Abstract: An optical disk player for compensating a waveform distortion of a read signal which is caused due to a skew in the track tangential direction of an optical disk. An optical disk is constructed in a manner such that a skew amount of the irradiated portion of a recording surface of the optical disk for a light beam irradiated onto the recording surface of the optical disk is detected from the pickup and transmitting characteristics of a read signal generated from the pickup are controlled in accordance with the detected skew amount. A waveform distortion of the read signal due to a warp or distortion existing in the track tangential direction of the optical disk can be compensated and the recording data can be accurately reproduced.

Abstract: A spindle servo apparatus for an optical disk player, which detects a maximum inversion interval or a maximum period from a read signal acquired from an optical disk by pickup means, compares the detected maximum inversion interval or maximum period with a reference value, and drives a spindle motor in accordance with the comparison result. When a tracking servo apparatus is inactive, the spindle servo apparatus sets the reference value greater than the one set when the tracking servo apparatus is active. It is therefore possible to cope with the case where the maximum inversion interval or maximum period which is detected from the read signal is erroneously determined longer than the actual length.

Abstract: A beam power control apparatus comprising a beam generator for emitting a recording beam, a detector for detecting the light intensity of the recording beam and generating the corresponding detection signal, a sample pulse generator to generate a sample pulse corresponding to the duration holding a lower and/or higher level in an information signal being recorded, sample-and-hold circuit for sample-and-holding the detection signal in response to the sample pulse, and feedback control system for controlling the light intensity of the recording beam taking a lower and/or higher level constant in accordance with the detection signal sample-and-held. The sample pulse generator stops the generation of the sample pulse if the duration of the holding lower and/or higher levels of the information signal is shorter than a predetermined time length.

Abstract: Optical disk information recording apparatus and reproducing apparatus are designed to efficiently improve the transfer rate in information recording and reproduction, and have compatibility with the existing recording apparatus and reproducing apparatus using a single light beam while keeping the disk form with a single spiral track structure. Beam spots are simultaneously irradiated on a plurality of different radial positions on a disk at a pitch of a predetermined number of tracks to independently record various information signals, and the optical head is allowed to jump over a predetermined number of tracks every time the disk makes a predetermined number of turns.

Abstract: Optical disk information recording apparatus and reproducing apparatus are designed to efficiently improve the transfer rate in information recording and reproduction, and have compatibility with the existing recording apparatus and reproducing apparatus using a single light beam while keeping the disk form with a single spiral track structure. Beam spots are simultaneously irradiated on a plurality of different radial positions on a disk at a pitch of a predetermined number of tracks to independently record various information signals, and the optical head is allowed to jump over a predetermined number of tracks every time the disk makes a predetermined number of turns.

Abstract: An optical pickup is provided with a slider for transporting the optical pickup in a direction of crossing a track on an optical disk, and a tracking unit mounted on the slider movably in the direction of crossing the track. A rough seeking mode to access a desired track on the optical disk at a high speed is set as one operation mode of the optical pickup.

Abstract: A method of performing a reproduction of a high-speed audio data in a CD-ROM player comprises the steps of; reading EFM demodulated data from the disk at a high speed, writing the thus read data one after the other into a CD-ROM data storage as an input buffer of an audio signal processing section, reading out the written data at the same frequency as the sampling frequency thereof, transmitting the data read out from the CD-ROM data storage sequentially to the audio signal processing section, stopping the EFM demodulated data writing operation to the CD-ROM data storage when the address for writing the data is on the verge of exceeding the address which is not read out yet, simultaneously jumping the optical disk back for a certain pitch corresponding to a predetermined number of tracks to read in again, and resuming the data writing operation from the point where the data writing was previously stopped when a predetermined number of vacant addresses is made in the CD-ROM data storage by the above data readi

Abstract: A spindle control apparatuses for a disk player allows a quick search of recorded data on a disk carrying a plurality of types of data that should be read out at different reading velocities. A spindle servo loop is rendered open in response to a command and a normal rotational velocity of the disk necessary to read out recorded data at a specific address is computed. Then the disk's rotational velocity is accelerated or decelerated in a single step until it coincides with the designated rotational velocity and the servo loop is closed when these velocities coincide with each other. This allows quick and stable locking of the spindle servo loop during the searching period, so that the searching velocity is raised considerably.

Abstract: A spindle servo circuit for controlling the speed of rotating a disk. The loop gain of the servo loop is changed in response to the change in the linear velocity when the linear velocity is changed by changing the frequency of a master clock. With this feature, stability of the servo characteristic is always assured so that the speed of data recording is increased by the increase in the linear velocity.

