CN1155209A - Collection correction for errors different on right - Google Patents

Abstract

A convergence correction circuit, for a cathode ray tube projecting images having keystone, differential sinusoidal and differential right-edge curl distortions, comprises generators for horizontal-rate, generally sinusoidal, horizontal-rate sawtooth and horizontal-rate pulse waveforms. A summer combines the horizontal-rate waveforms into a horizontal-rate composite waveform. A multiplier and an amplifier generate as an output signal a product of the horizontal-rate composite waveform and a vertical-rate sawtooth waveform. A convergence correction coil is coupled for receiving the output signal and generating a dynamic magnetic field correcting the keystone, differential sinusoidal and differential right-edge curl distortions.

Description

The error convergence correction that the right is different

Relate generally to convergence correction of the present invention field.

The axle because three projection cathoderay tubes of all that use in the projection TV set (CRT) differ from one another, and in three projection tubes two are with respect to panel screen disalignment, and shown in the legend in Fig. 4 lower right corner, projection TV set suffers multiple image deflects.Dynamic convergence correction need produce multiple convergence correction signal, and they are added on the row and one group of auxiliary convergence correction coil in the field deflection coil assembly of each CRT.

Have in the projection TV set of curved slab CRT of concave curvature in use, the different sinusoid distortions relevant with the trapezoidal distortion of red and blue image are identified.Consult Fig. 1, this distortion makes on image in a left side (UL) and bottom right (LR) quadrant, the blue look horizontal scanning line (dotted line among Fig. 1) of the image that one width of cloth should be assembled is on green line and red line, and on image in right (UR) and bottom left (LL) quadrant, under green line and red line.Equally, on image in right (UR) and bottom left (LL) quadrant, the red horizontal scanning line of the image that one width of cloth should be assembled (chain-dotted line among Fig. 1) is on green line and blue line, and in the bottom right (LR) and a last left side (UL) quadrant of image, under green line and blue line.This distortion is expert at, and to go up amplitude be zero to scanning center's line (HCL), and increase progressively towards visual top and bottom direction.

Shown in figure two, second kind of distortion makes redness and blue horizontal scanning line in the differently distortion up and down of the left side of image.Have been found that this distortion is owing to assemble slow cause of response time in the power amplifier.

As shown in Figure 3, the third total distortion of all projection TV sets is a trapezoidal distortion.Because the light shaft positive cross of green CRT is in the screen center of panel, green image does not almost have trapezoidal distortion.Equally, comprise within the plane of shielding horizontal center line, and, almost do not have red and blue vertical trapezium distortion perpendicular to panel because the optical axis of red and blue CRT is in.Yet red and blue CRT departs from the screen center in the horizontal direction, and tilts inwards.Red and blue CRT respectively is installed in the side of green CRT.This arrangement causes red and blue form and aspect etc. and opposite trapezoidal distortion.Red and blue image has a parallel left side and right hand edge, and disperses round about at top and bottom.Now used one to represent the signal of line sawtooth and field frequency sawtooth waveforms product to proofread and correct trapezoidal distortion.Sort signal is also used term " row sawtooth * field sawtooth " expression.Other convergence correction waveforms are equally also represented with the term of other product of signals.As shown in Figure 6, this product is a field frequency bow tie output signal, and wherein the line frequency sawtooth has amplitude peak at visual top and bottom, is zero in horizontal centre line place amplitude.Horizontal phase is reversed at horizontal centre line place.Therefore, red and blue keystone correction waveform must be that polarity is added on the red and blue field convergence correcting coil on the contrary and mainly.

Since many convergence signals all add be expert at and the convergence correction coil of field deflection coil on, the correction of specific convergence errors or distortion is tended to disturb the correction of other convergence errors.The problem that is caused by different sines and left hand edge and right hand edge distortion distortion at first is the correction to this distortion, secondly is that the correction to this distortion does not influence other convergence corrections.

