Abstract: The present invention is related to a compound represented by formula (I) wherein —X— is —NH— or —S—; —Z— is —O— or —S—; R3, R5 and R6 are each independently a hydrogen atom, substituted or unsubstituted alkyl, or the like; R7 is a cyano, substituted or unsubstituted amino, or the like; R7? is each independently a halogen; b is 0 or 1; or a pharmaceutically acceptable salt thereof, or a pharmaceutical composition comprising thereof.

Abstract: The present invention is related to a compound represented by formula (I) wherein —X— is —NH— or —S—; —Z— is —O— or —S—; R3, R5 and R6 are each independently a hydrogen atom, substituted or unsubstituted alkyl, or the like; R7 is a cyano, substituted or unsubstituted amino, or the like; R7? is each independently a halogen; b is 0 or 1; or a pharmaceutically acceptable salt thereof, or a pharmaceutical composition comprising thereof.

Abstract: An optical disk medium in which high density recording/reproducing is possible, an information recording method and an information reproducing method using it are provided. A pit composed of a phase change material and a recording film different from it are provided on an optical disk. The phase change pit has a pattern of a single frequency. A mark having a size on the same level as the phase change pit can be formed by melting a single phase change pit while recording and controlling the optical absorbance and the temperature of the recording film at the region. A single phase change pit is molten while reproducing. Since the optical characteristics of the molten region are different from the optical characteristics of other regions, only data at the molten region can be reproduced by a super-resolution effect.

Abstract: Super-resolution technology was proposed for generating marks smaller than the optical resolution in order to record data at high density on the optical disk. However, the achievable high density of the super-resolution technology was limited due to fluctuation of the region exhibiting the super-resolution effect due to the grain size or the molecular size comprising the super-resolution film. However fluctuation in the region exhibiting the super-resolution effect is reduced by utilizing recording marks possessing their own super-resolution effect and also by separating the recording marks from each other.

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: An optical disk apparatus for correcting astigmatism that influences the read/write. If there is astigmatism, and auto-focus and tracking control are in operation, then a push-pull signal amplitude and a 2T signal amplitude vary with the variation of an amount of spherical aberration, resulting in two cases. In one case, the amount of spherical aberration to give the maximum value of push-pull signal amplitude agrees with the amount of spherical aberration to give the maximum value of 2T signal amplitude, and in the other case the two amounts do not agree. If there is no astigmatism, two amounts agree each other. If there in no agreement, then correction is made by using an astigmatism correcting element until the agreement is reached between the two. In the case where two amounts agree, specification is made for the existence and angle of astigmatism, and correction is made by using focus error signals from adjacent tracks.

Abstract: This optical pickup has a nonvolatile memory from which data can be electronically read out, and stores as data the difference between the spherical aberration when the readout signal jitter reaches a minimum, and the spherical aberration when the tracking error signal amplitude reaches a maximum. The positioning of an optical detector or detection lens is adjusted so that the focus error signal is almost zero when the readout signal jitter reaches a minimum. 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: There are provided parts where respective addresses of grooves on both sides of a land are identical to each other, and selection marks indicating validity of the parts are disposed. The selection marks determines the validity by taking advantage of the fact that there occurs a difference in wobble waveform in the land between a case of wobble data of the grooves on both sides of the land are identical and a case of the wobble data differ from each other. In this case, the wobble address method having an advantageous format efficiency can be used in combination with land/groove recording capable of narrowing down tracks, so that a reproduction method using a large capacity optical disc capable of high-density recording can be implemented.

Abstract: Disclosed here is an apparatus and method for realizing write/read of mass information by reducing cross-talk components that are apt to increase in narrow tracks when various disturbances and variations are recognized. In order to achieve the above object, the apparatus is provided with a plurality of equalizers for correcting frequency characteristics of signals reproduced from a plurality of spots, then outputs from those equalizers are subjected to a computing process to correct tap coefficients of the equalizers sequentially so as to minimize the influence of the subject cross-talk, thereby realizing stable reduction of the cross-talk components.

Abstract: An information recording medium having a plurality of tracks, wherein the respective tracks at least include: a plurality of segments, and having redundancy of identical information being maintained in at least two of the segments of the same track.

Abstract: An optical disk apparatus for correcting astigmatism that influences the read/ write. If there is astigmatism, and auto-focus and tracking control are in operation, then a push-pull signal amplitude and a 2T signal amplitude vary with the variation of an amount of spherical aberration, resulting in two cases. In one case, the amount of spherical aberration to give the maximum value of push-pull signal amplitude agrees with the amount of spherical aberration to give the maximum value of 2T signal amplitude, and in the other case the two amounts do not agree. If there is no astigmatism, two amounts agree each other. If there in no agreement, then correction is made by using an astigmatism correcting element until the agreement is reached between the two. In the case where two amounts agree, specification is made for the existence and angle of astigmatism, and correction is made by using focus error signals from adjacent tracks.

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: This optical pickup has a nonvolatile memory from which data can be electronically read out, and stores as data the difference between the spherical aberration when the readout signal jitter reaches a minimum, and the spherical aberration when the tracking error signal amplitude reaches a maximum. The positioning of an optical detector or detection lens is adjusted so that the focus error signal is almost zero when the readout signal jitter reaches a minimum. 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: An optical disk medium in which high density recording/reproducing is possible, an information recording method and an information reproducing method using it are provided. A pit composed of a phase change material and a recording film different from it are provided on an optical disk. The phase change pit has a pattern of a single frequency. A mark having a size on the same level as the phase change pit can be formed by melting a single phase change pit while recording and controlling the optical absorbance and the temperature of the recording film at the region. A single phase change pit is molten while reproducing. Since the optical characteristics of the molten region are different from the optical characteristics of other regions, only data at the molten region can be reproduced by a super-resolution effect.

Abstract: Super-resolution technology was proposed for generating marks smaller than the optical resolution in order to record data at high density on the optical disk. However, the achievable high density of the super-resolution technology was limited due to fluctuation of the region exhibiting the super-resolution effect due to the grain size or the molecular size comprising the super-resolution film. However fluctuation in the region exhibiting the super-resolution effect is reduced by utilizing recording marks possessing their own super-resolution effect and also by separating the recording marks from each other.

Abstract: Disclosed here is an apparatus and method for realizing write/read of mass information by reducing cross-talk components that are apt to increase in narrow tracks when various disturbances and variations are recognized. In order to achieve the above object, the apparatus is provided with a plurality of equalizers for correcting frequency characteristics of signals reproduced from a plurality of spots, then outputs from those equalizers are subjected to a computing process to correct tap coefficients of the equalizers sequentially so as to minimize the influence of the subject cross-talk, thereby realizing stable reduction of the cross-talk components.

Abstract: There are provided parts where respective addresses of grooves on both sides of a land are identical to each other, and selection marks indicating validity of the parts are disposed. The selection marks determines the validity by taking advantage of the fact that there occurs a difference in wobble waveform in the land between a case of wobble data of the grooves on both sides of the land are identical and a case of the wobble data differ from each other. In this case, the wobble address method having an advantageous format efficiency can be used in combination with land/groove recording capable of narrowing down tracks, so that a reproduction method using a large capacity optical disc capable of high-density recording can be implemented.