Abstract: When a phase shift is to be evaluated, based on a difference between an output from a waveform equalization circuit to equalize an input reproduced signal to a predetermined target equalization characteristic and the target equalization characteristic, the phase shift of the reproduced signal relative to a channel clock, a group delay characteristic with respect to the frequency of the waveform equalization circuit is fixed. Hence, an equalized waveform as an output from the waveform equalization circuit can preserve phase shift information of the inputted reproduced signal to correctly detect the phase shift of the reproduced waveform using the equalized waveform. It is hence possible to realize, with high precision, optimal value learning of various parameters for the recording, reproduction, and servo by use of the phase shift as an index.

Abstract: An optical disk reproducing device for controlling false detection of synchronization signals due to intersymbol interference, and stably improving accuracy of frequency acquisition of a phase locked loop (PLL) even when offset and so on occur. A signal width close to an original mark length is obtained to use for frequency acquisition of the PLL by, for example, using two different slice thresholds and taking a width between a rising of a result of slicing at one threshold and a falling of a result of slicing at the other threshold as a synchronization signal width. When asymmetric properties due to offset, asymmetry, etc. occur, an amount of corrections on the slice threshold is calculated, and it is reflected on a threshold previously set to always obtain a correct synchronization signal width.

Abstract: When executing an replacement process on a multi-layer recording optical disc, alternate recording regions are successively used starting at the nearest spare area from an objective lens regardless of the layer where the replacement process is generated. Alternatively, in the spare area of each layer, a priority spare area is provided for executing an alternation with a higher priority by shifting the radial position from the other layer. Alternatively, arrangement is performed so that the radial position or the alternative recording start radial position of the spare area of each layer is not superposed on the upper or the lower layer spare area.

Abstract: When a phase shift is to be evaluated, based on a difference between an output from a waveform equalization circuit to equalize an input reproduced signal to a predetermined target equalization characteristic and the target equalization characteristic, the phase shift of the reproduced signal relative to a channel clock, a group delay characteristic with respect to the frequency of the waveform equalization circuit is fixed. Hence, an equalized waveform as an output from the waveform equalization circuit can preserve phase shift information of the inputted reproduced signal to correctly detect the phase shift of the reproduced waveform using the equalized waveform. It is hence possible to realize, with high precision, optimal value learning of various parameters for the recording, reproduction, and servo by use of the phase shift as an index.

Abstract: An optical disc apparatus capable of deriving optimum laser beam power even when OPC areas overlap with one another and a method for the apparatus. OPC result is recorded to an optical disc and OPC (area-saving OPC) that reduces an area use quantity by using the OPC result is executed and optimum laser power is determined.

Abstract: The present invention provides a projection display apparatus realizing improved operability at the time of registration adjustment irrespective of a use situation of the apparatus. In the case where misregistration occurs between primary color lights, video signals for three colors are corrected (registration adjustment is performed) so as to reduce the misregistration in accordance with an input adjustment value. An image inverting process is performed on an input video signal so that the image is inverted in a display screen. By a configuration by the user, the image is properly inverted in the display screen. When the image inverting process is performed, an adjustment value, with a sign different from that in the misregistration direction in a coordinate system where the image is not inverted, is input by an operation on the display screen.

Abstract: The present invention provides a projection display apparatus realizing easy recognition of the effect of registration adjustment. The projection display apparatus includes: a light source; a spatial light modulation device modulating, on the basis of a video signal, each of primary color lights for color display emitted from the light source; projecting means for projecting, onto a screen, each of the primary color lights modulated by the spatial light modulation device; and correcting means for correcting, based on a given correction value, the video signal for each of the primary color lights so as to reduce misregistration between the primary color lights projected on the screen, and supplying the corrected video signal to the spatial light modulation device. Validation/invalidation of correction on the video signal by the correcting means is switched in accordance with an operation from the user.

Abstract: It is to provide an optical disc recording apparatus and a recording power control method that are adapted to high-speed recording and can set an optimal erasing power with high accuracy. A test writing signal detector reproduces a test writing signal of a predetermined mark length or space length with varied power, and detects the number of error mark signals and an amplitude value of an envelope. A controller obtains a first threshold Pe0 of the erasing power based on the number of error mark signals in a region where laser power is low, and obtains a second threshold Pe1 of the erasing power based on the amplitude value in a region where the laser power is high. Then, the controller sets an optimal value of the erasing power from an average value of the first and second thresholds.

Abstract: Each layer includes a data recording area and a test writing area divided into a plurality of small areas, wherein the small areas of the test writing area are recorded in advance so that other each layer can make a combination of recorded and unrecorded states with respect to the small area, where OPC is carried out, in a layer where OPC is carried out. Moreover, OPC is carried out to each small area, where a combination of recorded/unrecorded states of other each layer differs from each other, to thereby calculate, as the optimum power, an average value of the result of each OPC or a central value of the dispersion thereof.

