Abstract: The invention relates to a data recording apparatus in which a shuffling process for enabling a reproduced image to be easily seen in a high speed reproducing mode of a digital VTR is performed to data to be recorded. As a recording unit to perform the shuffling process, (16×16) macroblocks are set. A process for forming line segments to draw cross lines adapted to divide the recording unit into four equal parts and deleting line segments among four macroblocks around a cross point of the cross lines is repetitively performed until a curve obtained by tracing edges of the formed line segments passes through all of the macroblocks. Further, the line segments are concealed at a position where the curve passes through the same macroblock twice, thereby allowing the curve to pass through the same macroblock once. The order of the recording positions of sync blocks on a tape is specified by the order of drawing the curve P2.

Abstract: Method and apparatus for recording digital data transport stream units such as application packets in sectors of a disk type recording medium such as a digital versatile disk and create and record management information for the recorded transport stream units. In case that a single transport stream unit is divided and then recorded across two sectors, header information of the preceding sector including management information which is created corresponding to each transport stream unit is generated, and the size of the header information and transport stream units to be recorded in the preceding sector is compared with the size of a sector. If the size difference is 1 byte, an invalid header data distinguishable from normal application header extension information is inserted to maintain the correspondence between each transport stream unit to be recorded in the preceding sector and its management information.

Abstract: A recording and reproducing apparatus includes a recording block for recording, on a recording medium, image data and error information indicative of presence or absence of any error in the image data, a reproducing block for reproducing the image data and the error information from the recording medium, an interpolating block for interpolating the reproduced image data on the basis of the reproduced error information, a mode change-over block for changing over a recording mode between a first recording mode in which the image data and the error information are recorded while the recording medium is transported at a first speed and a second recording mode in which the image data and the error information are recorded while the recording medium is transported at a second speed different from the first speed, and a control block for controlling and causing, in response to the change-over of the recording mode, the recording block to record the error information indicative of the presence of any error together w

Abstract: A PLL circuit is disclosed which extracts phase difference information of a high S/N ratio from a readout signal uses the phase difference information for PLL control. An A/D converter samples the input signal to produce a digital signal. A pattern string detector identifies a type of an input pattern string formed from a plurality of successive sample values successively outputted from the A/D converter and outputs pattern string identification information which indicates an identification result. A phase difference generator outputs phase difference information which indicates a phase error of the output of the A/D converter based on the pattern string identification information and the output of the A/D converter. A loop filter, a D/A converter and a voltage controlled oscillator generate a clock signal from the phase difference information to control the sampling timing of the A/D converter.

Abstract: A magnetic card reader for causing a magnetic card to make a move relative to a magnetic head and reproducing data on the magnetic card by the magnetic head, said magnetic card reader includes an amplifier for amplifying a magnetic signal provided by the magnetic head, a peak detection section for detecting a peak point of amplifier output from the amplifier output, a data reproduction section for reproducing digital data based on the interval between the peak points, an anomaly detection section for detecting an anomaly of the peak point interval and an output value storage section for converting the amplifier output from analog form into digital form every predetermined time and storing the provided data.

Abstract: The capacity and realized data rate of a data storage medium is increased by storing multiple bits per symbol using digital modulation techniques. Both phase and amplitude modulation techniques can be applied so that each symbol includes two or more bits that are represented by in-phase and quadrature phase portions of the signal corresponding to the data on the medium.

Abstract: A recording apparatus for digital signals which effectively utilizes production equipments or components for a magnetic tape to assure long-time recording of high-quality signals on the magnetic tape. In this magnetic recording apparatus for digital signals, two-track data in the DV format is recorded in the same data pattern on a sole track of a magnetic tape 8 mm in width. Extension data are also recorded on this sole track along with the two-track data in the DV format.

Abstract: An apparatus and method for converting and improving an existing analog audio recording as it is converted into a digital format with reliable tone detection and interpretation. Specifically, the digitized audio undergoes three tone detection processing steps: silence detection and removal, anomaly detection and removal and page/chapter identification.

Abstract: The present invention provides an integrated controller to process both optical reads and optical writes of multiple optical media. The integrated controller includes a host interface; a buffer manager coupled to the host interface; an embedded memory coupled to the buffer manager; an integrated encoding/decoding engine coupled to the buffer manager; a data channel interface coupled to the integrated encoding/decoding engine; and an integrated servo/recording processor coupled to the integrated encoding/decoding engine and the data channel interface, where the integrated servo/recording processor includes a set of write strategies. The present invention provides a controller which integrates the functionality of the conventional controllers into an integrated processor. With the controller in accordance with the present invention, a single drive may be provided which can read CD-based and DVD-based formats, read and write to Write Once Media, and read and write to Rewritable Media.

