摘要:
A method for rating an information recording medium according to the present invention includes the steps of: receiving a digital read signal, which has been generated based on an analog read signal representing information that has been read from the information recording medium, and shaping the waveform of the digital read signal; subjecting the shaped digital read signal to maximum likelihood decoding, thereby generating a binarized signal showing a result of the maximum likelihood decoding; and calculating the quality of the digital read signal based on the shaped digital read signal and the binarized signal. If the quality of the read signal is calculated by a PRML method in which a number of zero-cross portions are included in a merging path of a minimum difference metric, the quality is calculated by using only a state transition pattern in which only one zero-cross portion is included in a merging path of a non-minimum difference metric.
摘要:
An information processing device for processing specific information recorded to a recording medium that has a characteristic identification unit and a processing unit. The characteristic identification unit identifies the reflection characteristic of the recording medium. The processing unit processes the specific information recorded to the recording medium according to the identified reflection characteristic. The reflection characteristic is either a first characteristic such that the reflectance of light reflected by a recorded region of the recording medium (referred to as first reflectance) is greater than the reflectance of light reflected by an unrecorded region of the recording medium (referred to as second reflectance), or a second characteristic such that the first reflectance is less than the second reflectance.
摘要:
An integrated circuit includes: a signal processor, which receives an input signal and generates a processed signal, representing processing information obtained by subjecting the input signal to predetermined processing, and at least one type of internal signal including internal information obtained during the processing; at least one memory storing the processing information; an interface exchanges signals with an external device; and a controller controlling the signal processor, memory and interface. On receiving a first instruction from the external device through the interface, the controller controls the signal processor and memory such that the processing information is once stored in the memory and then output to the external device via the interface. In response to a second instruction, the controller controls the signal processor and memory such that the internal information is once stored in the memory and then output to the external device via the interface.
摘要:
An adaptive equalization apparatus comprises an equalizer for equalizing a playback signal read from a recording medium, using tap coefficients; a maximum likelihood decoder for subjecting an equalized signal outputted from the equalizer to maximum likelihood decoding; a first delay unit for delay-adjusting the playback signal to make the signal coincide with the timing of a tentative decoded signal that is obtained in the process of maximum likelihood decoding; a second delay unit for delay-adjusting the equalized signal to make the signal coincide with the timing of the tentative decoded signal; and a coefficient adaptive controller for adaptively controlling the tap coefficients so that an error in the maximum likelihood decoding is minimized, on the basis of the tentative decoded signal, an output of the first delay unit, and an output of the second delay unit.
摘要:
An optical disc has a plurality of sectors, where each of the plurality of sectors includes a plurality of frames. A sub information bit value of “0” or “1” is assigned to the plurality of frames constituting a sector, excluding the first and last frames. Edge positions are displaced so that leading/lagging errors appear in accordance with a certain rule when data fields of the frames to which the sub information bit value “1” is assigned are read. Edge positions are displaced so that leading/lagging errors appear in accordance with a reversal of the certain rule when data fields of the frames to which the sub information bit value “0” is assigned are read.
摘要:
An optical disc drive usable with discs to which data is continuously recorded and discs having a sector format can quickly resume playback signal output after passing imperfection causing potential reading errors, and plays disc with few read errors. A detection signal generator detects DC level fluctuation in the playback signal read from the disc and generates a detection signal tracking the DC level fluctuation. A selector selects a detection signal or a null signal without valid polarity based on the detection signal generated by the detection signal generator and input to the selector. A clamping unit performs a clamping process to suppress DC level fluctuation in the playback signal based on the detection signal when the selection unit selects the detection signal, and does not perform the clamping process when the selection unit selects the null signal. A signal processor performs specific signal processes based on clamping unit output.
摘要:
A recording/producing device for writing data on a recording medium, or reading data from the recording medium, wherein data matching a recording pattern so specified as to include a plurality of mutually different sets of mark lengths and space lengths is written on the recording medium, and the data is then read to generate data signals. An edge shift detector uses data signals to measure the edge shift amount of a mark formed on a recording medium for each set of a mark length and a space length. A record controller sets a recording parameter for each set of a mark length and a space length based on the measured edge shift amount.
摘要:
A frequency and phase control apparatus includes an analog/digital conversion section for converting a reproduction signal into a multiple bit digital signal based on a clock signal; a maximum likelihood decoding section for converting the multiple bit digital signal into a binary signal; a pattern detection section for detecting a pattern of the binary signal; and a determination section for determining whether or not the multiple bit digital signal and the clock signal are in synchronization with each other based on the detection result. When the determination result of the determination section indicates that the multiple bit digital signal and the clock signal are in synchronization with each other, the maximum likelihood decoding section generates a binary signal based on a first state transition rule; otherwise, the maximum likelihood decoding section generates a binary signal based on a second state transition rule.
摘要:
A recording control apparatus includes a waveform rectification section for receiving a digital signal generated from an analog signal representing information reproduced from an information recording medium, and rectifying a waveform of the digital signal; a maximum likelihood decoding section for performing maximum likelihood decoding of the digital signal having the waveform thereof rectified, and generating a binary signal representing a result of the maximum likelihood decoding; a reliability calculation section for calculating a reliability of the result of the maximum likelihood decoding based on the digital signal having the waveform thereof rectified and the binary signal; and an adjusting section for adjusting a shape of a recording signal for recording the information on the information recording medium based on the calculated reliability.
摘要:
An optical disc recording apparatus records a digital content onto an optical disc so that the perfect copying of the digital content is difficult without proper authorization. The optical disc recording apparatus includes a formatter for generating a channel signal corresponding to primary digital information, a secret key storing unit for prestoring secondary digital information, a pseudo random number generator for generating a pseudo random number series, an XOR for logically inverting the pseudo random number series according to each bit of the secondary digital information, a PE modulator for generating a PE modulation signal according to the logically inverted pseudo random number series, a phase modulator for modulating the phase of each edge of the channel signal by a fixed slight time according to the value of the PE modulation signal, and a recording channel for forming recording marks on a DVD according to the modulated channel signal.