DE1287117C2 - DEMODULATION CIRCUIT FOR PAL COLOR TELEVISION SIGNALS - Google Patents
DEMODULATION CIRCUIT FOR PAL COLOR TELEVISION SIGNALSInfo
- Publication number
- DE1287117C2 DE1287117C2 DE1966F0048437 DEF0048437A DE1287117C2 DE 1287117 C2 DE1287117 C2 DE 1287117C2 DE 1966F0048437 DE1966F0048437 DE 1966F0048437 DE F0048437 A DEF0048437 A DE F0048437A DE 1287117 C2 DE1287117 C2 DE 1287117C2
- Authority
- DE
- Germany
- Prior art keywords
- color
- signals
- delay
- line
- hand
- 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.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03D—DEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TO ANOTHER
- H03D1/00—Demodulation of amplitude-modulated oscillations
- H03D1/22—Homodyne or synchrodyne circuits
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N11/00—Colour television systems
- H04N11/06—Transmission systems characterised by the manner in which the individual colour picture signal components are combined
- H04N11/12—Transmission systems characterised by the manner in which the individual colour picture signal components are combined using simultaneous signals only
- H04N11/14—Transmission systems characterised by the manner in which the individual colour picture signal components are combined using simultaneous signals only in which one signal, modulated in phase and amplitude, conveys colour information and a second signal conveys brightness information, e.g. NTSC-system
- H04N11/16—Transmission systems characterised by the manner in which the individual colour picture signal components are combined using simultaneous signals only in which one signal, modulated in phase and amplitude, conveys colour information and a second signal conveys brightness information, e.g. NTSC-system the chrominance signal alternating in phase, e.g. PAL-system
- H04N11/165—Decoding means therefor
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Power Engineering (AREA)
- Processing Of Color Television Signals (AREA)
Description
Bei einer bekannten Farbdemodulationsschaltung werden, wenn die demodulierten Signale wieder in für nach dem PAL-Verfahren modulierte Fernseh- 4» eine andere Frequenzlage umgesetzt werden. Da zur signale wird das Empfangssignal in drei Kanäle auf- Rückumsetzung Spitzengleichrichter genügen, bleibt gespalten, wobei in einem Kanal das hochfrequente der Vorteil der geringen Toleranz für die Laufzeit-Farbsignal direkt an einer Additionsstufe und in glieder erhalten.In a known color demodulation circuit, when the demodulated signals are back in for television 4 »modulated according to the PAL method, a different frequency range can be implemented. There for signals, the received signal will be converted into three channels split, whereby in one channel the high frequency has the advantage of the low tolerance for the transit time color signal obtained directly at an addition stage and in terms.
einem zweiten Kanal über eine Laufzeitkette von Die übliche Technik zur Korrektur von Phaseneiner Laufzeit einer Zeilendauer geleitet wird und 45 fehlern durch Nachregeln oder Nachziehen des Oszilsodann in der ersten Addierstufe mit dem unverzö- lators kann bei der neuen Schaltung ohne weiteres angerten Signal kombiniert wird. In einer zweiten gewendet werden. Ferner ist es möglich, statt der üb-Addierstufe wird das um 180° in seiner Phase ge- liehen Umpolung des Oszillators, welcher den Syndrehte Signal mit dem in der erwähnten Laufzeitkette chrondemodulator für die /-Komponente speist, auch verzögerten Signal kombiniert. An den Ausgängen 5° die Phase des in den /-Kanal eintretenden Signals der beiden Addierstufen entstehen die farbträger- periodisch um 180° umzukehren oder das Vorzeichen frequenten /- und ß-Komponenten, die anschließend des demodulierten /-Signals periodisch zu vermittels Synchrondemodulatoren demoduliert und tauschen.a second channel over a delay chain of the common technique for correcting phases of one Running time of a line duration is passed and 45 errors are then caused by readjustment or readjustment of the oscillator in the first adder stage with the non-delay device can easily be added with the new circuit Signal is combined. To be turned in a second. It is also possible instead of the over-adding stage the polarity reversal of the oscillator, which rotates the syndrome, is borrowed by 180 ° in its phase Signal with the chrome demodulator for the / component feeds in the mentioned delay chain, too delayed signal combined. At the outputs 5 ° the phase of the signal entering the / channel of the two adding stages, the color subcarriers are created periodically by 180 ° or reverse the sign frequency / - and ß-components, which are then periodically mediated by the demodulated / signal Synchronous demodulators demodulate and swap.
