CN1005305B - Television receiver comprising an automatic radio-freouency resonance circuit adjustment circuit - Google Patents

Abstract

The present invention relates to a television receiver which comprises an automatic adjusting line used for a radio-frequency resonant loop (8) of the television receiver. Two carrier waves are used for supplying radio frequency input of the television receiver, and the product of amplitudes of the two carrier waves is formed by that a detection line (37) is coupled to an output end (5) of a radio frequency line (8). The radio-frequency resonant loop is adjusted to cause the product to reach a maximum (at a 77 point), and thus, a correct and simple adjusting method is provided.

Description

Have a rf resonant circuit and regulate the television receiver of circuit automatically

The present invention relates to a kind of television receiver that a rf resonant circuit is regulated circuit automatically that has.In this circuit, produce a setting signal, by means of two carrier waves of the radio frequency part that is added to television receiver be coupled to an output signal of the detection line of radio frequency part output, the setting that is used for proofreading and correct rf resonant circuit.

The patent application in Europe discloses a kind of television receiver of above-mentioned pattern for No. 0109661, and wherein two carrier waves one after the other are applied to the radio frequency part of receiver.And a wave detector is connected to the output of receiver radio frequency part, and a signal is added to microprocessor, and the latter is with a kind of method that does not further describe, and the off resonance of reaction radio frequency part radio-frequency line is till tuning curve satisfies a standard of being scheduled to.

Target of the present invention is to provide a kind of adjusting circuit, it to the mutual amplitude of two carrier waves than insensitive.

Therefore, television receiver according to the present invention's described pattern in starting a section, it is characterized in that: detection line comprises that one is used for making that setting signal depends mainly on the circuit of the product of two carrier amplitude, is to arrange to be used for regulating this setting signal to maximum and regulate circuit; And the frequency of these two carrier waves equals the frequency of pix carrier of TV signal and the frequency of sound carrier respectively, and detection line comprises that one is used to detect the circuit with amplitude of the signal of difference frequency between the carrier frequency, and this amplitude is that the product with the amplitude of these two carrier waves is directly proportional basically.

The applicant once found, reached peaked method with such main product of regulating two carrier amplitudes, tuning circuit always can regulate itself be transferred to correct tuning, irrelevant with the amplitude ratio of two carrier waves.

Therefore, according to a kind of television receiver of the present invention, be the automatic adjusting that is suitable for very much realizing rf resonant circuit, be transferred to a transmitter signal that receives.Wherein each amplitude of two carrier waves can be an arbitrary value.

The adjusting of a continuous action, it must not be predetermined original position starting from the tuning curve always, can be by obtaining to differential circuit of detection line equipment, this differential circuit is to be used for setting signal is formed the variation of an amplitude product, and one is used for the harmonic ringing of radio circuit, is to obtain from a harmonic ringing conversion line by differential circuit control.The harmonic ringing conversion line is used for making the circuit of the sign modification of harmonic ringing to be formed by one, conversion is produced by the harmonic ringing conversion line, is decided by to react the product of the symbol that symbol that amplitude product that harmonic ringing changes changes and former harmonic ringing change.

Now, the present invention can consult accompanying drawing as an example, give more detailed description.

In these figure:

Fig. 1 illustrates a kind of television receiver of the present invention with a square line map.

Fig. 2 is the possible specific embodiments that a harmonic ringing conversion line is described with a square line map.It is used for television receiver of the present invention.

Fig. 3 illustrates that with a square line map harmonic ringing conversion line further may embodiment.It is used for television receiver of the present invention.

Fig. 4 illustrates that with a square line map one regulates a possible embodiment of a circuit part.It is used for television receiver of the present invention, all can be regulated a plurality of rf resonant circuits that comprise.

Fig. 5 illustrates that with a square line map one regulates another possible embodiment of a circuit part.It is used for a kind of television receiver of the present invention, all can be regulated a plurality of rf resonant circuits that comprise.

