Abstract: In order to record audio signals on a magnetic record carrier, there is produced a high frequency pulsed signal which contains the low frequency information pertinent to the audio signal. This high frequency pulsed signal is produced in a manner such as to be substantially free of any signal component which has a frequency lying in the frequency range of the low frequency audio signal. As a result, cross-talk produced during recording on a plurality of tracks can be substantially reduced.

Abstract: An erasing device for a magnetic video recorder is disclosed which includes a means for reproducing a code signal and a video signal from a magnetic medium. The code signal is discriminated to decide whether the video signal is a field video signal or a frame video signal. When the video signal is discriminated to be the frame video signal, the erasing device erases the video signal over a broader range than when the video signal is discriminated to be a field video signal.

Abstract: A technique and associated arrangement for detecting loss of phase/frequency lock in a phase lock loop, particularly for a magnetic disk drive servo system the phase lock loop detects timing asynchronism and loss of lock.

Abstract: The present invention relates to a control circuit for a double deck cassette tape recorder, and comprises switches, resistors, transistors and diodes. A plurality of transistors control the specific circuitry functions of the tape recorder. These transistors are in turn controlled either by switches, directly or indirectly, through other transistors. The present invention offers advantages such as simple structure, low production cost, ease of operation and prevention of confusion or mistakes in operation.

Abstract: In an arrangement for recording data or a magnetic recording medium, the inputs of an amplifier whose outputs are connected to a magnetic head are preceded by filters which delay magnetic bias signals and data signals supplied to the amplifier and limit their steepness. Undesirably high voltages at the magnetic head as a consequence of excessively steep edges of a write current supplied to the magnetic head are thus avoided, and the reliability of the recording of the data on the magnetic recording medium is increased.

Abstract: This invention relates to method and apparatus for recording and/or reproducing a PCM (pulse-code-modulated) digital audio signal. According to this invention, all samples are recorded by a predetermined data format so that it becomes possible to satisfactorily and accurately record and/or reproduce PCM digital audio signals which are not synchronized with each other.

Abstract: A magnetic reproducing apparatus in which a synchronizing signal is read only if the signal of an erase signal at a set frequency is less than a predetermined level.

Abstract: An improved cassette tape recorder is provided for storing the time message, generated by the real time clock of the central processing unit, into a tape region between a first record and a second record immediately behind the time message so that it can be digitally displayed everytime it is necessary. The time message includes time data of year, month, day, week, hour, minute and second, etc.

Abstract: A mode of writing synchronization information on a magnetic recording carrier (DISC) where the information is written in binary code and distributed over a plurality N of tracks, each track being associated with at least one reference zone (ZRP.sub.ij) which includes a group of preamble information (ZSY.sub.ij +ZSA.sub.ij), a group of absolute address information (ZAD.sub.ij), and a group of fine-position information (GDP.sub.ij). According to the invention, the mode of writing is characterized in that the preamble information group includes a first subgroup (ZSY.sub.ij) of synchronizing information preceding a second subgroup of automatic gain control (ZCA.sub.ij). The invention is applicable to magnetooptical memories.

Abstract: A magnetic tape recording signal level automatic adjustment device includes: a reproduced signal level attenuator responsive to an attenuation changeover instruction for attenuating the level of a reproduced signal from a PCM audio signal reproduction device by a predetermined quantity; and an attenuation controller responsive to a sampling instruction for comparing the reproduced signal level with a reference value and outputting the attenuation changeover instruction when the reproduced signal level exceeds the reference value.

Abstract: An information signal reconstructing method and apparatus for use in an optical disk system is provided. Data stored on an optical disk in a binary format is optically scanned by a photodetector to provide a detection signal. The average of this detection signal is first determined and then, using the thus determined average, the detection signal is subjected to an amplitude limiting operation so that there is obtained an output signal as an information signal reflecting the binary information of the data stored on the optical disk. During the amplitude limiting operation, the signal is so processed to have the same positive and negative amplitudes with respect to the average which is set at a zero level.

Abstract: A rotary head type digital signal reproducing device for reproducing digital signals recorded on a tilted track of a magnetic tape. The recording device includes rotary heads HA,HB which reproduce digital signals recorded on the magnetic tape; a memory 23, connected to the rotary heads, for storing the reproduced signals; a correcting circuit 24, connected to the memory, for correcting signal errors in the stored digital signals; a digital to analog converter 25, connected to the correcting circuit, for converting the digital signals to analog signals; a tracking circuit 27, connected to the memory, for generating a tracking error signal from the digital signals; and a reel motor 28, connected to the tracking circuit, for controlling a reel 16 of the magnetic tape in accordance with the tracking error signal.

