Abstract: A hydrogen storage system is disclosed and includes a storage unit including a plurality of unit storage containers, in which metal hydride materials are respectively provided in an interior thereof and which are connected to each other in parallel, and a thermal fluid line defining a thermal fluid passage, which passes via the plurality of unit storage containers continuously and through which a thermal fluid flows for heating or cooling the unit storage containers, thereby enhancing a storage performance and an efficiency of the hydrogen.

Abstract: A hydrogen storage device includes a storage container having an accommodation space in an interior thereof, a first metal hydride material provided in the interior of the storage container and that stores hydrogen, and a second metal hydride material provided in the interior of the storage container and that stores the hydrogen at a pressure that is different from that of the first metal hydride material. An advantageous effect of restraining an excessive rise of a pressure of the storage container and enhancing safety and reliability may be obtained.

Abstract: An angle measurement system using a magnet and provided with first and second tracks includes an absolute angle calculation unit configured to calculate an absolute angle of a position of the magnet by using a 1-1th digital signal obtained by measuring a magnetic field signal of the first track and converted into a digital signal, a 1-2th digital signal obtained by measuring the magnetic field signal of the first track and converted into a digital signal, a 2-1th digital signal obtained by measuring a magnetic field signal of the second track and converted into a digital signal, and a 2-2th digital signal obtained by measuring the magnetic field signal of the second track and converted into a digital signal.

Abstract: Provided are a focus search apparatus and method for performing a focus search after moving an optical pickup to a focus-on point according to a signal output from a sine wave generator so that a stable and smooth focus search is performed. In the focus search method, a sine wave is generated in response to a focus search command. The focus search is performed using an optical pickup in response to the sine wave. The optical pickup is driven in response to an amplitude of the sine wave during the focus search and in response to a filtered focus error signal during a focus servo.

Abstract: Provided are an apparatus and method for detecting a type of an optical disc inserted into an optical disc system and/or adjusting a track balance in the optical disc system by detecting voltages of a focus error signal and a tracking error signal. For detecting a type of an optical disc inserted into an optical disc system, the apparatus comprising: an analog-to-digital converter that converts a focus error signal into n-bit voltage data; and a duty measurer that compares the n-bit voltage data with a positive noise voltage level and a negative noise voltage level, upcounts by a predetermined value if the n-bit voltage data is higher than the positive noise voltage level or lower than the negative voltage level, and outputs the upcounted result as a duty of the focus error signal.

Abstract: Provided are an apparatus and method for detecting a type of an optical disc inserted into an optical disc system and/or adjusting a track balance in the optical disc system by detecting voltages of a focus error signal and a tracking error signal. For detecting a type of an optical disc inserted into an optical disc system, the apparatus comprising: an analog-to-digital converter that converts a focus error signal into n-bit voltage data; and a duty measurer that compares the n-bit voltage data with a positive noise voltage level and a negative noise voltage level, upcounts by a predetermined value if the n-bit voltage data is higher than the positive noise voltage level or lower than the negative voltage level, and outputs the upcounted result as a duty of the focus error signal.

Abstract: Provided are a focus search apparatus and method for performing a focus search after moving an optical pickup to a focus-on point according to a signal output from a sine wave generator so that a stable and smooth focus search is performed. In the focus search method, a sine wave is generated in response to a focus search command. The focus search is performed using an optical pickup in response to the sine wave. The optical pickup is driven in response to an amplitude of the sine wave during the focus search and in response to a filtered focus error signal during a focus servo.

Abstract: In an apparatus and a method for correcting asymmetry in an optical disk reproduction system, an analog RF signal is received from an optical diode and an asymmetry-corrected signal is output as a digital EFM signal. The apparatus includes envelope detectors for detecting upper and lower envelopes of the RF signal, a level controller for controlling the level of the sum of the upper envelope and the lower envelope and for outputting signal having the controlled level, and a comparator for comparing the level of the signal output from the level controller with the level of the RF signal and for outputting the comparison result as the digital EFM signal.

Abstract: In an apparatus and a method for correcting asymmetry in an optical disk reproduction system, an analog RF signal is received from an optical diode and an asymmetry-corrected signal is output as a digital EFM signal. The apparatus includes envelope detectors for detecting upper and lower envelopes of the RF signal, a level controller for controlling the level of the sum of the upper envelope and the lower envelope and for outputting signal having the controlled level, and a comparator for comparing the level of the signal output from the level controller with the level of the RF signal and for outputting the comparison result as the digital EFM signal.

Abstract: An optical disc player system for reproducing optical discs is provided. The system includes a digital signal processor for processing a data signal having a format read from an optical disc and reproducing the optical disc. The system includes a plurality of decoders for decoding data of different formats. The system includes a data output unit which selects the data output from the digital signal processor or the decoded data output from the decoders. The data output unit converts the selected data into an analog signal and outputs the converted signal to a corresponding channel. A controller enables one of the decoders depending on the data format of the optical disc and controls the selection operation of the data output unit, and a buffer memory for storing data output from the plurality of decoders depending to the data format or operation mode of the optical disc.

