Abstract: An adaptive writing method of a high-density optical recording apparatus and a circuit thereof. The circuit includes a discriminator for discriminating a magnitude of a present mark of input NRZl data and magnitudes of leading and/or trailing spaces of the input NRZl data, a generator for controlling the waveform of a write pulse in accordance with the magnitude of the present mark of the input NRZl data and the magnitudes of the leading and/or trailing spaces of the input NRZl data to generate an adaptive write pulse, and a driver for driving a light source by converting the adaptive write pulse into a current signal in accordance with driving power levels for respective channels of the adaptive write pulse. The widths of the first and/or last pulses of the write pulse waveform are varied in accordance with the magnitude of the present mark of input NRZl data and the magnitude of the leading and/or trailing spaces, thereby minimizing jitter to enhance system reliability and performance.

Abstract: A method of generating write pulse control signals adaptive to various optical recording media, and a recording apparatus adopting the method. In the write pulse control signal generating method, timing data is made with respect to starting and/or ending positions of pulses, relative to rising and falling edges of a mark, wherein the timing data includes a first pulses, a multi-pulse train, a last pulse and a cooling pulse, and the starting and ending positions of the pulses are varied for various optical recording media. The timing data is stored, and then a bias power control signal, an erase power control signal, a peak power control signal and a cooling power control signal are generated in synchronism with an input nonreturn to zero inverted (NRZI) signal, based on the timing data for each optical recording medium. The recording apparatus can store write pulses, which are adaptive to various optical recording media, in the form of timing data, and generate base signals based on the timing data.

Abstract: An adaptive recording method and apparatus for optimizing power of a laser diode is provided. In a method for optimizing read power, peak power and bias power for overwrite pulses and supplying the same to the laser diode, the adaptive recording method includes the steps of discriminating the mark size of input NRZI (Non Return to Zero Inversion) data, and varying power of the overwrite pulses in accordance with the discriminated mark size.

Abstract: An optical recording/reproducing apparatus which controls the power of a laser diode (LD) and a method therefor. A current power level of an optical signal output by the LD is compared with a reference level and the output of the LD is controlled according to the comparison result. A photo detector (PD) monitors the current power level of the optical signal output by the LD. The current power level is compared with a reference level and power to the LD is controlled based on the comparison. Two different control loops are provided. In a first loop, comparison data is continually provided and in a second loop, sampled comparison data is provided based on a non return to zero inverted (NRZI) signal. Rapid change in an optical output is controlled using the different loops according to a kind and state of a medium such as a disc.

Abstract: An adaptive recording method and apparatus for optimizing power of a laser diode in high density optical recording. The mark size of input NRZI (Non Return to Zero Inversion) data is discriminated and the power of overwrite pulses is varied in accordance with the discriminated mark size, optimizing read power, peak power and bias power for overwrite pulses, to supply optimized pulses to the laser diode.

Abstract: An optical recording power controlling apparatus and method, in which the determination conditions for received Non Return to Zero Inverted (NRZI) data and the varying range of the optical recording power level are set depending on the multiple-speed of recording and the type of an optical medium, and the varying range of the optical recording power level is controlled so that optical recording power provided to a light emitting device is optimal for the multiple-speed of recording and the type of an optical medium. In the optical recording power controlling apparatus, a system control unit sets the discrimination conditions of received data to be recorded and the varying range of the optical recording power level, depending on the multiple-speed of recording and the type of an optical medium.

Abstract: There is provided an adaptive recording method for recording binary data having marks and spaces by irradiating a light signal onto an optical recording medium and adaptively adjusting the power of the light signal according to the correlativity between the length of a mark currently being recorded and the lengths of leading/trailing spaces, the adaptive recording method including the steps of (a) checking the output characteristics of a light signal generating apparatus for generating the light signal, and (b) controlling the power of the light signal by referring to the power of the light signal corresponding to the correlativity and the output characteristics in recording the data on the optical recording medium. The adaptive recording method allows accurate recording control by updating light output control data with respect to a power setting value according to variation in the output characteristic of the laser diode.

Abstract: An adaptive writing method of a high-density optical recording apparatus and a circuit thereof. The circuit includes a discriminator for discriminating a magnitude of a present mark of input NRZI data and magnitudes of leading and/or trailing spaces of the input NRZI data, a generator for controlling the waveform of a write pulse in accordance with the magnitude of the present mark of the input NRZI data and the magnitudes of the leading and/or trailing spaces of the input NRZI data to generate an adaptive write pulse, and a driver for driving a light source by converting the adaptive write pulse into a current signal in accordance with driving power levels for respective channels of the adaptive write pulse. The widths of the first and/or last pulses of the write pulse waveform are varied in accordance with the magnitude of the present mark of input NRZI data and the magnitude of the leading and/or trailing spaces, thereby minimizing jitter to enhance system reliability and performance.

Abstract: A laser diode driver, and driving method, for driving a laser diode in an optical recording/reproducing apparatus, having an auto laser power control (APC) operation, an optical pickup device, and an optical recording/reproducing apparatus, and method therefore, using the laser diode driver. The laser diode driver includes a multiplexer, a pulse generator, a differential amplifier, and an adder. The multiplexer selectively outputs drive potentials, such as a peak power drive potential, a bias power drive potential, a read power drive potential, and the like, corresponding to power levels of a laser signal, in response to a select signal applied to the multiflexer.

