Abstract: The invention relates to the reading of digital optical recordings at very high density (CD, DVD, etc.). Reading is done by a PRML (“Partial Response Maximum Likelihood”) technique which uses a model of analog response to the recording of an isolated information bit. Customarily, the response model is represented by four or five signal samples having standardized levels 1 or 2. To take account of particular phenomena of super-resolution reading, the invention proposes the use of a model having 6 to 10 samples that can take 4 or 5 standardized levels. This model can result from the superposition of two simpler models having only two possible levels of samples taken from 1, 2 and 3.

Abstract: An optical recording medium and a method of recording and reproducing of the optical recording medium are provided, which are capable of recording and reproducing data with reliability even when blue or blue violet laser light is used as irradiation light. The optical recording medium has a recording layer in which a recording mark composed of a plurality of cavities is formed by irradiation of the laser light. The recording layer is configured so that, in a plan view taken in a direction of irradiation of the laser light, cavities lying in an area of the center and its vicinities of the recording mark, out of the plurality of cavities, include cavities greater than ones lying around the area.

Abstract: An optical controller includes a light source for emitting light, an object lens for condensing light emitted from the light source, a light detection unit for receiving light reflected on an optical information recording medium and outputting a signal corresponding to the amount of the light, and a laser control unit for controlling the amount of the light emitted from the light source to the information recording surface on which information is to be recorded or reproduced, based on the recording state of an information recording surface disposed closer to the object lens than an information recording surface on which the information is to be recorded or reproduced.

Abstract: A reproduction data recording method for an optical storage medium. The method comprises storing additional data to a first temporary region of a memory device; reading the first recorded data from the optical storage medium and storing the first recorded data to the first temporary region; reading a data segment of the second recorded data from the optical storage medium and storing the data segment to a second temporary region of the memory device; reading the first recorded data from the first temporary region and the data segment from the second temporary region, and decoding the first recorded data and the data segment to confirm accuracy of the first recorded data; reading the first recorded data and the additional data from the first temporary region, and encoding the first recorded data and the additional data to generate encoded data; and writing the encoded data to the optical storage medium.

Abstract: An optical pickup device includes a diffraction grating 12 for separating an emitted light beam into at least three light beams. The diffraction grating 12 is divided into three regions by dividing lines D1 and D2 extending in a first direction parallel to a tangent line of a track of an optical information recording medium. A second region 12B is divided into four sub-blocks by a dividing line D3 extending in the first direction and a dividing line D4 extending in a second direction that crosses the first direction. The sub-blocks located diagonally opposite to each other have a same phase, and the sub-blocks located adjacent to each other have a phase difference of approximately 180 degrees. The first region 12A has a phase difference of approximately 90 degrees from each sub-block of the second region 12B, and the first region 12A has a phase difference of approximately 180 degrees from the third region 12C.

Abstract: An attenuation-amount adjusting circuit includes: a light irradiating unit that alternately irradiates a laser beam of a writing level and a laser beam of a readout level on an optical disk that has a groove formed by a wobble pattern and plural markers indicating physical positions in the groove; a light receiving unit that receives reflected light of the laser beam irradiated on the optical disk and converts the reflected light into a reproduction signal; and a writing-waveform attenuating unit that attenuates an amplitude level of a writing waveform corresponding to the reflected light of the laser beam of the writing level in the reproduction signal according to a position from a rising edge of the writing waveform.

Abstract: An optical data carrier includes at least one session in which one or more tracks are stored, wherein each session includes a plurality of data frames, and wherein each data frame includes controlling data and content data coded in a first format. In place of at least part of at least one bit sequence which would be included within said content data and which would correspond to constant data with respect to a second format into which said content data would be converted during a reading process, if said one or more tracks had been transferred onto said optical data carrier in accordance with a predetermined CD standard, the at least part of the at least one bit sequence is represented by a bit sequence which does not correspond to constant data with respect to said second format.

Abstract: An information recording apparatus for recording data on an information recording medium includes a logical-format-image manager configured to generate logical-format-image data; a logical-format-image storage unit configured to store the logical-format-image data generated by the logical-format-image manager; and a recording controller configured to exercise control so that the logical-format-image data stored in the logical-format-image storage unit is recorded on an information recording medium during periods of suspension of recording of user data on the information recording medium, the periods of suspension being provided intermittently on the basis of an amount of user data stored in a buffer for storing user data.

Abstract: An optical recording medium is provided with at least a substrate, light absorbing and heat generating parts each of which absorbs light and generates heat, and recording parts, and each of the recording parts are formed between two recording tracks.

Abstract: An optical disc signal processing apparatus comprising: a binarizing circuit configured to compare a level of an RF (Radio Frequency) signal obtained by photoelectrically converting a reflected light of a laser beam applied to an optical disc and a level of a DC signal, to output a binarized signal for reproducing information recorded on the optical disc, a level of the DC signal being adjusted to a level at which jitter included in the binarized signal is minimized.

