Taiyo Yuden Co., Ltd.

Mitsuo Sekiguchi

Hiroya Kakimoto

Fuyuki Miyazawa

Isao Matsuda

Katsuhiro Oyama

Ryuichi Sunagawa

Atsuo Shimizu

Yoshikazu Takagishi

Keiichi Ida

Masashi Yamada

Yoshikazu Sato

Tetsuharu Kubo

Hiroya 16-20 Ueno 6-Chome Kakimoto

Hiraya Kakimoto

A recording condition approximate to the optimal is obtainable for a media even if unknown to the drive. A technique is provided that is effective for improving the signal quality, particularly, at a Wobble and Lpp. By regulating an intermediate pulse condition PWD, Tmp of a recording pulse configured with a top pulse, an intermediate pulse and a last pulse, the pit width W in a saturation code is controlled. The pit length and phase in the saturation code is controlled based on a front phase correction amount Ttop and rear phase correction amount Tlast.

Optical-information recording apparatus and method and signal processing circuit

Novel evaluation indexes are introduced to allow both a total evaluation of data recording and an evaluation of individual detection patterns. A data recording evaluation method includes a step of reproducing a result of data recording performed on an optical disk and identifying a predetermined detection pattern in a reproduction signal, a step of detecting a signal state of the reproduction signal associated with the predetermined detection pattern, and a first calculation step for calculating a first evaluation index value based on the detected signal state and a reference state identified from the predetermined detection pattern. When there is a plurality of predetermined detection patterns as described above, a second calculation step is further provided for calculating a second recording state evaluation index value using the first evaluation index value calculated from each of the predetermined detection patterns. Data recording can be properly evaluated using the first and second recording state evaluation index values.

Data recording evaluation method and optical disk recording and reproduction device

It is an object of the present invention to provide a recording condition closer to an optimum even for a medium unknown to a drive, and more particularly to provide a method especially effective when applied to code identification methods, such as PRML, wherein codes are identified based on amplitude information of an RF signal. In order to accomplish the object, an RF signal received from a photo-receiving partof a pickup is converted into sampling data by an A/D converter, and a Viterbi decoderperforms code determination using the sampling data. Codes included in a reproduction signal are then determined by synchronizing recording pulses with the reproduction signal using the result of the code determination. Then, the result is used to specify a part to be detected in the codes, and finally an amplitude of the specified part is detected.

Optical information recording device, optical information recording method, and signal processing circuit

An optical information recording reproduction device is disclosed, in which aberration detection is stably performed, so that an excellent record grade can be achieved. An RF signal is subjected to differential operation along a time axis of the signal, the RF signal being obtained from reflected light including primary light situated in the periphery of a primary dark ring enclosing zero-order light in a central portion of a beam spot formed on a pit; pulse signal waveforms are represented in an absolute value form, the pulse signal waveforms being generated in correspondence with front and rear ends of the beam spot on the time axis; the pulse signal waveforms represented in the absolute value form are stored into a storage medium; the stored, two pulse signal waveforms are combined to generate a beam profile of the beam spot formed on an optical recording medium; and a beam spot diameter, spherical aberration, and coma aberration of a record laser beam are adjusted based on the beam profile.

Optical information recording reproduction device

A recording condition on a media is optimized by introducing a new evaluation index. An apparatus for optical information recording and reproducing includes: a measurement means for recording codes including a specific code in a medium for optical information recording and reproducing, reproducing the codes from the medium for optical information recording and reproducing, and measuring, from a reproduced signal of the codes, a peak value of amplitude of a reproduced signal related to the specific code, the peak value being a maximum value or a minimum value of the amplitude of the reproduced signal related to the specific code; a statistic calculation means for calculating preset statistic by using a plurality of peak values at the same or different recording places, the plurality of peak value having been obtained by the measurement means; and a condition decision means for deciding at least one of a recording laser power condition and a recording pulse condition by using the statistic. The peak value and the statistic thereof serving as a new evaluation index are effective for evaluation of the apparatus for optical information recording and reproducing or setting of a recording condition in the specification.

Apparatus and method for optical information recording and reproducing

It is an object of certain inventive aspects to provide a recording condition closer to an optimum even for a medium unknown to a drive, and more particularly, to provide means for obtaining a preferable recording condition even for a high-speed recording in which conducting a test recording is difficult. In order to accomplish the object, a power and a phase of a recording pulse are simultaneously corrected at predetermined timing, depending on a recording speed or a recording position such as an inner or outer circumference. For instance, a phase shift &#x394;Phase generated due to a continuing recording from an inner circumference to an outer circumference at &#xd7;2 speed is corrected simultaneously with a correction of a power shift at the timing when a recording speed is changed from &#xd7;2 to &#xd7;4. For the other recording speed, in the same manner as above, a power and a phase shift are simultaneously corrected at every time when a recording speed is changed.

There are provided an optical recording method, an optical recording apparatus, a one-chip CPU device, and a computer program. Reference data corresponding to a recording condition of a first recording layer, a physical characteristic value correlated with the recording condition, and a physical characteristic value correlated with a recording condition of a second recording layer are extracted from a data table in a memory, and the recording condition of the extracted reference data is set as a recording condition of a recording medium as an information recording target. When no correlated reference data exists, the closest reference data are extracted from the data table, and a recording pulse condition suitable for recording information on the second recording layer of an optical disk as the information recording target is extracted on the basis of the correlation between the recording condition of the reference data and the physical characteristic value.

