Abstract: Optical disk recording device includes a beam projection section for projecting a light beam onto a write-once optical disk, and a photodetector having two light receiving surfaces divided in a radial direction of the optical disk for detecting reflected light from the optical disk, and wobble-signal reproduction circuitry for reproducing a wobble signal on the basis of reflected light detection signals output from the two light receiving surfaces of the photodetector. The wobble-signal reproduction circuitry includes peak-holding circuits for, when the optical disk device is in a reproduction mode, detecting and holding respective upper envelopes of the two light detection signals from the photodetector. The wobble-signal reproduction circuitry also includes holding circuits for, when the optical disk device is in a recording mode, detecting respective lower envelopes of the two light detection signals from the photodetector.

Abstract: An optical disk system comprises an optical disk device and control circuitry. The optical disk device stores user data and transfers an analog signal representing the user data to the control circuitry. The control circuitry sub-samples the analog signal to generate a sub-sampled signal. The control circuitry up-samples and re-times the sub-sampled signal using a control signal to generate an up-sampled and re-timed signal. A digital feedback loop in the control circuitry generates the control signal.

Abstract: An output device digitally stores data on a data carrier. The output device includes a reading unit, a data converter unit, and an output unit, provided with data reconstruction elements. Data to be reproduced can be processed by control data components contained in a start block. The control data components can be stored in a control data storage unit connected to the data reconstruction elements by way of a start block detector unit. This enables fast reproduction of large amounts of data, particularly digitized audio data.

Abstract: An optical record carrier (10) comprises a recording layer for recording information in a pattern of optically detectable marks in substantially parallel tracks (11-15). Neighboring tracks are separated by edges (16-20). Control information is encoded in a modulation of the transverse position of the even-numbered edges (16, 18, 20). The modulation of neighboring even-numbered edges have a mutual fixed phase shift. The modulation of the odd-numbered edges (17, 19) is such as to enhance the amplitude of a push-pull signal when scanning the tracks (11, 12) neighboring such an odd-numbered edge (17).

Abstract: The present invention has an objective of providing a digital data reproduction apparatus and a method for correcting a reproduced signal digitization level in which the signal quality of a reproduced signal from a recording medium is kept high while ensuring the reproduction stability. The digital data reproduction apparatus includes: reproduced signal digitization means for digitizing a reproduced signal; synchronization means for producing a clock whose phase is synchronized with a leading edge and a trailing edge of the digitized signal produced by the reproduced signal digitization means; and jitter detection means for integrating and thereby converting absolute values of phase errors between the digitized signal and the clock to a voltage value. The apparatus further includes digitization level correction means for correcting a reproduced signal digitization level so as to minimize a signal produced by the jitter detection means.

Abstract: A recording information reproducing apparatus which can reduce a residual phase error in a read signal caused due to an influence by a time base fluctuation. A read signal read out from a recording medium is sampled at a timing according to a clock signal, thereby obtaining a read sampling value sequence. An oscillation signal whose phase is synchronized with the read sampling value sequence is formed as a clock signal. A sampling value sequence which is obtained at a time point when the phase in the read sampling value sequence is deviated by an amount corresponding to a phase error occurring in the read sampling value sequence is obtained as a corrected read sampling value sequence. By performing a decoding process to the correction read sampling value sequence, information data is obtained.

Abstract: An information reproducing apparatus for reproducing digital record information recorded on an information record medium is provided with: a generating device for reading out the digital record information from the information record medium to thereby output a reproduction signal; a sampling device for sampling the reproduction signal by using a sampling clock signal having a predetermined sampling frequency to thereby output the sampled reproduction signal; a detection device for detecting a direct current level of the sampled reproduction signal by extracting a zero-cross sample value, which is a sample value contained in the sampled reproduction signal and is the closest sample value to a zero level in the sampled reproduction signal, from the sampled reproduction signal; a correcting device for correcting the sampled reproduction signal by subtracting the detected direct current level from each sample value of the sampled reproduction signal to thereby output the corrected sampled reproduction signal; and

Abstract: The present invention provides an optical disc drive apparatus comprising: an optical unit (2) for reading out a data recorded on an optical disc (1) from a position specified by a servo signal; a signal processor (4) for calculating and amplifying the data which has been read out by said optical unit (2); a microcomputer (5) provided with software for performing a calculation for a servo processing and a system control according to an output signal from said signal processor (4); and a servo driver (3) for performing a servo processing via said optical unit according to an output signal from said microcomputer.

Abstract: This invention prepares two control voltage to be input to a VCO circuit. The first control voltage is used to continuously change the oscillation frequency of the VCO circuit. The second control voltage is used to continuously change the first control voltage/oscillation frequency characteristics. The invention also includes a phase detecting circuit for comparing the phase of the data read from a disk with that of the output from the voltage-controlled oscillator, a frequency detecting circuit for comparing the frequency of the data read from the disk with that of the output from the voltage-controlled oscillator, a first filter circuit for equalizing signals representing the detection results obtained by the phase detecting circuit and the frequency detecting circuit, and a second filter circuit for extracting only a low-frequency component from the output from the first filter circuit. The output from the first filter circuit is used as the first control voltage.

Abstract: An amplitude detector for signals having a periodical character, recorded on a recording medium, including a first delay line and a second delay line, wherein an average maximum value of the detected signal is stored in the first delay line for each one of a predetermined number of detection instants within a detection period, and an average minimum value of the detected signal is stored in the second delay line for each one of the detection instants, means for determining an average level between the average maximum and minimum values for each detection instant on the basis of the output signals of the two delay lines, and means for comparing the current signal to be detected for a given detection instant with the average level for the detection instant so as to provide a detection signal.

Abstract: A method for recording audio data onto a compact disc so as to discourage unauthorized copying thereof, the method including sampling a source audio data stream to determine at least one source audio data portion thereof the a derivative function of a sequence of samples of the source audio data portion is substantially constant, modifying the source audio data stream by substituting the source audio data portion with a substitute audio data portion, recording the modified audio data stream into at least one frame of the compact disc the frame has a P-channel, and setting the value of the P-channel that corresponds to the substitute audio data portion to 1.

Abstract: A method, circuit and system for selectively and adaptively effecting conditioning of selected samples of a read signal in storage technologies. A circuit embodying the present invention includes sample logic, arithmetic logic and conditioning logic. The sample logic receives samples and provides a main sample and one or more selected neighbor samples. The arithmetic logic compares the main sample to the neighbor samples toward determining satisfaction of selected conditioning criteria. If the selected conditioning criteria are satisfied, the conditioning logic selectively and adaptively effects level conditioning as to the main sample. Further, the level conditioning is combined with a rule compliance system to insure the read data is following the protocol of the data coding format being used.