Abstract: A digital arithmetic operation circuit includes a plurality of arithmetic operation blocks, a control signal generator and a selector. The plurality of arithmetic operation blocks receive a plurality of digital input signals and perform different arithmetic operations on the received digital input signals, in parallel, to output operation result signals. The a control signal generator receives a plurality of digital input signals and generates a control signal based on the digital input signals. The selector selects one of the operation result signals, in response to the control signal, to output the selected operation result signal. After the control signal generator supplies the control signal to the selector, the selector outputs the selected operation result signal as soon as the selected operation result signal is supplied to the selector.

Abstract: A method and apparatus for running an analog portion (162) of a read/write channel (108) from a highly regulated power supply (260). The apparatus includes an analog portion (162), a clock synthesizer (154), and a highly regulated power supply (260) connected to the analog portion (162) and the clock synthesizer (154). The analog portion (162) and the clock synthesizer (154) both comprise high voltage transistors which operate in a first voltage range and low voltage transistors which operate in a second voltage range, wherein the first voltage range is within the second voltage range. The highly regulated power supply (260) supplies power that is within the first voltage range to the analog portion (162) and the clock synthesizer (154). The method includes generating power that is within the first voltage range using the highly regulated power supply (260), and supplying the power to the analog portion (162) and the clock synthesizer (154).

Abstract: The invention relates to a digital-signal processing apparatus for playing back a digital signal recorded on a recording medium, wherein the digital signal is recorded onto the recording medium by delimiting the digital signal at predetermined time intervals into blocks and then processing each of the blocks to convert the digital signal into at least first coefficient data prescribing the amplitude of the digital signal or first coefficient data prescribing the amplitude of a component obtained as a result of conversion of the digital signal and second coefficient data for prescribing the waveform of the digital signal in conjunction with the first coefficient data, and the digital-signal processing apparatus selectively updates the first coefficient data of the digital signal recorded on the recording medium.

Abstract: A magnetoresistive (MR) head of a hard disk drive provides a readback signal from a data storage disk. The readback signal is high pass filtered, amplified, sampled and digitized to obtain a digital readback signal. A thermal component of the digital readback signal is removed from the digital readback signal by an efficient nonlinear process in which an envelope of the digital readback signal is estimated to obtain upper and lower envelope sequences. The upper and lower envelope sequences are averaged to derive the estimated thermal component to be subtracted from the digital readback signal.

Abstract: A data acquisition apparatus acquires an analog input signal from an analog sensor, and generates digital data based on the analog input signal for processing by a personal computing apparatus. The analog input signal generated by the analog sensor has a voltage component which varies according to a condition sensed by the analog sensor. The data acquisition apparatus includes a first conversion circuit, such as a voltage-to-frequency converter, coupled to the analog sensor which receives the analog input signal and generates an analog information transfer signal having a signal component which varies in relation to the voltage component of the analog input signal. A signal transfer device, such as a portable audio record/playback device, records the analog information transfer signal and transfers it to a first audio input of the personal computing apparatus.

Abstract: Sampling data with wide bi-phase code symbols includes sampling a wide bi-phase code symbol in the data a number (N) of times to produce samples of data, selecting a subset of the samples, determining which sample in the subset of samples has a largest magnitude, and selecting a subset of samples in a subsequent wide bi-phase code symbol based on a sample in a previous subset that has the largest magnitude.

Abstract: A method and data storage device determine an equalized signal-to-noise ratio in the storage device. The equalized signal-to-noise ratio is determined by generating an analog read signal, passing the read signal through an equalizer in the storage device, and sampling the equalized signal using an analog-to-digital converter in the storage device. The samples from the analog-to-digital converter are then used in the equalized signal-to-noise calculation.

Abstract: A circuit and a method of operation for detecting a bit sequence from an analog waveform representing the bit sequence and at least one other parameter associated with the analog waveform are disclosed. Detection includes digitizing the analog waveform and at least one other parameter using at least one analog to digital converter. The resulting digital numbers are synchronized in time by a plurality of registers so that the outputs of the registers always change simultaneously. The outputs of the registers are concatenated to form an address. The address is input into a read-only memory that looks up a most likely bit detected that has been predetermined for that address and stored in the read-only memory. The bits read from the read-only memory by the addresses are output periodically to form the bit sequence.

