EP0527795A1 - Video recorder with improved sound recording - Google Patents

Video recorder with improved sound recording

Info

Publication number
EP0527795A1
EP0527795A1 EP19910908241 EP91908241A EP0527795A1 EP 0527795 A1 EP0527795 A1 EP 0527795A1 EP 19910908241 EP19910908241 EP 19910908241 EP 91908241 A EP91908241 A EP 91908241A EP 0527795 A1 EP0527795 A1 EP 0527795A1
Authority
EP
European Patent Office
Prior art keywords
frequency
sound
carrier
nicam
recording
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP19910908241
Other languages
German (de)
French (fr)
Inventor
Hans-Jürgen Kluth
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Deutsche Thomson Brandt GmbH
Original Assignee
Deutsche Thomson Brandt GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Deutsche Thomson Brandt GmbH filed Critical Deutsche Thomson Brandt GmbH
Publication of EP0527795A1 publication Critical patent/EP0527795A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/76—Television signal recording
    • H04N5/78—Television signal recording using magnetic recording
    • H04N5/782—Television signal recording using magnetic recording on tape
    • H04N5/78213—Television signal recording using magnetic recording on tape involving recording in different depths of the magnetic tape
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N9/00—Details of colour television systems
    • H04N9/79—Processing of colour television signals in connection with recording
    • H04N9/80—Transformation of the television signal for recording, e.g. modulation, frequency changing; Inverse transformation for playback
    • H04N9/802—Transformation of the television signal for recording, e.g. modulation, frequency changing; Inverse transformation for playback involving processing of the sound signal
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N9/00—Details of colour television systems
    • H04N9/79—Processing of colour television signals in connection with recording
    • H04N9/80—Transformation of the television signal for recording, e.g. modulation, frequency changing; Inverse transformation for playback
    • H04N9/82—Transformation of the television signal for recording, e.g. modulation, frequency changing; Inverse transformation for playback the individual colour picture signal components being recorded simultaneously only
    • H04N9/83—Transformation of the television signal for recording, e.g. modulation, frequency changing; Inverse transformation for playback the individual colour picture signal components being recorded simultaneously only the recorded chrominance signal occupying a frequency band under the frequency band of the recorded brightness signal
    • H04N9/835—Transformation of the television signal for recording, e.g. modulation, frequency changing; Inverse transformation for playback the individual colour picture signal components being recorded simultaneously only the recorded chrominance signal occupying a frequency band under the frequency band of the recorded brightness signal involving processing of the sound signal

