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: 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: 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: 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: 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: 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 pickup of an optical reproducing/recording apparatus having a laser diode generating an optical signal with a current power value, and a laser diode power control device automatically controlling an output of the laser diode. The laser diode power control device has a sampler sampling the current power value of the optical signal from the laser diode, an operation unit outputting a target output value based on a comparison of the sampled current power value and a basic power value depending on a type of medium that is to receive the output of the laser diode, and a controller controlling the output of the laser diode based on the target output value.

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 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 apparatus for controlling the power of a laser diode, which can prevent fluctuation in the laser power of the laser diode at a record/playback area of an optical disc. The apparatus for controlling the power of the laser diode includes a controller which controls an automatic power control of the laser diode (APC controller), interposed between an up/down counter and a laser diode driver, the APC controller latching the output of the up/down counter in synchronism with a periodic synchronization signal, and outputting the latch result to the laser diode driver. Therefore, the power level of the laser diode can be periodically controlled according to subdivided control modes, so that the laser power level remains resilient to external noise, compared to a continuous control operation through the entire mode.

Abstract: A refrigerant cycle system in which the arrangement of a connecting pipe for connection between a compressor and an accumulator is improved effectively to recover oil collected in the accumulator to the compressor. The accumulator is installed to be separate from the compressor. A connecting pipe is arranged between the compressor and the accumulator to feed a refrigerant gas separated in the accumulator to the compressor. An oil recovery hole is provided at an inlet portion of the connecting pipe received in the accumulator such that it is arranged at a level higher than a highest level portion of the connecting pipe located outside of the accumulator. A second accumulator may be connected between the connecting pipe and the compressor while being directly installed at the compressor. In this case, the connecting pipe has an outlet portion connected to the second accumulator.

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: 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: 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 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: A write control method which varies a write power in response to a recording speed, a recording density, and a type of recording medium, and an optical disc recording apparatus suitable for the write control method. The write control method includes preparing a plurality of standard power values corresponding to recording speeds or recording densities for a plurality of record marks, selecting one of the plurality of standard power values with respect to a record mark to be recorded according to a recording speed or a recording density, and controlling write power of a laser beam according to the selected standard power value. The write control method and apparatus improve recording performance of an optical disc recording apparatus by differently setting write power values according to recording speeds, recording densities, and types of recording media.

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: The invention related to a laser diode power control apparatus in an optical drive capable of driving an optical media by high-speed, which uses a fine-tuning pulse to provide a recording pulse type suitable for high-density optical media. The laser diode power control apparatus includes a pulse generating unit, a control unit, and a transmitting unit. The pulse generating unit generates a recording pulse for each channel. The control unit controls the pulse generating unit by determining whether to apply a fine-tuning pulse to the recording pulse for each channel based on the type of the optical medium and the driving speed of the optical drive for the optical medium. The transmitting unit transmits a power level for each channel according to the recording pulse output from the pulse generating unit.

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.