Abstract: A method and system for estimating a step length in a pedestrian navigation system is provided. The method of estimating a step length in a pedestrian navigation system includes calculating a walking frequency and an acceleration variance of a pedestrian by using acceleration data acquired from an acceleration sensor, calculating a walking distance of the pedestrian by using GPS data acquired from a GPS receiver, and estimating a step length of the pedestrian by using the calculated walking frequency, acceleration variance, and walking distance.

Abstract: Disclosed is a method and apparatus for controlling the record and reproduction of optical record medium in which plural non-record regions having different phase are arranged between recordable data regions for the distinction in the shape of the data region. The method and apparatus performs the servo using focus error signal and tracking error signal averaged by the low pass filter at the header region of the optical disc. Especially, the tracking servo is performed by holding a fixed DC off-set value at the header region existing on the L/G switching or holding the tracking error value of the previous same track region. As a result, the exact header region is detected, the track sliding phenomenon is removed, and the tracking servo is stabilized, resulting in preventing the degeneration of the record and reproduction characteristics.

Abstract: Disclosed herein is an apparatus for manufacturing a polycrystalline silicon ingot for solar batteries having a door control device using a hinge. The apparatus includes a vacuum chamber, a crucible, a susceptor which surrounds the crucible, a heater which heats the crucible, and an insulation plate which is disposed below the susceptor and has an opening therein. The apparatus further includes a cooling plate which moves upwards through the opening of the insulation plate and comes into close contact with or approaches the lower end of the susceptor, a cooling plate moving unit which actuates the cooling plate, a temperature sensor which measures the temperature of the crucible, and a control unit which controls the temperature in the crucible and the cooling plate moving unit. Furthermore, a door is provided on the insulation plate to open or close the opening of the insulation plate. The hinge is provided between the door and the insulation plate.

Abstract: Disclosed is a tilt controlling method and apparatus in which an FE signal track at a point where an RF signal is the maximum or an RE signal track at a point where a jitter is the minimum is detected as a tilt control signal to induct a DC component according to the disk shape and an AC component according to the surface vibration of the disk. Further, the fact is used that an RF envelope has a maximum value when the disk is parallel to an object lens or there is no tilt. Thus, in a tilt initialization step, a tilt track as the RF Max. is obtained for one rotation and the central potential of this track is set as a tilt control reference voltage, and when the RF envelope becomes a phase corresponding to a condition of a controller or a differential value of the RF envelope in the tilt window signal becomes a desired phase, tilt control is started so that the RF envelope always has the maximum value.

Abstract: The method for reproducing records for the optical recording medium detects and compensates for detrack, tilt and defocus, having advantages in that: (1) the magnitude and the direction of detrack, tilt and defocus can be detected from a difference signal (for example, a read channel 2 signal or a tracking error signal obtained by processing the read channel 2 signal) between optical reflecting signals detected at the header fields staggered on the basis of the tract center, and compensates for detrack, tilt and defocus, thereby preventing deterioration of data quality caused by detrack, tilt and defocus during a recording/reproducing operation and enabling the stable operation of the system; and (2) the focus servo is rapidly stabilized to enable real-time recording as well as the stable operation of the system.

Abstract: A track jump method for an optical recording/reproducing medium is provided. In the track jump method, once a track jump command is input, a track jump operation is held until a falling edge of a header mask signal is detected. The track jump starts at the falling edge of the header mask signal and ends before a rising edge of the header mask signal so that a TZC signal is not influenced by a header during the track jump. Therefore, the track jump can be exactly and stably performed. In particular, when the track jump command is input, a PLL of a wobble signal is inhibited, and a PLL-wobble signal is held to a previous value obtained before the track jump is performed, during the track jump, or a header mask signal is generated using a read channel signal which is not influenced by a wobble period, until a wobble signal becomes stable after a trackjump. During a normal servo, a header mask signal is generated using a PLL-wobble signal to mask a header area.

Abstract: A land/groove track discriminating method and apparatus for an optical recording medium having a land/groove structure which can stably discriminate the kind of a track even in an unstable state of the system. The kind of the track is discriminated by using the differential characteristic of a tracking error signal in a header region, by using the relation that the phase of a wobbling signal in the lang track is opposite to the phase of the wobbling signal in the groove track, or by comparing phase levels of delayed first and second header region signals. Accordingly, the servo control suitable to the kind of the track can be performed at a proper time, and thus an accurate tracking control can be performed with respect to an optical disc having the land/groove track structure.