Different sinusoidal distortion red with blue in horizontal line all is sine-shaped.Therefore, the sinusoidal correction of line frequency be multiply by a sawtooth and can be used for proofreading and correct it.Red and blue different sinusoidal distortion can be multiply by a serrated signal by the serrated signal of being expert at and is added in order to proofread and correct on the same delegation serrated signal that produces the keystone correction signal to produce the former sinusoidal signal of will going of keystone correction signal.Sinusoidal phase is such selection, makes the peak of row sawtooth and peak, the end slope that amplitude limit and zero cross point have increase occur.

The different distortion in the left side can produce the blasting pulse by the retrace interval of being expert at, and also is before multiplying each other with the field serrated signal this blasting pulse to be added on be expert at signal and the row serrated signal, to accelerate the response speed of amplifier.

, successfully reduce to represent after the crosstalking of line frequency electric current in field deflection coil by each field deflection coil is added identical damping people, found that identical damping also proofreaied and correct the different distortion distortion in the visual left side.In addition, when each field deflection coil was used identical damping, the row serrated signal was moved forward in time, with the central point of alignment field skewed crossing (skew) control.Yet the change of this phase place has caused the 4th kind of distortion, and it makes red and blue horizontal scanning line produce different distortion up and down at the right hand edge of image respectively, as shown in figure 11.

Determined that the different distortion in the right can produce a negative pulse by the linear signal from row the right, and multiplying each other before, this negative pulse has been added to and generally is sinusoidal signal and goes and proofreaied and correct on the row of serrated signal with the field serrated signal.

Comprised by the correcting circuit of the image of distortion with cathode-ray tube display: the device that produces line sawtooth; Producing line frequency in general is sinusoidal wave device; Produce the device of line frequency pulse; Being used for the addition line sawtooth, is sine wave and impulse waveform in general, to determine the device of a line frequency composite wave-shape; Be used for producing the device of the product of line frequency composite wave-shape and field frequency waveform as output signal, this line frequency composite wave-shape is coupled to the product generation device by DC; Be used for amplifying the device of output signal; And be coupled with cathode ray tube, the correcting coil that is used for accepting the output signal after amplifying and produces dynamic magnetic field in response to output signal, this output signal contains first component of proofreading and correct trapezoidal distortion, proofreaies and correct the second component of red/blue different sinusoidal distortion and is used for proofreading and correct the three-component of the different right hand edge distortion distortion of red/orchid.

According to the characteristics of the contrive equipment of being told about, the correcting circuit that is subjected to the image of distortion with cathode-ray tube display comprises: the device that produces line sawtooth; Produce the device of line frequency pulse; Producing line frequency in general is sinusoidal wave device; Be used for the addition line sawtooth, pulse and sinusoidal wave to determine the device of a line frequency composite wave-shape; Be used for producing line frequency composite wave-shape and the field frequency waveform product device as output signal, this line frequency composite wave-shape is coupled to the product generation device by DC; Be used for amplifying the device of output signal; And with the correcting coil of cathode ray tube coupling, be used for accepting the output signal after amplifying and produce dynamic magnetic field in response to output signal, this output signal contains first component of proofreading and correct trapezoidal distortion, proofreaies and correct the second component of red/blue different sinusoidal distortion and is used for proofreading and correct the three-component of the different right hand edge distortion distortion of red/orchid.A projection TV set comprises: three cathode ray tubes, each cathode ray tube have a field deflection coil and each field deflection coil to be connected in series mutually; Three equal damping resistances, each damping resistance that equates is connected in the two ends of a field deflection coil in parallel; Be used for three line-repetitive waveform additions of each cathode ray tube, so that determine the device of a line frequency composite wave-shape for each cathode ray tube; Be used for producing for the line frequency composite wave-shape of each cathode-ray tube and the product of the field frequency waveform that supplies each cathode-ray tube, its device as the output signal that supplies each cathode-ray tube; Amplify device for the output signal of each cathode-ray tube; With three correcting coils, each correcting coil is coupled to a cathode ray tube, be used for accepting to pass through the output signal of the cathode ray tube that amplifies, and in response to this output signal is that cathode ray tube produces a dynamic magnetic field, this output signal contains first component of proofreading and correct trapezoidal distortion, proofreaies and correct the second component and the three-component that is used for proofreading and correct red/blue right hand edge distortion distortion of red/blue sinusoidal distortion.

