U.S. Philips Corporation

Albert M Rijckaert

Edmond De Niet

Josephus A Kahlman

Peter H De With

Adrianus J Denissen

Joannes A Van Der Kop

Marinus Ah Looykens

Wilhelmus Jacobus Van Gestel

Gerrit J Keesman

Ronald W Saeijs

Henricus Marie Ruyten

Eric H Persoon

Hartmut Schandl

Werner A Heijnemans

Johannes J Schoenmakers

Stephanus J Nijssen

Johannes F Hoefnagels

Anthonie Walraven

Pieter G Van Leeuwen

Johannes J Van Vlerken

Dietfried Suss

Martijn H Hofelt

Hugo A Cramer

Jacobus P Beun

Roelof Vreeken

An apparatus for recording a digital information signal and a subcode signal in slant tracks (FIG. 1) on a record carrier (140), includes an input (111) for receiving the digital information signal and an input (123) for receiving the subcode signal. Portions of information of the subcode signal are accommodated into subcode signal blocks (FIG. 2) and portions of information of the information signal are accommodated into information signal blocks (main sync blocks, FIG. 1). The subcode signal blocks and the information signal blocks are combined into a composite signal for recording the tracks on the record carrier. Time code signals are generated and accommodated in specific subcode signal blocks in the subcode signal recording portion having sequence numbers that satisfy the following formula:

Recording of subcode signals in slant tracks on a record carrier

In a system (1) for recording and/or reproducing information signals on/from at least one record carrier (13), which system comprises an apparatus (2) and at least one cassette (3) for use in the apparatus (2), each cassette (3) comprises at least one indicator which by means of one of its parameters indicates at least one characteristic value of an element of the cassette (3), and the apparatus (2) comprises a detection device (97, 101, 78) for the detection of this indicator parameter. At least one electrical impedance (R5, R6) is arranged in a cassette (3) as an indicator of a cassette (3), the impedance value of this impedance defining the parameter for the indication of a characteristic value, and the detection device (97, 101, 78) being adapted to directly or indirectly detect the parameter defined by the impedance value of the at least one impedance (R5, R6).

System for recording and/or reproducing information signals, as well as

When recording a preamble signal and nT precoded data, a switch is provided for obtaining a serial datastream of the preamble signal and the precoded data for recording in a track on a record carrier. Various solutions are described for improving syncword detection upon reproduction of the recorded data. In one such solution, an nT precoder is provided. The nT precoder includes a signal combination unit and a delay unit for realizing a signal delay of nT. Further, a switching unit is provided having a first and a second input, an output and a control signal input. The second input of the switching unit is coupled to an output of the signal combination unit, and the output of the switching unit is coupled to an input of the nT delay unit.

Apparatus for recording a digital information signal in a track on a

A magnetic-tape recording/reproducing arrangement of the 'helical scan' type adapted to record and/or reproduce a digitally coded video signal, includes a coding device (3). In the recording mode, the coding device (3) performs channel-encoding upon a digital recording signal (C) so as to form a channel signal (D) for recording on the magnetic tape (7.1). In the reproduction mode, the coding device (3) performs channel-decoding upon the channel signal (H) read from the magnetic tape (7.1), so that a digital reproduction signal is formed which is a replica of the original recording signal (C). For this purpose, the coding device (3) includes a data sequence generator (3.3) adapted to generate a data sequence (E) defined by the polynomial P(X)=X.sup.15 +X.sup.A +1, where A=7 or 8. Furthermore, the coding device (3) may include an XOR circuit (3.2) in which the signal (C, H) to be processed is combined with the generated data sequence (E), and a selection circuit (3.1) for selecting the signal to be processed (C, H) from the recording signal (C) and the channel signal (H), in dependence upon the mode of operation of the recording/reproducing arrangement.

Magnetic-tape recording/reproducing arrangement comprising a coding

A method and device for use with helical scan data recording by implementing a Reed-Solomon product code, a unitary medium comprising such data, and a cassette comprising such medium. Error protective data encoding for use with rotary head helical scan tape-recording is done by providing a first word-wise Reed-Solomon code along each recording track defined in first code words, and a second Reed-Solomon code defined in second code words. The first and second Reed-Solomon codes together form a product code format. Each second codeword has a sequence of symbols across a plurality of contiguous tracks. The symbols of a single second codeword have substantially uniform displacements between contiguous symbols both in a direction parallel to a length of the tape, and also in a direction perpendicular to a length of the tape. Each second codeword extends substantially along a length of the tracks associated to the recording.

