Abstract: There is provided an optical disc reproducing method capable of reproducing a non-finalized DVD+R. When a seek operation is performed from a present address on the non-finalized DVD+R to an outer circumferential side target address, the outer circumferential direction total jump number of tracks is calculated from a difference between the present address and the target address. When a first condition is satisfied in which the present address is in an inner circumferential zone, the target address is in a second outer circumferential zone, and the outer circumferential direction total jump number is 701 to 2500, the jump number of tracks is set to 340 smaller than the outer circumferential direction total jump number, and a traverse seek using a moving mechanism to move an optical pickup in a radius direction by 340 is performed.

Abstract: An apparatus for converting a groove/land polarity on an optical medium, comprises a physical identification (PID) detector for detecting a first PID value from a first sector, a sector information unit for providing an information which includes a second PID value indicative of either a second sector or at least one reference groove/land changing point, a sector counter for counting a first value whose an initiation is set by the sector information unit based on the information and/or by the PID detector based on the first PID value, and a comparing unit for determining at least one oncoming groove/land changing points, when the first value approaches a second value predetermined in or generated by the sector information unit according to the information.

Abstract: A method for demodulating a tracking error signal comprising the steps of (A) demodulating the tracking error signal when starting motion, (B) demodulating the tracking error signal after motion has started, and (C) demodulating the tracking error signal before and after lens motion stops.

Abstract: The invention relates to a track-jump control device, and in particular, to a track-jump control device for determining track-jump timing in an optical disc drive. A track-jump control device of a PUH comprises an L/G position indicator, a header alignment controller, and a jump controller. The L/G position indicator calculates an amount of sectors between the current position and an upcoming L/G switch point to generate a distance value. The header alignment controller controls the destination position locating in a safe area between two headers, and then generating a jump enabling signal. The jump controller coupled to the L/G position indicator and the header alignment controller determines track-jump timing according to the distance value and the jump enabling signal.

Abstract: The present invention discloses an apparatus and method for accurately converting a groove/land polarity upon a groove/land track change on an optical medium, by way of initially deciding a reference groove/land changing point or a decoded PID of any one specific sector formed on the optical medium. By counting a specific number of sectors from the reference groove/land changing point or the specific sector, a subsequent groove/land changing point will easily be approached for converting the groove/land polarity, and even the other oncoming track changing points on the optical medium also can be determined.

Abstract: The invention relates to the identification of the direction of the relative movement between a scanning beam of an optical scanner and the tracks of optical storage media. Use is made of the fact that the amplitude of the component TW of a track error signal TE, said component being brought about by wobble of the tracks, is maximal in the track center and minimal in the region between the tracks. A signal TW is thus present which does not assume its maxima and minima across the scanning location x at the same places as the track error signal TE. The invention describes devices and methods for determining the movement direction DIR of the scanning beam from the phase shift between the two signals.

Abstract: A method for controlling long seeking operation in an optical disc drive is provided. The optical disc drive includes a sled actuator, a pickup head installed on the sled actuator for reading and/or writing data in an optical disc, and a controller for controlling the sled actuator to move together with the pickup head. The method includes the steps of (a) receiving remaining tracks information indicating a number of tracks remained to be crossed by the sled actuator and/or the pickup head; (b) receiving velocity information indicating a velocity of the sled actuator and/or the pickup head; (c) receiving acceleration information indicating an acceleration of the sled actuator and/or the pickup head; (d) driving the sled actuator to move according to the remaining tracks information, the velocity information, and the acceleration information.

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: The present invention provides an information disc recording/playback apparatus which includes a track cross detection means, a track cross direction detection means, a rotation angle detection means, and a count means, detects the track pitch of a disc, evaluates the vibration amount, vibration speed, or vibration acceleration considering the track pitch of the disc, and determines a maximum rotation speed that is lower than the allowable vibration amplitude, vibration speed, or vibration acceleration of the information disc recording/playback apparatus. The present invention also provides a vibration detection method for the information disc recording/playback apparatus. This information disc recording/playback apparatus can perform vibration detection using a single threshold value that is independent of the type of the disc, without using an acceleration sensor, and further, the apparatus can accurately perform vibration detection even when direction detection is difficult.

Abstract: An apparatus for reading from or writing to optical recording media, having a photodetector and a phase detector for detecting a phase difference between output signals of the photodetector. An object of the present invention is to propose an apparatus in which a phase signal which is as correct as possible is generated. A further object of the invention is to specify a method of which a correct track error signal is determined using a phase detection method. According to the invention, the apparatus has an edge sequence detector for detecting the sequence of edges of the output signals, and a signal blocking unit for blocking the output signal of the phase detector. In particular, the output signal of the phase detector is blocked when an impermissible sequence of zero crossings of phase detected signals.

Abstract: An apparatus detects the number of tracks traversed on an optical disk. The apparatus includes a differentiation part for differentiating an output signal of a bandpass filter provided on an adjacent stage which eliminates a low DC component, a high frequency component and noise of an inputted modulation signal. A sample trigger generating circuit generates top and bottom signals in response to a data signal outputted through the differentiation part and a signal outputted through a comparator. A top hold part and a bottom hold part holds the data signal at top and bottom. A subtraction part performs a subtraction to obtain a difference between the top and bottom signals outputted from the top and bottom hold parts, thereby resulting in counting the number of the tracks traversed, while increasing a jumping speed required for a detection of the number of the tracks traversed.