Fig. 6 is the various oscillograms that occur in Fig. 4 and Fig. 5 circuit.

In Fig. 1, a TV signal that includes pix carrier and sound carrier that receives is added to the input 1 of radio frequency part 3.After this TV signal is amplified, be added to an input 7 of mixing part 9 through output 5.

Mixing part 9 also has an input 11, from an oscillator signal of the output 13 of oscillator 15, be added to it above.So from the output 17 of mixing part 9, obtain an intermediate-freuqncy signal, and it be added to an input 19 of intermediate-frequency section 21.

The output 23 of intermediate-frequency section 21 is so with an intermediate-freuqncy signal of having amplified, be added to the input 25 of demodulator 27.Thereby, producing a vision signal and an intercarrier signal at the output 29 of demodulator 27, the frequency of this intercarrier signal is frequency poor of pix carrier and sound carrier.And its amplitude is decided by the product of pix carrier and sound carrier amplitude.

The signal of demodulator 27 outputs 29 is added to the input 31 of the image display portion 33 of handling vision signal, and is added to the input 35 of detection line 37, and in this circuit, it is to be added to one to aim at the tuning filter 39 of intercarrier frequency.

This filter 39 has an output 41, only can produce intercarrier signal on it.It is added to the input 45 of gate circuit 43 and voice signal processing section 47, and for example by convention, this sound signal processing part 47 is made up of a limiting amplifier 49, a frequency demodulator 51 and a low frequency part 53.

The output 29 of demodulator 27 is also connected to an input 55 of a synchronous signal processing circuit 57.This circuit produces a line frequency pulse signal according to the TV signal of demodulation, be added to its output 59, and produce a field frequency clock signal, be added to output 61, another input 62 of synchronizing signal process circuit 57, be connected to the output 41 of filter 39, and receive therefrom and the relevant information of voice signal appearance.The identification signal whether indication pictures and sounds carrier wave occurs, the output 63 of supply synchronizing signal process circuit 57.

A gate signal input 65 of gate circuit 63 receives a gate signal from the output 59 of synchronizing signal process circuit 57, and when line synchronizing signal occurred, it made gate circuit 43 conductings.The result has and the irrelevant amplitude of image content at the signal of the output 71 of gate circuit 43.This signal is exactly so-called setting signal, through amplifier 73 and amplitude detector 75, is added to the input 77 of differential line 79 from the output 71 of gate circuit 43.

Differential line 79 adds to 81 1 signals of output of detection line 37, and its symbol and amplitude are decided by the amplitude variations of amplitude detector 75 output signals.Thereby the amplitude variations that is decided by these two carrier amplitude products.This signal is added to an input 83 of a harmonic ringing conversion line 85.

Harmonic ringing conversion line 85 also has an input 87, and it receives the pulse signal from an output 89 of pulse generator 91.

The input 93 of pulse generator 91 receives the field frequency clock signal from synchronizing signal process circuit 57 outputs 61.And in the identification signal of input 95 receptions from synchronizing signal process circuit 57 outputs 63.If do not receive image or sound carrier, the pulse generator 91 that reacts this signal just stops to produce pulse.An output 97 of pulse generator 91 is added to a gate signal gate signal input 99 of gate circuit 101.

Gate circuit 101 as a result, when the pictures and sounds signal occurs, with the output 29 of demodulator 27, periodically are connected to the input 103 of automatic gain control (AGC) signal generating circuit 105.Do not have the image and (or) when not having voice signal, connect foregoing circuit continuously.AGC signal generating circuit 105 is added to an input 107 of intermediate-frequency section 21 with an AGC signal, and is added to the input 109 of radio frequency part 3.

