Abstract: A helical type tape recording and reproducing system records blocks of user data-of predetermined size by reformatting the user data blocks into physical blocks that are recorded on tape. The system format includes helical tracks in which user data blocks are recorded and longitudinal tracks for storing address information relating to the physical layout of the tape and to the content of the recording in the helical area. The system includes a partition access bookkeeping feature that stores information relating to locations at which searching or recording has been performed during a current load of a tape in the system, which is useful in accomplishing efficient searching for user data recorded on the tape. The present invention is directed to system search capabilities, including longitudinal searching along the tape and searching in the helical recording area of the tape.

Abstract: A digital video/audio recording and reproducing apparatus comprising a video signal high-efficiency encoder having a variable reduction rate, an audio signal high-efficiency encoder having a variable reduction rate, and a controller for controlling the reduction rates in both of the high-efficiency encoders. The reduction rates in both of the high-efficiency encoders are controlled in such a manner that the sum of the information amount of the video signal and that of the audio signal, after high-efficiency encoding, is maintained constant. When recording multi-channel audio signals, the reduction rates in both of the high-efficiency encoders are controlled according to the number of audio signal channels to be recorded. The high frequency components of the high-efficiency encoded video and audio signals are recorded at the end portions of recording tracks on a magnetic tape, while the low frequency components thereof are recorded in the central portion of the recording tracks.

Abstract: A digital servo track pattern for a magnetic medium which can be recorded and reproduced by a recording and reproducing system. The servo track pattern has a plurality of digital mark patterns recorded thereon, each of said digital mark patterns having a leading identifier field of digital bits, a trailing identifier field of digital bits and a field of digital synchronizing data located between said leading and trailing identifier fields. The leading identifier field of digital bits is electrically equivalent during reproducing while the medium is moving in a first direction to the trailing identifier field of digital bits while the medium is moving in a direction opposite to said first direction.

Abstract: This invention relates to a method for recording a positioning signal on a disk having a projection pattern. The method includes rotating a magnetic disk having a magnetic layer on a non-magnetic substrate having a projection pattern thereon, flowing the first DC current to a magnetic head, moving the magnetic head in the direction of the diameter over the magnetic disk whereby to magnetize the whole magnetic layer of the magnetic disk in the first direction, then rotating the magnetic disk, flowing the second DC current to the magnetic head, moving the magnetic head in the direction of the diameter over the magnetic disk whereby to magnetize only the magnetic layer of the projection portion of the magnetic disk in the second direction opposite to the first direction so as to record a positioning signal on the magnetic disk.

Abstract: A storage device includes a substrate, a magnetic storage medium provided on the substrate, information being magnetically stored in the magnetic storage medium, a head unit, and a reciprocating mechanism provided on the substrate, the reciprocating mechanism causing the head unit to reciprocate in a plane parallel to a surface of the magnetic storage medium, wherein, while the head unit is being moved by the reciprocating mechanism, information is recorded in or reproduced from the magnetic storage medium via the head unit. The reciprocating motion of the head unit is provided by piezoelectric elements on arms supporting the head, which move the head with a predetermined stroke width in simple harmonic motion.

Abstract: A reproduction signal processing apparatus includes a memory circuit storing a predetermined pattern for deciding equalizing characteristics of an automatic equalizer in response to variation of a reproduction signal, a pattern converting circuit for converting the predetermined pattern outputted from the memory circuit into an equalization target pattern serving as a target of the equalization and correction by the automatic equalizer, an equalization error calculating circuit for producing an equalization error from the equalization target pattern and the equalization signal outputted from the automatic equalizer, and the automatic equalizer executing a partial response waveform process of the reproduction signal on the basis of the equalization error, for correcting the predetermined equalizing characteristics of the automatic equalizer by tracing the fluctuation of the reproduction signal.

Abstract: A digital audio reproduction system for compact discs, digital audio tapes and other similar systems suppresses digital noise present in the frequency band immediately above the audio band. Digital preprocessing combined with narrow output filters result in significant noise suppression without adverse distortion of the desired audio signal. The digital preprocessor may be combined with digital oversampling filters into a single integrated circuit or microprocessor.

Abstract: A look ahead detector based on a delay line is used in a pulse amplitude qualifier circuit to qualify detected peaks in a system for the recovery of magnetically recorded digital information. The analog signal is delayed by one cell period to create a delayed replica which is applied to the peak detector. The difference between the analog signal and the delayed replica is applied to a hysteresis flip flop to create a qualifying signal based on a threshold value proportional to the analog signal to gate the peak detected in the delayed replica.

Abstract: A record storage format conversion method and a system which is capable of mitigating a load imposed on the memory by decreasing the number of accesses to the memory for finding out a CKD record of concern upon format conversion of the CKD records into FBA records while allowing the capacity of a memory required for holding the track data to be decreased. All gaps inclusive of inter-record gaps and inter-field gaps are deleted from variable length records of one track recorded in a variable length format employed in an external storage device of a general-purpose computer. The track data thus obtained is divided into management units each of a predetermined size corresponding to an integral multiple of the size of the fixed length block of the fixed length record.

