Abstract: An optical disc apparatus for recording test data on a predetermined area of an optical disc under varied recording powers to determine an optimum recording power based on the quality of a signal obtained by reproducing the recorded test data. The test data is recorded under adverse recording conditions so as to evaluate the amount of change in quality of the reproduction signal. In order to create adverse recording conditions, the optical disc is tilted or the laser is defocused. A recording power for which the change in signal quality due to the deteriorated recording conditions is sufficiently small is determined as an optimum recording power capable of providing adequate recording margin.

Abstract: An optical disk recording apparatus capable of recording data in an optical disk using an optimized recording power is provided. Data formed beforehand in an embossed part of the optical disk are reproduced with a predetermined reproducing power, using an optical pick up unit, and an evaluation index is determined by an evaluation index determining part of a control unit from an envelope of the signal which is produced with the reproducing power. Test data are recorded in a test area of the optical disk by varying the recording power and the test data thus recorded are reproduced with the reproducing power to determine the evaluation index. A control unit sets the evaluation index obtained from the embossed part as a target evaluation index. Desired data are recorded with the recording power corresponding to the target evaluation index.

Abstract: A recording apparatus for an erasable optical disk, which includes: a first part which measures a modulation degree of a signal reproduced from an area of the optical disk at a time of overwriting first data recorded in the area with second data; a second part which determines a first write power level corresponding to the modulation degree measured by said first part based on a relation between write power levels and modulation degrees of signals reproduced from a test recording area of the optical disk, the signals being recorded therein with the corresponding write power levels different from one another; a third part which obtains a target modulation degree corresponding to a type of and a recording rate for the optical disk from one of tables prestoring modulation degrees corresponding to optical disk types and recording rates; and a fourth part which obtains a write power level for overwriting from the first write power level based on a comparison between the target modulation degree and the modulation

Abstract: An optical disk drive for optimizing laser power to be used at the time of recording operation. In a DVD-R drive and a DVD-RW drive, a controller performs OPC to set recording power and records RMD serving as recording management data in an RMA serving as a recording management area. The RMD are verified. When the RMD can be read, the number of PI errors in the RMD is detected. If the number of PI errors is equal to or less than an allowable value, data are recorded in a data area at that recording power. If the number of PI errors exceeds the allowable value, OPC is again performed, to thereby reset the recording power.

Abstract: In an optical disk device in which the focus offset for writing of data can be optimized, a mark is written onto an optical disk at a predetermined focus offset and a change in the signal quality is detected by replaying the mark at various focus offsets. The predetermined focus offset is adjusted based on the change in the signal quality so that the focus offset is set at an optimal value. When an error rate is employed to represent the change in the signal quality, a range of focus offset in which the error rate does not exceed a predetermined value is found. By adjusting the predetermined focus offset for the reference optical disk based on the detected range of focus offset, an optimal focus offset is set.

Abstract: An optical disk apparatus for recording data on an optical disk. Prior to recording data on the optical disk, a controller records test data in a test area of the optical disk, thereby optimizing write power. After having recorded the test data, the controller computes a difference between jitter or an error rate obtained when test data are overwritten at write power higher than that used for recording test data and jitter or an error rate obtained when test data are overwritten at write power lower than that used for recording the test data. A jitter or error rate difference is detected while write power is changed. Write power at which the jitter or error rate difference is smaller than or equal to a predetermined threshold value is selected as optimum write power, and data are recorded in a data area.

Abstract: An optical disk apparatus which can record data by means of transition between an amorphous state and a crystalline state and enables overwriting of data. Test data are recorded into a test area of an optical disk by radiating a laser beam of recording power. The recorded test data are erased by radiating a laser beam of erasing power to the test area of the optical disk while a rotational speed of the optical disk is varied. An erasure performance for erasing the test data is computed at each rotational speed, and the erasure performance is compared with the predetermined threshold value. The higher the rotational speed, the lower the erasure performance. From among the rotational speeds at which superior erasure performance is achieved, the maximum rotational speed is selected. Data are written over the data area of the optical disk at the thus-selected maximum rotational speed.

Abstract: A recording apparatus for an erasable optical disk includes: a first determination part which determines a maximum of modulation degrees of signals reproduced from a test recording area of the optical disk, the signals being recorded in the test recording area with corresponding write power levels different from one another; and a second determination part which determines an optimum write power level corresponding to a target modulation degree obtained from the maximum of the modulation degrees based on a relation between the modulation degrees and the write power levels, wherein the recording apparatus records data on the optical disk with the optimum write power level.

Abstract: An optical disk device which reproduces address information embossed and formed on an optical disk. Return light of laser light is detected by a photodetector which is split into at least two components along the radial direction and signals representing the return light are output. Address information is reproduced by selectively switching between a summation signal and a difference signal between two signals. When there is a focus deviation, the summation signal of two signals is used to reproduce the address information and when the optical disk is tilted, the difference signal of two signals is used to reproduce the address information.

Abstract: An optical disc apparatus in which the inclination of an optical axis of laser light relative to an optical disc is adjusted. When data is recorded, laser light is irradiated at recording power in mark periods and irradiated at reproducing power or erasing power in space periods. Immediately after the beginning of the mark periods, no pits are ye formed even though recording power is applied and the amount of reflected light has a level corresponding to the inclination of the optical axis of laser light relative to the optical disc without influence exerted by the pits. Also in the space period, the amount of reflected light has a level corresponding to the inclination of the optical axis of laser light relative to the optical disc. By sampling the reflected light signal at the instant following to the beginning of the mark period or space periods, the inclination is adjusted so as to maximize the sampled signal level.