According to the characteristics of the contrive equipment of being told about, a projection TV set comprises: a plurality of cathode ray tubes, each cathode ray tube have a field deflection coil and each field deflection coil to be connected in series mutually; A plurality of damping resistances, a respective coil is connected in parallel in each damping resistance and the field deflection coil; In order to produce the device of line sawtooth shape; In order to produce the device of line frequency impulse waveform; In general in order to produce line frequency is sine-shaped device; Be used for the addition line sawtooth, impulse wave and be sinusoidal waveform in general is so that determine the device of line frequency composite wave-shape; Be used for producing line frequency composite wave-shape and the field frequency waveform product device as output signal, this line frequency composite wave-shape is that DC is coupled to the product generation device; Be used for amplifying the device of output signal; With with the coupling of one of them cathode ray tube, be used for accepting the output signal after amplifying and produce the correcting coil of dynamic magnetic field in response to output signal, this output signal contains first component of proofreading and correct trapezoidal distortion, proofreaies and correct the second component of red/blue different sinusoidal distortion and is used for proofreading and correct the three-component of the different right hand edge distortion distortion of red/orchid.These damping resistances can equate.

Trapezoidal distortion is locating from axle owing to cathode ray tube; Red/blue different sinusoidal distortion is the geometry owing to the face-plate of a cathode-ray tube; And the right hand edge distortion is before moved with respect to the line flyback pulse time by the reset pulse of horizontal sawtooth, makes the central point of square crossing move and the influence of adjustment substantially to the center.

Above-mentioned and other characteristics of the present invention and superiority will become more apparent by reading following narration and accompanying drawing.

Fig. 1 is the figure that is used for illustrating the different sinusoidal distortion that horizontal line is red with blue.

Fig. 2 is the figure of the left hand edge distortion distortion that is used for illustrating that horizontal line is different

Fig. 3 is the figure that is used to illustrate trapezoidal distortion.

Fig. 4 is the block diagram of projection TV set, and it comprises and be used to proofread and correct trapezoidal distortion, the circuit of the different sinusoidal distortion of red and blue look and horizontal different left hand edge distortion distortion in the horizontal line.

Fig. 5 is the schematic diagram of the parabolic shape generator shown in Fig. 4.

Fig. 6 is used to be illustrated as the figure of proofreading and correct the employed waveform of trapezoidal distortion.

Fig. 7 is the schematic diagram of the sine-wave generator shown in Fig. 4.

Fig. 8 be as shown in Figure 4 the line sawtooth generator and the schematic diagram of amplitude limiter.

Fig. 9 is with the schematic diagram of the convergence correction waveform output circuit shown in the square frame form in Fig. 4.

Figure 10 is with the schematic diagram of the AN614 integrated circuit shown in the square frame form in Fig. 4.

Figure 11 is the figure that is used to illustrate horizontal line the right distortion distortion.

Figure 12 is the block diagram of projection TV set, and it comprises and be used to proofread and correct trapezoidal distortion, the circuit of red with blue different sinusoidal distortion and horizontal different the right distortion distortion in the horizontal line.

Figure 13 and Figure 14 are the schematic diagrames in order to the damping of field deflection coil in the explanation projection TV set.

Figure 15 is the schematic diagram of the parabolic shape generator shown in Figure 12.

Figure 16 is the schematic diagram of the line sawtooth generator shown in Figure 12.

In Fig. 4, a projection TV set is shown, and totally is marked with label 1 with square frame and schematic form.Receiver comprises synchronizing signal separator 2 and chroma processor 3, and input responds to shows signal separately.Row synchronized component H and field synchronization component V add respectively be expert at and field deflection circuit 4 and 5 on.For the red R that chroma processor 3 produces, green G, blue B signal provides three Projection CRT 80,81 and 82 respectively.Use lens 84, each CRT shows the monochrome image corresponding to its color on screen 83.Has only green CRT81 perpendicular to screen 83.Each side of red and blue CRT at green CRT.Depart from screen center and inclination inwards in the horizontal direction.As mentioned above, this structure produces red and blue equating and opposite trapezoidal distortion.Red and blue image has a parallel left side and right hand edge and top margin of dispersing on the contrary and base.

