摘要:
A recording method of an information recording medium includes: (a) storing management information; (b) reading out the management information; and (c) recording. The information recording medium has two recording layers. A first recording layer is placed nearer to a source of a laser and a recording direction thereof is from the inner side to the outer side of the information recording medium. A recording direction of a second recording layer is from the outer side to the inner side. In the (a) storing, management information indicating a recording status of the information recording medium is recorded in a management information area of the information recording medium. In (b) reading out, the management information is read out from the management information area. In (c) recording, recording processing is performed by skipping a part of an area based on the management information.
摘要:
In a track offset adjusting method of an information recording medium, data are recorded onto first and second tracks of an information recording medium. No data are recorded on at least one of tracks adjacent to each of the first and second tracks. After the data recording onto the first and second tracks, data are recorded onto the third track adjacent to the inner circumferential side of the first track and onto a fourth track adjacent to the outer circumferential side of the second track. Thereafter, reproduction signal qualities of the first and second tracks are calculated on the basis of reproduction signals obtained by reproducing the data recorded on said first and second tracks. The track offset is adjusted on the basis of the reproduction signal qualities of the first and second tracks.
摘要:
Reproduced signals are equalized by the least square technique by using a predetermined number of data samples binarized by a Viterbi decoder. Even when data written on an optical disk is unknown, the data can be equalized in a stable manner and can be reproduced at a low error rate without instability factors such as divergence due to interference.
摘要:
An information playback apparatus includes a first FIR filter, ideal signal generator, weighted equalization error calculator, and coefficient calculator. The first FIR filter generates an equalized waveform by equalizing, to a partial response waveform, a playback data string obtained by playing back a recorded signal recorded on an information recording medium. The ideal signal generator generates a target waveform serving as an equalization target. The weighted equalization error calculator calculates a data string by performing convolution computation for an equalization error which is a difference between the equalized waveform and the target waveform, on the basis of one of the playback data string and the equalized waveform input from the first FIR filter and the target waveform input from the ideal signal generator. The coefficient calculator calculates a tap coefficient for the first FIR filter on the basis of the data string input from the weighted equalization error calculator, and outputs the tap coefficient to the first FIR filter. An information playback method is also disclosed.
摘要:
An optical disk device includes an optical head unit, a drive means and a recording surface state determination means, and determines the type of an optical disk based on a state of the information recording surface. The information recording surface includes a management region on which management information is recorded and formed by a guiding groove or a prepit sequence and a data recording region on which a user data is recorded and on which a track formed by a guiding groove or a prepit sequence. The optical head unit irradiates a focused beam onto the information recording surface of an optical disk which rotates. The drive means drives to move the focused beam along a radial direction of the optical disk by driving the optical head unit. The recording surface state determination means determines a state of the information recording surface based on a reflected light of the focused beam. The optical disk device determines the type of the optical disk based on a state of the information recording surface in a determination region being set to straddle between a management region and the data recording region.
摘要:
An information playback apparatus includes a first FIR filter, ideal signal generator, weighted equalization error calculator, and coefficient calculator. The first FIR filter generates an equalized waveform by equalizing, to a partial response waveform, a playback data string obtained by playing back a recorded signal recorded on an information recording medium. The ideal signal generator generates a target waveform serving as an equalization target. The weighted equalization error calculator calculates a data string by performing convolution computation for an equalization error which is a difference between the equalized waveform and the target waveform, on the basis of one of the playback data string and the equalized waveform input from the first FIR filter and the target waveform input from the ideal signal generator. The coefficient calculator calculates a tap coefficient for the first FIR filter on the basis of the data string input from the weighted equalization error calculator, and outputs the tap coefficient to the first FIR filter. An information playback method is also disclosed.
摘要:
In a method of obtaining a reproduction signal with good quality from a data recording medium, two actual signals are generated as first and second signals I1 and I2 from detection signals obtained from the data recording medium. A coefficient k which has linear correlation with a tilt is calculated based on the first and second signals I1 and I2. A reproduction signal in which influence of the tilt is eliminated, is reproduced by using the coefficient k and the first and second signals I1 and I2.
摘要:
In order to evaluate the quality of a signal recorded on an optical recording medium, a target signal is obtained based on a predetermined data string and a predetermined partial response characteristic, and for each clock cycle, an equalization error is calculated that is a difference between the target signal and a signal reproduced each clock cycle. Further, the product of the equalization errors calculated at different times is obtained, and based on the obtained product, the quality of a signal is evaluated.
摘要:
In a method of obtaining a reproduction signal with good quality from a data recording medium, two actual signals are generated as first and second signals I1 and I2 from detection signals obtained from the data recording medium. A coefficient k which has linear correlation with a tilt is calculated based on the first and second signals I1 and I2. A reproduction signal in which influence of the tilt is eliminated, is reproduced by using the coefficient k and the first and second signals I1 and I2.
摘要:
In an optical disk medium, land recording tracks (1) are coupled by first and second coupling portions (3 and 4) at a particular radial position to form a tilt detecting mark SM.