Abstract: A system for detecting an off-track amount of a present head position with respect to a normal position of a desired track on a disc in a disc storage unit in which a closed loop control is employed to control the position of a magnetic head. A repetitive pattern is stored as reference information in each reference information region on the disc in such a way that it is deviated in the longitudinal direction of a track from the repetitive patterns stored in the adjacent regions. When the reference information in the two adjacent regions is read out by the head, a ramp signal whose gradient is varied in accordance with the position of a desired track is generated in synchronism with the readout of the reference information. The ramp signal is used as a threshold value and the numbers of the repetitive pattern signals obtained from the signals read out from the reference information in the two adjacent regions which are in excess of the threshold value is counted.

Abstract: A compact-disc digital audio player is described in which a user can store preferred selections on selected discs in a memory. The player can identify the disc from the subcode on the disc and can read the corresponding preferred selection out of the memory to play this preferred selection.

Abstract: A stepper motor is coupled via a motion translating mechanism to a transducer for transporting the latter across parallel tracks on a magnetic tape. The transducer has an abutment secured thereto. Rotatable about an axis parallel to the direction of transducer movement relative to the magnetic tape, a rotary stop member is geared to the stepper motor thereby to be driven in synchronism with the linear travel of the transducer. The rotary stop member has a stop arm protruding therefrom for engaging the abutment on the transducer when the latter moves to a limit position on one side of the tracks on the magnetic tape, thereby locking the stepper motor against rotation in one direction via the gearing. Preferably, the stop member has another stop arm engageable with the abutment when the transducer reaches another limit position on the other side of the tape tracks, with the consequent locking of the stepper motor against rotation in the other direction.

Abstract: A video disk recording method and the recorded disk in which a video signal is frequency-multiplexed with a digital data signal into respective frames which are asynchronous to each other. A time code is recorded in both types of frames. The time is incremented periodically but the period in one of the types of frames is occasionally varied to compensate for the asynchronism.

Abstract: An electric control system for an apparatus for writing and reading data on and from a flexible magnetic disk under the control of host equipment such as a central processor unit having an associated controller. The control system includes a time setting circuit responsive to stepping pulses, by which the magnetic head is transported from track to track on the disk, for determining an access time to be elapsed from the moment the head starts to be transported from any track on the disk to any other track thereon to the moment the head becomes stably positioned on the new track. Connected to the time setting circuit is an index pulse suppressor circuit which suppresses any index pulse, indicative of the rotation and angular position of the magnetic disk, that is generated during each access time and which permits the delivery to the host equipment of the subsequent index pulses that are generated after the lapse of the access time.

Abstract: A method and apparatus for measuring the flying height of a slider supporting a magnetic transducer in-situ in a direct manner in an operational magnetic disk storage system. The method and apparatus produce relative motion between the magnetic transducer and a magnetic recording medium at a first velocity so that the resulting air bearing positions the magnetic transducer slider at a first flying height from the magnetic medium. A single signal of constant periodicity is written over a predetermined area of the recording medium by the magnetic transducer, and a readback signal is sensed from the predetermined area of the recording medium to produce a first signal. The flying height of the magnetic transducer slider is lowered to substantially zero, and a readback signal is sensed at the lowered flying height to produce a second signal. The first flying height is then calculated as the ratio, expressed in decibels, of the first and second signals times the wavelength divided by a constant.

Abstract: In an automatic tracking system for a magnetic recording and reproducing apparatus wherein tracking is controlled so as to increase an amplitude of a reproduced signal which is delivered from a rotary head for reproducing a track recorded by a helical scan system, the amplitudes of the reproduced signal are detected at a plurality of points of time within one rotational cycle of the rotary head, and the tracking is controlled so as to increase a minimum value among the detected values at the plurality of points of time.

Abstract: A high density information record of the electrostatic capacitance type which comprises a record substrate on which signal information is recorded as geometric variations. The substrate is made of a vinyl chloride resin, and carbon black which is purified by electrolysis to remove impurities therefrom.

Abstract: Disclosed is an apparatus in which a picture signal is converted into digital signals and the digital signals are recorded into a recording medium, and which is suitable to perform dubbing of the digital signals reproduced from the recording medium. The apparatus employs the component method in which a luminance signal and chrominance signals constituting a picture signal are recorded separately from each other. According to the component method, the sampling frequency of the chrominance signal is set to be about 1/3-1/4 of that of the luminance signal, and therefore the recording/reproducing of a picture signal is carried out after the bit rate of the digital luminance signal is converted into a value equal to the bit rate of the digital chrominance signal.

Abstract: In a multitrack motion analyzer in which video information representing a scene is recorded at a fast frame rate and played back at a slower frame rate, digital data timing and synchronization signals relating to each recorded frame is simultaneously recorded on a separate track as bipolar return to zero (BRZ) FM signals. A Non Return to Zero (NRZ) bit serial digital data signal and synchronous data clock signal are encoded as BRZ digital data signals and then frequency modulated so that the "1" bit, the "0" bit, and the "return to zero" signal levels of the BRZ data signal are converted to three frequencies. The three frequencies are integral multiples and synchronous to the data rate of the NRZ digital data signal so as to eliminate uncertainty between bit boundaries and allow packing more bits per unit time for a given carrier bandwidth. Additionally, accurate synchronization information is recorded and recovered by inserting a missing clock in the BRZ data stream.