Definitions

  • the invention is based on a video recorder according to the preamble of claim 1.
  • a video recorder is known as a so-called VHS video recorder or S-VHS video recorder with HiFi sound recording by means of frequency-modulated sound carriers.
  • NICAM carrier with DOPSK differentially encoded guadrature phase shift modulation keying method
  • This sound carrier has a frequency of 5.85 MHz.
  • VHS video recorders are not intended and also not suitable for recording such an additional sound carrier.
  • NICAM signal For the recording of the sound information of such a NICAM signal, it is therefore necessary to decode the NICAM signal and the NF sound signals obtained thereby on a longitudinal track running parallel to the band edge as NF signals or in the form of frequency-modulated sound carriers along the Record helical traces. Then, however, the recording of the actual sound signal on the longitudinal track or the helical track would no longer be possible. It would also go through the decoding and re-encoding reduces the quality. The quality features of NICAM would thus be partially lost in the recording, as would the consignment identification signals contained in the NICAM signal.
  • the invention is based on the object of designing a video recorder in such a way that the NICAM signal can also be recorded with full quality, being compatible with the previous sound recording, and the quality features of NICAM are retained in full.
  • the invention is based on the following consideration.
  • the possibility of recording an additional signal in a lower magnetic layer independently of the signal in the upper magnetic layer is therefore advantageously used for recording an additional sound signal.
  • NICAM sound carrier By recording the NICAM sound carrier in the lower magnetic layer there are several advantages.
  • the previous customary recording of LF sound signals on the longitudinal track of the magnetic tape and with frequency-modulated sound carriers along the oblique tracks in the deeper layer can be completely preserved.
  • the result is a T ⁇ n multinorm recorder which can record the LF signals, the sound carriers frequency-modulated with the sound signals and the NICAM sound carriers independently of one another.
  • the special quality features of the NICAM signal are completely preserved, _ . _
  • NICAM sound carrier By mixing the NICAM sound carrier with a mixing carrier that is coupled to the line frequency, time errors in the sound carrier are automatically compensated for during playback.
  • Crosstalk between neighboring. th tracks in the lower layer is largelyanna ⁇ on, because a space between these tracks, a - so-called turf is provided '.
  • high crosstalk attenuation is achieved between the frequency-reduced NICAM sound carrier in the lower magnetic layer and the image signals in the upper magnetic layer, because these signals are recorded in two different magnetic layers.
  • This separate recording acts like a recording on separate tracks or separate recording media.
  • the invention is particularly advantageously applicable to an S-VHS video recorder.
  • the circuitry is low because the heads and associated circuits for recording in the deeper magnetic layer are already present in a video recorder with hi-fi sound.
  • a frequency-selective circuit is provided during recording and / or during playback, which detects the presence of the NICAM-type sound carrier. When this sound carrier is recognized, this circuit generates a switching voltage which automatically switches the recording circuit or the playback circuit of the recorder to operation with the sound carrier of the NICAM type.
  • the invention is not limited to a NICAM sound carrier, but can be used in general for sound carriers which are modulated with digital sound signals in the NICAM manner.
  • Fig. 1 shows the frequency spectrum of the signals in the upper
  • FIG. 2 shows the frequency spectrum of the signals in the __ __
  • Fig. 3 is a block diagram for recording and Fig. 4 is a block diagram for playback.
  • Ml mixed carrier for converting F into Fm
  • M2 mixed carrier for converting N to Nm
  • N NICAM sound carriers
  • Nm frequency-reduced NICAM sound carriers
  • Tl frequency-modulated sound carrier with 1.4 MHz ⁇ 0.2 MHz
  • T2 frequency-modulated sound carrier with 1.8 MHz ⁇ 0.2 MHz
  • the image carrier B frequency-modulated with the luminance signal Y is recorded with magnetic heads K 1 with a gap width of 0.2 ⁇ m in the upper layer S1 of the magnetic tape T in the frequency range of approximately 1.2-10 MHz.
  • the hatched static frequency range extends from 5.4 - 7.0 MHz.
  • the frequency carrier Fm also called "color under" is recorded.
  • two frequency-modulated sound carriers T1, T2 are first recorded in the lower layer S2 of the magnetic tape T with the magnetic heads K2 having a larger gap width of approximately 0.4 'to 0.45 ⁇ m.
  • the received NICAM sound carrier N is converted with the mixed carrier M into the sound carrier Nm with a reduced frequency at a frequency of 2.9 MHz and recorded in this frequency position.
  • Tl, T2, Nm are thus recorded, while N and M 'are not recorded.
  • the CVBS-PAL signal at the terminal 1 in the isolating stage 2 is split into the luminance signal Y and the modulated color carrier F.
  • Y passes through the sub-pre-amplification stage 3, the main pre-emphasis stage 4, and the amplitude limiter 5 to the FM modulator 6, which supplies the image carrier B to the adder stage 8 via the amplifier 7.
  • the ink carrier F is fed to the converter 10 via the bandpass 9 with a pass range of 4.43 + 0.6-0.8 MHz.
  • the line synchronizing pulses are separated from Y in the separating stage 11 and converted in the converter 12 to the frequency f5 of the mixed carrier M1.
  • the mixed carrier M1 passes through the high pass 13 to the other input of the converter 10.
  • the color carrier F is converted to the color carrier Fm with the frequency f2, which passes through the low pass 14 to the other input of the adder 8.
  • the adder 8 supplies the signal according to FIG. 1, which is recorded on the magnetic tape T with the heads K 1.
  • a transmitter signal is received with a NICAM sound carrier and processed in the tuner 16.
  • the NICAM sound carrier N is separated and fed to the converter 19 via the bandpass filter 18 with a pass band of 5.85 ⁇ 0.4 MHz.
  • the converter 19 supplies the frequency-reduced NICAM sound carrier Nm with the frequency f4, which reaches the adder 21 via the bandpass filter 20 with the pass band of 2.9 ⁇ 0.4 MHz.
  • the sound carriers T1, T2 are also fed to the adding stage 21. 2 reaches the heads K2 via the amplifier 22 and is recorded there on the magnetic tape T.
  • FIG. 4 shows the playback circuit for the recording circuit according to FIG. 3.
  • the modulated image carrier B passes through the delay stage 24 and the amplitude limiter 25 to the FM demodulator 26, which supplies the luminance signal Y.
  • This passes through the low-pass filter 27 with a cut-off frequency of approximately 5 MHz and the deemphasis stage 28 to the terminal 29.
  • the color carrier Fm reaches the converter 31 via the low-pass filter 30 with a cut-off frequency of 0.7 MHz to the isolating stage 32, which delivers line-frequency pulses with the frequency fH to the converter 33.
  • the converter 33 supplies the mixing carrier M1 with the frequency f5, which passes through the low-pass filter 34 to the other input of the converter 31.
  • the converter 31 supplies the color carrier F with the frequency fl, which reaches the terminal 37 via the bandpass 35 and the delay stage 36 with a delay time of two lines.
  • the CVBS signal is formed from Y and F, which is available at terminal 39 for image reproduction.
  • the signal according to FIG. 2 is sampled with the heads K2. From the exit of the track switch between heads K2 the switch 40, the two sound carriers Tl, 2 are evaluated with the bandpass filter 41 and fed to the FM demodulator 42.
  • the LF audio signals NF1, NF2 obtained in this way reach inputs of the antenna modulator 43, to which the CVBS signal is also fed via the line 44.
  • the pass band 45 With the pass band 45 with a pass band of 2.9 ⁇ 0.4 MHz, the sound carrier Nm is evaluated and fed to the converter 46.
  • the line-frequency voltage with the frequency fH is converted in the converter 47 to the mixed carrier M2 with the frequency f6 and fed to the other input of the converter 46 via the bandpass 50.
  • the converter 46 again supplies the original NICAM sound carrier N with the frequency f3, which reaches the antenna modulator 43 via the bandpass 48.
  • the antenna ⁇ modulator 43 generates an RF carrier at terminal 49, the 'ignalen with the composite video signal, the two sound NF1, NF2 and the NICAM Tonträ ⁇ N eng is modulated.
  • Terminal 49 is preferably connected to the antenna input of a television receiver which also contains a NICAM decoder.
  • a frequency-selective circuit With a frequency-selective circuit, the presence of the NICAM sound carrier N with the typical frequency of 5.85 MHz can be recognized and a switching voltage can be generated which, when the NICAM sound carrier N is present, automatically switches over to the output of a NICAM decoder causes.
  • Such a detection and switching device can also be contained in the recorder itself, e.g. the circuit for processing. to switch on the NICAM sound carrier only in the presence of a recorded NICAM sound carrier.
  • the magnetic heads Kl have an azimuth angle of ⁇ 6 °, while the magnetic heads K2 have an azimuth angle of ⁇ 30 °.
  • the recording in the upper layer S1 according to FIG. 1 is preferably carried out without a space, so-called turf.
  • the recording with K2 in the deeper layer S2 takes place with a O 1/17628 _ 8 . __ _