Abstract: An optical disk apparatus for recording and reproducing data using a grove and a land of an optical disk. For data recording and reproducing using a groove, a groove focus position is used. For data recording and reproducing using a land, a land focus position is used. When shifting from a groove to a land or vice versa, a boost amount of an equalizer or power of a laser beam is temporarily increased for compensation of delay in response of a focus actuator.

Abstract: An optical disk device in which the laser light power for writing data onto an optical disk is optimized. Test data is written onto an optical disk while laser light power is varied and the laser light power is optimized based on the quality of replayed signals of the test data. The space value of the replayed signal of the test data is detected and, when the space value is a value which should not exist, it is judged that 3T mark period is missing or excessively written and the laser light power in which such a space value is obtained is removed from the candidates for the optimum laser light power. Also, jitter and error rate of the replayed signal are detected. Even when the jitter is at a desirable value, if the error rate is greater than or equal to a predetermined value, the laser light power in which such an error rate is obtained is removed from consideration as a possible optimum laser light power.

Abstract: The present invention provides a data-recordable optical disk device. Test data is recorded in a predetermined area of an optical disk while varying recording power level, and an optimum recording power level is selected based on reproduced signal quality of the test data. When the optimum recording power level does not exceed an allowable recording power level of the laser diode, data is recorded at that optimum recording power level. When the optimum recording power level exceeds the allowable recording power level of the laser diode, the recording strategy is changed to a low-power strategy. A low-power strategy is, for example, a strategy having an increased recording pulse width compared to that of a standard strategy. An optimum recording power level is selected for the low-power strategy, and data is subsequently recorded.

Abstract: An optical disc apparatus for recording test data on a predetermined area of an optical disc under varied recording powers to determine an optimum recording power based on the quality of a signal obtained by reproducing the recorded test data. The test data is recorded under adverse recording conditions so as to evaluate the amount of change in quality of the reproduction signal. In order to create adverse recording conditions, the optical disc is tilted or the laser is defocused. A recording power for which the change in signal quality due to the deteriorated recording conditions is sufficiently small is determined as an optimum recording power capable of providing adequate recording margin.

Abstract: An optical disk device for driving an optical disk having an emboss section and a data section comprises an optical pickup for replaying address information by irradiating a laser beam onto the emboss section of an optical disk and writing data by irradiating the laser beam onto the data section of the optical disk, and a control unit for controlling the focus position when address information is replayed at the emboss section and the focus position when data are written onto the data section to a common focus position. By using the common focus position as the focus position when the emboss section is replayed and as the focus position when the data are written to the data section, it is possible to eliminate any need for rapidly switching the focus position at the boundary between the emboss section and the data section.

Abstract: In an optical disk device in which the focus offset for writing of data can be optimized, a mark is written onto an optical disk at a predetermined focus offset and a change in the signal quality is detected by replaying the mark at various focus offsets. The predetermined focus offset is adjusted based on the change in the signal quality so that the focus offset is set at an optimal value. When an error rate is employed to represent the change in the signal quality, a range of focus offset in which the error rate does not exceed a predetermined value is found. By adjusting the predetermined focus offset for the reference optical disk based on the detected range of focus offset, an optimal focus offset is set.

Abstract: An original reference value table containing converted values of image data on the entire color space is made based on known look-up tables of a printer and a correction printer, and a reference value table is wholly or partly corrected adequately so that the results of printing performed by the correction printer by referring to the original reference value table may be similar to the results of printing performed by the printer while the mutual non-linearity of converted values held in the reference value table is maintained, thus making a reference value table with an improved precision of color reproduction.

Abstract: In a method for improving the color reproducibility of printed matter to be produced by a printing press in proof print produced by a proof press, a look-up table containing converted values of image data over the entire color space with respect to the proof press is created, the look-up table is corrected based on the color of a printing paper for the printing press and a paper exposed area factor in the proofing, and proof print is created by the use of the corrected look-up table.

Abstract: A recording apparatus for an erasable optical disk includes: a first determination part which determines a maximum of modulation degrees of signals reproduced from a test recording area of the optical disk, the signals being recorded in the test recording area with corresponding write power levels different from one another; and a second determination part which determines an optimum write power level corresponding to a target modulation degree obtained from the maximum of the modulation degrees based on a relation between the modulation degrees and the write power levels, wherein the recording apparatus records data on the optical disk with the optimum write power level.

Abstract: A recording apparatus for an erasable optical disk, which includes: a first part which measures a modulation degree of a signal reproduced from an area of the optical disk at a time of overwriting first data recorded in the area with second data; a second part which determines a first write power level corresponding to the modulation degree measured by said first part based on a relation between write power levels and modulation degrees of signals reproduced from a test recording area of the optical disk, the signals being recorded therein with the corresponding write power levels different from one another; a third part which obtains a target modulation degree corresponding to a type of and a recording rate for the optical disk from one of tables prestoring modulation degrees corresponding to optical disk types and recording rates; and a fourth part which obtains a write power level for overwriting from the first write power level based on a comparison between the target modulation degree and the modulation