Abstract: A piezoelectric ultrasonic motor includes a piezoelectric stator including a metal tube with an inner space and piezoelectric elements mounted on the outer circumference of the metal tube, a rotary shaft including a rotation bar inserted into the inner space of the metal tube, and a rotation member provided around the rotation bar in contact with the piezoelectric stator. The piezoelectric stator strains with an electric field applied thereto, and the rotation member rotates in response to the strain of the piezoelectric stator. A power transmission member is provided at one portion of the rotation bar to transmit the rotation of the rotation member to an object to be transported. With face contact the motor achieves stable actuation together with enhanced force and sufficient strain, and a flexibility to be applied to various apparatuses such as a camera module.

Abstract: Disclosed is a method and apparatus for controlling the record and reproduction of optical record medium in which plural non-record regions having different phase are arranged between recordable data regions for the distinction in the shape of the data region. The method and apparatus performs the servo using focus error signal and tracking error signal averaged by the low pass filter at the header region of the optical disc. Especially, the tracking servo is performed by holding a fixed DC off-set value at the header region existing on the L/G switching or holding the tracking error value of the previous same track region. As a result, the exact header region is detected, the track sliding phenomenon is removed, and the tracking servo is stabilized, resulting in preventing the degeneration of the record and reproduction characteristics.

Abstract: Method and device for controlling an optical recording/reproducing device, for detecting a wobble signal in advance during free running when only a focus servo is turned on, carrying out wobble PLL, detecting the present rotating speed of the optical disk from the wobble signal, and controlling the spindle to reach to a target speed quickly, thereby stabilizing the servo in advance before regular data recording/reproduction, and enhancing performance of the optical recording/reproduction device.

Abstract: Device and method for detecting a non-writable region of an optical recording medium, wherein a read channel 1 signal and a read channel 2 signal are sliced at respective slice levels to produce header mask signals, and a header region which is a non-writable region is determined for the header mask signal taking the slice levels and written/unwritten regions ion the disk, whereby permitting stabilization of servos because servo error signals, such as a tracking error signal, and a focus error signal can be held exactly at a header region even if the servos are not stable, that prevents deterioration of a data quality in writing and reading, and permitting to shift an optical pickup to a desired position and accurate measurement of an amount of eccentricity because there is no influence of the header in a track jump and a disk eccentricity measurement.

Abstract: A method and apparatus for generating an optimum recording power before recording user data in a recordable optical recording medium is disclosed. According to the method and apparatus, an optimum power calibration (OPC) is performed in the unit of a sector, and the start position of the respective physical sector can be synchronized. Thus, the optimum recording power can be determined even in a DVD-R/RW in which a PCA area exists but no OPC method is prescribed. Also, the degree of OPC can be heightened, and the limitation of the PCA area can be overcome. The method and apparatus also enables an easy and accurate search of the start position even in an odd sector where LPP data is recorded in odd positions.

Abstract: In a weak-magnetic field sensor a rectangular ring-shaped magnetic core is wound by exciting circuit patterns and detecting circuit patterns, and weak-magnetic field sensors are implemented in x-axis and y-axis directions, respectively, to precisely calculate azimuth, thereby sensing a weak-magnetic field having a strength similar to that of earth's magnetic field. The sensor includes a magnetic core having first and second cores connected in parallel to each other; exciting coils wound around the first and second cores, respectively, to supply alternating excitation current to the magnetic core; and a detecting coil alternately arranged together with the exciting coils on the same surfaces on which the exciting coils are formed, and wound around the first and second cores, in order to detect variation of magnetic fluxes generated in the magnetic core.

Abstract: A track jump method for an optical recording/reproducing medium is provided. In the track jump method, once a track jump command is input, a track jump operation is held until a falling edge of a header mask signal is detected. The track jump starts at the falling edge of the header mask signal and ends before a rising edge of the header mask signal so that a TZC signal is not influenced by a header during the track jump. Therefore, the track jump can be exactly and stably performed. In particular, when the track jump command is input, a PLL of a wobble signal is inhibited, and a PLL-wobble signal is held to a previous value obtained before the track jump is performed, during the track jump, or a header mask signal is generated using a read channel signal which is not influenced by a wobble period, until a wobble signal becomes stable after a track jump. During a normal servo, a header mask signal is generated using a PLL-wobble signal to mask a header area.

