Abstract: A song in a music player is replaced by another song in a server in accordance with the user's estimated preferences and wishes and without requiring the user to become conscious of individual songs. A CPU (3) in the music player (30) or a CPU (11) in a server (10) detects or receives the size of a free space in a flash memory (34) and a playback history (a substantial playback count Kp, which denotes the number of times a song was continuously played for a duration not shorter than a predetermined one, or a skip count Ks, which denotes the number of times a song was played for a duration shorter than a predetermined one) of every song recording in the flash memory (34), and judges whether any song should be deleted from the flash memory (34) to permit a song to be downloaded into the music player (30) from the server (10). If any song should be deleted, the CPU selects a song having a small (minus) evaluation function K (e.g., K=2Kp?Ks) as the song to be deleted.

Abstract: A method of eliminating home-in noise of an optical disc drive without a home limit switch and using a variable step counter, includes: resetting the variable step counter, which counts steps of a stepping motor of an optical pickup, to zero regardless of a position of the optical pickup, when power is applied to the optical disc drive; driving a servomechanism at the position of the optical pickup and then reading a sub-code value of the optical disc to confirm a current position of the optical pickup; calculating a number of tracks from the current position of the optical pickup to a home position and converting the number of tracks into a step counter value to obtain a step counter value of the home position; and moving the optical pickup to the home position through an access operation. The step counter value of the home position is an integer varying depending on the position of the optical pickup when power is applied.

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: 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: An optical disc system with improved signal regulation capabilities and a method for implementing several improvements in the capabilities are disclosed, in that the signals containing information regarding the position of an objective lens in the tracking direction can be acquired accurately and the access to optical discs can be carried out. In the method for acquiring with high precision the signals containing information on the position of the objective lens in the tracking direction, these signals are regulated in response to an access request specifying an access target region on the optical recording disc provided thereon with tracks in the shape of spiral or concentric circle, corresponding to a zone to be regulated including the access target region to be regulated out of a plurality of regulating zones formed by dividing a plurality of the tracks utilizing regulation information acquired previously.

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: 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: In a configuration in which side beams scan in positions that are offset with respect to a main beam by approximately (¼+n)P or (¾+n)P in the radial direction of an optical disk, a differential signal is generated from push-pull signals of the return lights of the side beams to generate a track-cross signal. In a configuration in which side beams scan in positions that are offset with respect to a main beam by approximately (¼+n)P or (¾+n)P in the radial direction of an optical disk, far-side or near-side light detection results of the return lights of the side beams are processed and computed with respect to a push-pull signal of the return light of the main beam.

Abstract: A method and apparatus for canceling noise from track cross signal includes binarizing the track cross signal with reference to at least two reference values, and removing noise from the binarized track cross signal based on a command speed according to which a tracking actuator moves a pickup. Accordingly, it is possible to remove noise from a track cross signal so as to obtain information regarding precise speed of track searching or position on the track, irrespective of the searching speed.

Abstract: In track jumping operation, an acceleration/deceleration pulse generation portion measures the TE signal amplitude during track jumping, and modifies the acceleration/deceleration time of the acceleration/deceleration pulse according to the measured amplitude to drive a tracking actuator. Also, the acceleration/deceleration pulse generation portion measures the movement time from the start of acceleration until a certain location is reached, and modifies the peak value of the deceleration pulse according to the measured time to drive the tracking actuator.

Abstract: A method of eliminating home-in noise of an optical disc drive without a home limit switch and using a variable step counter, includes: resetting the variable step counter, which counts steps of a stepping motor of an optical pickup, to zero regardless of a position of the optical pickup, when power is applied to the optical disc drive; driving a servomechanism at the position of the optical pickup and then reading a sub-code value of the optical disc to confirm a current position of the optical pickup; calculating a number of tracks from the current position of the optical pickup to a home position and converting the number of tracks into a step counter value to obtain a step counter value of the home position; and moving the optical pickup to the home position through an access operation. The step counter value of the home position is an integer varying depending on the position of the optical pickup when power is applied.

Abstract: An apparatus to control a step motor in an optical disk driving system to move a sled which transfers a pickup unit, including a playing unit, a coarse search unit, and a driving unit. The playing unit generates a first step pulse at a first interval of time set by a disk speed according to a comparison between a sled control signal and a tracking driving signal in a playing mode with a predetermined threshold. The coarse search unit generates a second step pulse at a second interval of time stored in a table according to a number of motion steps and a motion direction corresponding to an amount of motion of the pickup unit due to operations in a search mode. The driving unit drives the step motor based on the first and second step pulses.

Abstract: Disclosed herein is a method of compensating for variations in the track pitches of optical discs. The method includes the step of activating a focus servo and inactivating a tracking servo so as not to trace the tracks of the optical disc. Thereafter, the pickup assembly is transferred across the optical disc to generate the traverse signal caused by differences between the amounts of light reflected by the tracks of the optical disc and the other portions of the optical disc. The traverse signal is shaped into a pulse wave, and the number of pulses of the traverse signal is counted. The rotation number of the optical disc is measured and stored. The track pitch of the rotating optical disc is calculated. Finally, a target track number is calculated, and a seek operation is performed.

Abstract: A method for track seeking of a reading head in an optic disk drive is disclosed. In seeking a track in a disk. the track number and the direction in the fine seek are used for adjusting a voltage waveform in the rough seek. The variation of an optic disk drive due to mechanic friction or torque variation of motor can be overcome so as to achieve the same accuracy as being installed with a speed sensor. Since no speed sensor is required to be installed on the track seeking means, the cost in manufacturing is reduced greatly.

Abstract: A track seeking and track locking method in an optical storage device capable of computing protection intervals such that any state transition of the TEZC signal and the RFZC signal within the computed protection interval is prohibited. The method is also capable of preventing the interference of the TEZC and the RFZC signal due to glitches in the TE signal and the RFRP signal, thus reducing track errors and speed computational errors.

Abstract: A plurality of periodical signals are generated as the moving body moves. The periodical signals are given respective fundamental values. The fundamental value of one of the periodical signals that has a maximum value is detected sequentially. An extension value is generated in such a manner as to be incremented or decremented when the detected fundamental value changes from one unit repetition range to another. Position detection information of the moving body is constructed as a combination of the detected fundamental value and the extension value. The position detection information is stored.

Abstract: A fast-acting method of regenerating track crossing signals for track searches across unrecorded areas on read/write optical discs is provided. This is accomplished by comparing the in-phase and quadrature-phase track crossing signals generated by the optical pickup head when a track search is being performed. A blank signal is generated when no quadrature-phase signal transition occurs between two successive in-phase signal transitions. Fake quadrature-phase signals are continuously generated. Upon occurrence of a blank indicating signal, the fake quadrature-phase signals are immediately supplied to the track crossing counter mechanism in place of the missing quadrature-phase signals. As a result, there is no loss of track count.

Abstract: Even if an assumed value of a track pitch and an actual value thereof are different from each other, an optical pickup (2) can be positioned at a target position at high speed, which can realize higher-speed access.