Abstract: In a optical disc system with constraint length equal to or greater than 5, under assumption that continuous 2T count included in a predetermined evaluation bit array is denoted by i and that length of evaluation bit array of interest is given by (5+2i), judgment is passed on whether binary bit arrays include the evaluation bit array. Previously prepared are the error vectors calculated on the basis of target signals corresponding to the evaluation bit arrays and the target signals derived from the binary bit arrays, and the selection of a desired error vector is performed depending on the result of the judgment. At the same time, an equalized error vector is calculated from the target signal derived from the binary bit array and the reproduced signal, and the inner product of the equalized error vector and the selected error vector is calculated.

Abstract: A method for evaluating reproduced signal wherein when Euclidean distance is calculated by judging the coincidence between a binary bit array and a predetermined evaluation bit array in the evaluation of the quality of reproduced signal, in a large capacity optical disc system with constraint length equal to or greater than 5, the assumption is made that the continuous 2T count included in a predetermined evaluation bit array is denoted by i and that each evaluation bit array is composed of a main bit array having a bit length of (5+2i) and auxiliary bit arrays added before and after the main bit array; judgment on whether binary bit arrays include the predetermined evaluation bit array, is concentrated on the coincidence judgment of the main bit arrays; and at the same time, the Euclidean distance between the reproduced signal and the target signal corresponding to the evaluation bit array is calculated with respect to each main bit array and the results of such calculations are separated and counted.

Abstract: The present invention is to detect an envelope defect of a read signal due to a fingerprint on a surface of a disc, an inter-layer interference of a dual disc, or the like which is a factor of a read error of an optical disc, and is to improve a read capability of an optical disc drive while avoiding a read error by performing an appropriate processing. Means for detecting an envelope defect and means for counting the number of appearances of the envelope defect are included in the present invention. A read condition for factors of a read error is set at the time of a read retry, and a read condition suitable for the decoding of a readout signal containing an envelope defect is set at the time of detection of the envelope defect in the present invention.

Abstract: In an optical disc having N (N is an integer larger than or equal to 3) information recording layers of rewritable or recordable type, each of the information recording layers includes an test area to adjust conditions for recording and reproduction and the test areas are arranged so that the radial positions thereof overlap those of other layers. Recording test is performed only to an area smaller than or equal to 1/N of the test area of each layer and any other area is always unrecorded (write inhibited).

Abstract: The invention provides an optical disk that enables high-speed reproduction of address signals. A wobble address system for optical disk supports various types of synchronization, such as phase synchronization, bit synchronization, word synchronization, etc., to be established easily with high detection reliability with the use of an self-orthogonal code. Thus, the invention provides a method for easily synchronizing an address signal, i.e., high-speed reproduction of the address signal. Further, by virtue of an efficient modulation system of the address signal and redundancy thereof, it becomes possible to detect address information with high reliability. This capability is particularly effective in optical recording/reproduction with a blue light source whose signal light quantity and reproduction quality are prone to reduce.

Abstract: A highly efficient and reliable reproduced signal evaluation method and an optical disc drive using that method in which assuming that the number of 2T's appearing successively in a predetermined evaluation bitstream is i, the evaluation bitstream is divided into a main bitstream (5+2i) long and sub bitstreams at the ends of the main bitstream. The check process to determine whether a predetermined evaluation bitstream is included in the binarized bitstreams is replaced with a main bitstream agreement check. This can prevent an increase in the circuit size. At the same time, by separately summing up for each main bitstream the calculated results of Euclidean distance between the reproduced signal and the target signal corresponding to the evaluation bitstream, the size of an evaluation summing circuit can be reduced.

Abstract: A power adjustment method in which a modulation index is calculated from reproduced signals of patterns recorded by irradiating light onto an optical information recording medium with a recording power varied and an optimum power of irradiation light is set up using the modulation index. The power adjustment method includes calculating an optimum value PcO of a predetermined correction term Pc using a relation of a value obtained by subtracting the predetermined correction term Pc from the recording power and the modulation index, finding a value Pth of the recording power at which the modulation index becomes substantially zero in the relation of the value obtained by subtracting the optimum value PcO from the recording power and the modulation index, and setting up a value obtained by multiplying the value of Pth by a predetermined constant as a recording power of each of the recording patterns.