Each CRT provides deflecting coil.Each line deflector coil comprises a home court deflecting coil 86, a main line deflector coil 87, one is used for assist field deflecting coil 88 and secondary row deflecting coil 89 that is used for the horizontal convergence correction that vertical convergence is proofreaied and correct, the various coils of each CRT are on demand to red, green and blue respectively in addition suffix R, G and B are distinguished.The overall system that produces various convergence waveforms is indicated with label 6.

Convergence system 6 receives and/or produces a plurality of different wave, these waveforms are converted with various combined methods, the summation and/or multiply each other, so that 6 compound convergence waveforms to be provided, expression is to red row (∑ RH), Red Square (∑ RV), green row (∑ GH), green (∑ GV), the correction of blue row (∑ BH) He Lanchang (∑ BV).∑ RV output signal is coupled to convergence correction coil 88R by output amplifier 71.∑ GV and ∑ BV output signal are coupled to their convergence correction coils separately by output amplifier 72 and 73 respectively.

Only being used for producing, the circuit of such convergence correction waveform (being designated as waveform I) is shown specifically at Fig. 4.Waveform I is the first kind of correct convergence waveform CCW1 (I) that is input to convergence correction waveform combiner circuit 70.Waveform CCW1 (I) is the product that waveform multiplies each other.The output signal of multiplier is coupled to convergence correction waveform combiner circuit 70 by transistor Q70 buffering and by electric capacity 70 interchange AC.Other convergence correction waveforms are input signal CCW2 to CCWN.May need 40 kinds or more this convergence correction waveform.

Waveform I represents the product of two signals.Signal is the field frequency sawtooth waveforms shown in waveform F normally.The field frequency sawtooth waveforms has 4.25V peak-peak voltage and 5.3V DC level.Xiao Liang dimension correction is realized by add the sine wave of field frequency by a small margin shown in waveform G on field sawtooth F in vertical direction.The sinusoidal wave G in field has 0.2V peak-peak voltage and 0.1V DC level.Field sawtooth F and sinusoidal wave G be by resistance R 60, addition in the resistance summation network that R61 and R62 constitute.This has just proofreaied and correct the gain of visual top and the correction of bottom line scan line.Another signal is waveform H, and itself is waveform C, D and E sum.

The generation of waveform H is from being added in the line frequency parabolic shape that sine-wave generator 10 is labeled as waveform A, and sine-wave generator 10 produces the sine wave that is designated as waveform C.Line frequency parabolic shape positive peak voltage+5.6V, negative peak voltage-0.1V.And the line frequency parabolic shape causes main scanning be delayed about 5 seconds in assembling power amplifier after.In order to obtain horizontal scanning line straight in the image, it is necessary being configured as the parabolic shape.This line frequency parabolic shape can be produced by circuit shown in Figure 5 90, is perhaps produced by the circuit shown in Figure 12 and Figure 15 190.Consult Fig. 5, produce a constant current Idc by power supply 91.Transformable electric current I ac is in node 95 and electric current I dc addition.This recombination current gives electric capacity 91 chargings.Because the line flyback pulse from horizontal-deflection circuit 4 makes transistor Q93 with the line frequency conducting, capacitor C 91 is discharged periodically through reset circuit 94.As a result, line frequency serrated signal as shown in the figure is coupled to integrator 92 by AC.Integrator 92 comprises the operational amplifier U1 that has integrating capacitor C90 and comprise the DC bias circuit of R90.Output parabolic waveform A is coupled to node 95 as variable current Iac by AC.The clamp circuit 93 that is connected on integrator 92 outputs comprises transistor Q90, Q91 and resistance R 91.