In addition, radio frequency part 3 has a harmonic ringing input 111, and it receives a harmonic ringing from the output 113 that merges circuit 115, and one or several resonant tank is tuning in the decision radio frequency part 3.In this case, harmonic ringing is to be merged with the tuning correction signal that is added to input 123 by the oscillator tuning signal that is added to input 117 to form.The signal of input 117 is from the output 119 of a tuning circuit 121, and it also is added to the harmonic ringing input 122 of oscillator 15.The signal of input 123 is from the output 125 of harmonic ringing conversion line 85.

In the tuning correction signal of harmonic ringing conversion line 85 outputs 125, regulate itself now to such numerical value, be exactly that the pulse that changes by the input 87 of harmonic ringing conversion line 85 of harmonic ringing is produced.At the input 83 of harmonic ringing conversion line 85, produce the product amplitude variations of a minimum.And each radio circuit is therefore tuning like that, is exactly the product amplitude as setting signal, at the output of amplitude detector 75 in its maximum.

Input 87 those ends of harmonic ringing conversion line 85 are connected to an input 127 of multiplier 129, and its another input 131 is connected to the output 133 of another amplifier 135.This amplifier has an input 137, is connected to the input 83 of harmonic ringing conversion line 85.Its another input 139 is connected to the output 141 of delay circuit 143.The input 145 of delay circuit 143 through an amplitude limiter 147, is coupled to the output 149 of multiplier 129.This output 149 through an integrating circuit 151, also is coupled to the output 125 of tuning conversion line 85.

Multiplier 129 and 135 forms a step generation circuit with delay circuit 143 and amplitude limiter 147.It is the tuning step that is used for producing radio frequency part 3.In the pulse that the input 127 of multiplier 129 receives, supply with its 149 1 pulses of output, its symbol and amplitude are determined by its symbol and the amplitude of input 131 signals.The symbol of this signal is determined by the symbol of each signal on the input 137 and 139 of another multiplier 135.And its amplitude is only determined by the amplitude of input 137 signals.Because amplitude limiter 147 is to affact input 139 in signalling channel.The symbol that signal on another multiplier 135 inputs 139 has is the symbol of the last step of multiplier 129 outputs 149.And the signal at the input 137 of another multiplier 135 has this symbol, and the amplitudes that change in tuning of radio frequency part 3, is produced through integrating circuit 151 by above-mentioned step.Thereby produced by the product amplitude variations on the output 81 of detection line 37.As its result, radio frequency part 3 tuning is the minimum value of the product amplitude variations of the output 81 of detection line 37 being transferred to it, and be corresponding with these carrier amplitude maximum product.Find in the practice,, can realize correct tuning like this for all amplitude ratios.

Because the symbol of step was decided by the symbol of front step afterwards, and be decided by so the symbol of the product amplitude variations that produces.Regulating action need go on always, and till reaching the amplitude maximum product, when surpassing this maximum, controlling party is reverse to automatically.

Change at a harmonic ringing, and when regulating circuit with afterreaction, the signal of the input 99 of automatic gain control (AGC) response gate transmission line 101 disconnects.Pulse generator 91 can make like this, makes tunning effect and setting effect alternately take place, and its example will provide below.

Replacement is carried out the automatic tuning of continuous action to a transmitter signal that receives, if wish like that, it can be once tuning selectively, for example be used for channel selection, can be to the signal tuning of two carrier combination, this composite signal is added to an input of radio band 3, and may be produced by receiver.The result can be stored in the container later on.

Particularly when the radio frequency resonant that adopts a continuous action is regulated circuit, the decline of Mid Frequency would rather be split up into the setting signal part that is used for obtaining the part of vision signal and is used for obtaining regulating as rf resonant circuit, in the part that is used for obtaining vision signal, so can adopt the automatic gain control (AGC) of a continuous action, be used in the image that shows, preventing that the rf resonant circuit adjusting from producing interference.

One to be used for rf resonant circuit in order making, to be adjusted to the circuit of a transmitter signal that receives automatically, also be applicable to and be transferred to a transmitter weak signal that receives, clearly, preestablishing of rf resonant circuit must be satisfied higher requirement than aiming at a stronger transmitter signal.