Abstract: A magnetic card reader for causing a magnetic card to make a move relative to a magnetic head and reproducing data on the magnetic card by the magnetic head, said magnetic card reader includes an amplifier for amplifying a magnetic signal provided by the magnetic head, a peak detection section for detecting a peak point of amplifier output from the amplifier output, a data reproduction section for reproducing digital data based on the interval between the peak points, an anomaly detection section for detecting an anomaly of the peak point interval and an output value storage section for converting the amplifier output from analog form into digital form every predetermined time and storing the provided data.

Abstract: An apparatus and method for converting and improving an existing analog audio recording as it is converted into a digital format with reliable tone detection and interpretation. Specifically, the digitized audio undergoes three tone detection processing steps: silence detection and removal, anomaly detection and removal and page/chapter identification.

Abstract: An apparatus for recording and reproduction of medical information comprises an input/output unit for inputting and outputting personal medical history information of individual patients, a processor for fetching digital personal medical history information supplied from the input/output unit and digital examination image information supplied externally and for applying a predetermined data processing to the two types of digital information, a digital audiotape (DAT) unit loaded with a DAT which is a magnetic cassette tape adapted for recording and reproduction of digitized audio signals, for recording and reproducing the digital information about personal medical history and examination images supplied from the processor on and from a recording medium in the form of the DAT, and a display unit for reproducing and displaying an examination image recorded in the DAT unit.

Abstract: Methods and apparatus for increasing the density of data storage on a magnetic medium by using variations in positioning of magnetic transitions to encode bits. Conventionally encoded bits are written to the medium as sequences of magnetic transitions according to an encoding standard. Additional bits are encoded on the medium as deviations from a nominal position of magnetic transitions separating conventionally encoded bits. The deviation from the nominal position is within an allowable range of tolerance for the standard followed in encoding the conventionally encoded bits. In order to prevent accumulation of error, additional bits are only encoded in transitions separating a pair of conventionally encoded bits. The first and last transitions of the pair do not have additional bits encoded as deviations of transition locations. This technique allows the encoding of one additional bit for every two conventionally encoded bits.

Abstract: A reproducing apparatus for reproducing digital data from a recording medium, the digital data including information data and ID data of the information data. The reproducing apparatus checks the reliability of currently reproduced ID data by using the current ID data and ID data reproduced before the current ID data, and corrects an error in the reproduced information data in accordance with the reliability check result.

Abstract: An analog-to-digital converter 16 includes first and second analog-to-digital converters 22 and 24 both of which receive an input signal. The first analog-to-digital converter 22 is configured to be centered around a first signal level point while the second analog-to-digital converter 24 is configured to be centered around a second signal level point. A decoder 26 receives inputs from the two analog-to-digital converters 22 and 24 and selects between the first analog-to-digital converter 22 output and the second analog-to-digital converter 24 output.

Abstract: A phase-synchronizing circuit includes a phase error detection circuit detecting a phase-error in a given clock signal and producing an output indicative of the phase-error as a first phase-error signal, a phase-error creating circuit creating a second phase-error signal determined so as to minimize a time for establishing a phase-synchronization for the clock signal, and a selection circuit selectively supplying the first or second phase-error signal selectively to a phase control circuit.

Abstract: A magnetoresistive (MR) head of a hard disk drive provides a readback signal from a data storage disk. The readback signal is high pass filtered, amplified, sampled and digitized to obtain a digital readback signal. A thermal component of the digital readback signal is removed from the digital readback signal by an efficient nonlinear process in which an envelope of the digital readback signal is estimated to obtain upper and lower envelope sequences. The upper and lower envelope sequences are averaged to derive the estimated thermal component to be subtracted from the digital readback signal.

Abstract: There is provided a data storage device concurrently allowing storage of data that can be reproduced in higher quality and storage of data that can be used also in a data transmission path with a lower transfer speed. The data storage device comprises an A/D converter 103 for sampling analog audio signals based on a sampling frequency, a DSP 104 for compressing sample data sequentially output from the A/D converter 103, a storing and reading control unit 107 for storing the compressed data sequentially output from the DSP 104, and a control unit 105 for controlling the DSP 104 and the storing and reading control unit 107 for dividing the sample data sequentially output from the A/D converter 103 into a group under odd number of turns and a group under even number of turns, compressing the groups at each different compression rate and storing them on different storage areas A and B, respectively.