The horizontal reset pulse is the AC coupling, therefore has only its rising edge that capable parabolic shape is resetted.About 5 microseconds just began integration before this feasible reset pulse of being expert at finished.The DC current offset that is added to the U1 inverting input by resistance R 90 tilts the line frequency parabolic shape as the input of integrator, so that make its peak value center of sweeping of being expert at about 5 delicate before.In general parabolic shape continues as negative direction after the peak value, takes place and will export reset-to-zero until flyback pulse.Yet, when DC biasing is tilted capable parabolic shape, can cause undershoot and the useful part of the capable parabolic shape reset pulse of being expert at about 5 is finished when delicate before beginning.This makes horizontal line at image the right bifurcated (flair).Clamp circuit 93 with negative sense parabolic shape amplitude limit approximately-100mv.This is in order to obtain the optimizing level of straight horizontal scanning line on image the right after measured.This level is crucial, even still kept by clamp circuit 93 when temperature changes.Transistor Q91 accepts the almost constant electric current of about 1mA at its collector electrode.By the base stage of the sub-fraction inflow transistor Q90 of this electric current of the DC β parameter of transistor Q91 decision and determine base stage to emitter voltage, this voltage is fed and applies, and it also is that collector electrode is to emitter voltage.The electric current that flows through transistor Q90 during clamp is approximately 10mA.Transistor Q90 and Q91 are same kind, are operated under the similar ambient temperature.Collector current is higher in transistor Q90, and the base stage that makes it is to emitter voltage big than Q91, and the about 100mV of this difference varies with temperature and is tending towards remaining unchanged.

Be expert at the first half of reset pulse of the integration of row parabolic shape was reset owing to integrating capacitor C90 is discharged by transistor Q92 in the time, and was begun in the back half the time of the reset pulse of being expert at.The function that is integrated during this period is under the voltage of capacitor C 91 because the caused negative sense capacitor discharge of effect of resistance R 92 and transistor Q93.This makes the positive slope of increase during delicate in the row parabolic shape at 5 of integration, rather than as the positive slope that reduces of parabolic shape feature.This bifurcated (flaring) of row parabolic shape helps to make horizontal scanning line more straight on the visual left side.

Return and consult Fig. 4, row parabolic waveform A through by pass filter and phase shift, is illustrated as the waveform C of " row is sinusoidal " with generation in sine-wave generator 10, this waveform positive going zeror crossing crosspoint is about 5 delicate before the line scanning mid point, DC mean value is 1.35V, and the peak-to-peak amplitude value is 1.6V.The schematic diagram of sine-wave generator 10 as shown in Figure 7.The row parabolic shape is by the network low-pass filtering that comprises resistance R 10, R11, R12 and capacitor C 10, C11.Signal through filtering is cushioned by transistor Q10, and this pipe is by resistance R 13 emitter bias.

Return and consult Fig. 4, the capable serrated signal that line sawtooth generator 20 produces shown in waveform D.Row sawtooth generator 20 is illustrated in greater detail among Fig. 8.Current source makes capacitor C 20 chargings.Because transistor Q20 conducting, electric capacity is discharged rapidly in the beginning of 10 delicate line flyback pulses.Line flyback pulse is that the 22V peak-to-peak value has positive peak+18v and negative peak-4V, shown in waveform B.Be expert at retrace interval 10 of the waveform D that is produced is 0V in delicate and increases to peak value 3.6V in scan period.DC mean value is 1.5V.

Voltage divider by be connected in series in+resistance R 43 and R42 between 12V and the ground constitute.The node of resistance R 43 and R42 constitutes the resistance summing junction 45 to sinusoidal wave C of row and line sawtooth D, and sinusoidal wave C of row and line sawtooth D are coupled to summing junction 45 by resistance R 40 and R41 respectively.

