Hitachi, Ltd.

Hitachi Video Engineering, Incorporated

Other

Hitachi-lg Data Storage, Inc.

Hitachi-lg Storage, Inc.

Takehiko Sekine

Atsushi Saito

Toshimitsu Kaku

Takuya Mizokami

Naozane Yoshida

Hisataka Sugiyama

Hiroshi Hirayama

Tetsuya Fushimi

Akihiro Asada

Takashi Hoshino

Toru Kawashima

Takahiro Sunada

Yosiho Suzuki

Yutaka Nagai

The disk recording apparatus and method are arranged to specify a recording address and a recording position on an optical disk with a wobble PM (phase modulation) format through the use of a wobble reproduced signal and a track reproduced signal. The recording apparatus operates to detect address information and a synchronous signal on the optical disk that correspond with the wobble reproduced signal and the track reproduced signal sent from the optical disk respectively. Then, the address information required for specifying a disk recording track and the synchronizing timing required for specifying a linking position are selected from the detected states.

Disk recording apparatus and disk recording method

For protecting the recording from shifting in the position, by conducting sync detection, correctly, from land pre pits, in an optical type recording disc, even if sync pattern errors, in more detail, synchronization is conducted on a recording circuit, with certainty, even if an even sync pattern erroneously changes into an odd sync pattern. When the even sync pattern is detected from an odd sync pattern detection window, a sync lock flag is turned into a condition of unlock. When the sync lock flag continues a lock condition for 16 sectors, the synchronization is carried out on a detection cycle counter and a recording cycle counter.

Optical disk recording apparatus and optical disk recording method

A laser waveform generation function is provided in a laser driving waveform generatornear a laser. A recording clock generatoris included in the laser driving waveform generatorto generate a clock with a frequency higher than that of a synchronizing clock. This allows a recording laser current (waveform) to be generated without transmission of a high frequency signal from the modulatorFurther, because the synchronizing clockis stopped upon a reproduction operation including reproduction operation in an ID unit, undesired effects on a reproduction operation such as ID reproduction can be reduced. Because the response speed of the recording clock generatorcan be changed, a high precision clock can be generated. Thus, a high-precision recording laser current (waveform) can be generated.

Information recording and reproducing apparatus for updating the waveform of a laser based on position information

A laser waveform generation function is provided in a laser driving waveform generator near a laser A recording clock generator is included in the laser driving waveform generator to generate a clock with a frequency higher than that of a synchronizing clock This allows a recording laser current (waveform) to be generated without transmission of a high frequency signal from the modulator Further, because the synchronizing clock is stopped upon a reproduction operation including reproduction operation in an ID unit, undesired effects on a reproduction operation such as ID reproduction can be reduced. Because the response speed of the recording clock generator can be changed, a high precision clock can be generated. Thus, a high-precision recording laser current (waveform) can be generated.

Information recording and reproducing apparatus having semiconductor laser drive circuitry in its pickup

A beam is irradiated to an information recording medium having land tracks and groove tracks alternately formed on a track formed in turn on an information recording surface thereof and pre-pits so pre-formatted as to deviate from the center of the track, a return beam of the irradiated beam is received by detectors split into two parts in a track direction to obtain a differential signal, the pre-pit is detected from this differential signal and control of recording and reproducing processings is executed by using the pre-pit detection signal so obtained as the reference.

Method for recording and reproducing information by pre-pits detection

Method and apparatus for recording/reproducing by pre-pits detection

If information is to be recorded on and reproduced from a recording medium in correspondence between a code train in the form of a run-length-limited code and the positions of the leading edge and the trailing edge data of a status transition pattern such as pits, recording domains, a sync signal is inserted at regular intervals in the information converted in the form of the run-length-limited code. The sync signal is constituted by a code train capable of deciding that the sync signal includes a code not existing in the conversion rule into a run-length-limited code during reproduction using a leading edge data or trailing edge data relative to the transition pattern.

Data recording/reproducing device

Information recording/reproducing device and method in which a

Information recording/reproducing device and method for

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Yokohama, Japan

Takehiko Sekine