摘要:
An optical recording/reproduction method and device that can perform control for optimizing the amount of spherical aberration in a multilayered optical disc in a short period of time. When the objective lens is displaced in the focusing direction, the amplitude value of the focusing error signal detected just after leaving the focal position of a given first recording layer and the amplitude value of the focusing error signal detected just before passing through the focal position of a given second recording layer other than the first recording layer are measured with a particular spherical aberration, the amplitude ratio of amplitude values is calculated, the difference between spherical aberration and the optimal spherical aberration for the second recording layer is approximated as a function of the amplitude ratio, the optimal spherical aberration is calculated on the basis of this approximation, and the spherical aberration is set.
摘要:
An optical recording/reproduction method and device that can perform control for optimizing the amount of spherical aberration in a multilayered optical disc in a short period of time. When the objective lens is displaced in the focusing direction, the amplitude value of the focusing error signal detected just after leaving the focal position of a given first recording layer and the amplitude value of the focusing error signal detected just before passing through the focal position of a given second recording layer other than the first recording layer are measured with a particular spherical aberration, the amplitude ratio of amplitude values is calculated, the difference between spherical aberration and the optimal spherical aberration for the second recording layer is approximated as a function of the amplitude ratio, the optimal spherical aberration is calculated on the basis of this approximation, and the spherical aberration is set.
摘要:
An optical information processing method and apparatus performs a light irradiating and receiving step, a signal processing step, and an adjusting step of a spherical aberration and a focus offset on the basis of shift amount of first and second control devices and a performance evaluation value. The performance evaluation values for first, second, third and fourth points in an x and y coordinate system are detected, in which an x-coordinate is one of the shift amount of the first control device and the shift amount of the second control device and a y-coordinate is the other, the first point, second and third points having the same y-coordinate and different x-coordinates with each other, the fourth point being provided on a first straight line passing through the first point and being different from the first point.
摘要:
An optical information processing method and apparatus performs a light irradiating and receiving step, a signal processing step, and an adjusting step of a spherical aberration and a focus offset on the basis of shift amount of first and second control devices and a performance evaluation value. The performance evaluation values for first, second, third and fourth points in an x and y coordinate system are detected, in which an x-coordinate is one of the shift amount of the first control device and the shift amount of the second control device and a y-coordinate is the other, the first point, second and third points having the same y-coordinate and different x-coordinates with each other, the fourth point being provided on a first straight line passing through the first point and being different from the first point.
摘要:
According to a method for setting the laser beam power applied to reproduce information recorded on an optical disc, information recorded in a region on the optical disc is reproduced using three or more test reproduction powers (S22B), the number of reproductions until the degradation of the quality of the reproduced signal reaches a prescribed value is determined as the degradation number of reproductions (S22F), the relation between the test reproduction power and the degradation number of reproductions is approximated by a curve, and a reproduction power restricting the degradation of the reproduced signal quality to a predetermined amount or less over a certain guaranteed number of reproductions is determined (S25F). In optical reproduction from an optical disc on which information is recorded, the optimum power of irradiation for reproduction can be set, and degradation of the information due to the reproducing light can be prevented.
摘要:
According to a method for setting the laser beam power applied to reproduce information recorded on an optical disc, information recorded in a region on the optical disc is reproduced using three or more test reproduction powers (S22B), the number of reproductions until the degradation of the quality of the reproduced signal reaches a prescribed value is determined as the degradation number of reproductions (S22F), the relation between the test reproduction power and the degradation number of reproductions is approximated by a curve, and a reproduction power restricting the degradation of the reproduced signal quality to a predetermined amount or less over a certain guaranteed number of reproductions is determined (S25F). In optical reproduction from an optical disc on which information is recorded, the optimum power of irradiation for reproduction can be set, and degradation of the information due to the reproducing light can be prevented.
摘要:
To adjust the parameters of a write strategy for recording data on an optical recording medium, the jitter value of a reproduced signal obtained from recorded data is detected. If the jitter value exceeds a prescribed threshold, a write strategy parameter having a comparatively small effect on the jitter value is adjusted, and subsequent data are written on the recording medium using the adjusted parameter. Parameters are selected for adjustment in ascending order of their effect on the jitter value. Stable data recording can thereby be carried out without significant jitter degradation.
摘要:
To adjust the parameters of a write strategy for recording data on an optical recording medium, the jitter value of a reproduced signal obtained from recorded data is detected. If the jitter value exceeds a prescribed threshold, a write strategy parameter having a comparatively small effect on the jitter value is adjusted, and subsequent data are written on the recording medium using the adjusted parameter. Parameters are selected for adjustment in ascending order of their effect on the jitter value. Stable data recording can thereby be carried out without significant jitter degradation.
摘要:
A recording method for an optical disc having at least three recording layers (11, 12, 13, 14), in which test recording areas are formed in the odd-numbered recording layers (11, 13) and the even-numbered recording layers (12, 14) in positions that are mutually non-overlapping in the thickness direction of the optical disc, the test recording areas in the odd-numbered recording layers are formed in positions mutually aligned in the thickness direction, and the test recording areas in the even-numbered recording layers are formed in positions mutually aligned in the thickness direction. The time for test recording for determining the optimal recording power can be shortened.
摘要:
Before new information is recorded on a comparatively deep recording layer in a multilayer optical recording disc, a predetermined target value of a reproduced signal parameter is read from the disc itself or from a separate storage unit, the recorded/unrecorded states of the shallower recording layers are determined, and the target value is corrected on the basis of these states. The correction is based on a predetermined difference in the value of the reproduced signal parameter caused by a difference in the recorded/unrecorded states of the shallower recording layers. The corrected target value is used in calibration of the recording power by means of a test write. This correction of the target value permits reliable recording on a multilayer optical disc without delaying the start of the recording process.