Summing junction 45 is difference input pins 5 that DC is coupled to signal multiplier 60, for example the AN614 of Panasonic (Panasonic) multiplier.Relative difference input pin 1 is by being connected in series in+voltage divider biasing that resistance R 50 between 12V and the ground and R51 constitute.By being approximately 3.4V, equaled before the line scanning mid point DC value of about 5 line sawtooths when delicate and the sinusoidal wave sum of row than the bias level that forms.Since the both sides of difference input all in the same manner with+the 12V power supply is a benchmark, any variation of this power supply all is cancelled.This DC coupling is a kind of unconventional bias structure for resembling this multiplier of AN614.Usually it is coupled to by AC and is taken advantage of power supply.For example, the combination of expression waveform F and G " with " signal is the pin 3 that is coupled to multiplier 60 by capacitor C 61AC.

The DC coupling promptly is different left hand edge distortions with solving another problem.The solution requirement retrace interval of being expert at adds pulse enable signal and assembles the response time of output amplifier and accelerate, and the different distortion red and orchid of the visual left side is flattened directly.If adopt the AC coupling, this flyback pulse can increase the response distortion of scan period.This is because composite wave-shape has a new DC mean value and drifts about, the balance point that makes differential amplifier from scan period required time remove.DC coupling allows to add pulse and do not upset the balance of scan period amplifier at retrace interval.In addition, have been found that adopting DC to be coupling in retrace interval can use very large pulse, and the indoor design that the peak value of output can be exaggerated device is controlled.The response that this means power amplifier can be adjusted with pulse duration rather than pulse amplitude.

Adjusting power amplifier with the pulse duration can realize by transistor Q30.According to waveform B, the line flyback pulse of peak-to-peak value 22V also is an input of amplitude limiter circuit 30.As shown in Figure 8, amplitude limiter circuit 30 comprises resistance R 30 and Zener diode CR30.The rated value of Zener diode CR30 is 6.8V.The output of amplitude limiter circuit 30 is one, and to have positive peak be 6.8V, negative peak is-and the line flyback pulse of the amplitude limit of 0.6V.Peak-to-peak value is the line flyback pulse of 7.4V is coupled to transistor Q30 by capacitor C 30 and the voltage divider AC that has resistance R 31 and R32 to constitute a base stage.Transistor Q30 is in the rising edge conducting of the line flyback pulse of amplitude limit, and ends in the time by capacitor C 30 and resistance R 31 decisions.The collector electrode of transistor Q30 also is connected to summing junction 45, and is added to capable sine wave and line sawtooth.The end product of summation is shown among the waveform H.

Have been found that the differently distortion of distortion up and down of this as shown in Figure 2 red and blue horizontal scanning line that makes the visual left side, do not rely on the above-mentioned the sort of line flyback pulse that adds an amplitude limit at summing junction 45 also can obtain proofreading and correct.The correction of the distortion distortion that this visual left side is different also can realize with the line frequency electric current in the suppressed field deflecting coil by adding equal damping for each field deflection coil.

Consult Figure 13, field deflection circuit 5 drives home court deflecting coil 86.Field deflection circuit 5 needs specific load resistance to guarantee suitable operating state; Need 270 Ω load resistances in this case.The home court deflecting coil 86 that is connected in series is and 270 Ω resistance parallel connections.In this structure, the effect of a coil of home court deflecting coil 86 central authorities similarly is by the voltage generator of other two coils loadings in the home court deflecting coil 86 in the time of high frequency.Big line frequency circulation can be by a corresponding coil-induced central coil that enters home court deflecting coil 86 in main line deflector coil 87 and the auxiliary deflection coil 89.Because the home court deflecting coil is connected, the line frequency circulation of induction flows through other two coils of home court deflecting coil 86.Each home court deflecting coil of parallel resistance damping by to equate as shown in figure 14, can suppress this circulation.The numerical value of damping resistance is selected like this, three damping resistances be equate and three the damping resistance sum equal the load resistance value that field deflection circuit 5 requires.

Yet, as shown in figure 11, use this damping to cause the convergence distortion on image the right in the phase place of the serrated signal of the being expert at M combinational circuit early.Definite says, red line distortion is towards horizontal center line and blue line twist away from its horizontal center line.

