摘要:
The present invention provides a measure for getting read/write control information stored within a space of a predetermined size in a format that ensures compatibility with media of a lower order or an older generation even if the size of the read/write control information increases significantly as the storage densities of information storage media rise in the near future. On an information storage medium, a data sequence is writable as a combination of marks and spaces. The medium has at least one information storage layer, which has an information storage area to store information and a control information area for use to perform a read/write operation on the at least one information storage layer. The control information area stores at least one set of control information, which includes a first kind of write pulse information including information to be used as a reference value and a second kind of write pulse information including information to be used as an offset value. The size of the offset value is at least a half as large as that of the reference value.
摘要:
The present invention provides a measure for getting read/write control information stored within a space of a predetermined size in a format that ensures compatibility with media of a lower order or an older generation even if the size of the read/write control information increases significantly as the storage densities of information storage media rise in the near future. On an information storage medium, a data sequence is writable as a combination of marks and spaces. The medium has at least one information storage layer, which has an information storage area to store information and a control information area for use to perform a read/write operation on the at least one information storage layer. The control information area stores at least one set of control information, which includes a first kind of write pulse information including information to be used as a reference value and a second kind of write pulse information including information to be used as an offset value. If the pulse width or pulse position of a write pulse is definable with a precision of 1T/n (where T is a channel clock pulse width and n is a positive integer), the size of the offset value is large enough to define at least an n/2 range.
摘要:
An optical information storage medium according to the present invention has at least one information storage layer. The optical information storage medium has a management area that stores at least one unit containing control information about the optical information storage medium. The control information includes a format number, which provides information about at least a write strategy type and a write pre-compensation type, and a write strategy parameter, which provides information about the magnitude of shift in an edge position, or variation in the pulse width, of a write pulse train to form a recording mark. And the value of the format number changes according to a combination of the write strategy type and the write pre-compensation type.
摘要:
An optical information storage medium according to the present invention has at least one information storage layer. The optical information storage medium has a management area that stores at least one unit containing control information about the optical information storage medium. The control information includes a format number, which provides information about at least a write strategy type and a write pre-compensation type, and a write strategy parameter, which provides information about the magnitude of shift in an edge position, or variation in the pulse width, of a write pulse train to form a recording mark. And the value of the format number changes according to a combination of the write strategy type and the write pre-compensation type.
摘要:
A writing method according to the present invention is a method for writing a data sequence as a combination of marks and spaces on an information recording medium by condensing a laser beam through a lens. The writing method is characterized in that a cooling pulse for recording a mark that is even shorter than the limit of optical resolution of the laser beam and another cooling pulse for recording a mark that is still longer than the limit of the optical resolution of the laser beam are applied under mutually different conditions.
摘要:
A reproduction signal evaluation method according to the present invention relates to adjustment of an edge portion between a shortest mark and a shortest space in a data sequence including marks and spaces in combination that is recordable on an information recording medium. In a pattern including a shortest mark and a shortest space adjacent before or after the shortest mark, a shift amount of an edge of the shortest mark is obtained from a differential metric calculated regarding one of a first pattern in which a space adjacent to the shortest mark and not adjacent to the shortest space is longer than the shortest space; and a second pattern in which a mark adjacent to the shortest space and not adjacent to the shortest mark is longer than the shortest mark.
摘要:
A phase difference error detecting unit detects a phase difference error component included in a phase difference component; a phase difference correcting unit corrects a first signal having the phase difference component as an angle of a cosine function and a second signal whose angle of the cosine function differs from that of the first signal by approximately π/2 based on the detected phase difference error component; a phase operating unit operates a phase difference component from the first signal and the second signal corrected by the phase difference correcting unit; and the phase difference correcting unit obtains the corrected first signal and the corrected second signal by rotating a coordinate point represented by the first signal and the second signal on a polar coordinate plane by an angle corresponding to the phase difference error component.
摘要:
When ld0 denotes an initial optical path length that is a length of an optical path, along which the signal light travels, as converted using a refractive index in vacuum, lm0 denotes an initial optical path length that is a length of an optical path, along which the reference light travels, as converted using a refractive index in vacuum, Δl denotes a fluctuation width of a difference in optical path lengths between the signal light and the reference light as converted using a refractive index in vacuum, λ0 denotes a central oscillation wavelength of the wavelength-variable laser, and Δλ denotes an oscillation wavelength variable range of the wavelength-variable laser, then an initial optical path difference |ld0−lm0| satisfies |ld0−lm0|>(Δl/Δλ)λ0.
摘要:
When ld0 denotes an initial optical path length that is a length of an optical path, along which the signal light travels, as converted using a refractive index in vacuum, lm0 denotes an initial optical path length that is a length of an optical path, along which the reference light travels, as converted using a refractive index in vacuum, Δl denotes a fluctuation width of a difference in optical path lengths between the signal light and the reference light as converted using a refractive index in vacuum, λ0 denotes a central oscillation wavelength of the wavelength-variable laser, and Δλ denotes an oscillation wavelength variable range of the wavelength-variable laser, then an initial optical path difference |ld0−lm0| satisfies |ld0−lm0|>(Δl/Δλ)λ0.
摘要:
A reproduction signal evaluation method according to the present invention relates to adjustment of an edge portion between a shortest mark and a shortest space in a data sequence including marks and spaces in combination that is recordable on an information recording medium. In a pattern including a shortest mark and a shortest space adjacent before or after the shortest mark, a shift amount of an edge of the shortest mark is obtained from a differential metric calculated regarding one of a first pattern in which a space adjacent to the shortest mark and not adjacent to the shortest space is longer than the shortest space; and a second pattern in which a mark adjacent to the shortest space and not adjacent to the shortest mark is longer than the shortest mark.