KR900000126B1 - Multi-system television receiver - Google Patents

Abstract

The appts. receives signals of a number of different system with a number of different subcarrier wave frequencies. A detector produces frequency data representing the detected frequency of the subcarrier wave. A detector produces system data representing the detected system. A detector detects the channel change and a circuit holds the frequency and system data on change of the detected channel. TV circuits are set in a condition in compliance with the frequency and system data. The system pref. has an APC loop including vibrating elements coupled to a VCO for oscillation at different frequncies.

Description

Multi-system television receiver

1 is a circuit diagram showing a subcarrier generating circuit according to the present invention.

2 is a circuit diagram showing a subcarrier generating circuit and its related components in accordance with a preferred embodiment of the present invention.

3 is a graph showing waveforms obtained at various places in the circuit of FIG.

4 is a block diagram showing modification of a subcarrier generation circuit according to the present invention.

5 is a circuit diagram of a low pass filter replaced with a low pass filter shown in FIG.

* Explanation of symbols for main parts of the drawings

3: low pass filter 4: voltage controlled oscillator

5a, 5b: quartz crystal vibrator 6: switching circuit

7: phase detector 8: flip-flop

12 capacitor 13 switch

14: channel selector 15: pulse generator

17 capacitor 18 switch

19 band filter 23 holding circuit

26 SECAM circuit 27 PAL / NTSC detector

28: TV signal detector 30: Acoustic trap

32: video trap 33: demodulator

35: SECAM erased (KILLER)

The present invention relates to a multi-system television receiver having a subcarrier generation circuit that can be operated on a number of different systems.

In the world, there are many other types of television broadcasting systems, such as PAL systems, SECAM systems, NTSC systems, and others.

Television broadcast with two or more systems may be used anywhere in the world. Videotapes recorded under other systems may also be used.

In order to enable the reproduction of color television signals of other systems, color television receivers for receiving and reproducing color television signals of other systems have been developed. However, television receivers are referred to as multisystem television receivers.

Signal formats for the MTSC system and the PAL system are very similar to each other. Therefore, in color signal processing circuits, in particular subcarrier wave oscillators in prior art multi-system television receivers, an auto phase controller (APC) phase detector and a killer phase detector are commonly used for both systems. Furthermore, a multi-system television receiver has detection means for detecting the type of television system now received to switch the various circuits necessary to process the television signal into an image that can be viewed on a CRT.

As an example, according to the PAL system, a subcarrier wave with a frequency of 4.43 MHz is used in most places, but in some places a 3.58 MHz subcarrier wave is used. 3.58 MHz subcarrier waves are commonly used for MTSC systems. Furthermore, one VTR tape recorded under the MTSC system uses 3.58 MHz and the other uses a 4.43 MHz subcarrier wave.

Accordingly, prior art multi-system television receivers capable of receiving television signals from PAL and NTSC systems, or reproducing VTR tapes recorded under multiple systems, have two subcarrier waves with different frequencies of 4.43 MHz and 3.58 MHz. Two oscillators are used to generate them.

Appropriate switching means are provided for this purpose to select one oscillator for generating the required subcarrier wave.

Therefore, prior art multisystem television receivers require two oscillators resulting in high production costs. Again suitable switching means are needed to select one oscillator.

In order to eliminate the above-mentioned drawbacks, a multi-system television receiver having an improved subcarrier generation circuit has been proposed by the same inventor as the present invention and is assigned to Japanese Patent Application Laid-Open No. 58-152070, which is assigned to the same assignee as the present application. Was released.

According to this publication 58-152070, only one oscillator is provided to generate a subcarrier wave at another frequency and automatically selects and calculates a subcarrier wave having a suitable frequency to receive a television signal. Details of the subcarrier generation circuit disclosed in this publication 58-152070 are described below in connection with FIG.

In FIG. 1, reference numeral 1 denotes a burst gate circuit which separates and generates a burst gate signal from a chrominance signal according to a burst gate pulse during horizontal scanning.

Reference numeral 2 denotes a phase detector for an automatic phase controller (APC), (3) a low pass filter, and (4) a voltage controlled oscillator (VCO). These circuits (2), (3) and (4) define an automatic phase controller (APC), so that the voltage controlled oscillator 4 produces a subcarrier signal.