If the distortion of the different left sides obtains proofreading and correct by the damping that each field deflection coil is equated, that is petty, and transistor 30 can be used for correcting the right distortion distortion.Consult Figure 12 and Figure 16, be used to produce capable serrated signal M from the horizontal pulse J of the morning that parabolic shape generator 190 produces.

Consult Figure 15, parabolic shape generator 190 is similar to the parabolic shape generator shown in Fig. 5, and just parabolic shape generator 190 has the feedback loop of two increases, makes parabolic shape A stable more and not quite responsive to component tolerances.The voltage ratio that peak amplitude control ring 191 is provided with the amplitude of line frequency parabolic shape A with by low deviation Zener diode CR190 and is adjusted by AC and is coupled to the amplitude of line sawtooth of integrating circuit 92 with the peak amplitude of the 5.6V that keeps line sawtooth A.Early stage horizontal pulse length control ring 192 the voltage ratio at the average dc voltage value of the negative-going pulse that is equaled resistance R 190 and resistance R 191 two ends total voltages by early stage horizontal pulse signal J excitation and total amplitude and resistance R 190 and R191 node place, and adjust the electric current that flows into operational amplifier U1 through resistance R 90, so that keep the negative-going pulse width and the ratio between line-scanning period of determining by the ratio of resistance R 190 and resistance R 190 and R191 sum.The width of negative-going pulse is to be adjusted into (10/57) (63.5 μ s), perhaps 11 μ s in the parabolic shape generator 190 of Figure 15.

Consult Figure 16, line sawtooth generator 120 is similar to the line sawtooth generator 20 shown in Fig. 8, and just line sawtooth generator 120 is resetted by preposition horizontal pulse signal J, and this pulse has the effect of serrated signal M with respect to the phase place of horizontal reset pulse of going in advance.

Row the right linear signal K is got by row serrated signal M, and is used for opening " on " transistor Q30.The negative pulse that produces at the collector of transistor Q30 is added to capable sinusoidal signal C and row serrated signal M through gain decision resistance R 106.This composite signal multiply by a serrated signal F then, to produce waveform II.

The right linear signal K of row is one and follows the last several delicate triangular pulses of capable serrated signal M; Its peak value is 0.8V, is zero At All Other Times.The voltage of row sawtooth generator 120 outputs is coupled to the base stage of transistor Q100 by capacitor C 100.In case row serrated signal M reaches about 2.7V level, the abundant conducting of transistor Q100 " on " makes the emitter of transistor Q100 follow the tracks of row serrated signal M.Therefore the capable serrated signal M's of output tracking of transistor Q100 is last several delicate so that produce the right linear signal K of row.The base-emitter knot pressure drop of diode CR100 compensation transistor Q100.

Then, going right linear signal K is coupled to the base stage of transistor Q30 by resistance R 105.When the right linear signal K of row surpasses the base-emitter threshold voltage of Q30, transistor Q30 conducting " on ".The negative pulse that produces at the collector of transistor Q30 is coupled to the capable input pin 5 of multiplier 60 by resistance R 106, and negative pulse is produced composite wave-shape L with capable sinusoidal signal C and line duration sawtooth signal M mutually at summing junction 45 there.

From the effect of the pulse of transistor Q30 is to make that the right peak value of capable composite wave-shape L is subsidiary a little to flatten.When this effect be multiply by field sawtooth signal F and and then delivered to red and blue amplifier 74 and 75, as shown in Figure 9, amplifier was its anti-phase amplification, and the different distortion in the right is corrected.

Consult Fig. 9, resistance R 73 and R74 are respectively trapezoidal controlling resistance R75 and the R76 resistance that centers really.Their numerical value is so selected, and trapezoidally when its transfers at the center is roughly proofreaied and correct.Resistance R 71 and R74 regulate control sensitivity and control range.