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Recording Or Reproducing By Magnetic Means (AREA)
  • Television Signal Processing For Recording (AREA)

Abstract

On transfère en outre une porteuse son NICAM modulée avec des signaux sonores numériques. La tâche consiste à concevoir le magnétoscope VHS de telle façon que cette porteuse son puisse être enregistrée en plus des autres signaux sans perte de qualité. C'est pourquoi la porteuse son NICAM est enregistrée dans une couche plus profonde (S2) avec de secondes têtes magnétiques (K2) en multiplexage de fréquence avec des porteuses son à bande latérale unique à fréquence réduite. Applicable notamment à un magnétoscope S-VHS à enregistrement sonore multinormes.In addition, a NICAM sound carrier modulated with digital sound signals is transferred. The task is to design the VHS VCR in such a way that this sound carrier can be recorded in addition to the other signals without loss of quality. This is why the NICAM sound carrier is recorded in a deeper layer (S2) with second magnetic heads (K2) in frequency multiplexing with sound carriers with single sideband at reduced frequency. Applicable in particular to an S-VHS video recorder with multinorm sound recording.

Description

Videorecorder mit verbesserter TonaufZeichnung Video recorder with improved sound recording
Die Erfindung geht aus von einem Videorecorder gemäß dem Oberbegriff des Anspruchs 1. Ein derartiger Videorecorder ist als sogenannter VHS-Videorecorder oder S-VHS-Videore¬ corder mit HiFi-Ton-Aufzeichnung durch frequenzmodulierte Tonträger bekannt.The invention is based on a video recorder according to the preamble of claim 1. Such a video recorder is known as a so-called VHS video recorder or S-VHS video recorder with HiFi sound recording by means of frequency-modulated sound carriers.
In nordischen Ländern wie Schweden, Finnland, Norwegen ist es bekannt, zusätzlich zu den üblichen Bildsignalen und Ton¬ signalen ein digitales Tonsignal für zwei Sprachen oder für Stereo in Form eines sogenannten NICAM-Trägers mit DOPSK- o- dulation (differentially encoded guadrature phase shift keying ethod) zu übertragen. Dieser Tonträger hat eine Fre¬ quenz von 5, 85 MHz.In Nordic countries such as Sweden, Finland, Norway it is known, in addition to the usual picture signals and sound signals, a digital sound signal for two languages or for stereo in the form of a so-called NICAM carrier with DOPSK (differentially encoded guadrature phase shift) modulation keying method). This sound carrier has a frequency of 5.85 MHz.
Übliche VHS-Videorecorder sind für die Aufzeichnung eines derartigen zusätzlichen Tonträgers nicht vorgesehen und auch nicht geeignet. Für die Aufzeichnung der Toninformation ei¬ nes solchen NICAM-Signals ist es daher notwendig, das NICAM- Signal zu decodieren und die dadurch gewonnenen NF-Tonsigna¬ le auf einer parallel zur Bandkante verlaufenden Längsspur als NF-Signale oder in Form frequenzmodulierter Tonträger entlang den Schrägspuren aufzuzeichnen. Dann wäre jedoch die Aufzeichnung des eigentlichen Tonsignalε auf der Längsspur oder der Schrägspur nicht mehr möglich. Außerdem würde durch die Decodierung und Neucodierung die Qualität verringert. Die Qualitätsmerkmale von NICAM würden somit bei der Auf¬ zeichnung teilweise verloren gehen, ebenso die im NICAM-Si- gnal enthaltenen SendungskennungsSignale.Conventional VHS video recorders are not intended and also not suitable for recording such an additional sound carrier. For the recording of the sound information of such a NICAM signal, it is therefore necessary to decode the NICAM signal and the NF sound signals obtained thereby on a longitudinal track running parallel to the band edge as NF signals or in the form of frequency-modulated sound carriers along the Record helical traces. Then, however, the recording of the actual sound signal on the longitudinal track or the helical track would no longer be possible. It would also go through the decoding and re-encoding reduces the quality. The quality features of NICAM would thus be partially lost in the recording, as would the consignment identification signals contained in the NICAM signal.
Der Erfindung liegt die Aufgabe zugrunde, einen Videore¬ corder so auszubilden, daß das NICAM-Signal zusätzlich mit voller Qualität .kompatibel zu der bisherigen Tonaufzeichnung aufgezeichnet werden kann und die Qualitätsmerkmale von NICAM voll erhalten bleiben.The invention is based on the object of designing a video recorder in such a way that the NICAM signal can also be recorded with full quality, being compatible with the previous sound recording, and the quality features of NICAM are retained in full.
Diese Aufgabe wird durch die im Anspruch 1 angegebene Erfin¬ dung gelöst. Vorteilhafte Weiterbildungen der Erfindung sind in den Unteransprüchen angegeben.This object is achieved by the invention specified in claim 1. Advantageous developments of the invention are specified in the subclaims.