Although the straightforward procedure that obtains setting signal is arranged, product amplitude in this case as previously mentioned, clearly selects other possible methods all can meet this requirement.Therefore, can be synchronously or non-synchronously detect the amplitude of each carrier wave, and the numerical value that detects can multiply each other each other, perhaps at first detects the amplitude of a carrier wave, and the amplitude of this value of detecting with another carrier wave multiplied each other, and then detect the amplitude of this carrier wave.Can select carrier wave arbitrarily, the amplitude product is added a numerical value or takes advantage of a coefficient, just can be used for obtaining the setting signal of differential line 79 inputs 77 by means of a detection.

Along with suitably constructing the detection circuit, also can periodically produce carrier signal.For instance, for example burst signal or teletext synchronizing signal if hope is such, can be used for automatic adjusting.So adopt the carrier wave that alternately takes place, this machine produces to become a kind of alternative possibility way.In television receiver, the detection circuit can be arranged in different places selectively, for example can be placed on the output of radio band.

Automatically regulate the decision setting signal maximum of amplitude product-subordinate, also can be further used for being placed on detection circuit other resonant tanks before.

Though the coupling of rf resonant circuit, through combiner circuit 115, as described, cause a quick adjustment be tuned to oscillator tuning.Such coupling does not need fully.If wish like that, these two tuning enforcements can be made irrelevant each other.

In this case, pulse generator 91 is controlled by field pulse.Other pulse frequency, for example line frequency can use selectively.

When using microprocessor in television receiver, this processor can comprise a part of regulating circuit, and the output signal of differential line would rather be converted to digital signal and give microprocessor processes, because this digital signal needs less figure place.

Fig. 2 illustrates the embodiment of an accommodation of harmonic ringing conversion line 85, all uses identical reference number to represent with corresponding part among Fig. 1.

The multiplier 129 of Fig. 1 and amplitude limiter 147, merging here replaces with change over switch 155.Its switching signal input 157 companies of being connected to take advantage of the output 133 of multiplier 135.And the input 161 of balanced circuit 159 is connected to the input 87 of harmonic ringing conversion line 85.Amplitude limiter 163 is to be arranged in the input 83 of harmonic ringing conversion line 85 and to connect to take advantage of between the input 137 of multiplier 135.Therefore do not influence the generation of step at the amplitude of input 83 signals.

Fig. 3 illustrates harmonic ringing and produces 85 1 possible more digitized concrete schemes of circuit.With corresponding part among each figure of front, all use identical reference number to represent.

Connect herein and take advantage of multiplier 135 to be constituted by an anti-phase XOR gate.And the function of Fig. 1 multiplier 129 is to be carried out by a lifting/lowering input 165 of lifting/lowering counter 151.This counter is used as an integrator, and its a count signal input 167 is connected to the input 87 of harmonic ringing conversion line 85.The array output 169 of counter 151 through a digital-to-analog converter 171, is coupled to the output 125 of harmonic ringing conversion line 85.

If being three rf resonant circuits, must automatically regulate Fig. 4, how the example that constitutes with a differential line 79 and a harmonic ringing conversion line 85.All use identical reference number to represent with corresponding part among each figure of front.The number of circuit component is by the sampling that helps using and keeps circuit, gate circuit and special differential line to be limited.

In Fig. 6, the input and output waveform of pulse generator 91 is all to represent with the 91 relevant identical reference numbers of input and output of pulse generator described in Fig. 4.