Abstract: A servo device for a disc player detects when the level of an error signal formed according to the output signal of the pickup is equal to or higher than a predetermined value, to provide a detection output. The device also detects when the frequency of the error signal is equal to or higher than a predetermined value, to provide another detection output. Then, it is determined from these detection outputs whether, during the closure of the servo loop, an oscillation occurs within the servo system by the servo convergence or by external interruption, so that the oscillation of the servo system can be positively detected and servo convergence resumed. The system may be implemented in either hardware or software.

Abstract: A disk playing apparatus having a compensating circuit for compensating phase and frequency characteristics of a read signal from a disk, wherein a compensation characteristic of the compensating circuit is varied according to a linear velocity. The disk playing apparatus includes means for reading information from the disk and means for outputting velocity information indicative of a reading speed from the disk by the reading means. The compensation characteristic is varied according to the velocity information. Accordingly, in the case of a CLV disk, a flat group delay characteristic is always obtained irrespective of changes in the linear velocity.

Abstract: In a tracking servo system for use in a disc player having a pickup, for playing an information recording disc having a recording track, the peak value of the tracking error signal obtained during a track jump operation is detected, and at least one of the pulse width and the pulse height of the deceleration pulse for the jump operation is varied in response to the detected peak value. With this feature, an appropriate control amount for the track jump operation corresponding to the track pitch is obtained even if there is a change in the track pitch.

Abstract: A tracking servo system for use in a disc player having a pickup, for playing an information recording disc having a recording track, the tracking servo system comprises an equalizing circuit for compensating for the frequency characteristic of the tracking error signal for the tracking servo operation, the equalizing circuit means performing a compensating operation in accordance with a predetermined compensation characteristic during a normal playback of the recording disc.

Abstract: A PLL circuit for use in a disk playing apparatus is constructed such that an oscillation output of a VCO is frequency divided at a frequency dividing ratio corresponding to a designated linear velocity in the disk playing apparatus. The frequency divided signal is derived as a reproduction clock signal and a gain of a variable gain amplifier which amplifies a phase error signal and uses the amplified signal as a control voltage of the VCO is changed in accordance with the designated linear velocity, so that a stable loop characteristic is always obtained.

Abstract: There is provided a tracking servo apparatus of a disk player comprising: off-track detecting means for detecting that an information reading spot of a pickup does not exist on an information recording track of a disk and for generating an off-track signal; and level control means for increasing an amplitude of a tracking error signal when the off-track signal exists, whereby the stable tracking servo operation can be executed.

Abstract: To perform a track jumping operation, fine adjustment means is forcibly driven by a speed error signal corresponding to a difference between a moving speed of an information detection point and a predetermined reference speed so that the information detecting point is controlled to jump over tracks at the predetermined reference speed and more a designated distance. Simultaneously, rough adjustment means is forcibly driven by an integrator means which integrates the speed error signal.

Abstract: A high-speed search method for searching a target address and for use in a disc player system having a slider for positioning a pickup for reading an information signal recorded on a disc as tracks, in a disc radius, and a tracking servo system for causing an information detecting point of the pickup to follow the track. An accelerating-and-decelerating move control mode in which the slider is accelerated and subsequently decelerated with the tracking servo loop open, and a constant speed move control mode in which the slider is moved at a constant speed by using address data obtained from a signal from the pickup are prepared, and a distance from a present position of the pickup to the target address is detected.

Abstract: A carriage driving apparatus for a disk player in which the stability and responsiveness of the feedback loop are improved. The carriage driving apparatus includes a driving coil disposed in a magnetic path extending in the radial direction of a disk for driving a carriage carrying a pickup in the forward/backward direction of the magnetic path in response to a driving current, a velocity detecting coil disposed in the magnetic path for generating a velocity detection output in accordance with changes in flux, and velocity detection correcting device, including a leakage correction equalizer and arithmetic circuit, for correcting the detection output of the velocity detecting coil in accordance with the frequency and intensity of the driving current flowing in the driving coil.

Abstract: A disk player and a method for operating a disk player in which the picture scanning speed for both a constant angular velocity disk and a constant linear velocity disk are made constant and independent of the characteristics of the slider which carries the pickup or of the radial position of the pickup relative the inner radius of the disk. During a jump operation, the number of tracks detected by a track counter is compared with a designated value, and the jump operation is repeated if a scanning command is still present at the end of the previous operation. In the case of a constant angular velocity disk, the designated value is a fixed value, whereas the designated value is calculated in accordance with the present position of the pickup for a constant linear velocity disk.

Abstract: A servo loop particulary useful for a focusing or tracking servo in an optical disk. The peak-to-peak value of an error signal in the servo loop is detected while the optical pickup is being driven perpendicularly to the disk in focusing or transversely to the disk in tracking. The detected peak-to-peak value is used to adjust the gain of a variable gain amplifier included in the servo loop.