Die Erfindung beruht auf folgender Überlegung. In der tiefe¬ ren Magnetschicht ist neben zwei aufgezeichneten FM-Tonträ- gern ausreichend Frequenzbandbreite verfügbar, in der ein in der Frequenz herabgesetzter NICAM-Tonträger aufgezeichnet werden kann. Die Möglichkeit, in einer tieferen Magnet¬ schicht unabhängig von dem Signal in der oberen Magnet¬ schicht ein zusätzliches Signal aufzuzeichnen, wird also vor¬ teilhaft für die Aufzeichnung eines zusätzlichen Tonsignals ausgenutzt.The invention is based on the following consideration. In addition to two recorded FM sound carriers, there is sufficient frequency bandwidth available in the lower magnetic layer in which a frequency-reduced NICAM sound carrier can be recorded. The possibility of recording an additional signal in a lower magnetic layer independently of the signal in the upper magnetic layer is therefore advantageously used for recording an additional sound signal.
Durch die Aufzeichnung des NICAM-Tonträgers in der tieferen Magnetschicht ergeben sich mehrere Vorteile. Die bisherige übliche Aufzeichnung von NF-Tonsignalen auf der Längsspur des Magnetbandes und mit frequenzmodulierten Tonträgern ent¬ lang den Schrägspuren in der tieferen Schicht kann vollstän¬ dig erhalten bleiben. Es ergibt sich also ein Tσn-Multinorm- recorder, der die NF-Signale, die mit den Tonsignalen fre¬ quenzmodulierten Tonträger und den NICAM-Tonträger unabhän¬ gig voneinander aufzeichnen kann. Die besonderen Qualitäts¬ merkmale des NICAM-Signales bleiben vollständig erhalten, _ . _By recording the NICAM sound carrier in the lower magnetic layer there are several advantages. The previous customary recording of LF sound signals on the longitudinal track of the magnetic tape and with frequency-modulated sound carriers along the oblique tracks in the deeper layer can be completely preserved. The result is a Tσn multinorm recorder which can record the LF signals, the sound carriers frequency-modulated with the sound signals and the NICAM sound carriers independently of one another. The special quality features of the NICAM signal are completely preserved, _ . _
weil eine Decodierung und Neucodierung des NICAM-Signals nicht notwendig ist. Durch die Mischung des NICAM-Tonträgers mit einem Mischträger, der mit der Zeilenfrequenz verkoppelt ist, werden automatisch Zeitfehler in dem Tonträger bei der Wiedergabe ausgeglichen. Ein Übersprechen zwischen benachbar- . ten Spuren in der tieferen Schicht wird weitestgehend ausge¬ schaltet, weil zwischen diesen Spuren ein Zwischenraum, ein - sogenannter Rasen, ' vorgesehen ist. Außerdem wird eine hohe Übersprechdämpfung zwischen dem in der Frequenz herabgesetz¬ ten NICAM-Tonträger in der tieferen Magnetschicht und den Bildsignalen in der oberen Magnetschicht erreicht, weil die¬ se Signale in zwei verschiedenen Magnetschichten aufgezeich¬ net sind. Diese getrennte Aufzeichnung wirkt wie eine Auf¬ zeichnung auf getrennten Spuren oder getrennten Aufzeich¬ nungsträgern. Die Erfindung ist insbesondere vorteilhaft an¬ wendbar bei einem S-VHS-Videorecorder. Der Schaltungsaufwand ist gering, weil bei einem Videorecorder mit HiFi-Ton die Köpfe und zugehörigen Schaltungen für die Aufzeichnung in der tieferen Magnetschicht ohnehin vorhanden sind. Vorzugs¬ weise ist bei der Aufnahme und/oder bei der Wiedergabe eine frequenzselektive Schaltung vorgesehen, die die Anwesenheit des Tonträgers der NICAM-Art erkennt. Diese Schaltung er¬ zeugt bei Erkennung dieses Tonträgers eine Schaltspannung, die die Aufnahmeschaltung oder die Wiedergabeschaltung des Recorders selbsttätig auf den Betrieb mit dem Tonträger der NICAM-Art umschaltet. Die Erfindung ist nicht auf einen NICAM-Tonträger beschränkt, sondern ganz allgemein für Ton¬ träger anwendbar, die nach der NICAM-Art mit digitalen Tonsi¬ gnalen moduliert sind.because decoding and re-encoding of the NICAM signal is not necessary. By mixing the NICAM sound carrier with a mixing carrier that is coupled to the line frequency, time errors in the sound carrier are automatically compensated for during playback. Crosstalk between neighboring. th tracks in the lower layer is largely ausge¬ on, because a space between these tracks, a - so-called turf is provided '. In addition, high crosstalk attenuation is achieved between the frequency-reduced NICAM sound carrier in the lower magnetic layer and the image signals in the upper magnetic layer, because these signals are recorded in two different magnetic layers. This separate recording acts like a recording on separate tracks or separate recording media. The invention is particularly advantageously applicable to an S-VHS video recorder. The circuitry is low because the heads and associated circuits for recording in the deeper magnetic layer are already present in a video recorder with hi-fi sound. Preferably, a frequency-selective circuit is provided during recording and / or during playback, which detects the presence of the NICAM-type sound carrier. When this sound carrier is recognized, this circuit generates a switching voltage which automatically switches the recording circuit or the playback circuit of the recorder to operation with the sound carrier of the NICAM type. The invention is not limited to a NICAM sound carrier, but can be used in general for sound carriers which are modulated with digital sound signals in the NICAM manner.