Abstract: An optical information recording/reproducing apparatus includes an optical source unit that emits an optical beam toward an optical information recording medium mounted on the apparatus, an optical receiving unit that receives a reflected beam of the optical beam reflected from the optical information recording medium or a transmitted beam of the optical beam transmitted through the optical information recording medium to output an output signal in response to the reflected beam or transmitted beam, and a distinction unit that discriminates whether the optical information recording medium is a hologram disk for recording information by using a holography or a reflection-type optical disk for reproducing information by virtue of the reflected beam, in accordance with the output signal output.

Abstract: The present invention provides a projection display apparatus realizing improved operability at the time of registration adjustment irrespective of a use situation of the apparatus. In the case where misregistration occurs between primary color lights, video signals for three colors are corrected (registration adjustment is performed) so as to reduce the misregistration in accordance with an input adjustment value. An image inverting process is performed on an input video signal so that the image is inverted in a display screen. By a configuration by the user, the image is properly inverted in the display screen. When the image inverting process is performed, an adjustment value, with a sign different from that in the misregistration direction in a coordinate system where the image is not inverted, is input by an operation on the display screen.

Abstract: Amplitude and frequency of a high-frequency signal superposed on a reproduction laser beam are changed in accordance with a reproduction spot diameter on the surface of the recording layer upon discrimination of an optical disk in initial adjustment after insertion of the optical disk and change of a layer of a multi-layer optical disk. Further, the high-frequency signal is not superposed on the reproduction laser beam until end of the discrimination and change to a target layer upon discrimination of the optical disk and change of a layer of a multi-layer optical disk.

Abstract: A multilayered optical disk an information recording method and information reproducing method utilizing the disk includes three or more recordable or rewritable information recording layers, which has, among the plurality of information recording layers, at least a first recording layer and a second recording layer located on a side nearer to a light incident surface than the first recording layer, and which respectively has a first test area configured by a plurality of segments in the first recording layer, a second test area configured by a plurality of segments in the second recording layer, and comprising a specific area in which there is recorded information used to determine whether or not the respective segments in the first test area can be used.

Abstract: There are provided an optical disc device and its recording/reproducing method for managing the management information about plural optical discs efficiently. In the present invention, the management information about the plural optical discs is stored in a memory. Moreover, the management information about part or all of the optical discs stored in the memory is recorded in the optical disc.

Abstract: A need to effectively record data of various sizes on a large-capacity holographic memory capable of high-speed recording is achieved, for example, by curing a first part of the holographic recording which is able to be multiplex-recorded in one or more units of a predetermined volume, and by not recording/curing a second part which is not able to be multiplex-recorded in a predetermined volume at a timing when the first recording part is cured. Also the above need can be achieved by, another example, by adding dummy data to the second part. Alternatively, the second part can be recorded on another track, in which it is possible to record in different units, e.g. by bit recording in a track that utilizes a DVD recording format. According to the present examples, we can record data of various sizes on the holographic memory effectively while performing large-capacity and high-speed holographic recording.

Abstract: A recording and reproducing method has a recording pulse generating step of generating a recording pulse to set timing of a beam emitted from a laser according to data to be recorded on an information recording medium; a laser power control step of controlling a laser drive current according to a recording laser power; a beam detecting step of detecting a power of the beam emitted from the laser; a signal detecting step of detecting a signal level of a reproduction signal read out from the information recording medium; a step of binarizing the reproduction signal to generate a binarized signal; a step of generating a data signal synchronized with a reference clock signal with use of the binarized signal; and a step of detecting a shift in time interval between the binarized signal and the reference clock signal and feeding the shift back to the recording pulse.

Abstract: Test writing is executed while skipping areas where deviations are present on an optical disk to thereby improve accuracy and reliability of an optimum recording condition to be derived. A deviation detecting unit detects the deviations of a guide groove on the optical disk on the basis of a fluctuation amount of a focus error signal or a tracking error signal, and registers information of the detected deviations onto a memory. A test writing processing unit refers to the memory, and records and reproduces a test signal while skipping the areas where the deviations are detected.

Abstract: The present invention is to realize a proper inner zone layout in an optical disk having at least three layers. A test area is provided in the inner zone (inner circumference side area) in each of recording layers. The test areas of each layer are so disposed as to be prevented from overlapping with each other in the layer direction. Furthermore, the number of management information recording/reproduction areas overlapping with the test area in the layer direction at a position closer to the laser-incident surface than this test area is set equal to or smaller than one in each test area of each recording layer. The management information recording/reproduction areas are each so disposed as to be prevented from overlapping with the test areas in the respective recording layers in the layer direction on the disk substrate side of the test areas.

Abstract: An optical disc apparatus capable of deriving optimum laser beam power even when OPC areas overlap with one another and a method for the apparatus. OPC result is recorded to an optical disc and OPC (area-saving OPC) that reduces an area use quantity by using the OPC result is executed and optimum laser power is determined.

Abstract: In an optical disk apparatus, by obtaining the temperature in the vicinity of a laser in the apparatus, the power source voltage of the laser driver is controlled such that power consumed by the headroom of the laser driver is reduced to the maximum extent without deteriorating the current drive characteristic of the headroom when the temperature becomes higher. The laser driving current of the laser driver is monitored to control the power source of the laser driver such that the power consumed by the headroom is possibly reduced while maintaining the current drive characteristic of the headroom for the monitored current.