Differential line 79 has two samplings and keeps circuit 401 and 403, and they are connected to input 77 respectively.And their sampled signal input 405 and 407 is connected to the output 409 and 411 of pulse generator 91 separately respectively because like this, input 77 between two field pulses alternately by a sampling with keep circuit 401 or 403 samplings.Differential amplifier 413, it would rather be in big input signal amplitude and have less gain, and is not in little input signal amplitude.Difference between the output signal of sampling and maintenance circuit 401 and 403 is amplified, and it is added to the output 81 of differential line 79.Since the amplitude product change must be always subsequently sampling and previous sampling between poor, the change of output 81 signal codes of differential line 79 takes place in the time of must considering it always from the field duration to the field duration.

This signal from the output 81 of differential line 79 is added to multiplier 135.Its output 133 is at first by a sampling and 413 samplings of maintenance circuit.And hereafter, sample respectively by sampling and maintenance circuit 415,417.Their each sampled signal input 419 and 421,423 is connected respectively on pulse generator 91 each output 425,427 and 429.

Each is sampled and keeps the output 431,433 and 435 of circuit 413,415 and 417, is coupled to the input 443 of delay correction circuit 444 respectively through a gate circuit 437,439 and 441.For the change of output 81 signal codes of proofreading and correct above-mentioned differential line 79, from sampling and the output 433 that keeps circuit 415 to the signalling channel of input 443, also include an anti-phase circuit 445.Each gate circuit 437,439 and 441 gate signal input 447,449,451 are connected respectively to the output 453,445 and 457 of pulse signal generator 91.

The output 431,433 and 435 of sampling and maintenance circuit 413,415 and 417 further is coupled to 465,467,469 3 inputs of integration circuit 151 respectively via gate circuit 459,461 and 463.Gate circuit 459,461 and 463 signal input part 471,473 are connected with 427 with 477,425 of pulse generator 91 respectively with 475.

Delay correction circuit 444 is by one for example: its resistance be 62K Ω resistor 479 and for example its capacity formed by capacitor 481 series connection of 0.1 μ F.The tie point of this capacitor other end ground connection, resistor 479 and capacitor 481 is coupled to the input 483 of multiplier 135 via amplitude limiter 147.

Each input 465,467 and 469 of integration circuit 151 via resistance 485,487 and 489, is connected in series to 497,499 and 501 3 outputs with capacitor 491,493 and 495.Can be switched off from the adjustment signal of relevant here radio-frequency line.Wherein each resistor has a resistance, for example: 40K Ω.And each capacitor has a capacity, for example: 0.047 μ F.Each resistor 485,487 and 489 and each tie points of each capacitor 491,493 and 495 is connected respectively to the input of amplifier 503,505 and 507.Another input end grounding of each amplifier, and output is received 497,499 of integrated circuit 151 respectively, 501 3 outputs.

The working condition of circuit will be described in detail with reference to the oscillogram among the figure 6 among Fig. 4 now.

Two circulation regulating cycle TC in Fig. 6 ₁And TC ₂An even number with the field duration represents that regulating in this situation is to use and clock pulse TC ₁₁, TC ₁₂, TC ₁₃, TC ₁₄, TC ₁₅, TC ₁₆, TC ₂₁, TC ₂₂TC ₂₃, TC ₂₄, TC ₂₅, TC ₂₆6 field duration of starting are represented.

The automative interest increasing controlling circuit of television receiver (AGC-LOOP) response wave shape 97, respectively only with clock pulse TC ₁₄And TC ₁₅And TC ₂₄And TC ₂₅Be closed in the field duration of starting.So obtain an AGC (automatic gain control) voltage, and continue to keep in the remaining part of regulating cycle, till automative interest increasing controlling circuit was closed once more, this a kind of situation in back was considered to the hold mode of automatic gain control.