Abstract: A method and apparatus for controlling reproduction of an optical recording medium is disclosed. According to the method and apparatus, a moving direction of an object lens on a disc is detected from a slope of a differential phase detection (DPD) error signal in case that the tracking control of the disc is performed by the DPD error signal, and the tracking control is performed using the detected moving direction of the object lens. Thus, the proceeding direction of the object lens can be easily and accurately detected in the disc from which the detection of a mirror signal is not facilitated, i.e., in the disc whose tracking is controlled by the DPD error signal during reproduction. Since it can be easily discriminated whether the phase of the tracking error signal to be in a track-on state when a track servo is turned on is a land or a groove, the stability of the servo can be secured, and an automatic breaking can be achieved.

Abstract: A servo method for an optical recording medium for detecting a tracking error signal by a push-pull method is disclosed. Before a servo operation, an amount of DC offset per track is obtained as an object lens of an optical pickup is moved in a specified direction, and a tracking servo is performed by compensating for a tracking error signal based on an initial amount of DC offset obtained by multiplying the amount of DC offset generated per track by the number of jumped tracks when the object lens is shifted. After movement of a sled by driving a sled servo, a sled servo is performed by compensating for the tracking error signal based on a value obtained by subtracting an amount of sled movement from the initial amount of DC offset, and thus an optical beam can always follow a track center even when the DC offset is generated in the tracking error signal.

Abstract: A method of recording and reproducing an optical recording medium which detects a defocus and a tilt of the optical recording medium and compensates the detected defocus and tilt in a high-density optical recording medium. In a free running state in which only a focus servo is turned on, the amount of defocus offset that corresponds to a maximum level of a tracking error signal is detected in a plurality of positions on inner and outer peripheries of a disc, and a tilt-zero in the respective position is detected and stored, so that a tilt servo and a focus servo are performed with the value stored in the corresponding position during an actual recording/reproduction. The method can prevent the deterioration of quality of data due the defocus during recording/reproduction, enabling real time recording by quickly stabilizing the focus servo, and stable operation of the system.

Abstract: An apparatus and a method for compensating a tilt of an optical recording medium comprising a servo error generating unit for generating RF(Radio Frequency) signal and a servo error signal from an electric signal outputted from an optical pickup unit, a servo control unit for generating a focus operation signal and a tracking operation signal by signal-processing separately a focus error signal and a tracking error signal outputted from the servo error generating unit, performing a focus search at a certain position in order to detect tilt, and generating a tilt operation signal by detecting tilt, a focus servo operation unit for operating a focus actuator inside of the optical pickup unit by receiving the focus operation signal outputted from the servo control unit, and a tilt operation unit for compensating tilt by controlling the pickup unit in accordance with the tilt operation signal outputted from the servo control unit.

Abstract: A land/groove track discriminating method and apparatus for an optical recording medium having a land/groove structure which can stably discriminate the kind of a track even in an unstable state of the system. The kind of the track is discriminated by using the differential characteristic of a tracking error signal in a header region, by using the relation that the phase of a wobbling signal in the lang track is opposite to the phase of the wobbling signal in the groove track, or by comparing phase levels of delayed first and second header region signals. Accordingly, the servo control suitable to the kind of the track can be performed at a proper time, and thus an accurate tracking control can be performed with respect to an optical disc having the land/groove track structure.

Abstract: Disclosed is an apparatus for controlling eccentricity in a photo-record player and a control method thereof. A relative eccentric quantity is found from a TE signal (or, tracking driving voltage) induced per one revolution of disc ‘on track’and an eccentricity phase to be controlled is found from a periodicity of TE (or, tracking driving voltage) per one revolution of disc. A suitable compensating value for the relation between the found eccentricity quantity and phase is generated by taking FG representing a period of revolution as a reference. Then, the compensating value is used for an eccentricity control ‘on track’, or driving the tracking actuator on ‘seek’. Therefore, the present invention reduces a seek location error due to the eccentricity on ‘seek’, thereby enabling to increase a seek performance.