Abstract: A method for manufacturing a fine polymer including: generating superheated steam by a superheated steam generating unit (101); adjusting the pressure of the generated superheated steam by a pressure adjusting unit (102); receiving a polymer by a reception unit (103); heating the received polymer to a predetermined temperature by a heating unit (104); discharging the heated polymer through a first discharge port (111); and discharging the superheated steam through a second discharge port (121) at the same time as the time when the heated polymer is discharged. Here, the second discharge port (121) surrounds the first discharge port (111), and the first discharge port (111) and the second discharge port (121) face the same direction.

Abstract: An object of the present invention is to improve a conventional DPD method having a problem that a tracking servo becomes unstable due to a reduction in the accuracy of detecting a phase difference between short mark signals at an edge, in a case where the amplitudes of the short mark signals are very small, or where a readout signal contains large noise. To this end, the present invention provides a method for increasing the contribution ratio of long mark signals to generate a tracking error signal by causing a phase difference pulse to include information on a phase difference, and by causing the area of the pulse to be weighted according to the length of a mark/space adjacent to a concerned edge.

Abstract: A write power adjustment method and optical read/write apparatus for accurate optimum write power setup. Different levels of write power Pwm are used to perform a test write and calculate a modulation Mm corresponding to each level of write power Pwm. Different write power compensated values Pcn are used to calculate an evaluated value Smn=Mm×(Pwm?Pcn). Pcn that maximizes the linearity of the relationship between compensated write power (Pwm?Pcn) and evaluated value Smn is determined as an optimum write power compensated value PcO. Compensated write power PthO that provides a modulation of zero, that is, an evaluated value SmO of zero, when the relationship between compensated write power (Pwm?PcO) for PcO and evaluated value SmO is subjected to linear approximation is determined. PthO and optimum write power compensated value PcO are used to calculate a write power threshold Pth=PthO+PcO. A predetermined calculation is performed on Pth to determine optimum write power Popt.

Abstract: An object of the present invention is to stabilize the properties of nanofibers produced. Solution prepared by dissolving a polymeric substance in a solvent is supplied into a conductive ejection container having a plurality of ejection holes. The ejection container is rotated and electrostatic explosions of the solution discharged through the ejection holes are caused so that nanofibers are produced. In the above method for producing nanofibers, in the case where the amount of the solution contained in the ejection container exceeds a predetermined amount, the amount of the solution exceeding the predetermined amount overflow the ejection container. The overflowed solution is collected and resupplied to the ejection container.

Abstract: Provided is a nanofiber spinning method and device for producing a high strength and uniform yarn made of nanofibers with high productivity and at a low cost. The device includes: a nanofiber producing unit (2) which produces nanofibers (11) by extruding polymer solution, prepared by dissolving polymeric substances in a solvent, through small holes (7) and charging the polymer solution, and by allowing the polymer solution to be stretched by an electrostatic explosion, and which allows the nanofibers to travel in a single direction; a collecting electrode unit (3) to which an electric potential different from that of the charged polymer solution is applied, and which attracts the produced nanofibers (11) while simultaneously rotating and twisting the nanofibers, and gathers them for forming a yarn (20) made of the nanofibers (11); and a collecting unit (5) which collects the yarn (20) passed through the center of the collecting electrode unit (3).

Abstract: Provided is a nano-fiber manufacturing apparatus which manufactures nano-fibers by an electrostatic explosion, and has a low possibility of explosion even when a flammable solvent is used. The nano-fiber manufacturing apparatus (101) having an ejection unit (110) which ejects solution (200) that is raw material liquid for nano-fibers (200) to a manufacturing space in which the nano-fibers (200) are manufactured by an electrostatic explosion of the solution (200), and a charging unit which charges the solution (200). The nano-fiber manufacturing apparatus (101) includes a gas supply source (103) which supplies safety gas to change an atmosphere of the manufacturing space, in which the solution (200) is ejected, into a low oxygen atmosphere, and a partition (102) which maintains the manufacturing space at a lower oxygen atmosphere than an atmosphere of an outside space of the partition (102).