Optical recording method, optical recording apparatus, one-chip CPU device, and computer program

The present invention enables a recording condition closer to an optimum to be obtained even for media unknown to a drive. The present invention provides a method that is especially effective for the case where it is applied to a code identification scheme, such as PRML in which code identification is performed on the basis of information on the amplitude of an RF signal. A condition for a recording pulse comprised of a top pulse, an intermediate pulse and a last pulse is configured in a predetermined order, that is, a reference condition is first determined by a test recording involving an examination of recording quality and changes in conditions for a power and a pulse width, then a condition for the last pulse is determined by a test recording using the reference condition, and subsequently a condition for the intermediate pulse is determined using the reference condition and the last pulse. A phase shift is corrected by a test recording using the recording pulse obtained by configuring the above conditions.

In certain inventive aspects there are provided an optical recording method, an evaluation indicator acquiring method, an optical recording apparatus, and a CPU device, which can save a test time before recording information. An irradiation condition suitable for recording information on a first recording layer is extracted by recording and reproducing test information. The test information is recorded on and reproduced from a second recording layer. The irradiation condition suitable for recording information on the second recording layer is extracted on the basis of the test result for the first recording layer and the test result for the second recording layer. Accordingly, it is possible to save the test time for extracting the irradiation condition of the second recording layer.

Optical recording method, evaluation indicator acquiring method, optical recording apparatus, micro CPU device, and computer program

An optical information recording method in an optical recording generation method for performing recording and reproduction of information by radiating laser light which is pulse-modulated according to a recording waveform having a plurality of setting parameters onto a storage medium is disclosed. The method comprises reading information recorded in the storage medium; determining positions corresponding to a detection pattern from the detection pattern and a reproduction signal, the detection pattern being defined according to a specific parameter from among the plurality of setting parameters, and the reproduction signal being obtained by reading the information; detecting the state of the reproduction signal according to the result of the determination; generating an ideal reproduction signal according to the detection pattern; and obtaining a predetermined signal evaluation index value using the result of detection of the state of the reproduction signal and the ideal reproduction signal.

Optical information recording method and optical information regeneration recorder, and signal processing circuit, and recording reproduction program and information recording medium

An optical information recording reproduction device is disclosed which finds the correlation between the ratio of the minimum pit amplitude to the maximum pit amplitude of an RF signal obtained from the light reflected by the pits recorded on an optical disk in a tracking servo mode and spherical aberration in advance, and stores it. In recoding information on the optical disk, the optical information recording reproduction device calculates the ratio of the minimum pit amplitude to the maximum pit amplitude of the RF signal, and compares the calculation to the stored correlation, and feeds back to an aberration correction optical system and a driving mechanical system to correct the aberration into an aplanatic state.

Several drives individually carry out recording and playback with a reference medium that serves as a reference for quality for various media, obtaining characteristic values. The characteristic values are multiplied by a predetermined coefficient to obtain thresholds, and the thresholds are stored in predetermined storage areas of the respective drives. When information is to be recorded on a medium, recording and playback are carried out with the medium under a plurality of recording conditions involving variation in power or pulse width, thereby obtaining characteristic values. Then, an approximated curve is obtained from the characteristic values. The quality of recording on the medium is tested based on an amount of margin that is determined according to positional relationship between the approximated curve and the threshold.

Optical recording apparatus

In a recording method or apparatus, in order to set an optimal recording condition by a minimal number of times of testing, test recording is carried out while changing power and pulse width of recording pulses in a stepwise manner. Conditions for the test recording are concentrated in a region of a matrix defined by power&#xd7;pulse width.

Recording method, recording apparatus, and signal processing circuit for recording information on optical recording medium

The invention provides a method effective in detecting a reproduction signal in real time correction in which correction is simultaneously performed with recording. In this method, a laser beam emitted from a laser diodeis divided into a plurality of beam spots by a diffraction grating. One of the plurality of beam spots is used as a beam spot for recording, and another beam spot is used as a beam spot for reproduction. Reflected light components obtained from these beam spots are independently detected by a detector. A period for which a recording laser beam is in an ON state is referred to as a gate signal, and a mask is put on an RF signal obtained from a beam spot for reproduction, thereby selectively detecting pits reproduced when the recording laser beam is in the ON state.

Optical information recording device for detecting information during recording and method therefor

An optical information recording medium, recording and reproducing method and device for same, and an optical pickup, which enables high-density recording and high-speed recording. Recording or reproduction is performed to or from the optical information recording medium having a track pitch Tp of 1.0 &#x3bc;m&#x2266;Tp&#x2266;1.2 &#x3bc;m, using laser light having a wavelength &#x3bb; of 770 nm&#x2266;&#x3bb;&#x2266;830 nm, and a spot diameter Sd of 1.1 &#x3bc;m&#x2266;Sd&#x2266;1.3 &#x3bc;m.

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Gunma, Japan

Mitsuo Sekiguchi