Abstract: A method and apparatus for running an analog portion (162) of a read/write channel (108) from a highly regulated power supply (260). The apparatus includes an analog portion (162), a clock synthesizer (154), and a highly regulated power supply (260) connected to the analog portion (162) and the clock synthesizer (154). The analog portion (162) and the clock synthesizer (154) both comprise high voltage transistors which operate in a first voltage range and low voltage transistors which operate in a second voltage range, wherein the first voltage range is within the second voltage range. The highly regulated power supply (260) supplies power that is within the first voltage range to the analog portion (162) and the clock synthesizer (154). The method includes generating power that is within the first voltage range using the highly regulated power supply (260), and supplying the power to the analog portion (162) and the clock synthesizer (154).

Abstract: A decoding circuit has a nonlinear equalizer which employs a signal conditioning algorithm for conditioning a partial response sampled signal to eliminate intersymbol interference. The inventive decoding circuit has an analog-to-digital converter for sampling an analog signal, a linear equalizer for adjusting the amplitude and phase relations of the sampled signal, a nonlinear equalizer for conditioning the sampled signal and outputting a partial response sampled signal having two nonzero samples, and a partial response maximum likelihood detector, for detecting the partial response sampled signal having two nonzero samples.

Abstract: An appliance for recording and playing back audio signals, having a semiconductor memory which stores digital audio signals coded and compressed in a first format, a broadcast radio receiver for digital audio signals coded and compressed in a second format, a controller which is used to store audio signals received by the broadcast radio receiver in the semiconductor memory without recoding, and a playback part which can be used to render the audio signals stored in the semiconductor memory audible.

Abstract: A video/audio data coding circuit receives video/audio signals and compresses and multiplexes them. A recording signal processing circuit shuffles the audio/video data, adds ECCs, and codes them for recording. A CPU control circuit controls a control ECC block addition circuit to generate control ECC blocks and sends them to the recording signal processing circuit. At the same time, the CPU control circuit controls an optical head and a spindle motor. The data is written onto a disc by the optical head. And, after editing, the control ECC blocks are written. At playback time, the control ECC blocks are read from the disc and sent to a control ECC block playback circuit where they are played back. The CPU control circuit controls the optical head, spindle motor, and so on with the played-back control ECC blocks and commands. Video/audio data is read from the disc by the optical head. A played-back signal processing circuit decodes the data, checks for errors, and de-shuffles the data.

Abstract: A circuit and a method of operation for detecting a bit sequence from an analog waveform representing the bit sequence and at least one other parameter associated with the analog waveform are disclosed. Detection includes digitizing the analog waveform and at least one other parameter using at least one analog to digital converter. The resulting digital numbers are synchronized in time by a plurality of registers so that the outputs of the registers always change simultaneously. The outputs of the registers are concatenated to form an address. The address is input into a read-only memory that looks up a most likely bit detected that has been predetermined for that address and stored in the read-only memory. The bits read from the read-only memory by the addresses are output periodically to form the bit sequence.

Abstract: The optical disk reproducing apparatus and method reproduce data from an optical disk, and an error correction circuit included therein error corrects the reproduced data in data blocks of predetermined size to produce error corrected data. The error correction circuit selectively adds dummy data to the reproduced data to form the data blocks. System data is then separated from the error corrected data, and the transfer of the error corrected data to a memory is controlled based on the system data such that the dummy data in the error corrected data is not transferred to the memory.

Abstract: The invention includes a drive control integrated circuit with an intelligent and efficient tracing capability. The drive control integrated circuit executes operating instructions grouped into modules. The drive control integrated circuit stores the module numbers for executed modules in a memory. System designers can then retrieve the module numbers from the memory to assess the operation of the drive control integrated circuit. Some typical modules are read, write, seek, error, and servo modules. The drive control integrated circuit also stores operating parameters associated with the executed modules in the memory. Some typical operating parameters are instruction codes, head numbers, cylinder numbers, and error codes. The invention allows system designers to specify a particular trace operation and wait for the drive control integrated circuit to load the module numbers and operational parameters of interest into the memory.

Abstract: A reproducing apparatus for reproducing digital data from a recording medium, the digital data including information data and ID data of the information data. The reproducing apparatus checks the reliability of currently reproduced ID data by using the current ID data and ID data reproduced before the current ID data, and corrects an error in the reproduced information data in accordance with the reliability check result.