Abstract: In an apparatus and a method for correcting asymmetry in an optical disk reproduction system, an analog RF signal is received from an optical diode and an asymmetry-corrected signal is output as a digital EFM signal. The apparatus includes envelope detectors for detecting upper and lower envelopes of the RF signal, a level controller for controlling the level of the sum of the upper envelope and the lower envelope and for outputting signal having the controlled level, and a comparator for comparing the level of the signal output from the level controller with the level of the RF signal and for outputting the comparison result as the digital EFM signal.

Abstract: An apparatus and method for generating an eight-to-fourteen modulation (EFM) signal in an optical disk reproducing system, capable of accurately generating the EFM signal regardless of the kinds of defects of a disk. The apparatus for generating an EFM signal from a radio frequency (RF) signal reproduced from an optical disk, includes a data slicing unit for selecting, in response to a selection signal, a first slice reference level generated by correcting the asymmetry of the RF signal, or a second slice reference signal generated using peak and bottom envelopes of the RF signal and the first slice reference level, to be a third slice reference level. The data slicing unit slices the RF signal based on the third slice reference level and outputs the slicing result as the EFM signal. A selection signal generating unit generates the selection signal in response to the number of occurrences of error correction flags or EFM flags.

Abstract: In an apparatus and a method for correcting asymmetry in an optical disk reproduction system, an analog RF signal is received from an optical diode and an asymmetry-corrected signal is output as a digital EFM signal. The apparatus includes envelope detectors for detecting upper and lower envelopes of the RF signal, a level controller for controlling the level of the sum of the upper envelope and the lower envelope and for outputting signal having the controlled level, and a comparator for comparing the level of the signal output from the level controller with the level of the RF signal and for outputting the comparison result as the digital EFM signal.

Abstract: An optical disc player system for reproducing optical discs is provided. The system includes a digital signal processor for processing a data signal having a format read from an optical disc and reproducing the optical disc. The system includes a plurality of decoders for decoding data of different formats. The system includes a data output unit which selects the data output from the digital signal processor or the decoded data output from the decoders. The data output unit converts the selected data into an analog signal and outputs the converted signal to a corresponding channel. A controller enables one of the decoders depending on the data format of the optical disc and controls the selection operation of the data output unit, and a buffer memory for storing data output from the plurality of decoders depending to the data format or operation mode of the optical disc.

Abstract: In an apparatus and a method for correcting asymmetry in an optical disk reproduction system, an analog RF signal is received from an optical diode and an asymmetry-corrected signal is output as a digital EFM signal. The apparatus includes envelope detectors for detecting upper and lower envelopes of the RF signal, a level controller for controlling the level of the sum of the upper envelope and the lower envelope and for outputting signal having the controlled level, and a comparator for comparing the level of the signal output from the level controller with the level of the RF signal and for outputting the comparison result as the digital EFM signal.

Abstract: A tracking servo control apparatus for muting a tracking error signal when a mirror signal is generated, in an optical disk system, such as a compact disk player or a digital video disk, compensates for tracking gain and phase according to the tracking error signal. The apparatus includes a mirror setting unit for receiving the generated mirror signal and for generating a mirror signal by defining the mirror signal to predetermined minimum and maximum time intervals, a switch for outputting a muted tracking error signal while the defined mirror signal is activated, and otherwise, outputting the tracking error signal, and a tracking gain/phase compensator for receiving the output signal from the switch and compensating for the tracking gain and phase. Thus, the system can be stabilized by muting a tracking servo loop according to a mirror signal whose pulse width is defined to a predetermined window section.

Abstract: A digital data storage system which does not require the use of moving, mechanical components, and which utilizes semiconductor memory elements, thereby improving the reliability and extending the useful life thereof, and also minimizing the cost, complexity, and size thereof relative to conventional digital data storage systems, such as CD players and DAT devices. In a playback only embodiment, the digital data storage system includes a ROM, a system control microcomputer, a digital signal processor (DSP), and a D/A converter. In operation, the DSP is responsive to control signals generated by the system control microcomputer for reading out digital data, e.g., digital audio data, stored in the ROM, and decoding the read-out digital data. The D/A converter functions to convert the decoded read-out digital data into an analog output signal, e.g., an analog audio signal, and to supply the analog output signal to an output terminal.

Abstract: A digital data storage system which does not require the use of moving, mechanical components, and which utilizes semiconductor memory elements. In one embodiment, the digital data storage system includes a ROM, a system control microcomputer, a digital signal processor (DSP), and a D/A converter. In operation, the DSP is responsive to control signals generated by the system control microcomputer for reading out digital data, e.g., digital audio data, stored in the ROM, and decoding the read-out digital data. The D/A converter functions to convert the decoded read-out digital data into an analog output signal, e.g., an analog audio signal, and to supply the analog output signal to an output terminal. The digital data storage system of this embodiment is a playback-only system. In another embodiment, the digital data storage system includes all of the elements of the above-described embodiment, and further includes an A/D converter and an EEPROM, to facilitate the recording of digital data.