The voltage controlled oscillator 4 is provided with two crystal oscillators 5a and 5b which generate signals of frequency 3.58 MHz or 4.43 MHz. The switching circuit 6 is provided for selectively connecting one quartz crystal oscillator to the voltage controlled oscillator 4 in response to the frequency of the burst signal.

The phase detector 7 is further provided for killing. When the phase detector 7 stops calculating the normal signal, the flip-flop 8 reverses its condition for the reception of a drive pulse having a pulse width of about 200 milliseconds. The output of the flip-flop 8 is connected to the switching circuit 6 to select one vibrator.

The operation of the subcarrier generating circuit of FIG. 1 is as follows.

When a television signal of the NTSC system is received, a burst signal having a frequency of 3.58 MHz is separated from the burst gate circuit 1 and calculated. The burst signal is applied to both phase detectors 2 and 7. In this case, the switching circuit 6 acts to connect the crystal oscillator 5a with the VCO 4 in accordance with the output signal from the flip-flop 8, and simultaneously the APC loop outputs a burst signal having a frequency of 3.58 MHz. And operate in a synchronized relationship. The VCO 4 thus yields a subcarrier wave with a frequency of 3.58 MHz. In this way, once the APC loop is synchronized, the phase detector 7 calculates the detected signal of the phase that stops the addition operation of the flip-flop 8. Thus, the VCO 4 yields a typical 3.58 MHz subcarrier wave under stable conditions. If for some reason the control of the flip-flop 8 is delayed, the switching circuit 6 is operated to connect the crystal oscillator 5b (4.43 MHz) to the VCO 4. If the signal of the APC loop loses synchronization, thereby the output signal is not calculated from the phase detector 7. The flip-flop 8 thus changes its condition upon reception of the next drive pulse, whereby the switching circuit 6 is switched to connect the crystal oscillator 5a (3.58 MHz) to the voltage controlled oscillator 4. Thus, the APC loop is synchronized at frequency 3.58 MHz, and the VCO 4 yields a typical subcarrier wave at frequency 3.58 MHz.

Next, when the television signal of the PAL system is received at the change of the channel, a burst signal having a frequency of 4.43 MHz is separated from the burst gate circuit 1 and calculated. Therefore, by the output signal from the flip-flop 8, the switching circuit 6 is applied to connect the crystal oscillator 5B to the voltage controlled oscillator 4. Thus, the APC loops are synchronized with a burst signal with a frequency of 4.43 MHz and operate in relation. Therefore, the pre-controlled oscillator 4 calculates a subcarrier wave having a frequency of 4.43 MHz. In this way, once the autophase controller loop is synchronized at a frequency of 4.43 MHz, the phase detector 7 produces a signal whose phase has been detected to stop the flip-flop 8's addition operation. Thus, the voltage controlled oscillator 4 calculates a 4.43 MHz subcarrier wave in a stable condition.

The subcarrier generation circuit of the prior art described above has a number of drawbacks as described below.

The first drawback is the misoperation that occurs when the television signal of the SECAM system is received.

According to the SECAM system, the chrominance signal contains a subcarrier wave of frequency 4.25 MHz or 4.406 MHz, which is very close to the frequency of the Burst signal 4.43 MHz.

Therefore, if the signal component of the trailing edge of the horizontal synchronous signal where the burst signal of the PAL system or NTSC system is located enters while the TV signal of the SECAM system is received, the APC circuit makes a telescopic operation to produce a burr of 4.43 MHz. This can lead to incorrect operation as if the test signal is received.

A second drawback is a misoperation that occurs when a channel is changed from a channel of one broadcasting system such as a PAL system to a channel of another broadcasting system such as a SECAM system.

More specifically, according to the prior art subcarrier generating circuit, the low frequency pass filter forming the autophase controller loop has a relatively long time constant. Therefore, when a channel change between two different broadcasting systems is executed, it takes a relatively long time to detect the broadcasting system of the new selected channel and switch the switching circuit 6 to generate an appropriate subcarrier wave from the voltage controlled oscillator 4. During this time, the image on the screen is frequently distorted.

The last drawback is a misoperation caused by noise produced from the system detection circuit or the flip-flop circuit 8 for detecting the type of broadcast system that is now being received.

