摘要:
A laser drive circuit includes a first current supply unit which supplies a first drive current to a first laser diode based on a drive waveform signal generated by a drive waveform generating unit, a second current supply unit which supplies a second drive current to a second laser diode based on the drive waveform signal generated by the drive waveform generating unit, and a switching unit which selectively supplies the drive waveform signal generated by the drive waveform generating unit to one of the first current supply unit and the second current supply unit. The drive waveform generating unit may be part of the laser drive circuit, or may be separate from the laser drive circuit, and may include a drive waveform information storage unit which stores a recording strategy according to a type of disk.
摘要:
A laser drive integrated circuit and an optical disk apparatus using the laser drive integrated circuit for forming high-density marks. The optical disk apparatus includes a drive waveform information storage unit for storing at least one information of a drive waveform for driving a laser diode in response to a binary recording signal to be recorded in a recording medium, and a drive waveform decoder for decoding the drive waveform based on the information stored in the drive waveform information storage unit. A recording strategy can be changed in accordance with variations and fluctuations of recording media or characteristics of the recording media, while at the same time reducing a number of signal lines in flexible wiring and alleviating effects of signal distortion in the signal lines.
摘要:
A laser drive integrated circuit and an optical disk apparatus using the laser drive integrated circuit for forming high-density marks. The optical disk apparatus has a drive waveform information storage unit for storing at least one information of the drive waveform for driving a laser diode in response to a binary recording signal recorded in a recording medium and a drive waveform decoder for decoding the drive waveform based on the information stored in the drive waveform information storage unit. The recording strategy can be changed in accordance with the variations and fluctuations of recording media or the characteristics of the recording media, while at the same time reducing the number of signal lines of flexible wiring and alleviating the effect of the signal distortion.
摘要:
According to the present invention, in an optical disk apparatus constructed to supply signals for controlling a semiconductor laser drive circuit provided to an optical pickup from a signal processing circuit through a flexible cable, the semiconductor laser drive circuit is so constructed as to generate a drive current signal for the semiconductor laser on the basis of a binary signal and a clock signal which are supplied from the signal processing circuit through the flexible cable and the signal processing circuit is so constructed as to supply the clock signal during recording of data and stop the supply of the block signal during reproduction of data.
摘要:
According to the present invention, in an optical disk apparatus constructed to supply signals for controlling a semiconductor laser drive circuit provided to an optical pickup from a signal processing circuit through a flexible cable, the semiconductor laser drive circuit is so constructed as to generate a drive current signal for the semiconductor laser on the basis of a binary signal and a clock signal which are supplied from the signal processing circuit through the flexible cable and the signal processing circuit is so constructed as to stop supplying the block signal to the semiconductor laser drive circuit through the flexible cable during reproduction of data, and to start supplying the clock signal to the semiconductor laser drive circuit before recording of data.
摘要:
A laser drive (LD) unit 1 according to the present invention is provided with a laser drive waveform controller 6, into which information for setting the laser drive is entered from a controller 2, for generating a laser drive waveform on the basis of that information and supplying an indicated amperage; an LD current setting unit 7 for setting a laser drive current matching the indicated amperage; an LD current output unit 8 for varying the laser drive current on the basis of the laser drive waveform and supplying the current so varied to a laser diode 3; and a current setting corrector 9, into which a monitor signal obtained at the time of monitoring the laser beam emission from the laser diode 3 is monitored, for correcting the laser drive current set by the current setting unit 7 by using that monitor signal to adjust the power of the laser diode 3. The laser drive waveform controller 6, current setting unit 7, current output unit 8 and current setting corrector 9 are formed on the same substrate.
摘要:
A laser drive (LD) unit 1 according to the present invention is provided with a laser drive waveform controller 6, into which information for setting the laser drive is entered from a controller 2, for generating a laser drive waveform on the basis of that information and supplying an indicated amperage; an LD current setting unit 7 for setting a laser drive current matching the indicated amperage; an LD current output unit 8 for varying the laser drive current on the basis of the laser drive waveform and supplying the current so varied to a laser diode 3; and a current setting corrector 9, into which a monitor signal obtained at the time of monitoring the laser beam emission from the laser diode 3 is monitored, for correcting the laser drive current set by the current setting unit 7 by using that monitor signal to adjust the power of the laser diode 3. The laser drive waveform controller 6, current setting unit 7, current output unit 8 and current setting corrector 9 are formed on the same substrate.
摘要:
A laser driver for driving a semiconductor laser for use in recording information by irradiating light on an information recording medium includes a device, including a PLL circuit, for obtaining (1) information modulated in accordance with a predetermined rule and (2) a clock signal, and outputting a recording current signal corresponding to a modulation signal representing the modulated information through the PLL circuit. The PLL circuit oscillates at a high frequency in synchronism with the clock signal. The laser driver further includes a PLL unlock detection circuit for detecting an oscillating condition of the PLL circuit, and for outputting a detection signal indicative of the oscillating condition of the PLL circuit outside the laser driver as a monitor signal.
摘要:
An optical disk apparatus uses a laser driver which can measure the frequency of the high-frequency superimposed current of the semiconductor laser simply and accurately. The apparatus includes a semiconductor laser which emits a laser beam onto the optical disk, a laser driver which drives the semiconductor laser with a current, with the high-frequency current being superimposed thereon, and measures the frequency of the high-frequency current, and a main controller which controls the frequency of the high-frequency current produced by the laser driver by using the frequency measured by the laser driver.
摘要:
An optical disk apparatus uses a laser driver which can measure the frequency of the high-frequency superimposed current of the semiconductor laser simply and accurately. The apparatus includes a semiconductor laser which emits a laser beam onto the optical disk, a laser driver which drives the semiconductor laser with a current, with the high-frequency current being superimposed thereon, and measures the frequency of the high-frequency current, and a main controller which controls the frequency of the high-frequency current produced by the laser driver by using the frequency measured by the laser driver.