Method and device for use with helical scan data recording by

An apparatus of the helical scan type for reproducing a digital video signal from slant tracks (T) on a record carrier, the digital video signal having been recorded in first track portions (TP1) of the tracks. In an edit mode, the digital video signal is reproduced from the first track portions and a corresponding digital audio signal is recorded in second track portions (TP2) of the tracks. The apparatus includes at least one read head (RH) for reading the digital video signal recorded in the first track portions of the tracks and at least one write head (WH) for writing the second channel signal in the second track portions. The read head (RH) and the write head (WH) are positioned on a rotatable head drum at such a location relative to each other that when the read head reads the digital video signal from a first track portion of a first track (T.sub.i+24), the write head writes the second channel signal in a second track portion in a second track (T.sub.i), the second track being spaced a specified number (24) of tracks away from the first track.

Recording/reproducing apparatus of the helical scan type

A phase-locked loop includes an input terminal (1) for receiving a binary signal, a phase comparator (3) having a first input (2) coupled to the input terminal (1), having a second input (4), and having an output (5) coupled to an input (9) of a control-signal-controlled oscillator (10) via a control-signal generator unit (7). An output (11) of the oscillator is coupled to the second input of the phase comparator. The phase comparator derives a first pulse (P.sub.1) and a second pulse (P.sub.2) in response to a signal transition from a first value to a second value in the binary signal applied to the first input and an oscillation signal applied to the second input, the first pulse having a pulse width which is a measure of the phase difference between the binary signal and the oscillation signal, and the second pulse having a pulse width proportional to 1/2.f.sub.o, where f.sub.o is the frequency of the oscillation signal. The control-signal generator unit (7) derives a control signal from the first pulse and the second pulse and applies the control signal to the oscillator, and the control-signal generator unit derives such a control signal from the first pulse and the second pulse that the phase difference is controlled substantially toward zero.

Phase-locked loop, phase comparator for use in the phase-locked loop,

A reading apparatus for reading information recorded on a first longitudinal recording medium in the form of helical scanned information tracks, according to a first format in which the tracks have been recorded on the medium at a first track pitch and have a first track width, the information being read by the apparatus at a given tape velocity, the information being read from the first medium at a first bit rate, immediately adjacent tracks exhibiting alternately a first and a second azimuth angle, pilot tones being recorded in information tracks, the frequency of the recorded tones cycling through at least two different frequencies (f1, f2); and a second longitudinal recording medium recorded in the form of helical scanned information tracks, in accordance with a second, new, format in which the information track pitch is substantially twice the first track pitch, the information track width is greater than the first track width, the information being read from the second medium at substantially half the first bit rate, all of the information tracks on the second medium exhibiting the same azimuth angle, this angle being one of the first and second azimuth angles, immediately adjacent tracks containing pilot tones having mutually different ones of at the least two frequencies (f1, f2).

Information track format and reading and recording apparatuses therefor

An arrangement for producing a digital signal from an input (e.g., analog) signal obtained from a transmission medium. The arrangement includes a variable equalizer for equalizing the input signal as regards magnitude and phase as a function of frequency to produce an equalized signal, an equalizer control signal generator for generating first and second control signals for controlling the variable equalizer and a detector for producing the digital signal from the equalized signal. The arrangement further includes a bit array selector (i.e., a bit sequence detector) for generating one or two selection signals upon detection of one or more specific bit arrays (i.e., bit sequences) in the digital signal, and a sample-and-hold unit which samples one or more portions of the equalized signal under the influence of the one or two selection signals so as to produce at least one first sample value and at least one second sample value. The first and second control signals are derived in whole or in part from arithmetical combinations of the at least one first sample value and the at least one second sample value. The variable equalizer equalizes the input signal as regards magnitude in response to the first control signal and as regards phase in response to the second control signal.

Receiving arrangement including a variable equalizer, which variable

Video images are encoded by transform coding, resulting in data blocks each including a DC-coefficient and a plurality of AC-coefficients. The coefficients of a number of said transform blocks are variable-length encoded and transmitted. In order to avoid a complete loss of datablocks in case of a transmission error, the most significant codewords of a group of blocks are transmitted first so as to achieve that at least the DC-level of the blocks is likely to be retained. The coefficients may also be recorded on a videorecorder. Fast playback of recorded images so encoded, leads to very poor quality because some data blocks are not being read in the search mode. To improve this quality the DC-coefficients and if desired predetermined AC-coefficients of selected ones of the transform blocks to be recorded on one track are packed together to form a DC-packet and such packet is recorded on a selected part of the track. The DC-packet is chosen such that it can be read out as a unit at various search speeds, and can be read partially at higher search speeds.