In detail, according to the prior art multi-system television receiver, the system detection circuit detects and calculates a signal indicating the type of broadcast system it is now receiving. However, the system detection circuit makes error detection by the noise signal. For example, the noise signal is calculated at the time of reproducing a tape contained in the received broadcast signal or recorded under poor conditions or when a video search signal is added.

The present invention has been improved in view of substantially solving the above-mentioned drawbacks and is an improved multi-system television receiver which does not produce any noise signal caused by a change of channel between two different broadcasting systems or any misoperation due to any of the other reasons mentioned above. It is his essential purpose to provide.

It is also an essential object of the present invention to provide an improved multi-system television receiver, in particular capable of providing a stable image in a timely manner after a change of channel between two different broadcasting systems.

In achieving these and other objects, a multisystem television receiver according to the present invention is adapted to receive television calls from other systems, such as PAL systems, NTSC systems and SECAM systems, with a number of different subcarrier waves frequency. A frequency detection circuit for detecting a frequency of the subcarrier wave of the signal, calculating frequency data indicating the detected frequency, a system detection circuit for detecting a system of a television signal, and calculating system data indicating the detected system, and a channel change And a channel change detection circuit for detecting a signal, a holding circuit for holding system data and frequency data at the time of a change of a channel detected by the detection circuit, and a television circuit set under conditions compliant with the frequency data and the system data.

Moreover, according to a preferred embodiment of the present invention, a multi-system television receiver comprises an APC loop comprising a oscillating element coupled to an oscillator for oscillation of different frequencies and a voltage-regulated oscillator, a phase between the oscillating signal from the oscillator and the burst signal of the television signal. A phase detector for detecting a difference, a flip-flop controlled by a signal calculated from the phase detector, a circuit for generating a color cancellation signal for the SECAM system, and a circuit for selecting one vibration element for performing oscillation of a required frequency. Have

Further provided in the above-described preferred implementation is a pulse generation circuit which generates a channel change pulse upon a change of channel, wherein the autophase controller loop further has a low pass filter connected to a voltage controlled oscillator. The low pass filter has a time constant setting circuit for making the time constant of the low pass filter short when the channel change pulse is present.

In the preferred implementation described above, the phase detector also has a time constant setting circuit for making the time constant of the phase detector short circuit in the presence of a channel change pulse.

These and other objects and aspects of the present invention appear from the following description, taken in conjunction with the preferred embodiments, with reference to the accompanying drawings, wherein like reference numerals designate like reference numerals.

Referring to FIG. 2, a tuner 29 that receives a television signal and produces a tuned television signal is connected to an S-trap 30 and an image intermediate frequency (PIF) 31.

The output of the (PIF) 31 is connected to each of the SECAM circuit 26, the PAL / NTSC detector 27, and the video trap 32. A video trap, also coupled to a video circuit (not shown), is connected to the band filter BPF and the band amplifier 20. Accordingly, the band amplifier 20 calculates a chrominance signal applied to the burst gate circuit 1. The burst gate circuit 1 operates in response to a burst gate pulse. The output of the burst gate circuit 1 is connected to the phase detector 2 for use of the automatic phase controller APC.

The low pass filter 3 is connected to a phase detector 2 and coupled to a switching circuit 6 having crystal oscillators 5a and 5b for oscillation at different frequencies 3.58 MHz and 4.43 MHz ( 4) is connected. The automatic phase controller is constituted by a feedback loop containing a phase detector 2, a low pass filter 3 and a voltage controlled oscillator 4. Therefore, the voltage controlled oscillator 4 calculates a subcarrier signal having a frequency of 3.58 MHz or 4.43 MHz depending on the frequency of the burst signal in a method described in detail later.

According to a preferred embodiment, the low pass filter 3 has a capacitor 9 connected between a live line for driving a signal and a counter. The series connection of the resistor 11 and the capacitor 10 is also connected in parallel to the capacitor 9. Moreover, the series connection of the capacitor 12 and the normally closed switch 13 is connected in parallel to the capacitor 10. The on and off of the normally closed switch 13 is controlled by the pulse from the pulse generator 15 in the manner described later.

The output of the VCO 4 is applied to a PAL / NTSC demodulator that produces an R-Y signal or a B-Y signal. The output of the voltage controlled oscillator 4 is applied to the phase detector 7 which also receives the output signal from the burst gate circuit 1.