Abstract: An optical recording apparatus and method thereof form a mark and a space by radiating a laser signal corresponding to a recording pulse having a peak level and a bias level onto an optical recording medium. The optical recording apparatus includes a recording pulse generator to generate the recording pulse by overlapping a fine adjustment pulse with an amplitude less than the peak level and the bias level, and a laser diode to generate the laser signal according to the recording pulse.

Abstract: A differential type VCO (Voltage Controllable Oscillator) is disclosed. The VCO has a differential amplifier having a couple of transistors and a couple of LC tanks. At each LC tank, a transformer is connected to form a buffer. An oscillating signal is output through the buffer with no power consumption. Additionally, a capacitor is connected to the secondary coil of the transformer to form a bandpass filter, thereby attenuating a harmonic signal included in the oscillating signal.

Abstract: A write pulse generating apparatus includes a control unit which provides information on an optical recording medium type and information on a recording speed factor, and a control signal generating unit which determines a multi-pulse type which is to be generated in a multi-pulse interval based on the information recording medium type and recording speed factor. The generating unit generates a signal for controlling the light emitting device driving unit to generate a write pulse having the determined multi-pulse type. A control unit sets the level of the write pulse for up to an entire interval of a write mark and/or a write space according to the optical recording medium type and the recording speed factor.

Abstract: A differential type VCO (Voltage Controllable Oscillator) is disclosed. The VCO has a differential amplifier having a couple of transistors and a couple of LC tanks. At each LC tank, a transformer is connected to form a buffer. An oscillating signal is output through the buffer with no power consumption. Additionally, a capacitor is connected to the secondary coil of the transformer to form a bandpass filter, thereby attenuating a harmonic signal included in the oscillating signal.

Abstract: A resonator including a lower substrate having a groove, a dielectric filling the groove, a material film formed on the inner wall of the groove, the material film for preventing the permittivity from suddenly changing between the lower substrate and the dielectric, an upper substrate that is combined with the lower substrate to form a cavity, a conductive thin film formed on the lower surface of the upper substrate to face the dielectric and having a slot in contact with the material film and exposing the dielectric, and a strip line for a wave-guide that is formed on the upper part of the upper substrate and is connected to the conductive thin film. According to the resonator, the size of a cavity corresponding to a given resonance frequency can be reduced by filling a cavity with a dielectric (or magnetic material).

Abstract: A resonator including a lower substrate having a groove, a dielectric filling the groove, a material film formed on the inner wall of the groove, the material film for preventing the permittivity from suddenly changing between the lower substrate and the dielectric, an upper substrate that is combined with the lower substrate to form a cavity, a conductive thin film formed on the lower surface of the upper substrate to face the dielectric and having a slot in contact with the material film and exposing the dielectric, and a strip line for a wave-guide that is formed on the upper part of the upper substrate and is connected to the conductive thin film. According to the resonator, the size of a cavity corresponding to a given resonance frequency can be reduced by filling a cavity with a dielectric (or magnetic material).

Abstract: An apparatus for detecting abnormal states which prevents damage to a laser diode or data recorded on a disc and swiftly correcting the abnormal state. An overflow/underflow detector detects whether overflow or underflow of the laser diode occurs, by comparing a laser diode output power control value, which is output from the laser diode output power control circuit, with an overflow setting value and an underflow setting value. A mode switch switches an operation mode of the laser diode output power control circuit from a recording mode to a reproducing mode, in response to the detection result of the overflow/underflow detector.

Abstract: A method and an apparatus which controls write power of an optical driver by optimizing the number of channels used to drive a laser diode in a write mode while stabilizing the level of a write power voltage at an early stage of the write mode. The method of controlling the write power includes checking whether the write power provided to the laser diode included in the optical driver is stable, controlling the write power by increasing the number of channels used to control the write power so as to provide sufficient write power to drive the laser diode in response to the write power provided to the laser diode being unstable, and controlling the write power by using less channels than the channels used in response to the write power being unstable in response to the write power provided to the laser diode being stable. Accordingly, it is possible to reduce the size of a firmware by preventing channels unnecessary to perform a write mode from being used.

Abstract: An apparatus for and a method of controlling an output of a laser diode in an optical recording/reproducing apparatus. The apparatus includes a sampling circuit sampling a present power value output from the laser diode with a predetermined frequency, an arithmetic unit connected to the sampling circuit, outputting a control power value applied to the laser diode in response to the present power value output from the sampling circuit and a reference power value, and a controller connected to the sampling circuit and the arithmetic unit, generating control signals, which control the operations of the sampling circuit and the arithmetic unit.

Abstract: A method and an apparatus that automatically controls the optimum output of a laser diode. The apparatus automatically controls the output of a laser diode based on the results of a comparison between the current power value of an optical signal output from a laser diode and a basic power value. The apparatus includes: a sampler to sample the current power value output from the laser diode; a register unit to store the output of the sampler; a basic register unit to store a basic value; an operation unit to output a target output value applied to the laser diode based on the current power value and the basic power value stored in the register unit and the basic register unit; and a pulse generator to generate a control signal that controls the storing timing of the register unit based on recording data to be recorded by the laser diode.

Abstract: An apparatus for and a method of generating an optical recording pulse having multi-pulse patterns suitable for a high-density and high-speed optical medium are provided. The apparatus for generating the optical recording pulse having a multi-pulse chain includes a recording pulse generator generating the optical recording pulse and a controller connected to the recording pulse generator controlling the recording pulse generator so that according to the type of an optical medium or a recording speed of the optical medium, there can exist at least two different widths in respective pulses of the multi-pulse to form a mark on the optical medium.