Method of and system for transmitting and receiving digitally encoded

An apparatus for recording an electric signal (A) on a magnetic record carrier (1) includes at least one pair of write heads (K.sub.1, K.sub.2) having a mechanically rigid coupling to each other and arranged on a head drum (40). The record carrier (1) is wrapped around the head drum through a wrapping angle .alpha.. The pair of heads (K.sub.1, K.sub.2) writes pairs of tracks (T.sub.1, T.sub.2 ; T.sub.3, T.sub.4 ; . . . ) on the record carrier. The apparatus further includes a signal separator (4) for dividing the electric signal into consecutive blocks, after which the signal blocks having odd sequence number (B.sub.1, B.sub.3, . . . ) are applied to a first output (5) and the signal blocks having even sequence number (B.sub.2, B.sub.4 . . . ) are applied to a second output (6). In a time-base correction circuit (7) the signal blocks (A.sub.1, A.sub.2) are time expanded or compressed. .alpha. Differs from 180.degree.. Signal blocks having odd sequence numbers are delayed in time relative to signal blocks having even sequence numbers (16). Subsequently, the signal blocks thus processed are recorded. Time compression or expansion is effected by a factor of .alpha.*n/(180*(M+1), where n is the number of head pairs and M is the number of times within a specific time interval that a head pair which comes in contact with a record carrier during said time interval does not record a signal in the record carrier, this time interval being defined by those instants at which two consecutive track pairs are recorded by one or two head pairs.

Apparatus for recording and/or reproducing an electric signal on/from a

Receiving arrangement including a variable equalizer which variable

Arrangements for recording and reproducing datareduced videoinformation are described. The recording arrangement comprises a datareduction unit (3) and a formatting unit (4). The formatting unit (4) generates packets (P.sub.i) each having a first, second and third packet portion (PP.sub.1, PP.sub.2 and PP.sub.3). The first packet portion comprises a sync word (SW) and an identification word. The second packet portion comprises datareduced videoinformation of a first and a second datablock (MB.sub.0, MB.sub.1). A datablock comprises DC coefficients (DC.sub.i) and most significant and least significant AC coefficients (MAC.sub.i, LAC.sub.i). The videoinformation comprised in the first and the second datablock are stored in the second packet portion (PP.sub.2), such that the DC coefficients of the first datablock (DC.sub.0) are stored first, the plurality of most significant AC coefficients (MAC.sub.0) of the first datablock are stored next, the DC coefficients of the second datablock (DC.sub.1) are stored last in the second packet portion, and the plurality of most significant AC coefficients (MAC.sub.1) of the second datablock are stored before the DC coefficients of the second datablock in the second packet portion. This enables an improved reproduction of the videosignal in a feature mode.

Arrangement for recording or reproducing data reduced video information

A magnetic recording arrangement records a first digital signal, for example a subcode signal, in a first track portion (TP1), a second digital signal, for example a digital audio signal, in a second track portion TP2, and a third digital signal, for example a video signal, in a third track portion (TP3) in a track on a magnetic record carrier. The first, the second and the third track portions are separated from each other by edit gaps (G.sub.3, G.sub.4). Moreover, viewed in a direction from the beginning towards the end of the track, the first, the second and the third digital signals are recorded in this sequence in the first, the second and the third track portions, respectively, and the length of the third track portion is greater than the length of the second portion. Furthermore, the length of the second track portion is greater than the length of the first track portion. Preferably, the length of the edit gap (G.sub.3) between the first and the second track portions is smaller than the length of the edit gap (G.sub.4) between the second and the third track portion.

Arrangement for recording a first, a second and a third digital signal,

An apparatus for recording an electric signal (A) on a magnetic record carrier (1) includes at least one pair of write heads (K.sub.1, K.sub.2) having a mechanically rigid coupling to each other and arranged on a head drum (40). The record carrier (1) is wrapped around the head drum through a wrapping angle .alpha.. The pair of heads (K.sub.1, K.sub.2) writes pairs of tracks (T.sub.1, T.sub.2 ; T.sub.3, T.sub.4 ; . . . ) on the record carrier. The apparatus further includes a signal separator (4) for dividing the electric signal into consecutive blocks, after which the signal blocks having odd sequence number (B.sub.1, B.sub.3, . . . ) are applied to a first output (5) and the signal blocks having even sequence number (B.sub.2, B.sub.4 . . . ) are applied to a second output (6). In a time-base correction circuit (7) the signal blocks (A.sub.1, A.sub.2) are time expanded or compressed. .alpha. Differs from 180.degree. . Signal blocks having odd sequence numbers are delayed in time relative to signal blocks having even sequence numbers (16). Subsequently, the signal blocks thus processed are recorded. Time compression or expansion is effected by a factor of .alpha.*n/(180*(M+1), where n is the number of head pairs and M is the number of times within a specific time interval that a head pair which comes in contact with a record carrier during said time interval does not record a signal in the record carrier, this time interval being defined by those instants at which two consecutive track pairs are recorded by one or two head pairs.

Growing community of inventors

Eindhoven, Netherlands

Albert M Rijckaert