According to a preferred embodiment, the phase detector 7 is connected to a grounded capacitor 16. A series connection of the capacitor 17 and the normally closed switch 18 is also connected in parallel to the capacitor 16. The on and off of the normally closed switch 18 is also controlled by the pulse from the pulse generator 15 in the manner described below.

Channel selector 14 is coupled to pulse generator 15.

Whenever the broadcast channel is changed by the channel selector 14, the pulse generator 15 generates a short pulse as indicated by the waveform d in FIG. Short pulses are typically applied to each of the closed switches 13 and 18 so that they open temporarily for the duration of the pulse. When the switch 13 is open, the capacitor 12 is disconnected from the capacitor 10 thereby creating a time constant short of the low pass filter 3. Similarly, when the switch 18 is opened, the time constant of the phase detector 7 is short-circuited. When the time constants are shorted, the telescopic operation of the APC loop is fastened, whereby the subcarrier waves for the newly selected channel are calculated very quickly in the voltage controlled oscillator. This fast response is achieved even if the channel change is performed between two different broadcast systems with different subcarrier wave frequencies. Thus, a stable subcarrier wave is obtained immediately after the change of channel.

The phase detector 7 is provided for calculating the color erasing output applied to the band amplifier 20 and the flip-flop circuit 8. When the voltage controlled oscillator 4 produces a subcarrier signal having a frequency of 3.58 MHz, the flip-flop 8 generates a high in response to the signal obtained from the phase detector 7. Similarly, the flip-flop 8 generates a low when the voltage controlled oscillator 4 produces a subcarrier signal having a frequency of 4.43 MHz.

3 shows that the output of the flip-flop 8 as indicated by waveform a is applied to the AND gate 22a provided to the detection control circuit 22.

The detection control circuit 22 further includes an AND gate 22b and 22c and a pulse generator 22d. One input of the AND gate 22b is connected to the SECAM circuit 26, which calculates low when the received television signal is a SECAM system, as indicated by waveform b in FIG. One input of the AND gate 22c is connected to the PAL / NTSC 27 which yields low when the received television signal is an NTSC system and is low when it is a PAL system or SECAM system as indicated by waveform c in FIG. do.

The other inputs of the AND gates 22a, 22b, and 22c are connected to the pulse generator 22d. The pulse generator 22d has its input connected to an OR gate 22e having two inputs. One input of the OR gate 22e is connected to the pulse generator 15, and the other input thereof is connected to the television signal detector 28. The details of the pulse generator 22d are described later. The television signal detector 28 has two inputs, one for receiving a horizontal pulse and the other for receiving a synchronous pulse. Therefore, whenever a television signal obtained through an antenna (not shown), a cable (not shown) or from a video tape is received, the television signal detector 28 generates a peak as indicated by the waveform (e) in FIG. The television signal detector 28 thus calculates low while the channel is being changed. In this respect, the signal calculated by the television signal detector 28 is the same except that the signal calculated by the pulse generator 15 and these two signals are in phase out of phase. Moreover, the signal from the television signal detector 28 has an aspect in which a channel change recorded on the tape can also be detected when the videotape is reproduced. Therefore, whenever there is a channel change in the reproduced video tape, the pulse is not calculated from the pulse generator 15 but from the television signal detector 28.

Therefore, the OR gate 22e calculates a signal not only when the channel is actually changed but also when a channel change recorded on the video tape is detected.

3, the pulse generator 22d detects the rise of the waveform d or the rise of the waveform e and yields one short pulse having a pulse timing of t or t ', as indicated by the waveform f. Therefore, the AND gates 22a, 22b, and 22c can operate only when there is one short pulse, which is the actual channel change or a short time immediately after the channel change recorded on the video tape is executed.

The AND gates 22a, 22b and 22c are connected to the holding circuit 23 which is coupled to the return circuit 25. The return circuit 25 receives the signal from the television signal detector 28 and calculates a return signal when the channel is changed. Therefore, when the channel is selected, the output signal from the AND gate 22a is held in the holding circuit 23 and calculated from the output terminal 24A of the holding circuit 23. Similarly, the output signal from the AND gate 22b is held and calculated from the output terminal 24B and the output signal from the AND gate 22c is held and calculated from the output terminal 24C. If the holding circuit holds several data from the AND gates 22a, 22b and 22c immediately after the channel selection, the data is held as long as the selected channel is enlarged.