Die Erfindung wird im fogenden anhand der Zeichnung an einemThe invention is in the following with reference to the drawing on a
Ausführungsbeispiel erläutert. Darin zeigenExemplary embodiment explained. Show in it
Fig. 1 das Frequenzspektrum der Signale in der oberenFig. 1 shows the frequency spectrum of the signals in the upper
Magnetschicht, Fig. 2 das Frequenzspektrum der Signale in der __ __Magnetic layer, Fig. 2 shows the frequency spectrum of the signals in the __ __
tieferen Magnetschicht sowie den Mischträger, Fig. 3 ein Blockschaltbild für die Aufnahme und Fig. 4 ein Blockschaltbild für die Wiedergabe.deeper magnetic layer and the mixing carrier, Fig. 3 is a block diagram for recording and Fig. 4 is a block diagram for playback.
In der folgenden Beschreibung haben die verwendeten Symbole folgende Bedeutung und Werte:In the following description, the symbols used have the following meaning and values:
kHz, Zeilen requenz MHz, Frequenz von F MHz, Frequenz von Fm MHz, Frequenz von N MHz, Frequenz von Nm MHz, Frequenz von Ml 6 = 560xfH = 8,75 MHz, Frequenz von M2kHz, line requency MHz, frequency of F MHz, frequency of Fm MHz, frequency of N MHz, frequency of Nm MHz, frequency of Ml 6 = 560xfH = 8.75 MHz, frequency of M2
F = modulierter PAL-FarbträgerF = modulated PAL color support
Fm = in der Frequenz herabgesetzter Farbträger (color under)Fm = color carrier with reduced frequency (color under)
Ml = Mischträger zum Umsetzen von F in FmMl = mixed carrier for converting F into Fm
M2 = Mischträger zum Umsetzen von N in NmM2 = mixed carrier for converting N to Nm
N = NICAM-TonträgerN = NICAM sound carriers
Nm = in der Frequenz herabgesetzter NICAM-TonträgerNm = frequency-reduced NICAM sound carriers
Tl = frequenzmodulierter Tonträger mit 1,4 MHz±0,2 MHz T2 = frequenzmodulierter Tonträger mit 1,8 MHz±0,2 MHzTl = frequency-modulated sound carrier with 1.4 MHz ± 0.2 MHz T2 = frequency-modulated sound carrier with 1.8 MHz ± 0.2 MHz
dabei gilt:the following applies:
f5 - fl = f2 f6 - f3 = f4f5 - fl = f2 f6 - f3 = f4
Gemäß Fig. 1 wird mit Magnetköpfen Kl mit einer Spaltbreite von 0,2 μm in der oberen Schicht Sl des Magnetbandes T im Frequenzbereich von etwa 1,2 - 10 MHz der mit dem Leuchtdich¬ tesignal Y frequenzmodulierte Bildträger B aufgezeichnet. Der schraffiert dargestellte statische Frequenzhub erstreckt sich von 5,4 - 7,0 MHz. Im Frequenzbereich unterhalb von B wird der in der Frequenz herabgesetzte Farbträger Fm, auch "color under" genannt, aufgezeichnet.According to FIG. 1, the image carrier B frequency-modulated with the luminance signal Y is recorded with magnetic heads K 1 with a gap width of 0.2 μm in the upper layer S1 of the magnetic tape T in the frequency range of approximately 1.2-10 MHz. The hatched static frequency range extends from 5.4 - 7.0 MHz. In the frequency range below B, the frequency carrier Fm, also called "color under", is recorded.
Gemäß Fig. 2 werden mit den Magnetköpfen K2 größerer Spalt¬ breite von etwa 0,4' - 0,45 μm in der, unteren Schicht S2 des Magnetbandes T zunächst zwei frequenzmodulierte Tonträger T1,T2 aufgezeichnet. Der empfangene NICAM-Tonträger N wird mit dem Mischträger M in den in der Frequenz herabgesetzten Tonträger Nm bei einer Frequenz von 2,9 MHz umgesetzt und in dieser Frequenzlage aufgezeichnet. Aufgezeichnet werden also Tl,T2,Nm, während N und M' nicht aufgezeichnet werden. Bei der Aufnahme erfolgt zunächst die Aufzeichnung gemäß Fig. 2 und danach die Aufzeichnung gemäß Fig. 1. Dabei wird die Auf¬ zeichnung gemäß Fig. 2 in der oberen Schicht Sl wieder ge¬ löscht.According to FIG. 2, two frequency-modulated sound carriers T1, T2 are first recorded in the lower layer S2 of the magnetic tape T with the magnetic heads K2 having a larger gap width of approximately 0.4 'to 0.45 μm. The received NICAM sound carrier N is converted with the mixed carrier M into the sound carrier Nm with a reduced frequency at a frequency of 2.9 MHz and recorded in this frequency position. Tl, T2, Nm are thus recorded, while N and M 'are not recorded. When recording, first the recording according to FIG. 2 and then the recording according to FIG. 1 takes place. The recording according to FIG. 2 in the upper layer S1 is deleted again.
