摘要:
It is an object of the present invention to improve reliability of defect management. By providing a plurality of management data areas each including a defect management area typically in a lead-in zone of a disc inner-side region enclosed by a circumference having a predetermined radius on a disc-shaped recording medium, reliability of the defect management can be obtained. In addition, by placing a plurality of the defect management areas (information areas Info1 and Info2) at locations, which are separated from each other in the radial direction of the disc-shaped recording medium, sandwiching a recording/reproduction condition adjustment area OPC having a relatively large size, the reliability of the defect management areas can be further improved. Furthermore, by providing each of the defect management areas with a plurality of recording areas, which include a currently used recording area for recording defect management information and spare recording areas each usable as a substitute for the currently used recording area, the currently used recording area can be replaced with one of the spare recording areas in accordance with an update count of the currently used recording area or error status of this currently used recording area.
摘要:
An optical disc having a circular track formed as a groove and/or land for recording data and wobbled. The track wobbling is performed on a constant unit of an FSK information bit portion based on a waveform obtained by FSK modulation of an information bit and a single frequency portion based on a waveform of a single frequency, so that the constant units are continuous. For the FSK modulation, two types of frequencies are used. One of the frequencies is a frequency identical to the single frequency and the other is different from the single frequency. The relationship of these frequencies is such that for a predetermined period of time, the wave number of these frequencies are even and odd.
摘要:
There is provided an optical disc having preformed thereon a spiral wobbled track as a grove and/or land along with data is to be recorded. The track is wobbled for a series of predetermined signal units each composed of an FSK information bit part based on a waveform resulted from FSK modulation of information bit and a singe-frequency part based on a waveform of a single frequency. The FSK modulation uses two different frequencies of which the one is the same as the single frequency and the other is different from the single frequency. These different frequencies are in such a relation that each of them has an even number of wobbles and an odd number of wobbles alternately in a predetermined cycle.