Sony Corporation

Sony Disc & Digital Solutions Inc.

Matsushita Electric Industrial Co., Ltd.

Koninklijke Philips Corporation N.v.

Tatsushi Sano

Tatsuya Inokuchi

Yoichiro Sako

Shunsuke Furukawa

Toru Aida

Akiya Saito

Yoriaki Kanada

Takashi Kihara

Yoshinobu Usui

Toshihiko Senno

Yoshiro Miyoshi

Shigeru Furumiya

Hiromichi Ishibashi

Junichi Minamino

Hiroshi Ogawa

Aalbert Stek

Cornelis Marinus Schep

Shin Masuhara

Toshimasa Miyoshi

Jacobus Petrus Josephus Heemskerk

Shinji Ohta

Mitsuyuki Bamba

Tadaaki Nomoto

Mitsuru Okabe

A phase-locked loop circuit that generates a clock signal synchronized with an input signal with a predetermined frequency, including an oscillator configured to oscillate and generate the clock signal; a converter configured to convert the input signal into a digital signal using the clock signal generated by the oscillator as a sampling clock; a frequency divider configured to divide a frequency of the clock signal generated by the oscillator to generate a comparison clock signal and send the comparison clock signal as a feedback; a normalizer configured to normalize an amplitude value of the digital signal generated by the converter; and an oscillation controller configured to control a phase of the clock signal generated by the oscillator so as to reduce a phase difference between the normalized digital signal generated by the normalizer and the comparison clock signal sent as a feedback by the frequency divider.

PLL circuit, recording apparatus, and clock-signal generating method

A clock generation circuit is provided that multiplies an input signal of a specific frequency by a specific multiplication factor and generates an output clock signal. The clock generation circuit includes a PLL circuit that multiplies the input signal and generates the output clock signal, and a correction circuit that changes the multiplication factor of the PLL circuit. The correction circuit changes the PLL circuit multiplication factor by increasing or decreasing the specific multiplication factor, the change being performed only during a correction interval for each correction cycle, the correction cycle being longer than one cycle of the input signal, and being performed such that a time difference between an input synchronizing signal synchronized with the input signal and an output synchronizing signal synchronized with the output clock signal is reduced. The PLL circuit multiplies the input signal by the changed multiplication factor during the correction interval.

Clock generation circuit, recording device and clock generation method

A push-pull signal is detected from light reflected from a disk-shaped storage medium on which wobbling grooves are formed as recording tracks and address information is recorded by forming pre-pits on lands between adjacent grooves. A fundamental amplitude variation signal indicating the fundamental amplitude variation of the push-pull signal is acquired, and a reference voltage is generated by adding an offset voltage to the fundamental amplitude variation signal. Pre-pits are detected by comparing the push-pull signal with the reference voltage. Because the reference voltage is produced on the basis of the fundamental amplitude variation signal indicating the variation components of the push-pull signal due to the wobbling of grooves and noise, the variation components due to the wobbling and noise are reflected in the reference voltage. Furthermore, the variation components of the push-pull signal corresponding to the pre-pits are also reflected to a properly small extent in the reference voltage.

Disk drive and pre-pit detection method

Data is arranged to one block obtained after a CIRC process so that a predetermined data pattern is recorded into a predetermined portion on a disc. By tracing back an encoding step of a Cross-Interleave Reed-Solomon Code (CIRC), a layout of recording data of one block before the CIRC process for allowing the predetermined data pattern to be recorded into the predetermined portion is obtained. An error correcting process of a CD-ROM mode 1 is executed. If a position of a parity coincides with data for forming the predetermined data pattern, a value of user data of an encoding sequence to form the parity is changed. After error correction encoding of a CD-ROM is executed, encoding of the CIRC is executed to the recording data of one block.

Data recording method and device

In a demodulation process of a first modulated signal and a second modulated signal, phase adjustment is automatically performed by generating, in response to demodulation results, an optimum phase value of a second internal reference wave for demodulating the second modulated signal. A phase of a second internal reference wave for demodulating the first modulated signal is also adjusted using the optimum phase value for the automatic adjustment.

Demodulator, disk drive device, and phase adjustment method

A recording method for converting m-bit data into n-bit (where n&#x3e;m) bit data whose run length is restricted and recoding the converted data on a recording medium, the recording method comprising the steps of when at least preceded data is data containing a special data pattern, lightening the restriction of the run length; and recording data so that the cumulative value of DC components per unit time increase when the data is reproduced in the state that the run length is restricted.

