Abstract: A first trial write process obtains an optimum recording power of a test pattern even with respect to data having different rules for the recording waveforms corresponding n type data length sets, and a second trial write process using this optimum recording power obtains optimum pulse width or optimum pulse edge position separately for each data length set. Based on the optimum recording power and optimum recording waveform obtained by these trial write processes, recording operation is performed so as to form all the data lengths with satisfactory accuracy, thereby making it possible to obtain a proper reproduced signal.

Abstract: A light source drive which modulates a light source so as to cause the same to emit a light, includes: a superposition current generation part which generates a superposition current approximately corresponding to a charging/discharging current needed for a capacitance occurring in parallel to the light source for a predetermined time period near at least one of a rising-up part and a decaying-down part of a waveform of a drive current for the light source; and an addition/subtraction part which adds to or subtracts from the drive current the superposition current generated by the superposition current generation part.

Abstract: A signal processing apparatus is provided with a converter for converting at least one analog light detection signal into a digital light detection signal, and a signal generator for generating at least one servo error signal by subjecting the digital light detection signal to a predetermined operation process. The signal generator has a function of modifying contents of the operation process.

Abstract: A comparator compares a time interval between a first synchronization signal and a second synchronization signal with a target value, and outputs an error therebetween. A frequency calculator calculates a set value of a pixel clock frequency based on the error output from the comparator, and outputs a frequency specification signal for specifying a pixel clock frequency according to the calculated set value. A frequency divider divides a high frequency clock generated by a high frequency clock generator by a frequency division ratio based on the frequency specification signal output from the frequency calculator, and generates the pixel clock.

Abstract: In an information recording method and apparatus, a sequence of sync frames indicative of data is recorded onto tracks of an optical recording medium. In the recording medium, prepits are formed on lands between the tracks at given intervals, and sync patterns, providing synchronization on a sync-frame basis, are inserted in the sync frames such that each sync pattern has a length in a track direction larger than a length of one of the prepits and a position of each sync pattern matches with a position of at least one of the prepits. Codes that represent sync patterns for the sync frames are selected such that each sync pattern is formed as a space on the recording medium. Modulation codes are generated based on the sync frames in which the selected codes are inserted, by modulating the sync frames containing the selected codes in accordance with a predetermined modulation scheme. A sequence of recording pulses is generated by converting the modulation codes through a predetermined conversion scheme.

Abstract: An optical information recording method and apparatus which records information on a recording medium by irradiating the recording medium with an irradiation light of a recording power to form a recorded-mark on the recording medium such that reflection coefficient from an area of the recorded-mark is different than a reflection coefficient from an area of the recording medium where the recorded-mark is not formed by a changing power of the irradiation light.

Abstract: An information recording method where different optimum recording power levels are determined for different mark lengths. At a first trial writing process, first predetermined test data, from which a specific pattern, e.g., 3T is removed, are written with recording power levels being shifted, and a first optimum recording power level is determined based on a reproduction signal of the recorded first test data. Then, at a second trial writing process, second predetermined test data that are constituted by 3T marks are written with the recording power level for the 3T marks being shifted, and with the recording power level for marks other than the 3T marks being set at the first optimum recording level, and a second optimum recording power level for the 3T marks is determined based on a reproduction signal of the recorded second test data.

Abstract: A disclosed device for generating a pulse-width modulated signal according to image data and based on a pixel clock signal includes a pixel clock generating unit configured to generate the pixel clock signal and a modulated data generating unit configured to generate the pulse-width modulated signal. The pixel clock generating unit includes a multi-phase clock signal generating unit, a comparing unit, a frequency calculation unit, a counting unit, and a pixel clock signal output unit. The modulated data generating unit includes a data converting unit, an edge time calculation unit, and a pulse-width modulated signal output unit.

Abstract: A light source driving unit includes a modulating signal generating section generating modulating signals based on driving waveform generating information of a light source, a current source selecting section selecting one or more currents output from current sources based on the modulating signals, a light source driving section generating a current having multi-levels based on the one or more currents selected and supplying the generated current to the light source to drive the light source so that light in multi-levels is generated from the light source, and a cancelling section adding a signal error amount which cancels differences in amounts of signal delays generated between the modulating signal generating section and the light source driving section at a stage prior to the current source selecting section.

Abstract: A signal processing apparatus is provided with a converter for converting at least one analog light detection signal into a digital light detection signal, and a signal generator for generating at least one servo error signal by subjecting the digital light detection signal to a predetermined operation process. The signal generator has a function of modifying contents of the operation process.