The output terminal 24A carrying data of the subcarrier frequency includes a switching circuit 6 and a band filter 19, a video trap 32, and an acoustic trap, which select any one of the crystal oscillators 5a and 5b. 30).

An output terminal 24B carrying data indicative of the SECAM system is connected to the SECAM circuit 26 to hold the SECAM circuit operating while the received television signal is the SECAM system.

An output terminal 24C carrying data indicating a PAL system or an NTSC system is connected to the PAL / NTSC demodulator 33 to operate the demodulator 33.

When the received television signal is a PAL system, the output terminal 24C calculates low and sets the demodulator 33 as a PAL demodulator. On the contrary, when the received television signal is an NTSC system, the output terminal 24C calculates the high and sets the demodulator 33 as the NTSC demodulator.

Next, the operation of the circuit of FIG. 2 is explained.

The television receiver according to the embodiment shown in FIG. 2 can be operated in five different broadcasting systems. That is, PAL system with 3.58MHz subcarrier wave, PAL system with 4.43MHz subcarrier wave, NTSC system with 3.58MHz subcarrier wave, NTSC system with 4.43MHz subcarrier wave, and SECAM system with 4.43MHz.

Assume channel selector 14 is now enabled to select a television signal of an NTSC system with a 3.58 MHz subcarrier wave. When the channel selector is activated, the pulse generator 15 calculates a pulse (first pulse of the waveform d) which acts on the pulse generator 22d to calculate one short pulse (the first pulse of the waveform f). .

While there is one short pulse, the flip-flop 8 calculates a high indicating that the subcarrier wave has a frequency of 3.58 MHz. The SECAM circuit 26 also calculates a low indicating that the received television signal is not a SECAM system, and the PAL / NTSC detector 27 calculates a high indicating that the received television signal is an NTSC system.

Therefore, when one short pulse (first pulse of waveform f) is calculated in the pulse generator 22d, each of the AND gates 22a and 22c is high (waveforms g and i). The AND gate 22b does not calculate a pulse (waveform h).

The signals from the AND gates 22a, 22b, and 22c are calculated in response to one short pulse and held in the holding circuit 23, and the signals are output to the output terminals 24A, 24B, and 24C, respectively. Calculates, me and high. These signals calculated at the output terminals 24A, 24B and 24C are held until the return circuit calculates the return signal, that is, until the next channel is changed.

The high from the output terminal 24A is applied to the switching circuit 6 to select the crystal oscillator 5a for oscillation with a frequency of 3.58 MHz. The high from the output terminal 24A is applied to the band filter 19 and to the videotape 32 and the acoustic trap 30 to select a band suitable for the 3.58 MHz subcarrier wave.

I from the output terminal 24B is applied to the SECAM circuit 26 to disable the SECAM circuit 26.

The high from the output terminal 24C is applied to the PAL / NTSC demodulator 33 to set the demodulator 33 as an NTSC demodulator. The data indicating the system of the television signal and the data indicating the frequency of the subcarrier wave are maintained only when the AND gates 22a, 22b and 22c are operable for a short time immediately after the channel change. As such, unwanted changes or variations of these data are not transmitted to various circuits such as the holding circuit 23 and the switching circuit 6. Thus, once the holding circuit 23 holds the data of the television signal received at the beginning of channel selection, such data does not change even when the television signal is shaken or when a noise signal appears in the television signal. Thus, the television receiver not only automatically sets the circuit to the proper conditions of the system of the received television signal but also maintains the set conditions as long as the channels remain the same. When the channel change is performed by the channel selector 14 or when the channel change signal as recorded on the video tape is reproduced, new data is set and held in the holding circuit 23.

The signals calculated from the output terminals 24A, 24B and 24C for television signals received by other systems are shown in the table below.

According to the embodiment shown in FIG. 2, the detection control circuit 22 uses AND gates 22a, 22b and 22c, but these AND gates can be replaced with other logic gates such as NOR gates, in which case The pulse applied to the gate is of negative type.

Referring to FIG. 4, a modification of the subcarrier generation circuit according to the present invention is indicated. The output of the flip-flop 8 is connected to an OR gate 34 which also receives a signal from the SECAM cancellation 35 of the SECAM circuit. The output of the OR gate 34 is connected to the switching circuit 6. The operation of this circuit is explained below.