The waveform I of Fig. 4 and Figure 12 and II explanation line frequency and two keystone waveforms of field frequency.In all cases, its P-to-P voltage is that 2.4V and dc voltage are 8.37V.Waveform I solves problem that different sinusoidal distortions and left side distortion propose and waveform II solves the problem that different sinusoidal distortions and the right distortion are proposed.At first be, different sinusoidal distortions and both sides distortion obtain proofreading and correct, and secondly are that the convergence correction that does not influence other is twisted on different sinusoidal distortion and both sides.In addition, can proofread and correct different sines and both sides distortion distortion very effectively by revising existing trapezoidal distortion convergence correction waveform.

Claims (14)

1. be used to show the correcting circuit of the cathode ray tube of the image that suffers distortion, described circuit comprises:

Device (45) is in order to make up three line-repetitive waveforms (C, M, K) to determine line frequency composite wave-shape (L);

Device (71,72,73) is in order to amplify output signal (II); With,

Correcting coil (88) is used for the described cathode ray tube that is coupled, to accept describedly to produce dynamic magnetic field through amplified output signal (II) and in response to described through amplified output signal (II); It is characterized in that:

Device (60), be used to produce described output signal (II), the product of a described line frequency composite wave-shape (L) and field frequency waveform (F), described have first component (M) that is used for proofreading and correct trapezoidal distortion through amplified output signal (II), is used for proofreading and correct the second component (C) of red/blue sinusoidal distortion and is used for proofreading and correct the three-component (K) of red/blue right hand edge distortion distortion.

2. according to the circuit of claim 1, it is characterized in that described trapezoidal distortion is locating from axle owing to described cathode ray tube, described red/blue sinusoidal distortion be owing to the geometry of the described face-plate of a cathode-ray tube described red/blue right hand edge distortion distortion moves forward with respect to the line flyback pulse time owing to the reset pulse of one of described line-repetitive waveform (M), with the central point of alignment field intersection (skew), and the adjustment at key.

3. according to the circuit of claim 1, it is characterized in that described line frequency composite wave-shape (L) is that DC is coupled to described product generation device (60).

4. according to the circuit of claim 1, its feature also is:

Install (120), be coupled to the line sawtooth shape (M) of described summing unit (45) in order to generation;

Device (10) is coupled to the line frequency of described summing unit (45) in order to generation, is generally sinusoidal waveform (C); And,

Device (R102, R103, R104, CR100, Q100) is used for producing the line frequency impulse waveform (K) that is coupled to described summing unit (45).

5. according to the circuit of claim 4, it is characterized in that described field frequency waveform (F) is a sawtooth waveforms.

6. the circuit according to claim 1 is characterized in that: described three line-repetitive waveforms generally are sinusoidal waveform (C), sawtooth waveform (M), and impulse waveform (K); And,

Described field frequency waveform (F) is a sawtooth waveform.

7. according to the circuit of claim 1, it is characterized in that described field frequency waveform (F) is a sawtooth waveform.

8. according to the circuit of claim 7, it is characterized in that it generally being that sinusoidal field frequency waveform (G) is added on the described field frequency sawtooth waveforms (F).

9. according to the circuit of claim 6, it is characterized in that: described generally is that sinusoidal waveform (C) is proofreaied and correct because the distortion that the panel geometry of described cathode ray tube causes.

10. according to the circuit of claim 6, it is characterized in that: described line frequency impulse waveform (K) is proofreaied and correct because the distortion that the reset pulse of one of described line-repetitive waveform (M) is caused with respect to the time reach of line flyback pulse, with alignment field the report to the leadship after accomplishing a task central point of (skew) and the adjustment at key.

11., it is characterized in that described composite set (45) is a summing unit according to the circuit of claim 1.

12., it is characterized in that described summing unit is resistance summing junction (R40, R41, R106) according to the circuit of claim 11.

13. circuit according to claim 11, the described device (60) that it is characterized in that being used to producing described output waveform (II) is the waveform multiplier, and described output signal (II) is a described line frequency composite wave-shape (L) and the product of described field frequency waveform (F).

14. according to the circuit of claim 1, its feature is the waveform multiplier in the described device (60) that is used to produce described output waveform (II), described output signal (II) is a described line frequency composite wave-shape (L) and the product of described field frequency waveform (F).

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