Taiyo Yuden Co., Ltd.

Fuyuki Miyazawa

Hiroya Kakimoto

Katsuhiro Oyama

Mitsuo Sekiguchi

Isao Matsuda

Yasuhito Hagiwara

Takaki Hamamoto

Yoshikazu Sato

Tetsuharu Kubo

Takuo Kodaira

Wakaaki Murai

Shinichi Kojo

Daizo Yokoyama

Kazunobu Takeguchi

Akihisa Endo

Hiraya Kakimoto

In one aspect, a load cell includes an elastic body, first optical unit, second optical unit, detector, and computation unit. The first optical unit has a light source, a first diffraction grating on which light from the light source is incident, and a light-receiving unit. The first optical unit is fixed to a first end portion of the elastic body and arranged within a hollow portion of the elastic body. The second optical unit has a second diffraction grating on which diffracted light from the first diffraction grating is incident to generate interference light. The second optical unit is fixed to a second end portion of the elastic body and arranged within the hollow portion. The detector detects the interference light. The computation unit computes a relative displacement amount of the second diffraction grating relative to the first diffraction grating on the basis of a signal obtained by the detector.

Load cell having a computation unit which computes displacement amount of the diffraction grating

A displacement measurement device includes: a light source; a first diffraction grating and a second diffraction grating arranged along a path of light from the light source and movable relative to one another, the first and second diffraction gratings generating diffracted light; an optical sensor that detects interference light produced by interference between &#x2212;nth order diffracted light generated as a result of the second diffraction grating diffracting +nth order diffracted light from the first diffraction grating and +nth order diffracted light generated as a result of the second diffraction grating diffracting &#x2212;nth order diffracted light from the first diffraction grating, where n is a natural number greater than or equal to 1; and a calculation unit calculating, according to a signal from the optical sensor, a relative displacement between the first and second diffraction gratings in a direction orthogonal to an optical axis of the first and second diffraction gratings.

Displacement measurement device and displacement measurement method

An optical unit includes: a first diffraction grating where light from a light source enters; a second diffraction grating that generates interference light as a result of diffracted light rays emitted from the first diffraction grating entering the second diffraction grating; and an optical member including a pair of reflective surfaces that are parallel and opposite to each other, the optical member being configured such that the pair of reflective surfaces respectively reflect &#xb1;mth-order diffracted light rays that are diffracted light rays of a specific order among a plurality of orders of the diffracted light rays emitted from the first diffraction grating so as to guide the &#xb1;mth-order diffracted light rays to the second diffraction grating, where m is a natural number.

Optical unit and displacement measuring device

An optical recording medium is provided having a recording layer that absorbs light with a wavelength of 350 nm to 500 nm, the optical recording medium having good recording playback properties even when the ambient temperature changes, and allowing playback distortion to be controlled even when stored in a high temperature environment. A write-once type optical recording medium including: a substrate; a reflective layer that reflects light with a wavelength of 350 nm to 500 nm on the substrate; a recording layer that absorbs light with a wavelength of 350 nm to 500 nm; and a light transmission layer with a single-layer construction that transmits light with a wavelength of 350 nm to 500 nm, the light transmission layer having a modulus of elasticity at 75&#xb0; C. that ranges from 50 MPa to less than 170 MPa.

Optical recording medium

An object of the present invention is to provide a recordable optical recording medium whose characteristics do not deteriorate when recording is conducted in a high-temperature environment. The present invention provides a recordable optical recording medium comprising a substrate as well as at least a reflection layer, recording layer, and light transmission layer provided on the substrate, wherein the recording layer of said optical recording medium contains (a) an azo metal complex dye and (b) another dye whose decomposition temperature is 240&#xb0; C. to 360&#xb0; C.

There is proposed an optical disk recording method that can prevent degradation of recording quality due to occurrence of thermal interference, and an optical disk recording reproduction device used in this recording method. The recording method has a step of executing a test record on an output proofing area of the optical diskwhile a spot diameter of the recording laser beam is varied, and deriving the relationship between the spot diameter and a characteristic value representing recording quality, a step of deriving a permissible range of a variation amount of the spot diameter on the basis of the derived relationship between the spot diameter and the characteristic value representing the recording quality; a step of irradiating a record region of the optical disk with the recording laser beam to detect spherical aberration while executing recording; and a step of executing aberration correction, in case the spherical aberration occurs, such that a variation amount of the spot diameter falls into the derived permissible range.

Recording method for optical disk and optical disk recording reproduction device

To ensure a favorable recording characteristic for a write-once recording medium for a bluish-purple laser, an optical information recording apparatus includes ways to write power to form recording marks, a space forming power to form spaces, a pulse width of a cooling pulse and ways to record information onto the optical information recording medium according to the setting of the write power, the setting of the space forming power and the setting of the pulse width of the cooling pulse. At this time, the pulse width of the cooling pulse and a ratio whose numerator is the write power and whose denominator is the space forming power have a preferable region of the recording characteristic, and information is recorded onto the optical recording medium by using values in this range.

Optical information recording apparatus and method

In order to ensure a favorable recording characteristic for a write-once recording medium whose recording layer is made of an organic dye having an absorption spectrum at a wavelength &#x3bb;=405 nm, this optical information recording apparatus includes a unit to set a write power to form recording marks, a space forming power to form spaces and a pulse width of a cooling pulse, and a unit to record information onto the recording medium according to the setting. The pulse width of the cooling pulse and a ratio of the space recording power to the write power are determined from a favorable region in a plane whose one coordinate axis represents the ratio and whose other coordinate axis represents the pulse width of the cooling pulse.

An optical disc recording method includes: determining that an optical disc to be recorded is an optical disc including a recording layer comprising organic dye; and controlling a laser such that space formation power Ps necessary for space formation is equal to or smaller than bias power Pbw. In a case wherein the relation of Ps&#x3c;Pbw is satisfied, the relation between the asymmetry value, &#x3b2; value, and main power Pw includes substantial linearity. Accordingly, control of the main power Pw can be performed with the asymmetry value and &#x3b2; value as evaluation indexes, and accordingly, disturbance or the like can be readily handled.

Optical disc recording method, optical disc recording/playback device, and optical disc

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

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 the present invention to improve a margin to meet good recording quality by conducting a realtime correction of a recording condition of a medium with different recording characteristics for inner and outer circumferences. To accomplish the object, control factors for power and a pulse width are independently detected and corrected using an mT pulse having a length of m'T as a pulse for power control and an nT pulse having a length of n&#x2032;T as a pulse for pulse width control; more specifically, power correction for mT pulse and pulse width correction for nT pulse are conducted in realtime, wherein a recording pulse stream including the mT pulse and nT pulse is irradiated onto a medium by a recording laser beam as well as pits and spaces formed by irradiation of the recording pulse stream are reproduced by a reproducing laser beam to detect the effects of power and pulse width variations independently.

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

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.

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Gunma, Japan

Fuyuki Miyazawa