Abstract: Embodiments of methods and systems for controlling access to information stored on memory or data storage devices are disclosed. In various embodiments, fluid-mediated modification of information or access to information is utilized. According to various embodiments, data storage devices designed for rotating access are described which include rotation-activated fluid control mechanisms.

Abstract: An optically-readable disk includes a device that disrupts readability of the disk when the disk is spun at an angular velocity substantially greater than required to play the disk in its intended playing device, or for when a defined integral of velocity and time is exceeded. The device may include a fluid container that disperses a data-disruptive fluid. The device may include a membrane or layer that is disrupted when the disk is rotated above a defined angular velocity, or when a defined integral of velocity and time is exceeded.

Abstract: A tracking error signal is generated with stability without being easily affected by a distribution fluctuation of light reflected from an optical disc or by a lens shift. An optical disc drive according to the present invention includes: an objective lens 5 with an aperture radius r0 for converging a light beam emitted from a light source 1; a polarizing hologram substrate 2 for dividing the beam reflected from the optical disc 6 into branched light beams; a photodetector substrate 6, on which at least some of the light beams are incident to generate signals representing the intensities of the light beams; and a shielding mask 16 for cutting off the beam partially.

Abstract: The invention discloses radio frequency zero crossing signal generators for optical disc drives, comprising a controllable low pass filter, a comparator, and a control circuit. The controllable low pass filter evaluates an average level of the magnitude of a radio frequency ripple from an optical disc drive. The comparator compares the radio frequency ripple to the average level evaluated by the controllable low pass filter to generate a radio frequency zero crossing signal. When the optical disc drive reads a fingerprint defect on an optical disc, the control circuit adjusts a cut-off frequency of the controllable low pass filter to adjust the speed at which the controllable low pass filter evaluates the average level.

Abstract: A two-dimensional digital data acquisition element includes: a pixel area having a plurality of pixels arranged in a matrix form, each of the pixels having a photoelectric conversion element to convert the reproduced light from the optical information recording medium to an electric signal; selection circuits which select the pixel; a readout circuit which reads out an electric signal of a pixel selected by the selection circuits; and a 1-bit AD converter which converts an output of the readout circuit to 1-bit digital data. A pitch ratio N between a pitch P1 of the unit data areas in the two-dimensional digital image information and a pitch P2 of the pixels in the pixel area defined as N=P1/P2 satisfies a relation A·n2/(An+1)<N<A·n2/(An?1) where A is the number of digital data in one-dimensional direction of one byte of the two-dimensional digital data and n is a natural number of at least 2.

Abstract: A driver circuit for use with a variety of OPU circuits has both a single-ended input and a differential input. The single-ended input is coupled to a single-ended signal path having a variable gain stage and a variable level shifter. The differential input is coupled to a differential signal path having a variable gain stage and a variable level shifter. The single-ended signal path and the differential signal path may be selectively coupled to an output. The respective variable gain stages and variable level shifters can be adjusted so that an output signal at the output has a desired dynamic range.

Abstract: A holographic storage and regeneration system includes a holographic recording medium, a light source, a spatial light modulator, and a conjugate servo light guidance portion. The light source generates a signal light and a reference light. The spatial light modulator modulates the incident signal light and makes it incident onto the medium along the incident direction of the signal light. The guidance portion guides a reference light to incident onto the medium in one direction and reflects it in another direction. A reference light and a signal light interfere with each other to produce a holographic interference fringe. The reflected reference light is guided into a first image sensor to be used to analyze the incident angle of the reference light. When the reference light incidents onto the fringe of the medium through the guidance portion in a reverse direction relative to another direction, a conjugate regenerated light is generated.

Abstract: A recording method for recording information into an information recording medium having a plurality of recording layers includes a step of recording information, for specifying a non-recording layer where user data are not recorded, onto at least one of the recording layers.

Abstract: There is provided an optical information recording/reproducing apparatus capable of obtaining a high super-resolution effect using an optical information recording medium in which a super-resolution thin film is formed. An optical information recording medium 1 having a super-resolution layer is irradiated with a laser light in a light emission pattern such that a bias light emission portion that does not cause the super-resolution layer to be in the state of super-resolution and a pulse light emission portion that causes the super-resolution layer to be in the state of super-resolution alternatively appear, and reflected light is detected. A reproduction signal based on the pulse light emission portion and a reproduction signal based on the bias light emission portion are acquired.

Abstract: The invention relates to a method for setting an optimum value of a write parameter for use in an optical recording apparatus for writing information on an optical recording medium by means of a radiation beam. The optimum value of a write parameter is found by curve-fitting a function and obtaining a characteristic write power level (PChar) from the curve-fitting function. It is then assessed if the characteristic write power level (PChar) qualify as an optimum value of a write parameter. If the characteristic write power level (Pchar) does not qualify as an optimum value of a write parameter then an iteration procedure is started, where the subsequent initial values of write power level (Pini, n), are given by Pini, n+1=A Pini, n+(1?A)Pchar, n, where A is a constant, and n is an integer. The invention also relates to an optical recording apparatus and an optical recording medium according to the invention.