Abstract: Nanofibers are formed from a polymer material by rotating a conductive rotating container having a plurality of small holes while supplying a polymer solution formed by dissolving a polymer material in a solvent into the rotating container, charging the polymer solution discharged from the small holes of the rotating container by charging means, and drawing the discharged filamentous polymer solution by centrifugal force and an electrostatic explosion resulting from evaporation of the solvent. The nanofibers from this production step are oriented and made to flow from one side toward the other side in a shaft center direction of the rotating container by a reflecting electrode and/or blowing means, or those nanofibers are deposited, to produce a polymer web. The nanofibers and the polymer web using these nanofibers can be produced uniformly by a simple configuration with good productivity.

Abstract: The invention provides an optical disk that enables high-speed reproduction of address signals. A wobble address system for optical disk supports various types of synchronization, such as phase synchronization, bit synchronization, word synchronization, etc., to be established easily with high detection reliability with the use of an self-orthogonal code. Thus, the invention provides a method for easily synchronizing an address signal, i.e., high-speed reproduction of the address signal. Further, by virtue of an efficient modulation system of the address signal and redundancy thereof, it becomes possible to detect address information with high reliability. This capability is particularly effective in optical recording/reproduction with a blue light source whose signal light quantity and reproduction quality are prone to reduce.

Abstract: A frequency characteristics compensation method that can be applied to various waveforms (strategies). When determining the amount of frequency compensation, a deteriorated part by frequency characteristics is compensated for with respect to the difference between the pulse power to be compensated and the power level immediately before it. The present invention can also be applied to variations in the performance, aged deterioration, and temperature characteristics.

Abstract: The focus offset FE0 corresponding to minimum jitter is learned in advance. When performing spherical aberration adjustment for each disk, the spherical aberration is adjusted so that the jitter reaches a minimum, while maintaining the focus offset at FE0. The invention provides a method for performing high-precision adjustment of the focus offset and spherical aberration, even in the case of a disk which does not have data recorded on it.

Abstract: The invention provides an optical disk that enables high-speed reproduction of address signals. A wobble address system for optical disk supports various types of synchronization, such as phase synchronization, bit synchronization, word synchronization, etc., to be established easily with high detection reliability with the use of an self-orthogonal code. Thus, the invention provides a method for easily synchronizing an address signal, i.e., high-speed reproduction of the address signal. Further, by virtue of an efficient modulation system of the address signal and redundancy thereof, it becomes possible to detect address information with high reliability. This capability is particularly effective in optical recording/reproduction with a blue light source whose signal light quantity and reproduction quality are prone to reduce.

Abstract: There are provided an interference type optical head and an optical disk apparatus, which have a signal amplification effect and which can be manufactured in sizes comparable to conventional optical heads. In an optical disk apparatus that performs signal amplification by making a light, which is used as a reference light without being irradiated on an optical disk and, interfere with reflected light from the optical disk, a corner cube prism that reflects the reference light is mounted on the same actuator as an objective lens. Further, there is provided a movable portion that adjusts the optical path length of the interfering light in accordance with the kind of optical disk being read and the recording layer being read. A wedge prism may be used for the movable portion, and a spherical aberration correction lens and an optical path length adjusting component may be moved integrally. Thus, a stable amplification effect may be obtained while keeping the overall size comparable to conventional apparatuses.

Abstract: The invention provides an optical disk that enables high-speed reproduction of address signals. A wobble address system for optical disk supports various types of synchronization, such as phase synchronization, bit synchronization, word synchronization, etc., to be established easily with high detection reliability with the use of an self-orthogonal code. Thus, the invention provides a method for easily synchronizing an address signal, i.e., high-speed reproduction of the address signal. Further, by virtue of an efficient modulation system of the address signal and redundancy thereof, it becomes possible to detect address information with high reliability. This capability is particularly effective in optical recording/reproduction with a blue light source whose signal light quantity and reproduction quality are prone to reduce.