Abstract: A timing recovery system encodes data while impressing recognizable patterns thereon, enabling precise timing during subsequent readback operations. An uncoded binary sequence is encoded using an m/n rate block coded sequence, incorporating a unique predetermined binary bit pattern that occurs with a selected level of frequency. The encoded sequence is stored on the recording medium as a series of flux transitions. To read back the stored data, a read head measures the flux transitions stored on the medium and generates a representative analog waveform. A sampler samples the waveform in accordance with a timing scheme provided by a timing circuit. The timing circuit adjusts the timing of the samples to ensure that the analog waveform is sampled at appropriate times to yield the most accurate results. The timing circuit evaluates two consecutive samples to identify samples associated with features of the analog readback waveform that corresponds to the predetermined bit patterns.

Abstract: A system and method are provided for calibrating a corner frequency of a tunable filter using an ADC code difference method. A method for calibrating a corner frequency of a tunable filter in a direct access storage device includes generating a signal having a frequency within a pass band of the tunable filter to be passed to the tunable filter. The gain of the signal is adjusted to a first threshold level. The corner frequency of the signal is shifted to a second threshold level, whereby the corner frequency of the tunable filter is calibrated at a desired frequency. A system for calibrating a corner frequency of a tunable filter in a direct access storage device includes calibrate control logic coupled to a tunable filter. A signal source generating a signal having a frequency within a pass band of the tunable filter to be passed to the tunable filter is coupled to the tunable filter by a variable gain amplifier. An analog-to-digital converter (ADC) is coupled to the tunable filter.

Abstract: A hard disk drive (HDD) having a control unit that reduces the number of control signals required to control the operation of the channel and amplifier. The HDD includes a control unit for controlling reading or writing data from or to a magnetic head, a preamplifier for amplifying the data from the magnetic head, and a channel module which is controlled by the control unit. The channel module converts digital data signals to data write signals and also converts analog signals from the preamplifier to digital signals. Control information is transmitted to the channel module over the data bus which is used to transmit or receive data read/write signals. The channel module performs control in response to transmitted control information.

Abstract: A portable computer system provides an operating system-independent digital data player. The computer system includes an operating system, a data storage medium to store a plurality of digitally encoded data files, and a digital data player to decode and play the plurality of digitally encoded data files in an operating system-independent digital data mode. The data storage medium may be any of the storage media for the computer system such as a hard disk drive, a CD-ROM drive, a DVD drive or removable data storage. A mini-display panel of the portable computer system displays control status information associated with playing of the plurality of digitally encoded data files in the digital data mode. The computer system further includes a digital data button to place the portable computer system in the digital data mode and a plurality of digital data control buttons to select a plurality of digital data control commands for the plurality of digitally encoded data files.

Abstract: There are provided multi-track recording/reproducing apparatus and method and a multi-track recording/reproducing program, which enable flexible setting of the number of reproducing tracks and that of recording tracks and also facilitates the setting. At least one track for recording is designated from a plurality of tracks, as desired. The number of tracks that can be reproduced is determined in response to the designation of the at least one track for recording. The number of tracks for reproduction is limited to the number of tracks that can be reproduced, by automatically muting at least predetermined one of tracks designated for reproduction, when the number of tracks designated for reproduction is larger than the number of tracks that can be reproduced.

Abstract: A method and data storage device determine an equalized signal-to-noise ratio in the storage device. The equalized signal-to-noise ratio is determined by generating an analog read signal, passing the read signal through an equalizer in the storage device, and sampling the equalized signal using an analog-to-digital converter in the storage device. The samples from the analog-to-digital converter are then used in the equalized signal-to-noise calculation.

Abstract: A digital tape recorder comprises means for recording video material onto video sections of a digital tape; and means for recording digital cataloguing data corresponding to the video material onto cataloguing data sections longitudinally interspersed between video sections on the digital tape.

Abstract: An apparatus for recording and reproducing information data, which comprises an operation control portion operative to perform such a control operation, when an external command is supplied to the control unit under a situation in which data reproducing portion is in operation to reproduce one of information data blocks from a first recording medium in the form of compressed data and data recording and reproducing portion is in operation to record recording information data obtained based on the reproduced information data block on a second recording medium and to reproduce the recording information data from the second recording medium in the form of the reproduced compressed data, as to cause the data recording and reproducing portion to cease its recording and reproducing operations, to cause the data reproducing portion to reproduce a newly selected information data block from the first recording medium in the form of the compressed data in accordance with the external command, and then to cause the data

Abstract: A signal is read out from a two-layered perpendicular magnetic recording medium by a composite head formed from a single-pole perpendicular recording head and magnetoresistance effect type reproduction head. The read-out signal is amplified by a head amplifier, passed through a low-pass filter, and converted into a digital signal by an analog/digital converter. A DC restoring circuit restores a DC component removed by the head amplifier using the output signal from the analog/digital converter. An adder adds the restored DC component to the output signal from the analog/digital converter, thereby restoring the head output terminal signal. A servo demodulation circuit generates a position error signal on the basis of the restored signal.