Abstract: A light source drive which modulates a light source so as to cause the same to emit a light, includes: a superposition current generation part which generates a superposition current approximately corresponding to a charging/discharging current needed for a capacitance occurring in parallel to the light source for a predetermined time period near at least one of a rising-up part and a decaying-down part of a waveform of a drive current for the light source; and an addition/subtraction part which adds to or subtracts from the drive current the superposition current generated by the superposition current generation part.

Abstract: A light source drive which modulates a light source so as to cause the same to emit a light, includes: a superposition current generation part which generates a superposition current approximately corresponding to a charging/discharging current needed for a capacitance occurring in parallel to the light source for a predetermined time period near at least one of a rising-up part and a decaying-down part of a waveform of a drive current for the light source; and an addition/subtraction part which adds to or subtracts from the drive current the superposition current generated by the superposition current generation part.

Abstract: A light source driving unit includes a modulating signal generating section generating modulating signals based on driving waveform generating information of a light source, a current source selecting section selecting one or more currents output from current sources based on the modulating signals, a light source driving section generating a current having multi-levels based on the one or more currents selected and supplying the generated current to the light source to drive the light source so that light in multi-levels is generated from the light source, and a cancelling section adding a signal error amount which cancels differences in amounts of signal delays generated between the modulating signal generating section and the light source driving section at a stage prior to the current source selecting section.

Abstract: A light source driving unit includes a modulating signal generating section generating modulating signals based on driving waveform generating information of a light source, a current source selecting section selecting one or more currents output from current sources based on the modulating signals, a light source driving section generating a current having multi-levels based on the one or more currents selected and supplying the generated current to the light source to drive the light source so that light in multi-levels is generated from the light source, and a cancelling section adding a signal error amount which cancels differences in amounts of signal delays generated between the modulating signal generating section and the light source driving section at a stage prior to the current source selecting section.

Abstract: In a method of transforming a recording power level into multi-levels by using an extra recording power level, the optimum value of each recording power level is obtained, thereby achieving recording with good accuracy. By including a first test writing step (S1–S3) of performing test writing of predetermined first test data while varying the recording power in stages, and calculating an optimum recording power from the reproduction signal, and a second test writing step (S4–S6) of setting the recording power to the calculated optimum recording power and performing test writing of predetermined second test data while varying in stages the extra recording power applied in a part of a time period in which the optimum recording power is applied, and calculating an optimum extra recording power from the reproduction signal, the recording power and the extra recording power are separately calculated by test writing, and with which information is recorded.

Abstract: A signal processing apparatus is provided with a converter for converting at least one analog light detection signal into a digital light detection signal, and a signal generator for generating at least one servo error signal by subjecting the digital light detection signal to a predetermined operation process. The signal generator has a function of modifying contents of the operation process.

Abstract: [Problem to be Solved]Accurate recording is achieved by obtaining each optimum pulse width and pulse edge position in a recording method that performs recording according to the rules of recording waveform using different pulse widths and pulse edge positions for individual data length sets with respect to the data length sets having the different relationship between the number of pulses and the data length. [Means for Solving the Problem] The first trial write process obtains an optimum recording power of a test pattern (S1 through S3) even with respect to data having different rules for the recording waveforms corresponding n type data length sets, and the second trial write process using this optimum recording power obtains optimum pulse width or optimum pulse edge position separately for each data length set (S4 through S6).

Abstract: Serially transferred data is over sampled with a multiphase clock signal generated as a result of shifting a predetermined frequency clock signal by a predetermined phase each, to obtain over sampling data; generating clock patterns, having mutually different phase states according to a data phase state of the over sampling data. A first phase pattern generated from the over sampling data is compared with a second phase pattern generated from the clock pattern, and the number of bits to extract from the over sampling data is controlled. A phase error of the over sampling data is detected based on the first phase pattern and the second phase pattern. Bits to extract from the over sampling data is selected to restore the data based on the phase state of the clock pattern and the phase error.

Abstract: A light source drive which modulates a light source so as to cause the same to emit a light, includes: a superposition current generation part which generates a superposition current approximately corresponding to a charging/discharging current needed for a capacitance occurring in parallel to the light source for a predetermined time period near at least one of a rising-up part and a decaying-down part of a waveform of a drive current for the light source; and an addition/subtraction part which adds to or subtracts from the drive current the superposition current generated by the superposition current generation part.

Abstract: A light source drive which modulates a light source so as to cause the same to emit a light, includes: a superposition current generation part which generates a superposition current approximately corresponding to a charging/discharging current needed for a capacitance occurring in parallel to the light source for a predetermined time period near at least one of a rising-up part and a decaying-down part of a waveform of a drive current for the light source; and an addition/subtraction part which adds to or subtracts from the drive current the superposition current generated by the superposition current generation part.