Abstract: The apparatus records and reads binary information on a magnetic disk having magnetizable surfaces subdivided into a plurality of concentric tracks in which the information is recorded in block form (sectors). A first electric motor rotates the magnetic disk at a substantially constant angular velocity, and a second motor (22) of stepping type is operable to position the magnetic recording and reading heads (16, 17) with respect to the recording tracks of the disk. On each track, each block of binary information contains prerecorded burst information which, when read by the corresponding magnetic head, is capable of causing micrometric rotary adjusting movements of the stepping motor to bring the magnetic head into precise alignment with the selected recording track and to hold it in that position. Thus amplitude information from two bursts either side of the center line of the track is compared (52, 55, 59, 58) to provide a signal (.mu.STEP) when the amplitude discrepancy exceeds a threshold, and a signal (.

Abstract: A recording/reproducing apparatus for an optical recording card is disclosed, which comprises an optical recording card (10) provided with an optical recording medium (11), a recording light source (5) for recording an information signal on the recording medium (11), a reproduction light source (1) for reproducing the information signal recorded on the recording medium (11) and a line sensor (15) for reading out the information recorded on the recording medium (11) from the light beam reflected from the recording medium (11). A light path of a light beam emitted from the recording light source (5), a light path of a light beam emitted from the reproduction light source (1), and a light path of the light beam reflected by the recording medium (11) are independent of one another.

Abstract: An apparatus for reproducing a pair of color component signals which have been time-axis compressed and recorded sequentially in recording tracks on a recording medium. During a reproducing operation, shift registers in the color component signal reproducing apparatus carry out time-axis expansions of the respective color component signals and restore the latter to the same timing. A write clock output interval for each of the shift registers is arranged intermediate one read clock output operation and a subsequent read clock output operation for that shift register so that overlap between the write and read operations can be prevented in a time axis processing circuit of simple construction.

Abstract: A rotating head wheel for a recorder wherein the head wheel is additionally displaceable in the direction of its axis of rotation. The displacement is produced by mounting the head wheel on a threaded spindle which rotates in the same direction as the head wheel and whose rate of rotation is variable.

Abstract: A recording format on a recording medium comprises a data portion (4) in which a data train should be recorded. The data portion (4) comprises a user data portion (44 and 47), a check data portion (45) and resynchronizing pattern portions (46). The data train is divided into m or 4 code words, each code word being n=148 bytes. The resynchronizing pattern portions (46) are added to the data train for every m.times.3=12 bytes of data to be recorded, and serves to recover data synchronization in the event that data synchronization is missed. Each code word having a check data portion (45) is capable of correcting errors of T bytes, and errors generated in each code word by missing of data synchronization can be corrected.

Abstract: An optical disc recording and reproducing apparatus incorporates apparatus for recording a modulated signal on an optical disc, using a laser beam, and apparatus for optically reading a signal recorded on the disc. In both recording and reproducing modes, an optical signal is produced from the disc and used to supply a control signal to a servo system, for controlling the position of the laser beam relative to the optical disc. Apparatus is provided for subtracting, from the servo control signal, the low frequency components in the modulated signal being recorded on the disc, to improve the accuracy of focus and tracking of the laser beam relative to the optical disc.

Abstract: Disclosed herein are an improved method and apparatus for optically reading pre-recorded magnetic information on a magneto-optic recording element. The invention addresses the technical problem of minimizing the adverse effect of unpredictable variations in the state of polarization of the beam of radiation used for read-out. Such variations may be produced, for example, by birefringence variations in a transparent layer or substrate through which the recorded information is recovered. According to the invention, the undesired polarization variations are sensed from the system's output signal, and an error signal representative of such variations is produced. Such error signal is used to adjust the state of polarization of the read-out beam prior to detection by the system's detector elements. Preferably, the read beam is directed through the combination of a quarterwave plate and a Faraday rotator, and the error signal is used to control the magnetic field of the Faraday rotator.

Abstract: An integral tape path assembly (110) includes a head subassembly (112), a buffer/guide subassembly (114) and a spaced sensor/guide subassembly (116), all mounted to a common tape path plate (118). The buffer/guide subassembly includes a buffer arm (126) which pivots about an axis shared by a fixed guide (128). A Hall-effect position sensor (186) can be mechanically calibrated via an aperture (142) in a housing (132). The speed sensor/guide subassembly includes a roller (148) which serves to guide the tape on the take-up side of the tape drive system and to drive a shaft (152) holding a speed indicator (156) for a speed sensor (158). The speed sensor/guide subassembly includes a fixed-orientation washer (206) for urging the tape against an upper flange (208) of the roller. The washer is off-center sprung to counter distorting forces engendered by the tape as it engages the roller.

Abstract: In a compatible recording and reproducing apparatus which is capable of recording and reproducing information on both a video disk and a digital audio disk, a relative angle between an optical axis of a laser beam emitted from a pickup and the disk is adjusted so as to be suitable for the disk loaded on the apparatus. Further, the movement of the pickup in the radial direction of the disk is regulated in accordance with the difference in the outer diameter of the two kinds of disks. A problem due to the difference of the track pitch in the two kinds of disks is solved by moving the pickup in a direction perpendicular to a radial direction of the disk. In addition, an objective lens for focusing the laser beam on the disk is selected within a predetermined range of an effective numerical aperture in order to simplify an optical system of the apparatus.

Abstract: A recorded data reproducing apparatus according to the invention includes a memory section having a gain data table for storing gain data determined in accordance with a cylinder position above a recording medium. Using the data representing the current cylinder position, the optimum gain data is determined from the gain data table, and supplied to a read pulse generator section under control by a control section. With this arrangement, the gain adjusting circuit is simplified, and the gain adjustment process is also simplified.