Therefore, from clock pulse TC ₁₆In the field duration of beginning, automatic gain control is to be in hold mode.The input 77 of differential circuit 79 is at clock TC ₁₆And TC ₂₁Between be sampled and holding circuit 403 sampling, be reflected in the waveform 411.In the field duration subsequently, differential circuit 79 is at clock pulse TC ₂₁And TC ₂₂Between be sampled and holding circuit 401 sampling, be reflected in the waveform 409.So, at the output 81 of differential circuit 79, as clock pulse TC ₂₁During appearance, the product that the amplitude of differential circuit input 77 produces can change, and this variation is to be caused by the pulse that gate circuit 459 is supplied with, and is reflected among the waveform 477.This pulse is integrated between the input 465 of integrating circuit 151 and output 497, and produces a tuning step, and therefore, the symbol of this pulse and amplitude have determined the symbol and the amplitude of tuning step.

When this pulse occurs, at the clock TC of integrating circuit 151 ₂₁Moment, the product amplitude variations that tuning step causes, be sent to its output 133 by multiplier 135, its symbol is also by its symbol decision of input 483 signals, and this signal is from amplitude limiter 147, therefore, and at output 133, this symbol of this signal equals the symbol of input 483 signals always.As long as the variation at the amplitude product of differential circuit 79 outputs 81 is positive.

The signal level of multiplier 135 outputs 133 is at clock signal TC ₂₁And TC ₂₂Between the end in cycle, be sampled and keep circuit 413 storages.Clock signal TC is appearring ₂₂In time, be reflected on the waveform 425.And remain there, up to clock signal TC occurring ₃₂The time, till sampling and keeping circuit 413 usefulness 425 such waveforms to carry out subsequently sampling.At clock signal TC ₂₂Before the appearance, clock signal TC is appearring ₁₂The time, clock signal TC is appearring by tuning step ₁₁The output level of the multiplier 135 that is produced has during this time appeared at the output 431 of sampling and keeping circuit 413.

The gate circuit 437 of response waveform 453 is from clock signal TC occurring ₂₁Up to clock signal TC occurring ₂₂Straight conducting.Owing to this reason, at the symbol of the signal of multiplier 135 inputs 483, through delay correction circuit 444 and amplitude limiter 147, by sampling with keep the symbol of the output signal of circuit 413 to be determined.It is used for relevant rf resonant circuit.It also is the output 497 of integrating circuit 151, clock signal TC occurring ₁₁The symbol of the tuning step of Fa Shenging before.

As long as the variation of product amplitude just remains at the input 139 of multiplier 135, that just means the controlling party of relevant radio-frequency line to being correct, the symbol of multiplier 135 output signals and subsequently the symbol of the tuning step signal of appearance be maintained.Like this, when the product amplitude becomes when negative, the inversion of symbol only can take place, that just means tuning to relevant radio-frequency line, surpassed its maximum, and controlling party is to therefore correcting.

Obviously, sampling and keep circuit 415 and 417, AND circuit 461,439 and 463,441 links together respectively, is used for other radio-frequency line, the latter can determine controlling party to and the numerical value of tuning step.

Sampling and maintenance circuit 413,415,417 AND circuit 437,439,441 respectively connect together, and delay correction circuit 444 in this case, still plays the function of the delay line of reference number 143 indications among each figure of front.

In Fig. 5,, all represent with identical reference number with corresponding each several part among each figure of front.The gate circuit 437,439,441 that links together with delay line 444 respectively among Fig. 4, amplitude limiter 147 and multiplier 135 all replace with anti-phase XOR gate 511,513 and 515.Their input is connected respectively to the input 83 of harmonic ringing translation circuit 85.And another input is connected respectively to the Q output 517 of d type flip flop 523,525 and 527, and Q goes out end 519 and Q output 521.

D type flip flop 523,525 and 527, the function of execution graph 4 samplings and maintenance circuit 413,415 and 417 respectively.In this case, only realize symbol storage, and do not realize the amplitude storage that d type flip flop 523,525 and 527 D input 529,531 and 533 are connected respectively to the output of anti-phase XOR gate 511,513 and 515.And Q output 535,519 and 537 passes through circuit 459,461 and 463 respectively, links to each other with 469 with the input 465,467 of integration circuit 151.

