Abstract: 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:N(i)={N(i-1)+1+2.multidot.p}mod2.sup.m,where p is an integer positive constant for which holds 0.ltoreq.p.ltoreq.2.sup.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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 f

Abstract: 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.

Abstract: 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.

Abstract: 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..

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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. .

Abstract: An arrangement for recording an information signal in a track (T.sub.0, T.sub.1, . . . ) on a record carrier (1), includes an input (20) for receiving the information signal, signal processing circuitry (21) for processing the information signal such that it can be recorded in the track, counting device (23) for counting and for generating an array of subsequent different count signals and for supplying the count signals to an output (24), recording apparatus (25, 26, 27) having at least one recording head (26) for recording the processed information signal in a track on the record carrier, and for recording the count signals in a track on the record carrier and a transport apparatus (34,35) for transporting the record carrier with a certain transport velocity (v.sub.t) in a longitudinal direction of the record carrier.

Abstract: In a helical-scan magnetic-tape apparatus having a scanning unit (102) comprising two diametrically opposed rotatable magnetic-head units (113, 114) which are movable over an actuating distance (A) in two opposite directions (r.sub.1, r.sub.2) by means of actuators (117, 118), the magnetic-head units, with the actuators not activated, are situated at a distance (X) from each other which is smaller than or equal to twice the actuating distance (A). During fast tape transport in a direction opposite to the tape transport direction with which information has been written in tracks on the magnetic tape each magnetic-head unit reads other tracks than those it would read during normal tape transport and/or the read sequence of the tracks is changed.

Abstract: In an arrangement comprising a phase control circuit the phase comparator, when receiving input pulses with which the clock pulses are in phase, will produce an output signal having a pulse frequency which is twice the pulse frequency of the input pulses. The ripple on the control-voltage for the oscillator to be controlled resulting therefrom is compensated for by adding to the output signal of the phase detector a signal which is opposite in phase to the output signal. The result is that only frequency- and phase errors produce a ripple (change) on the output signal.

Abstract: A helical-scan recorder for two-channel digital video recording comprises two pairs of write-read heads which are situated diametrically opposite each other. To simplify tracking it is proposed to record tracking, signals of different frequencies with one head of each of said pairs of heads and to read said tracking signals during recording via crosstalk, each time using the other head of each of said pairs of heads.

Abstract: An apparatus for reproducing information from a track of a magnetic record carrier by means of a reproducing head divided into two reproducing portions. The apparatus comprises an amplifier circuit having a pair of input terminals, connected to the outputs of the two reproducing portions, a first signal combination unit, at least one variable gain amplifier and an output terminal. The controllable amplifier is connected between the output of the signal combination unit and the output terminal of the amplifier circuit. The gain of the amplifier is controlled in such a way that upon application of the two signals to the input terminals of the amplifier circuit, a signal is obtained on the output terminal having an amplitude u which is in a fixed ratio to the amplitude of the larger of the two signals applied to the two input terminals.

Abstract: For a controlled positioning of a read element relative to a track to be read during the read-out of such a record carrier, low-frequency tracking signals may be recorded in the tracks. Instead of adding separate tracking signals to the information signal, these tracking signals are represented by the d.c. content of the information signal. During conversion of the information words of the information signal into channel words steps are therefore taken to provide two channel words whose d.c. content is equal but opposite for each information word. The choice between these two channel words is made depending on a control signal which depends on the desired tracking signal.