In Fig. 3 wird das FBAS-PAL-Signal an der Klemme 1 in der Trennstufe 2 in das Leuchtdichtesignal Y und den modulierten Farbträger F aufgespalten. Y gelangt über die Sub-Preemp- hasisstufe 3, die Haupt-Preemphasisstufe 4, und den Amplitu¬ denbegrenzer 5 auf den FM-Modulator 6, der über den Verstär¬ ker 7 den Bildträger B an die Addierstufe 8 liefert. Der Farbträger F wird über den Bandpaß 9 mit einem Durchlaßbe¬ reich von 4,43+0,6-0,8 MHz dem Umsetzer 10 zugeführt. In der Abtrennstufe 11 werden die Zeilensynchronimpulse von Y abge¬ trennt und in dem Umsetzer 12 auf die Frequenz f5 des Misch¬ trägers Ml umgesetzt. Der Mischträger Ml gelangt über den Hochpaß 13 auf den anderen Eingang des Umsetzers 10. In dem Umsetzer 10 wird der Farbträger F auf den Farbträger Fm mit der Frequenz f2 umgesetzt, der über den Tiefpaß 14 auf den anderen Eingang der Addierstufe 8 gelangt. Die Addierstufe 8 liefert das Signal gemäß Fig. 1, das mit den Köpfen Kl auf dem Magnetband T aufgezeichnet wird. Mit der Antenne 15 wird ein Sendersignal mit einem NICAM-Ton¬ träger empfangen und in dem Tuner 16 verarbeitet. In der Trennstufe 17 wird der NICAM-Tonträger N abgetrennt und über den Bandpaß 18 mit einem Durchlaßbereich von 5,85±0,4 MHz dem Umsetzer 19 zugeführt. Der Umsetzer 19 liefert den in der Frequenz herabgesetzten NICAM-Tonträger Nm mit der Fre¬ quenz f4, der über den Bandpaß 20 mit dem Durchlaßbereich von 2,9±0,4 MHz auf die Addierstufe 21 gelangt. Der Addier¬ stufe 21 werden außerdem die Tonträger T1,T2 zugeführt. Das dadurch gewonnene Signal gemäß Fig. 2 gelangt über den Ver¬ stärker 22 auf die Köpfe K2 und wird dort auf dem Magnetband T aufzeichnet.In Fig. 3, the CVBS-PAL signal at the terminal 1 in the isolating stage 2 is split into the luminance signal Y and the modulated color carrier F. Y passes through the sub-pre-amplification stage 3, the main pre-emphasis stage 4, and the amplitude limiter 5 to the FM modulator 6, which supplies the image carrier B to the adder stage 8 via the amplifier 7. The ink carrier F is fed to the converter 10 via the bandpass 9 with a pass range of 4.43 + 0.6-0.8 MHz. The line synchronizing pulses are separated from Y in the separating stage 11 and converted in the converter 12 to the frequency f5 of the mixed carrier M1. The mixed carrier M1 passes through the high pass 13 to the other input of the converter 10. In the converter 10, the color carrier F is converted to the color carrier Fm with the frequency f2, which passes through the low pass 14 to the other input of the adder 8. The adder 8 supplies the signal according to FIG. 1, which is recorded on the magnetic tape T with the heads K 1. With the antenna 15, a transmitter signal is received with a NICAM sound carrier and processed in the tuner 16. In the isolating stage 17, the NICAM sound carrier N is separated and fed to the converter 19 via the bandpass filter 18 with a pass band of 5.85 ± 0.4 MHz. The converter 19 supplies the frequency-reduced NICAM sound carrier Nm with the frequency f4, which reaches the adder 21 via the bandpass filter 20 with the pass band of 2.9 ± 0.4 MHz. The sound carriers T1, T2 are also fed to the adding stage 21. 2 reaches the heads K2 via the amplifier 22 and is recorded there on the magnetic tape T.
Fig. 4 zeigt die Wiedergabeschaltung für die AufnahmeSchal¬ tung gemäß Fig.. 3. Vom Ausgang des Umschalters 23, der spur- weise zwischen den Köpfen Kl umschaltet, gelangt der modu¬ lierte Bildträger B über die Laufzeitstufe 24, und den Ampli¬ tudenbegrenzer 25 auf den FM-Demodulator 26, der das Leucht¬ dichtesignal Y liefert. Dieses gelangt über den Tiefpaß 27 mit einer Grenzfrequenz von etwa 5 MHz und die Deemphasisst- ufe 28 auf die Klemme 29. Der Farbträger Fm gelangt über den Tiefpaß 30 mit einer Grenzfrequenz von 0,7 MHz auf den Umset¬ zer 31. Y gelangt außerdem auf die Trennstufe 32, die zeilen- frequente Impulse mit der Frequenz fH an den Umsetzer 33 lie¬ fert. Der Umsetzer 33 liefert den Mischträger Ml mit der Fre¬ quenz f5, der über den Tiefpaß 34 auf den anderen Eingang des Umsetzers 31 gelangt. Der Umsetzer 31 liefert den Farb¬ träger F mit der Frequenz fl, der über den Bandpaß 35 und die Laufzeitstufe 36 mit einer Verzögerungszeit von zwei Zei¬ len auf die Klemme 37 gelangt. In der Addierstufe 38 wird aus Y und F das FBAS-Signal gebildet, das an der Klemme 39 für die Bildwiedergabe zur Verfügung steht.FIG. 4 shows the playback circuit for the recording circuit according to FIG. 3. From the output of the switch 23, which switches between the heads K1, the modulated image carrier B passes through the delay stage 24 and the amplitude limiter 25 to the FM demodulator 26, which supplies the luminance signal Y. This passes through the low-pass filter 27 with a cut-off frequency of approximately 5 MHz and the deemphasis stage 28 to the terminal 29. The color carrier Fm reaches the converter 31 via the low-pass filter 30 with a cut-off frequency of 0.7 MHz to the isolating stage 32, which delivers line-frequency pulses with the frequency fH to the converter 33. The converter 33 supplies the mixing carrier M1 with the frequency f5, which passes through the low-pass filter 34 to the other input of the converter 31. The converter 31 supplies the color carrier F with the frequency fl, which reaches the terminal 37 via the bandpass 35 and the delay stage 36 with a delay time of two lines. In the adder 38, the CVBS signal is formed from Y and F, which is available at terminal 39 for image reproduction.