The output 453,455 and 457 of the pulse generator 91 of Fig. 5 all can save now.In all others, pulse generator 91 is identical with the pulse generator of Fig. 4.And the waveform of Fig. 6 still is suitable for.The relevant input of its reference number and pulse generator 91 is corresponding.

The output 425,427 and 429 of pulse generator 91, now not to be connected respectively to the sampling of Fig. 4 and to keep the input 419,421 and 423 of circuit 413,415 and 417, but be connected respectively to the clock signal C input 539,541 and 547 of d type flip flop 539,541 and 543.

Because d type flip flop can not provide the amplitude storage, the differential amplifier 413 of differential line 79 is made of an amplitude limiter.

In the circuit of Fig. 4, switch symbol by what paraphase circuit 445 was realized, here be the output 519 that adopts d type flip flop Q, symbol is fed back to anti-phase XOR gate 513 obtains.Rather than, use Q output 517 and 521 respectively as d type flip flop 523 and 527, symbol is fed back to anti-phase XOR gate 511 and 515 respectively.

As the circuit that is applicable to Fig. 4, automatic gain control (AGC) is in the field duration, with clock pulse TC later on ₁₄With TC ₁₅Work together, and at TC ₁₆Reach hold mode in cycle.Gate circuit 459 is added to the input 465 of integration circuit 151 with a pulse, clock pulse TC occurring ₂₁The time, response wave shape 477.Cause producing a tuning step at output 497.The supply voltage of d type flip flop be chosen such that be exactly their output can suppose be one on the occasion of or a negative value, therefore,, may be a positive or negative pulse, thereby determine the symbol of this tuning step by the pulse that tuning step produces.

The effect of differential line 79 is as described about Fig. 4, at clock pulse TC ₂₁And TC ₂₂Between during in, the symbol that product amplitude that will the tuning step of reaction changes is added to the relevant input of anti-phase XOR gate 511.Another input in anti-phase XOR gate 511 remains here at clock pulse TC ₁₂The symbol stored by d type flip flop 523 of response waveform 425 during this time.If the symbol that the product amplitude variations produces is positive, mean tuning circuit have correct controlling party to.So clock pulse TC occurring ₂₂The time, because the effect of anti-phase XOR gate 511, at the clock signal input terminal 539 of d type flip flop, response waveform 425, storage appears at this symbol of its output 517 again.If the symbol of product amplitude variations is born, so the symbol of storing becomes opposite sign at output 517, and the controlling party of tuning circuit is on the contrary.

In this case, gate transmission line 459,461 and 463 all is the Q output 535,519,537 that is connected to d type flip flop 523,525,527.They are to be used for being connected with the remainder of the circuit that does not show.By these circuits, can determine the symbol of product amplitude variations.If this part line construction difference may need the Q output of d type flip flop is connected to each above-mentioned gate circuit.

In some cases, for example may need the amplitude of a tuning step also to be decided by selected wave band.In the circuit of Fig. 4, this can adopt an adjustable this simple approach of attenuator to realize at the output of amplitude limiter 147.In the specific implementation of Fig. 5, adjustable attenuator for example is so can be placed on slave flipflop 523,525,527 in every bars passage of gate circuit 459,461,463.

Here must understand, by a kind of television receiver that the circuit that further describes is in the claims formed, the purpose of its every suit circuit.But image wherein and (or) sound reproduction partly omitted, as the part of video tape recorder, tuner, communal antenna system etc.

Claims (11)

1, a kind ofly include the television receiver that a rf resonant circuit is regulated circuit automatically, in this circuit, produce a setting signal, by means of two carrier waves that are added to receiver radio frequency part be coupled to an output signal of the detection line of radio frequency part output, be used for proofreading and correct the adjusting of rf resonant circuit, it is characterized in that: the frequency of these two carrier waves equals the frequency of pix carrier of TV signal and the frequency of sound carrier respectively, and detection line (37) comprises that one is used to detect the circuit (39 with amplitude of the signal of difference frequency between the carrier frequency, 75), this amplitude is that product with the amplitude of these two carrier waves is directly proportional basically.