Abstract: A magnetic recording apparatus of a digital picture signal comprising a block segmenting circuit for converting an input digital picture signal into data segmented by blocks composed of a plurality of picture elements, an encoding circuit for compressing and encoding the output data of the block segmenting circuit by blocks, and a channel encoding circuit for channel encoding the encoded output data from the encoding circuit, wherein the output data from the channel encoding circuit is recorded on a magnetic tape by a magnetic head mounted on a rotation drum, and wherein the magnetic recording apparatus of digital picture data is characterized in that the track pitch formed on the magnetic tape by the magnetic head is 5.5 .mu.m or less, the diameter of the rotary drum is 25 mm or less, and the rotating speed of the rotary drum is 150 rps or more, the track length per unit time is set to particular value thereby.

Abstract: A helical type tape recording and reproducing system records blocks of user data of predetermined size by reformatting the user data blocks into physical blocks that are recorded on tape, with the physical blocks being recorded as double frames. Each double frame is recorded on a set of successive helical tracks, preferably 32 tracks. Each double frame has system format data interleaved with the user data block data which identifies the double frame as being of a particular type. The present invention is directed to the types of double frames that are used to begin a recording, particularly an append recording which involves recording by the system at a previously recorded tape which may have been recorded by a different system, as well as the types of double frame that are used to end a recording.

Abstract: Specified modular arithmetic is applied to input digital data to divide the input data into two main codes and a subcode. Otherwise, input digital data is divided into two pieces of digital data according to a specified rule. The digital data is divided so that the original input digital data can be completely restored if the two main codes and the subcode or both of the divided data are used, and the original input digital data can be nearly correctly restored even when one of the main codes or one of the divided data is used.

Abstract: A magneto-optical disk driving apparatus of the magnetic field modulated recording type is generally provided with a magnetic biasing apparatus, which generates a magnetic field required to record or erase information signals on or from a magneto-optic recording medium. The magnetic biasing apparatus includes a magnetic circuit capable of recording or erasing the information signals on or from the magneto-optical recording medium and a slide member bonded to an open end of the magnetic circuit. The slide member is made up of a crosslinked setting resin, one or two lubricants contained in the setting resin, and a filler embedded in the setting resin. One of the lubricants has a linear molecular structure, whereas the other has a branched molecular structure. The filler is made up of a large number of porous particulates having a specific surface of from 100 to 1000 m.sup.2 /g (measured in accordance with the BET equation) and a large number of whiskers having a diameter in the order of submicrons or less.

Abstract: A circuit apparatus for driving a magnetic head to generate a magnetic field wherein a driving frequency of the magnetic head is increased and a recording density of an information recording medium is raised. In this circuit apparatus, a bridge circuit is constructed in which a chief coil for generating a magnetic field is arranged between a first connection node disposed between a serially connected first auxiliary coil and first switch element and a second connection node disposed between a serially connected second auxiliary coil and second switch element, and the magnetic field is modulated in accordance with an information signal by on-off control of the first and second switch elements to change the direction of current flowing in the chief coil. Further, third and fourth switch elements are respectively connected in parallel with the first and second switch elements so that a current path of the chief coil is separated from respective current paths of the auxiliary coils.

Abstract: A digital information reproducing apparatus is arranged to have a first envelope detecting circuit, a second envelope detecting circuit, an operating unit, a comparator, and a switching circuit. The first envelope detecting circuit serves to detect a envelope on the positive side of the output of an equalizing circuit. The second envelope detecting circuit serves to detect a envelope on the negative side of the output of the equalizing circuit. The operating unit serves to produce a difference of the outputs of the envelope detecting circuits. The comparator serves to compare an output of the operating unit with a predetermined signal level. The switching circuit serves to reduce a time constant on which charges stored in a capacitor of each of the envelope detecting circuits are discharged, based on the output signal of this comparator.

Abstract: The present invention relates to a digital image signal recording/reproducing apparatus and the method thereof which can maintain a track spacing whereto a digital image signal is recorded during a long time mode in the same way as in the normal mode when the digital image signal is recorded on the recording medium, so that the crosstalks between channels caused by narrowed channel spacing of a tape can be prevented to thereby obtain an effect of a clear picture without a picture quality degradation.

Abstract: An improved system for recording and playing back digital information in a special pulse-length modulation format on a disc-shaped record. The digital information is stored in a succession of alternating marks and spaces, both having lengths that are discretely variable in accordance with a succession of multi-bit binary code blocks.

Abstract: In a sector servo type hard-disk apparatus, in the case where a recording medium is not manufacture-formatted, gain control data is written/read in/from a CSS zone of the recording medium after power is turned on and before the first seek is executed. The write/read of the gain control data in/from the CSS zone is also executed in accordance with a peak level of an output signal from an AGC amplifier.

Abstract: Control software and hardware in the tape drive control unit creates and manages a header segment at the beginning of the magnetic tape. This header segment includes an administrative information section that contains data relating to the magnetic tape itself. The administrative information includes read/write status information such as the write protect status of the magnetic tape that enables the tape drive control unit to manage the data records written onto the magnetic tape without reference to any other source of administrative data. In addition, each data record written on the magnetic tape includes a header which denotes the read/write status of the data record.

Abstract: A magnetic field generation mechanism is confirmed by combining a plurality of magnets that generate magnetic fields in different directions. Since the magnetic field strength of the magnet for initialization magnetic field can be increased without increasing its thickness by providing a magnet for amplification that generates a magnetic field in a direction perpendicular to the magnet for initialization, a compact, thin device can be realized utilizing a magneto-optical recording device capable of direct overwrite on switched connection multilayer film. Further, by including a rotatable biased magnet, the device can also be used on prior art rewritable magneto-optical discs.