When the television signal of the NTSC system is received, the flip-flop 8 calculates a high in the manner described above. The high is then applied to the switching circuit 6 via the OR gate 34 and oscillated at 3.58 MHz by the crystal oscillator 5a. Thus, the APC loop synchronizes at frequency 3.58MHz, and the VCO generates a 3.58MHz subcarrier wave.

When the television signal of the PAL system is received, the flip-flop 8 calculates me in the manner described above. At that time, I am applied to the switching circuit 6 via the OR gate 34 and oscillated at 4.43 MHz by the crystal oscillator 5b. Thus, the APC loop synchronizes at the frequency 4.43 MHz and the VCO generates a subcarrier wave of 4.43 MHz.

When the television signal of the SECAM system is received, the SECAM erase 35 for SECAM color cancellation yields a high. Therefore, OR gate 34 yields a high value regardless of the signal from flip-flop 8. Thus, the switching circuit 6 is switched to oscillate at 3.58 MHz. In this case, a subcarrier wave component of frequency 4.25 MHz or 4.406 MHz contained in the chrominance signal is applied to the phase detector 2. Since such frequencies are very different at 3.58 MHz, the VCO 4 generates a subcarrier wave of 3.58 MHz without making any stretch operation by the APC loop.

In this case, the color canceling output calculated by the phase detector 7 is used to disable the color processing circuit for the NTSC / PAL system and to enable the color processing circuit for the SECAM system.

Referring to FIG. 5, a circuit diagram of a low pass filter is shown.

According to the low pass filter shown in FIG. 2, the series connection of the capacitor 12 and the normally closed switch 13 is connected in parallel to the capacitor 10 to short-circuit the time constant when the switch 13 is opened. According to the modification shown in FIG. 5, the series connection of the resistor 36 and the normally open switch 13 ′ is connected in parallel to the capacitor 10. Therefore, when the channel change is executed, the switch 13 'is closed to short the time constant. Thus, the low pass filter 3 shown in FIG. 2 is replaced by the low pass filter 3 shown in FIG.

While the invention has been fully described with reference to the preferred embodiments, many modifications and variations will be apparent to those trained in the art, the scope of the invention being not limited by the description of the preferred embodiments described above, but in the appended claims. It is limited only by.

Claims (5)

An APC comprising a crystal oscillator 5a, 5b coupled to the oscillator for oscillation of a frequency different from the voltage controlled oscillator 4, wherein a multisystem television receiver adapted to receive television signals of PAL, SECAM and NTSC systems A loop detector, a phase detector 7 for detecting a phase difference between an oscillation signal from the oscillator and a burst signal of a television signal, a flip-flop 8 controlled by a signal calculated from the phase detector, and a color for a SECAM system. SECAM cancellation 35 for generating an erase signal, and a switching circuit 6 controlled by the erase circuit and the flip-flop circuit for selecting one of the oscillation elements for executing oscillation of the required frequency. Multi-system TV receiver. 2. The low frequency filter as claimed in claim 1, further comprising pulse generating means (14, 15) for generating a channel change pulse when the channel is changed, wherein the APC loop further has a low pass filter (3) connected to a voltage controlled oscillator. The pass filter has time constant setting circuits (12, 13) for making a time constant of the low pass filter short circuit when a channel change pulse is present. 2. The phase detector (7) according to claim 1, further comprising pulse generating means (14, 15) for generating a channel change pulse upon channel change, and the phase detector (7) for producing a time constant of the phase detector short circuit when a channel change pulse is present. Having time constant setting circuits (17, 18). A multi-system television receiver adapted to receive television signals of multiple different systems with multiple different subcarrier wave frequencies detects the frequency of the subcarrier waves of the television signal and yields frequency data (a) indicating the detected frequencies. Frequency detecting means (7, 8), system detecting means (26, 27) for detecting system of the television signal and calculating system data (b, c) indicating the detected system, and channel for detecting channel change. Change detection means (14, 15, 28), holding means (23) for holding the frequency data and the system data at the time of the change of the channel detected by the detecting means, and a condition adapted to the frequency data and the system data. A multi-system television receiver characterized by having a television circuit (6, 19, 32, 30, 26, 33). 5. The frequency detector according to claim 4, wherein said frequency detecting means has a phase detector (7) for detecting a phase difference between a burst signal of a television signal and a subcarrier signal calculated from the oscillator (4). Connected to 7).

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