2, according to a kind of television receiver described in the claim 1, it is characterized in that: detection line (37) comprises that one is used for setting signal (at 77 ends) is produced the differential line (79) that an amplitude product changes (at 81 ends), and a harmonic ringing (at 111 ends) that is used for radio-frequency line is to obtain from a harmonic ringing conversion line (85) by differential line (79) control, this harmonic ringing conversion line comprises a circuit (139 that is used for making the symbol of harmonic ringing to change, 129), the sign change of harmonic ringing is produced by the harmonic ringing conversion line, and the symbol that is decided by to reflect symbol that amplitude product that a harmonic ringing changes changes and former harmonic ringing variation is (via 147,143) product.

3, according to a kind of television receiver described in the claim 2, its adjusting circuit is to be fit to be used for regulating a TV signal that receives, and the harmonic ringing conversion line comprises a step generator circuit and an integration circuit, it is characterized in that: the circuit (85) that produces step is arranged like that, be exactly the amplitude of step in the harmonic ringing, be decided by the amplitude (at 83 ends) of product amplitude variations.

4, according to a kind of television receiver described in above-mentioned arbitrary claim, its adjusting circuit is to be fit to be used for regulating a TV signal that receives, and it is characterized in that: regulating circuit can turn-off with a transmitter identification signal (57,43).

5, according to a kind of television receiver described in the claim 4, it is characterized in that: the transmitter identification signal is decided by the two the appearance of the sound carrier of the TV signal (55,57,63) that receives and pix carrier.

6, according to a kind of television receiver described in above-mentioned arbitrary claim, have one and regulate circuit, it is in the regulating cycle of one-period appearance, one after the other regulate several radioresonances loop, and detection line therein (37) comprises that one is used for forming the differential line (79) that a product amplitude changes (at 81 ends), it is characterized in that: differential line (79) comprises that two are used for sampling that a public input (77) is alternately sampled and keep circuit (401,403), the output of each sampling and maintenance circuit, be connected to an input of differential amplifier (413), and (TC TC) comprises that one controls the even number clock signal period of this adjusting to a regulating cycle.

7, according to a kind of television receiver described in the claim 6, comprise automatic gain control (AGC) signal generating circuit (105), when a rf resonant circuit is regulated, the generation of AGC signal is disconnected (101,97), it is characterized in that: when each part of regulating cycle regulating action did not take place, the generation of AGC signal was switched on (97).

8, according to a kind of television receiver described in above-mentioned arbitrary claim, it is characterized in that: one is used for the harmonic ringing (at 113 ends) of radio-frequency line, because a part of circuit (117,123), be that harmonic ringing from an oscillator (15) obtains, it determines the tuning of this television receiver.

9, according to a kind of television receiver described in the claim 1,3,6 or 7, it is characterized in that: differential line comprises a differential amplifier (413), and when the input amplitude became bigger, it had lower gain.

10, according to a kind of television receiver described in claim 6 or 7, it is characterized in that: what be coupled to differential line (79) output (81) is an input (139) of multiplier (135), its output (133), through a sampling and maintenance circuit (413), be coupled to another input (483), and the output (431) of sampling and maintenance circuit (413) is through a gate circuit (459), is coupled to an input (465) of an integrating circuit (151).

11, according to a kind of television receiver described in claim 6 or 7, it is characterized in that: the output (81) of differential line (79), it is an input that is coupled to an anti-phase XOR gate (511), the output of door is a D input (529) that is connected to d type flip flop (523), an output (517) of trigger is connected to another input of anti-phase XOR gate (511), and an output (535) of d type flip flop, be through a gate circuit (459), be coupled to an input (465) of an integrating circuit.

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