schließlich in einer Dekodierstufe in die Farbkompo- Die Erfindung wird im folgenden an Hand derfinally in a decoding stage in the color composition. The invention is described below with reference to the
nenten ER, EB und E0 umgeformt werden. 55 Zeichnungen erläutert, von denenelements E R , E B and E 0 are transformed. 55 drawings explained, of which
Bei diesem Verfahren wird an die genaue Einstel- F i g. 1 eine übliche PAL-DemodulationsschaltungIn this process, the exact setting is F i g. 1 a conventional PAL demodulation circuit
hung der Laufzeitverzögerung eine hohe Toleranz- undThe propagation delay has a high tolerance and
Anforderung gestellt. Die Bandbreite der Laufzeit- F i g. 2 eine erfindungsgemäße Ausführung zeigt,Requirement made. The bandwidth of the transit time F i g. 2 shows an embodiment according to the invention,
kette muß relativ groß sein, da beide Seitenbänder, In F i g. 1 ist das von einer Farbsignalquelle 1 aus-chain must be relatively large, since both side bands, In F i g. 1 is that from a color signal source 1
das eine Seitenband allerdings nur teilweise, über- 60 gehende farbträgerfrequente Signal an die Eingänge tragen werden müssen. In Laufzeitgliedern, die diesen dreier Kanäle gelegt. Von diesen enthält der erste Anforderungen genügen, ist die Signaldampfung rela- Kanal eine Umkehrstufe 2, welche die Phase des Sitiv groß, so daß eine hohe Nachverstärkung erforder- gnals um 180° umkehrt, der zweite Kanal eine Lauflich ist. zeitkette 3, einen Verstärker 4 und ein Korrektur-Zur Demodulation von Farbfernsehsignalen, die 65 glied 5 zur Feineinstellung der Laufzeit. Der dritte nach dem SECAM-System moduliert sind, ist bereits Kanal enthält keine zusätzlichen Glieder. Die am eine Schaltungsanordnung bekannt, bei der das de- Ausgang des ersten und zweiten Kanals auftretenden modulierte Farbartsignal einer Verzögerungsleitung Signale werden in der Addierstufe 6, die am Ausgangthe one sideband, however, only partially, passing over 60 color subcarrier-frequency signal to the inputs have to wear. In term elements that put these three channels. Of these, the first contains Requirements, the signal attenuation is rela- channel an inversion level 2, which is the phase of the positive large, so that a high level of reinforcement is necessary reversed by 180 °, the second channel a Lauflich is. time chain 3, an amplifier 4 and a correction for demodulating color television signals, the 65 member 5 for fine adjustment of the running time. The third are modulated according to the SECAM system, the channel is already does not contain any additional elements. The on a circuit arrangement is known in which the de- output of the first and second channels occur modulated chrominance signal of a delay line signals are in the adder 6, which is at the output
des zweiten und dritten Kanals erhaltenen Signals in der Additionsstufe 7 kombiniertof the second and third channel received signal in the addition stage 7 combined
Die Ausgänge der beiden Additionsstufen 6 und 7 sind an zwei Synchrondemodulatoren 8 bzw. 9 angeschlossen, die von dem Farboszillatc/ 10 einerseits über die Umkehrstufe 11, andererseits über eine die Phase um 90° verlagernde Stufe 12 mit der farbträgersynchronen Oszillatorfrequenz gespeist werden. Die Umkehrstufe 11 polt das Signal von Z^iIe zu Zeile um 180° um. Die beiden erhaltenen Signale / und Q werden an den-Eingang der Dekodierstufe 13 gelegt, an deren Ausgang in an sich bekannter Weise die Komponenten Ex, EG und EB erhalten werden.The outputs of the two addition stages 6 and 7 are connected to two synchronous demodulators 8 and 9, which are fed by the color oscillator 10 on the one hand via the reversing stage 11 and on the other hand via a stage 12 which shifts the phase by 90 ° with the color carrier-synchronous oscillator frequency. The inverter 11 reverses the polarity of the signal from line to line by 180 °. The two received signals / and Q are applied to the input of the decoding stage 13, at the output of which the components E x , E G and E B are obtained in a manner known per se.