Abstract: The subject invention provides a digital Storage System such as a Winchester Hard Disk Drive System having a motorized hard disk drive assembly which interacts with a head positioner to read and write data and timing instructions onto a plurality of disks driven by the assembly. The drive system includes a data separation circuit for reconstruction of data recorded on the hard disk. The data separation circuit includes a phase-locked loop system. The phase-locked loop system includes a phase comparison circuit, a voltage controlled oscillator, a control circuit including a capacitor for controlling said oscillator, and a charge pump for pumping up and pumping down the control circuit. Except for the phase comparison circuit, the entire phase-locked loop system is provided on a monolithic integrated chip.

Abstract: A digital signal recording and reproducing apparatus comprising a dynamic range compression/expansion apparatus. The compression/expansion apparatus receives a digital signal from, for example, an analog-to-digital converter and compresses the dynamic range of the digital signal and the so compressed digital signal is supplied to a recording signal processing circuit in the recording operation mode, while the apparatus receives a digital signal reproduction output from a recording/reproducing head and expands the dynamic range of the reproduced digital signal and the so expanded digital signal is supplied to, for example, a digital-to-analog converter in the reproducing operation mode.

Abstract: An information signal recording apparatus having a rotary recording head and a rotary erase head is arranged to control timing for a start of recording by the recording head on the basis of the reproduction output of the rotary erase head.

Abstract: A signal read out circuit included in a magnetic recording device is disclosed in which plural kinds of slice levels are used simultaneously for a reproduced analog waveform to produce a plurality of gate signals corresponding to the slice levels, and it is judged on the basis of the gate signals whether each portion of the reproduced waveform is correct or not in producing a digital output.

Abstract: A magnetic tape transfer printing apparatus including a drum mounted for rotation. A master magnetic tape having information recorded thereon is held in contact with a slave magnetic tape on a portion of the circumferential surface of the drum. A magnetic transfer bias field is applied to transfer the information from the master magnetic tape onto the slave magnetic tape. The drum contains a high-permeability magnetic material at least in the circumferential surface. This is effective to decrease the lateral component of the bias magnetic field and increase the vertical component of the bias magnetic field, thereby minimizing the degree of demagnetization of the master magnetic tape during the transfer printing process.

Abstract: A magnetic recording medium is provided comprising a flexible substrate and a ferromagnetic metal thin film layer on the substrate primarily comprising cobalt. When coercive force is measured by changing the measuring direction in a plane defined by a longitudinal direction of the substrate and a direction normal to the major surface of the substrate, the following relationship is met:(Hc.sub.max -Hc.sub.min)/Hc(O).ltoreq.0.9where Hc.sub.max is the maximum of the coercive force, Hc.sub.min is the minimum of the coercive force, and Hc(O) is a coercive force in the longitudinal direction of the substrate. The medium has in average at least 10.sup.5 /a.sup.2 protrusions per square millimeter of the surface, the protrusions having a height of 30 to 300 .ANG., where a is the distance as expressed in .mu.m of a gap in a magnetic head across which the medium is passed for recording and reproducing operation. The filling ratio of the ferromagnetic metal thin film layer is at least 0.7.

Abstract: A rotary head type digital tape recorder in which a PCM signal and sub data for control and the like concerned with the PCM signal are recorded and/or reproduced by rotary heads. The invention relates to a method and apparatus for transmitting and/or receiving a digital signal in such a type of digital tape recorder by using a data format such that when the serial data is input and output each of a predetermined number of words of the reproduced PCM signal and each symbol of the reproduced sub data are transmitted as a pair synchronously with the rotation of the rotary heads. Thus, a large amount of sub data can be input and output together with the PCM signal.

Abstract: A recording/reproducing system is provided with a PLL circuit for outputting data pulses and clock pulses on the basis of the read data reproduced from a magnetic recording medium. An external synchronization detection circuit is provided which detects the synchronization data (predetermined zero pattern data), recorded in synchronization areas of the magnetic recording medium, on the basis of the read data. When the synchronization data is detected, the synchronization detection circuit enables the PLL circuit to oscillate in synchronism with the read data. An internal synchronization detection circuit is provided, which detects the synchronization data (predetermined zero pattern data), as recorded in the synchronization areas of the magnetic recording medium, on the basis of data pulses derived from the PLL circuit and the clock pulses. A preventing circuit is further provided.