Abstract: A laser driving system and method using a write strategy technique where a write strategy signal is generated based on a set of pulses that include timing information and power level information. The set of pulses originate from a set of transmission signals that embody spaces and marks for both starting and changing the set of pulses.

Abstract: A laser driving device includes: a first pulse generating section; a second pulse generating section; a light emission waveform generating section; a light emission level pattern storing section; and a second storing section. The second storing section stores sampling pulse patterns. Therefore setting information of the sampling pulse can be selected without a control line.

Abstract: Disclosed herein is a hard disk apparatus, including: a magnetic recording medium; a recording head adapted to record information on the magnetic recording medium; a semiconductor laser adapted to be controlled for light emission in a cycle of a recording clock to irradiate a light spot upon the magnetic recording medium to carry out thermal assistance in magnetic recording by the recording head; a laser driving circuit adapted to drive the semiconductor laser at a timing and with optical power in accordance with a light emission timing signal and a laser power controlling signal; and a controller adapted to set laser power in accordance with at least one of characteristics of the magnetic recording medium, semiconductor laser and recording head and output the laser power controlling signal to the laser driving circuit so that the laser power is adaptively varied.

Abstract: The light intensity of a light beam emitted from a light source is appropriately controlled when the light beam is transmitted through a variable optical coupling efficiency device in an optical head. During a read mode, the light beam from the light source is incident on an optical disk at an intensity relatively weaker than that of the light source. By switching the optical coupling efficiency of the variable optical coupling efficiency device between a write mode and a read mode, the light intensity directed to an optical recording medium is substantially varied from the write mode to the read mode. This arrangement eliminates the need for substantially increasing the optical output power ratio of the light source of write power to read power.

Abstract: Disclosed herein is a laser driving apparatus, including: a driving unit adapted to current drive a laser device with a current value in accordance with a level of a signal supplied thereto; and an emission light waveform correction unit adapted to receive supply of a pulsed reference signal and generate, based on a correction timing pulse interlocked with a rising edge and/or a falling edge of a pulse, a correction signal having a level different from that of the reference signal and then supply the correction signal to the driving unit so that the shape of the emission light waveform of the laser device becomes close to that of a rectangular wave.

Abstract: A laser driving device includes: a first pulse generating section; a second pulse generating section; a light emission waveform generating section; and a light emission level pattern storing section.

Abstract: Disclosed herein is a laser driving device including: a sample-hold section; a first pulse generating section; a second pulse generating section; a light emission waveform generating section; a storing section; and a sampling pulse generating section.

Abstract: A laser driving device includes: a first pulse generating section; a second pulse generating section; a light emission waveform generating section; a light emission level pattern storing section; and a second storing section.

Abstract: A laser drive includes a variable output voltage source that can control an output voltage, a laser source connected to the variable output voltage source, a laser drive circuit that drives the laser source, and a monitoring controller that monitors an operating voltage of the laser drive circuit and controls the output of the variable output voltage source such that the monitored operating voltage becomes equal to a desired value.

Abstract: A laser driving device includes a storage unit that stores signal patterns for recording-waveform control representing level information of each divided driving signal to drive a laser device on a space and a mark based on the divided driving signals. Also, it includes a pulse generator that generates the reference pulse and the switching pulse based on a first transmission signal and a second transmission signal. The first transmission signal contains timing information for acquiring a reference pulse that represents a timing of repetitively switching between the space and the mark. The second transmission signal contains timing information for acquiring a switch pulse that represents a timing of switching the signals. Among level information for each of the signals in the storage, reference level information is read together with the reference pulse. Other level information after the reference level information is sequentially read for each switching pulse.

Abstract: A laser driving apparatus for a light source of an optical head apparatus includes a laser, a laser driving circuit, and a radio frequency current generation circuit for generating a radio frequency current to be superimposed on the drive current. The laser driving apparatus further includes a current monitor circuit, an optical detector for detecting an optical output of the laser; a selection circuit for selecting either of non-superimposing or superimposing the radio frequency current on the drive current, an APC circuit for controlling the optical output of the laser at a constant level, and a control circuit. The control circuit controls the amplitude of the radio frequency current on the basis of current values of the drive current on non-superimposing and superimposing or detection values of the optical output of the laser on non-superimposing and superimposing.

Abstract: An optical disc system includes a disc recording unit for recording an information signal on an optical disc by switching irradiation power of laser light to be applied to the optical disc in accordance with the information signal. The disc recording unit includes a semiconductor laser; a laser-power controlling circuit for outputting a laser-driving-current instruction signal; a recording-pulse generating circuit for outputting a laser-modulation timing pulse; a laser driving circuit for generating a laser driving current in accordance with the laser-driving-current instruction signal and the laser-modulation timing pulse; and a correction-data storage for storing as correction data the shift between the laser-modulation timing pulse and the pulse position of the laser driving current.