Abstract: A radio frequency ripple zero crossing signal calibration method for an optical disk reader undergoing a track following to track seeking transition is disclosed. The method utilizes sampling to obtain radio frequency ripple peak level during a track seeking operation and radio frequency ripple DC level during a track following operation and using their differences as a calibrated value. Through the calibrated value, the radio frequency ripple zero crossing slice level is modified so that a correct radio frequency ripple zero crossing signal is obtained during a track following to track seeking transition. In a track following to seeking transition, this arrangement prevents distortion of the radio frequency ripple signal and corresponding drift in the radio frequency zero crossing signal that may lead to errors in computing moving speed and counting tracks of the pickup head. Hence, search capacity of the optical disk reader is improved and the pickup head is better controlled.

Abstract: A method for playing a recording medium, in particular an optical storage disc, used to access titles more quickly. Stored in a run-in area of the recording medium is at least one address area that includes at least one address of a beginning of a title stored on the recording medium. The recording medium is played in a player having a read device. When the at least one address area is read out, the at least one address of a title beginning is converted to a start time of exactly one time unit and stored in a memory, with the start time corresponding approximately to the playing time of the recording medium up to the addressed title beginning. To position the read device at the beginning of the title, the track jump time is calculated directly from the corresponding start time stored in the memory.

Abstract: In a scanning apparatus, a scanning spot is moved along a path from one track to another track of the information carrier, the scanning spot is accelerated in a first stage of the movement and decelerating in a second stage of the movement. Initially during the movement a displacement of the scanning spot is derived from a first and a second position signal. The velocity of the scanning spot is estimated during movement along the path. After the estimated velocity of the scanning spot exceeds a first predetermined value during the first stage of the movement, the displacement of the scanning spot is derived from the first position signal and independent from the second position signal, during movement along the path. After the estimated velocity has decreased below a second predetermined value during the second stage of the movement, the displacement of the scanning spot is again derived from both the first and the second position signal, during movement along the path.

Abstract: Apparatus for providing fine search in a sled movement mechanism employing a stepping motor by controlling the speed with which the head jumps in succession to next neighboring tracts on a disc and by causing pickup movement accurately for a distance corresponding to the distance of movement of the objective lens to realize the fine search in the sled movement mechanism employing the stepping motor. Also, the distance of head movement in the radial direction of the disc can be prescribed and, upon interruption of the head jumping operation, the head can be subsequently transported a distance corresponding to the target number of track jumps.

Abstract: Optical disc systems and methods for controlling movement of an optical pickup to an innermost perimeter of an optical disc using track information are provided. For example, an optical disc system includes an optical pickup that includes a tracking actuator, a focus actuator, and an objective lens and radiates a laser beam onto the optical disc to detect light reflected from the optical disc. The optical disc system also includes a radio frequency amplifier, a sled motor, a servo driver, and a servo signal processor that includes an optical pickup movement determiner and outputs a servo control signal, the optical pickup movement determiner determining from a track-related signal whether tracks are detected on the optical disc at a current position of the optical pickup and outputting a track determination signal indicating whether the optical pickup has moved to the innermost perimeter of the optical disc, based on the determination result.

Abstract: A control system and method for controlling a sled of an optical storage device by using a stepping motor. The optical storage device includes a pick-up head having a lens and a sled. The control system includes a tracking actuator's controller used to receive a tracking signal TE for generating a tracking control signal TRO to control positions of the lens; a numerical controller connected with the tracking actuator's controller used to receive the tracking control signal TRO for generating a numerical control signal; a frequency converter connected with the numerical controller used to receive the numerical control signal for generating a pulse flag signal and a direction flag signal; and a ring generator connected with the frequency converter used to receive the pulse and direction flag signal for producing a sled control signal to drive the stepping motor for controlling the sled.

Abstract: A method for reducing the turn-back in response to an actual and a target speed in an optical storage device. The method includes the following steps: (a) determining whether the turn-back of the optical pickup head occurs; if the turn-back occurs, step (b) is executed and if the turn-back does not occur, a speed error is obtained according to the target speed and the actual speed; (b) determining whether the number of turn-back tracks is greater than a default value; if the number of turn-back tracks is not greater than the default value, the speed error is set to zero and if the number of turn-back tracks is greater than the default value, the speed error is obtained according to the target speed and an inversion of the actual speed and the actual track-seeking direction is inverted to correspond to the target track-seeking direction.

Abstract: A circuit and a method of detecting a mirror signal for an optical disc apparatus, the method includes detecting a bottom envelope from a radio frequency signal and providing a bottom envelope signal thereof, amplifying the bottom envelope signal according to a center level of the bottom envelope signal, and comparing the amplified bottom envelope signal with a predetermined comparison voltage to detect the mirror signal.