Data recording medium, and data recording method and device

A push pull signal is detected from a disk-shaped storage medium on which wobbling grooves are formed as recording tracks and address information is recorded by forming pre-pits on lands between adjacent grooves. The detected push-pull signal is compared with a reference voltage thereby generating a land pre-pit detection signal. Of pulses included in the land pre-pit detection signal, those pulses having a small pulse width are regarded as noise pulses and removed thereby obtaining a corrected land pre-pit detection signal. The number of pulses included in the land pre-pit detection signal is counted, and the reference voltage is controlled in accordance with the counted number of pulses.

Disk drive and detection method using pre-pit detection and push-pull signal generation

A recording method for converting m-bit data into n-bit (where n&#x3e;m) data whose run length is restricted and recording the converted data on a recording medium, the recording method comprising the step of selecting first n-bit data according to an immediately preceded n-bit data, first n-bit data immediately followed thereby, and second n-bit data immediately followed thereby so that the cumulative value of DC components per unit time becomes small.

Data recording medium, data recording method and device, and encode method and device

A recording method includes the steps of generating recording data in such a manner that, when m-bit data is converted into a data symbol of n bits (m&#x3c;n), and connection bits such that the summed value of DC components per unit time decreases are selected from among a plurality of connection bits and are added after the m-bit data symbol, the connection bits differing from connection bits which are added when the n-bit data symbol is a data symbol other than the special data symbol are added to generate recording data; and recording the generated recording data on a recording medium.

Data recording apparatus and associated methodology of affecting a digital sum variance

A recording method, wherein, when a certain portion of main data is recorded by being encoded by a first encoding method and the other portions of the main data is recorded by being encoded by a second encoding method, an encoding process is performed by the first encoding method so that, when data which is recorded in such a manner that the data encoded by the first encoding method is decoded by a decoding method corresponding to the first encoding method, and thereafter, is further encoded by the second encoding method, is decoded by a decoding method corresponding to the second encoding method, the sum value of DC components per unit time increases.

Digital data recording medium, recording method, recording device, reproduction method, and reproduction device

Six record areas for predetermined data that has been encoded and digitally modulated are formed in a data record area on a disc. The record areas have different offset compensation amounts. The offset compensation amounts allow all offset amounts that may take place in an error correction code encoder to be compensated. Thus, regardless of the offset amount generated by the error correction code encoder, encoded and modulated data that has been generated by the conventional EFM modulating system and recorded in one of the record areas securely causes DSV to deviate. Each of the record areas is set to a sufficient length that allows the effect of which DSV deviates to be recognized.

Data recording medium, data recording method, and device

A recording medium has a first area in which data encoded with a first error correction code is recorded and a second area in which data encoded with the first error correction code and data decodable with a second error correction code that is different from the first error correction code are mixedly recorded. Data that causes the cumulated value of a DC component per unit period of data reproduced from the second area to deviate is recorded in the second area.

Recording medium, recording method, recording device, and reproduction method and reproducer

The S/N ratio is improved for recording data to grooves (--) of an optical disc so that as much information as possible can be recorded at the lowest possible frequency band. An optical disc using wobble patterns to record different information has a first groove (-) having a first wobble pattern () in which one wobble period has a sharp rising edge and a gradual falling edge; and a second groove (-) having a second wobble pattern () in which one wobble period has a gradual rising edge and a sharp falling edge. Each of the first and the second wobble pattern is represented by a first fundamental and a second harmonic of a Fourier series. The polarity of the second harmonic, which is an even harmonic, of the second wobble pattern is opposite that of the first wobble pattern. A method for manufacturing this optical disc is also provided.

Optical disc with different wobble patterns in different grooves

A receiving apparatus including a receiving circuit for receiving data synchronized with a predetermined clock signal; a data detection circuit, for detecting values of at least three bits of received data in a cycle defined by a period started from a desired position and corresponding to a cycle of the clock signal; and a selecting circuit for selecting from the received data with the detected values the received data with the least change of the value with respect to the received data of values detected immediately before and after substantially in each cycle and outputting the value of the received data.

Receiving apparatus and method of same, recording apparatus and method of same, and data recording system

A method for generating a record information composed of a main information having a plurality of formats and a subsidiary information associated with said main information, is disclosed. A discriminative information for discriminating the formats of the main information is arrayed in a synchronizing part of the subsidiary information, and the encoding operation is controlled as a function of the discriminative information to generate the record information. The discriminative information is transmitted to an encoding system within the extent of the data format to enable encoding in accordance with the formats and under maintenance of operational synchronization.

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Kanagawa, Japan

Tatsushi Sano