Abstract: The present invention provides a method and device for processing servo error signals using a programmable circular linked list to minimize latency. The servo error signals are associated with servo channels. A plurality of data entries are stored in a circular linked list for processing a plurality of servo error signals with one data entry for each servo error channel. Each data entry includes a set of data for processing an associated servo error signal and each set of data includes a time interval that specifies a duration required for processing the associated servo error signal in a digital data format. The time required for converting an analog signal into the digital data format is determined and stored as an ADC conversion time. Then, a data entry is accessed from the circular linked list for processing a servo error signal associated with the data entry. Within the ADC conversion time, the servo error signal is converted into digital data.

Abstract: The present invention provides an apparatus having a microphone, an analog to digital converting circuit, a semiconductor memory, input device, and a controller. The analog to digital converting circuit converts an output signal from the microphone into a digital signal. The semiconductor memory stores the output signal from the analog to digital converting circuit. The input device at least carry out input of a record start and a record end. The controller, according to the input from the input device, carries out operation control for start and stop of writing into the semiconductor memory a digital signal from the analog to digital converting circuit. When the input device is operated and a predetermined time interval has passed, the controller controls to start writing the digital signal from the analog/digital conversion circuit into the semiconductor memory.

Abstract: When audio data is played back by, for example, a personal computer, contents are played back, a relationship with a playback process can be recognized even more easily than a conventional way. The displays showing the contents of play lists are arranged and displayed so that the contents become continuous in sequence in a playback sequence from the content which is currently being played back from a display of an operation element which causes an image of a playback process to appear or from a display showing the content which is currently being played back. When the playback of one piece of content of one play list from among a plurality of play lists is terminated, in a case where one piece of content of the other play list is played back, at least the content which is currently being played back and the content to be played back next are displayed so that the contents can be mutually distinguished from the other content.

Abstract: The present invention provides a digital signal reproduction apparatus and a digital signal reproduction method which employs fluctuation in a sampling or quantization process, so as to eliminate lack of depth feeling in digital data, increasing the pleasantness. In a case when a switch 19 is OFF and a switching circuit 20 is set to at terminal b, a clock generator 17 generates a master clock MCK having a 1/f fluctuation according to a signal generated by a fluctuation function generating circuit 18. This master clock MCK is supplied to a D/A converter 13, an aperture circuit 14, and a low pass filter 15. The D/A converter 13 converts a digital signal into an analog signal having an amplitude A with an amplitude fluctuation &Dgr;A (A±&Dgr;A). Thus, the D/A converter 13 is capable of adding a 1/f fluctuation in the amplitude direction (power axis direction) of the analog signal.

Abstract: An optical disk reproducing apparatus for reproducing digital signals in the form of a data frame including a lead-in block and data blocks from an optical disk including at least first and second recording surfaces each being readable from a same side of the optical disk. The data blocks include block addresses and data, and are recorded on the first and second recording surfaces. The lead-in block is recorded at a head of the data frame and includes disk information relating to a number of data blocks recorded on the first and second recording surfaces.

Abstract: A digital information recording-reproducing apparatus for recording and reproducing a digital information signal which includes a recording circuit for recording the digital information signal together with control information, and a reproducing circuit for detecting the recorded control information at a time the recorded digital information signal is to be reproduced, and reproducing the recorded digital information signal only if the detected control information satisfies a predetermined condition.

Abstract: A data reproduction apparatus for an optical disc system is provided. Included is an analog-to-digital converter (ADC) for sampling an input RF signal and outputting the sampled result, an adder for adding the sampled signal and an asymmetry correction signal. The added signal is output. A blank/defect detector is provided for generating a blank detection signal if no change in data is detected from the added signal during a predetermined interval of time. A correction signal generator is provided for calculating a digital sum value (DSV) from the received added signal, generating an asymmetry correction signal based on the calculated DSV, and outputting the generated asymmetry correction signal to the adder. A waveform equalizer is provided for waveform-equalizing the added signal. A decoder is provided for decoding the waveform-equalized signal and outputting the result.