Abstract: An optical recording medium driving apparatus which can obtain a tracking error signal necessary for an accurate track count. An optical recording medium driving apparatus for recording and/or reproducing data in/from an optical recording medium, where information can be recorded in plural tracks formed by land portions and groove portions provided between the land portions, based on a light emitted to the tracks. The apparatus includes a detector for detecting a position of the emitted light, a peak-hold circuit for holding a peak of a position detected signal outputted from the detector so as to output the position detected signal, a bottom-hold circuit for holding a bottom of the position detected signal so as to output the position detected signal, and a switching circuit for switching signals based on the output signals from the peak-hold circuit and bottom-hold circuit so as to output either signal.

Abstract: A center error signal is used to control the sled during fine search operations. The center error signal is used to synchronize the motion of a tracking actuator and a sled. A head is mounted on a sled in a disk drive. The sled is positioned by a sled motor and the head is positionally mounted on the sled. The head includes a lens that is optically coupled to a photo-sensor on the head. A tracking actuator positions the lens with respect to a track on the disk. A center error signal indicates a position of the lens with respect to a track on a disk. A tracks-to-jump signal specifies a predetermined number of tracks on the disk that the sled motor is to move. A modified tracks-to-jump signal is produced in response to the center error signal. The sled motor is controlled with the modified tracks-to-jump signal.

Abstract: Provided are a method and apparatus for canceling noise from a track cross signal, a method for controlling an optical disc drive, an optical disc drive, and an optical disc reproducing apparatus. The method for removing noise from a track cross signal includes (a) removing noise from the track cross signal by binarizing the track cross signal with reference to hysteresis set values that are determined according to a command speed for a tracking actuator; and (b) removing glitch noise from the binarized track cross signal based on a predetermined time value. Accordingly, it is possible to effective remove noise to obtain information regarding the precise speed and position of a desired track.

Abstract: Information recording area of an optical disk is divided radially into a plurality of recording areas with a boundary area interposed therebetween. The boundary area is formed as either a high-reflection area that presents a higher reflection light level than the divided recording areas or a low-reflection area that presents a lower reflection light level than the divided recording areas. When an instruction is given to move an optical head from a current point to the target point over the optical disk, a seek operation is performed up to the start point of one of the divided recording areas that contains the target point, while detecting, on the basis of a variation in the reflection light level, the boundary area located between another one of the divided recording areas that contains the current point and the divided recording area containing the target point.

Abstract: An optical disk apparatus for recording and reproducing data corresponding to a track length. The track length is obtained by subtracting a total length of an m (m: natural number) number of sectors from the distance by which a track is moved when a disk is rotated an n (n: natural number) number of times.

Abstract: A bandwidth control circuit and method for track-crossing signals used in an optical storage drive is used to generate a second track-crossing signal according to a first track-crossing signal transmitted from an pick-up device of the optical storage drive. The bandwidth control circuit has a first and a second low pass filters for filtering noise of the first track-crossing signal, and a track-crossing velocity calculation device for calculating a frequency of the second track-crossing signal. When the frequency of the second track-crossing signal is higher than a predetermined value, the first low pass filter is used to filter the noise of the first track-crossing signal. Otherwise, the second low pass filter is used to filter the noise of the first track-crossing signal. The method dynamically switches the low pass filters according to the frequencies of the track-crossing signals.

Abstract: A boundary position search method and an information recording apparatus are provided for rapidly transferring a recording/reproducing head to a boundary position between a recorded region and an unrecorded region of a recording disc when new information data is recorded on the recording disc. In response to a recording start instruction, the recording/reproducing head is first forcedly transferred in a radial direction of the disc, while confirmation is made as to the presence or absence of an RF signal carrying an information signal in a read signal. A slider unit is controlled to stop a transfer operation of the recording/reproducing head when a transition is detected from a state in which an RF signal exists to a state in which no RF signal exists.

Abstract: A control system and method for controlling a sled of an optical storage device by using a stepping motor. The optical storage device includes a pick-up head having a lens and a sled. The control system includes a tracking actuator's controller used to receive a tracking signal TE for generating a tracking control signal TRO to control positions of the lens; a numerical controller connected with the tracking actuator's controller used to receive the tracking control signal TRO for generating a numerical control signal; a frequency converter connected with the numerical controller used to receive the numerical control signal for generating a pulse flag signal and a direction flag signal; and a ring generator connected with the frequency converter used to receive the pulse and direction flag signal for producing a sled control signal to drive the stepping motor for controlling the sled.

Abstract: A disk calibration and search method in a disk drive is provided, in which, after an initialization step, a pickup is jumped to a first position and moved radially in a predetermined direction in response to pulses generated by a frequency generator. During this radial movement the number of tracks crossed are is counted. The counting is continued until a predetermined number of the pulses generated by the frequency generator have been generated. A calculated frequency generator track number is then obtained by dividing the counted number of tracks by the predetermined number of pulses generated by the frequency generator, i.e., calculating a unit track number of the disk per a single movement of the pickup, that is, the number of tracks the pickup moves per pulse generated by the frequency generator. The calculated frequency generator track number is stored in memory used to control the frequency generator for jumping the pickup during a search for a target track.