Eine Schaltung dieser Art ist ausführlich in der Zeitschrift NTZ, 17, Heft 3, S. 109 bis 121, beschrieben. A circuit of this type is described in detail in the journal NTZ, 17, issue 3, pp. 109 to 121.
Die in F i g. 2 gezeigte erfiidungsgemäße Schaltung unterscheidet sich von der bekannten Schaltung dadurch, daß Synchrondemodulatoren 8 und 9 einschließlich des Oszillators 10 und der phasenumpclendfcn und -verschiebenden Stufen 11 und 12 unmittelbar mit der Farbsignalquelle 1 verbunden sind. A.n den Ausgängen der Demodulationsstufen befinden sich zwei Laufzeitketten 3' und 3" und Additionsstufen 6' und 7'. Die Ausgänge der AdditionsstufenThe in F i g. 2 according to the invention shown differs from the known circuit in that synchronous demodulators 8 and 9 inclusive of the oscillator 10 and the phase pumping and shifting stages 11 and 12 directly are connected to the color signal source 1. A. are located at the outputs of the demodulation stages two runtime chains 3 'and 3 "and addition stages 6' and 7 '. The outputs of the addition stages
ίο sind wiederum mit der Dekodierstufe 13 verbunden. Da die den Laufzeitketten 3' und 3" zugeführten Signale bereits demoduliert sind, so können diese von wesentlich geringerer Bandbreite als bei der bekannten Schaltung sein und Tiefpaßcharakter haben. Hieraus ergeben sich die eingangs dargestellten Vorteile und Vereinfachungen.ίο are in turn connected to the decoding stage 13. Since the signals fed to the delay chains 3 'and 3 "are already demodulated, they can be from be significantly lower bandwidth than in the known circuit and have low-pass characteristics. From this the advantages and simplifications presented at the beginning result.
Hierzu 1 Blatt Zeichnungen1 sheet of drawings
Claims (1)
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE1966F0048437 DE1287117C2 (en) | 1966-02-16 | 1966-02-16 | DEMODULATION CIRCUIT FOR PAL COLOR TELEVISION SIGNALS |
GB423267A GB1168552A (en) | 1966-02-16 | 1967-01-27 | Demodulation Circuits for Colour Television Receivers |
AT151067A AT269960B (en) | 1966-02-16 | 1967-02-15 | Demodulation circuit for color television receivers |
NL6702276A NL149665B (en) | 1966-02-16 | 1967-02-15 | CIRCUIT FOR DEMODULATING A COLOR TELEVISION SIGNAL MODULATED ACCORDING TO THE PAL SYSTEM. |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE1966F0048437 DE1287117C2 (en) | 1966-02-16 | 1966-02-16 | DEMODULATION CIRCUIT FOR PAL COLOR TELEVISION SIGNALS |
Publications (2)
Publication Number | Publication Date |
---|---|
DE1287117B DE1287117B (en) | 1969-01-16 |
DE1287117C2 true DE1287117C2 (en) | 1976-09-02 |
Family
ID=7102240
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
DE1966F0048437 Expired DE1287117C2 (en) | 1966-02-16 | 1966-02-16 | DEMODULATION CIRCUIT FOR PAL COLOR TELEVISION SIGNALS |
Country Status (4)
Country | Link |
---|---|
AT (1) | AT269960B (en) |
DE (1) | DE1287117C2 (en) |
GB (1) | GB1168552A (en) |
NL (1) | NL149665B (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS4977533A (en) * | 1972-11-28 | 1974-07-26 |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
BE629045A (en) * | 1962-03-02 |
-
1966
- 1966-02-16 DE DE1966F0048437 patent/DE1287117C2/en not_active Expired
-
1967
- 1967-01-27 GB GB423267A patent/GB1168552A/en not_active Expired
- 1967-02-15 AT AT151067A patent/AT269960B/en active
- 1967-02-15 NL NL6702276A patent/NL149665B/en not_active IP Right Cessation
Also Published As
Publication number | Publication date |
---|---|
DE1287117B (en) | 1969-01-16 |
NL149665B (en) | 1976-05-17 |
GB1168552A (en) | 1969-10-29 |
AT269960B (en) | 1969-04-10 |
NL6702276A (en) | 1967-08-17 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
8339 | Ceased/non-payment of the annual fee |