | OPTICAL RECORDING AND READING DEVICE AND OPTICAL RECORDING AND READING METHOD - In an optical recording medium, even when a plurality of recording and reading layers are stacked, deterioration in the recording and reading signal quality thereof is suppressed. Furthermore, the transfer rate thereof can be increased. When recording or reading information by means of light irradiation on or from an optical recording medium having a plurality of recording and reading layers which are stacked in advance or formed eventually, an optical recording and reading device includes: a first optical system for irradiating a first beam to recording and reading layers to be a first target to perform recording or reading of information; and a second optical system for irradiating a second beam to recording and reading layers to be a second target to perform recording or reading of information. | 09-13-2012 |
20140169147 | OPTICAL RECORDING AND READING METHOD, OPTICAL RECORDING AND READING APPARATUS, OPTICAL RECORDING MEDIUM, AND METHOD FOR PRODUCING AN OPTICAL RECORDING MEDIUM - An optical recording medium includes a recording and reading layer that is previously staked or formed afterword and has no concavo-convex pattern for tracking control, and a servo layer in which a concavo-convex pattern or a groove for tracking control is formed. Information can be recorded in the recording and reading layer while tracking is performed using the servo layer. | 06-19-2014 |