Abstract: The light intensity of a light beam emitted from a light source is appropriately controlled when the light beam is transmitted through a variable optical coupling efficiency device in an optical head. During a read mode, the light beam from the light source is incident on an optical disk at an intensity relatively weaker than that of the light source. By switching the optical coupling efficiency of the variable optical coupling efficiency device between a write mode and a read mode, the light intensity directed to an optical recording medium is substantially varied from the write mode to the read mode. This arrangement eliminates the need for substantially increasing the optical output power ratio of the light source of write power to read power.

Abstract: The light intensity of a light beam emitted from a light source is appropriately controlled when the light beam is transmitted through a variable optical coupling efficiency device in an optical head. During a read mode, the light beam from the light source is incident on an optical disk at an intensity relatively weaker than that of the light source. By switching the optical coupling efficiency of the variable optical coupling efficiency device between a write mode and a read mode, the light intensity directed to an optical recording medium is substantially varied from the write mode to the read mode. This arrangement eliminates the need for substantially increasing the optical output power ratio of the light source of write power to read power.

Abstract: The light intensity of a light beam emitted from a light source is appropriately controlled when the light beam is transmitted through a variable optical coupling efficiency device in an optical head. During a read mode, the light beam from the light source is incident on an optical disk at an intensity relatively weaker than that of the light source. By switching the optical coupling efficiency of the variable optical coupling efficiency device between a write mode and a read mode, the light intensity directed to an optical recording medium is substantially varied from the write mode to the read mode. This arrangement eliminates the need for substantially increasing the optical output power ratio of the light source of write power to read power.

Abstract: A laser drive includes a variable output voltage source that can control an output voltage, a laser source connected to the variable output voltage source, a laser drive circuit that drives the laser source, and a monitoring controller that monitors an operating voltage of the laser drive circuit and controls the output of the variable output voltage source such that the monitored operating voltage becomes equal to a desired value.

Abstract: An object of the present invention is to remove a laser beam source noise in an optical disc device. An optical disc device comprises: a laser beam source which outputs a laser beam, a reproducing signal beam-receiver which receives a signal beam from an optical disc and generates a reproducing signal, a beam-source monitoring beam-receiver which detects the laser beam from the laser beam source, and a beam splitter which divides the laser beam from the laser beam source into the beams to the reproducing signal beam-receiver and to the beam-source monitoring beam-receiver; an output signal from the beam-source monitoring beam-receiver being used for removing a noise contained in the reproducing signal from the reproducing signal beam-receiver through a noise cancellation calculation.

Abstract: An optical disc system includes a disc recording unit for recording an information signal on an optical disc by switching irradiation power of laser light to be applied to the optical disc in accordance with the information signal. The disc recording unit includes a semiconductor laser; a laser-power controlling circuit for outputting a laser-driving-current instruction signal; a recording-pulse generating circuit for outputting a laser-modulation timing pulse; a laser driving circuit for generating a laser driving current in accordance with the laser-driving-current instruction signal and the laser-modulation timing pulse; and a correction-data storage for storing as correction data the shift between the laser-modulation timing pulse and the pulse position of the laser driving current.

Abstract: A laser driving apparatus for a light source of an optical head apparatus includes a laser, a laser driving circuit, and a radio frequency current generation circuit for generating a radio frequency current to be superimposed on the drive current. The laser driving apparatus further includes a current monitor circuit, an optical detector for detecting an optical output of the laser; a selection circuit for selecting either of non-superimposing or superimposing the radio frequency current on the drive current, an APC circuit for controlling the optical output of the laser at a constant level, and a control circuit. The control circuit controls the amplitude of the radio frequency current on the basis of current values of the drive current on non-superimposing and superimposing or detection values of the optical output of the laser on non-superimposing and superimposing.

Abstract: A tilt servo apparatus which can correct a tilt error at a high speed and with high precision irrespective of a magnitude of the tilt error even if a response speed of a liquid crystal device decreases is provided. An amount of change and an increase/decrease of a signal intensity are detected by changing a correction value of a tilt error correcting arrangement by a first correction width, and a correction width of the correction value and a correcting direction are determined on the basis of the detection result. When the amount of change of the signal intensity is smaller than a predetermined amount of change, the correction width is changed to a second correction width which is smaller than a first correction width. When it is larger than the predetermined amount of change, the correction width is changed to a third correction width larger than the first correction width. The correction width is also determined in accordance with a change in environmental temperature.