Mit den Köpfen K2 wird das Signal gemäß Fig. 2 abgetastet. Vom Ausgang des spurweise zwischen den Köpfen K2 umschalten- den Umschalters 40 werden die beiden Tonträger Tl, 2 mit dem Bandpaß 41 ausgewertet und dem FM-Demodulator 42 zugeführt. Die dadurch gewonnenen NF-Tonsignale NF1,NF2 gelangen auf Eingänge des Antennenmodulators 43, dem außerdem das FBAS- Signal über die Leitung 44 zugeführt wird. Mit dem Bandpaß 45 mit einem Durchlaßbereich von 2,9±0,4 MHz wird der Tonträ¬ ger Nm ausgewertet und dem Umsetzer 46 zugeführt. Die zeilen- frequente Spannung mit der Frequenz fH wird in dem Umsetzer 47 auf den Mischträger M2 mit der Frequenz f6 umgesetzt und über den Bandpaß 50 dem anderen Eingang des Umsetzers 46 zu¬ geführt. Der Umsetzer 46 liefert wieder den Original- NICAM- Tonträger N mit der Frequenz f3, der über den Bandpaß 48 auf den Antennenmodulator 43 gelangt. Der Antennenmodulator 43 ■ erzeugt an der Klemme 49 einen HF-Träger, der mit dem FBAS- Signal, den beiden Tons'ignalen NF1,NF2 und dem NICAM-Tonträ¬ ger N moduliert ist.The signal according to FIG. 2 is sampled with the heads K2. From the exit of the track switch between heads K2 the switch 40, the two sound carriers Tl, 2 are evaluated with the bandpass filter 41 and fed to the FM demodulator 42. The LF audio signals NF1, NF2 obtained in this way reach inputs of the antenna modulator 43, to which the CVBS signal is also fed via the line 44. With the pass band 45 with a pass band of 2.9 ± 0.4 MHz, the sound carrier Nm is evaluated and fed to the converter 46. The line-frequency voltage with the frequency fH is converted in the converter 47 to the mixed carrier M2 with the frequency f6 and fed to the other input of the converter 46 via the bandpass 50. The converter 46 again supplies the original NICAM sound carrier N with the frequency f3, which reaches the antenna modulator 43 via the bandpass 48. The antenna ■ modulator 43 generates an RF carrier at terminal 49, the 'ignalen with the composite video signal, the two sound NF1, NF2 and the NICAM Tonträ¬ N eng is modulated.
Die Klemme 49 ist vorzugsweise an den Antenneneingang eines Fernsehempfängers angeschlossen, der auch einen NICAM-Deco- der enthält. Mit einer frequenzselektiven Schaltung kann die Anwesenheit des NICAM-Tonträgers N mit der typischen Fre¬ quenz von 5,85 MHz erkannt und eine Schaltspannung erzeugt werden, die bei Anwesenheit des NICAM-Tonträgers N selbsttä¬ tig eine Umschaltung auf den Ausgang eines NICAM-Decoders bewirkt. Eine derartige Erkennungs- und Umschalteinrichtung kann auch im Recorder selbst enthalten sein, um z.B. die Schaltung zur Verarbeitung. des NICAM-Tonträgers nur bei Vor¬ handensein eines aufgezeichneten NICAM-Tonträgers einzuschal¬ ten.Terminal 49 is preferably connected to the antenna input of a television receiver which also contains a NICAM decoder. With a frequency-selective circuit, the presence of the NICAM sound carrier N with the typical frequency of 5.85 MHz can be recognized and a switching voltage can be generated which, when the NICAM sound carrier N is present, automatically switches over to the output of a NICAM decoder causes. Such a detection and switching device can also be contained in the recorder itself, e.g. the circuit for processing. to switch on the NICAM sound carrier only in the presence of a recorded NICAM sound carrier.
Die Magnetköpfe Kl haben einen Azimutwinkel von ±6°, während die Magnetköpfe K2 einen Azimutwinkel von ±30° haben. Die Aufzeichnung in der oberen Schicht Sl gemäß Fig. 1 erfolgt vorzugsweise ohne Zwischenraum, sogenannten Rasen. Die Auf¬ zeichnung mit K2 in der tieferen Schicht S2 erfolgt mit ei- O 1/17628 _ 8 . __ _The magnetic heads Kl have an azimuth angle of ± 6 °, while the magnetic heads K2 have an azimuth angle of ± 30 °. The recording in the upper layer S1 according to FIG. 1 is preferably carried out without a space, so-called turf. The recording with K2 in the deeper layer S2 takes place with a O 1/17628 _ 8 . __ _
ne sogenannten Rasen. Dieser Rasen ist vorteilhaft, weil wegen der niedrigeren Frequenzen eine Übersprechdämpfung durch die Azimutwinkel nicht mehr ausreichend wirksam ist. Das Übersprechen zwischen benachbarten Spuren wird also bei Kl im wesentlichen durch die Äzimutwinkel und bei K2 durch den Rasen zwischen den Spuren vermieden. ne so-called lawn. This lawn is advantageous because, due to the lower frequencies, crosstalk attenuation by the azimuth angles is no longer sufficiently effective. The crosstalk between adjacent tracks is thus largely avoided by the azimuth angle at Kl and by the lawn between the tracks at K2.

Claims

_ Q _P a t e n t a n s p r ü c h e _ Q _Patent claims
1. Videorecorder mit verbesserter Tonaufzeichnung, bei dem mit ersten Magnetköpfen (Kl) geringer Spaltbreite in einer oberen Magnetschicht (Sl) des Bandes (T) ein mit dem Leuchtdichtesignal (Y) modulierter Bildträger (B) und mit zweiten Magnetköpfen (K2) größerer Spaltbreite in einer tiefer liegenden Magnetschicht (S2) mit Tonsi¬ gnalen frequenzmoduiierte Tonträger (T1,T2) aufgezeich¬ net werden, dadurch gekennzeichnet, daß in der tieferen Schicht (S2) mit. den Magnetköpfen (K2) im Frequenzmulti- plex mit den Tonträgern (T1,T2) zusätzlich ein mit digi¬ talen Tonsignalen modulierter, in der. Frequenz herabge¬ setzter Tonträger (Nm) der NICAM-Art aufgezeichnet wird.1. Video recorder with improved sound recording, in the case of the first magnetic heads (Kl) having a small gap width in an upper magnetic layer (Sl) of the tape (T), an image carrier (B) modulated with the luminance signal (Y) and having second magnetic heads (K2) having a larger gap width frequency-modulated sound carriers (T1, T2) are recorded in a lower lying magnetic layer (S2) with sounds, characterized in that in the lower layer (S2) with. the magnetic heads (K2) in frequency multiplex with the sound carriers (T1, T2) additionally a modulated with digital sound signals, in which. Frequency reduced sound carrier (Nm) of the NICAM type is recorded.
2. Recorder nach Anspruch 1, dadurch gekennzeichnet, daß bei der Aufnahme und/oder bei der Wiedergabe eine fre¬ quenzselektive Schaltung vorgesehen ist, die den Tonträ¬ ger (N,Nm) der NICAM-Art erkennt und selbsttätig den Tonkanal auf die Aufnahme oder Wiedergabe dieses Tonträ¬ gers umschaltet.2. Recorder according to claim 1, characterized in that a frequency-selective circuit is provided during recording and / or during playback, which recognizes the Tonträ¬ ger (N, Nm) of the NICAM type and automatically the sound channel on the recording or playback of this sound carrier.
3. Recorder nach Anspruch 1, dadurch gekennzeichnet, daß bei der Wiedergabe der vom Band (T) abgetastete Tonträ¬ ger (Nm) mit einem Mischträger (M2) wieder auf seine Originalfrequenz (f3) umgesetzt wird.3. Recorder according to claim 1, characterized in that during the playback of the tape (T) scanned Tonträ¬ ger (Nm) with a mixing carrier (M2) is converted back to its original frequency (f3).
4. Recorder nach Anspruch 1, dadurch gekennzeichne , daß die Frequenz des für die Frequenzumsetzung verwendeten Mischträgers mit der Zeilenfrequenz (fH) verkoppelt ist.4. Recorder according to claim 1, characterized in that the frequency of the mixed carrier used for the frequency conversion is coupled to the line frequency (fH).
5. Recorder nach Anspruch 3, dadurch gekennzeichnet, daß der auf die Originalfrequenz (f3) umgesetzte Träger (N) an den Eingang eines Antennenmodulators (43) angelegt ist, der einen mit den Bild- und Tonsignalen modulier¬ ten HF-Träger liefert .5. Recorder according to Claim 3, characterized in that the carrier (N) converted to the original frequency (f3) is applied to the input of an antenna modulator (43) is, which delivers a HF carrier modulated with the image and sound signals.
Recorder nach Anspruch 1 , dadurch gekennzeichnet, daß die zweiten Magnetköpfe (K2 ) einen Azimutwinkel von ±30° aufweisen. Recorder according to claim 1, characterized in that the second magnetic heads (K2) have an azimuth angle of ± 30 °.
EP19910908241 1990-05-09 1991-05-02 Video recorder with improved sound recording Withdrawn EP0527795A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4014832 1990-05-09
DE19904014832 DE4014832A1 (en) 1990-05-09 1990-05-09 VIDEO RECORDER WITH IMPROVED SOUND RECORDING

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JP (1) JPH05506760A (en)
AU (1) AU7765491A (en)
DE (1) DE4014832A1 (en)
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WO (1) WO1991017628A1 (en)

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Publication number Priority date Publication date Assignee Title
EP0558821A3 (en) * 1992-01-08 1993-09-29 Deutsche Thomson-Brandt Gmbh Videorecorder
DE4200222A1 (en) * 1992-01-08 1993-07-15 Thomson Brandt Gmbh Video recorder with additional digital signal recording head - uses whole and part depth of magnetic tape coating for analogue and digital signal tracks respectively.
DE4218120A1 (en) * 1992-06-02 1993-12-09 Thomson Brandt Gmbh VHS video recorder - allows optional high quality display mode together with usual VHS mode

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JP2568819B2 (en) * 1985-09-20 1997-01-08 三菱電機株式会社 Intermittent magnetic recording / reproducing device
JPS63282901A (en) * 1987-05-14 1988-11-18 Matsushita Electric Ind Co Ltd Digital sound recording video tape recorder
EP0275041A3 (en) * 1987-01-09 1990-03-28 Hitachi, Ltd. Multiplex magnetic recording and reproducing apparatus of the rotary head type

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FI925036A0 (en) 1992-11-06
AU7765491A (en) 1991-11-27
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WO1991017628A1 (en) 1991-11-14
JPH05506760A (en) 1993-09-30
FI925036A (en) 1992-11-06

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