JPH075832A - Device for canceling moire - Google Patents

Abstract

PURPOSE:To provide a moire canceling device constituted of a circuit system different from a deflection system of a color television receiver, without necessitating for revising a connection of a circuit in the receiver and easy for mounting an electromagnetic control coil. CONSTITUTION:A coupling capacitor 36 is formed by arranging an electrode chip around a lead wire Lw18 of a horizontal deflection coil 18. An alternate signal S31 whose level (or polarity) is inverted at every line and a driving current i43 corresponding to signal s31 are formed synchronizing with a horizontal synchronizing signal Hsy taken out from the coupling capacitor 36. The driving current is supplied to a flexible substrate type control coil 44F loaded on a neck 19n of a color picture tube, and moire is canceled by displacing an electron beam in a prescribed direction. An output of a transformer 61 inserted between the lead wires of the horizontal deflection coil is rectified, and a power source voltage of the driving circuit of the control coil 44F is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moire canceling device suitable for a color picture tube having a color selecting mechanism.

[0002]

2. Description of the Related Art As is well known, in a current color image receiver, an aperture grill and a shadow mask are provided so that red, green and blue (R, G, B) electron beams are incident only on their corresponding phosphors. As described above, a color picture tube having a slit type color selecting mechanism is used.

When the spatial frequency such as the slit of the color selecting mechanism and the spatial frequency of the image on the screen of the picture tube or the scanning line are very close to each other, it is a peculiar feature that corresponds to the difference between the two spatial frequencies. An interference fringe pattern may appear on the screen and the image quality may be significantly impaired.

In order to reduce such moiré, in the conventional moiré canceling device, for example, as shown in FIG. 6, the horizontal synchronizing signal is phase-modulated.

That is, in FIG. 6, in the sync separation circuit 12 to which the composite video signal Scs is supplied from the video signal circuit 11 of the receiver 10, the vertical and horizontal sync signals Vsy and Hsy are separated. Then, the output of the vertical oscillator 13 to which the vertical synchronizing signal Vsy is supplied is supplied to the vertical output circuit 14, and the vertical deflection current i14 is supplied from the output circuit 14 to the vertical deflection coil 15.

Reference numeral 20 denotes an alternating signal forming circuit, which comprises a phase modulating circuit 21 and a modulating signal forming circuit 22, and the horizontal synchronizing signal Hsy from the separating circuit 12 is commonly supplied to both circuits 21 and 22. In the circuit 22, for example, a pulse train whose polarity is inverted every horizontal scanning period (line) is formed as the modulation signal S22 based on the horizontal synchronization signal Hsy, and is supplied to the phase modulation circuit 21.

Then, the phase synchronizing horizontal synchronizing signal S21 is supplied from the modulating circuit 21 to the horizontal oscillator 16,
The phase-modulated horizontal oscillation output S16pm is the horizontal output circuit 17
The horizontal deflection current i17pm, which has been phase-modulated from the output circuit 17, is supplied to the horizontal deflection coil 18.

As is well known, both deflection coils 15 and 18 are mounted in a predetermined direction on the neck portion of a color picture tube 19 so that the electron beams of the three primary colors R, G and B are directed vertically and horizontally. Biased.

Therefore, in the moire canceller of FIG. 6, on the screen of the picture tube 19, adjacent scanning lines are slightly shifted in the horizontal directions opposite to each other, and the slit type color having the spatial frequency component in the horizontal direction. Moire with the sorting mechanism is reduced and deterioration of image quality is prevented.

[0010]

However, in the conventional moiré canceling device as shown in FIG. 6, the horizontal synchronizing signal Hsy is supplied to the horizontal oscillator 16 via the phase modulation circuit 21 of the alternating signal forming circuit 20. Therefore, if the phase modulation circuit 21 fails, the horizontal oscillator 16 receives the synchronization signal H.
Since sy is not supplied, there was a problem that the video of the receiver was out of sync.

Further, the moire cancel device of FIG. 6 has a problem that it cannot be applied to a color picture tube having a round-hole type shadow mask having a spatial frequency component in the vertical direction.

In order to solve the above-mentioned problems, the present applicant has already proposed "a moire canceling method and apparatus" in a patent application (reference number S92011257) dated October 2, 1992. . Below, FIG.
An example of the proposed moire canceling device will be described with reference to FIG.

FIG. 7 shows the entire structure of the already proposed example, and FIGS. 8 and 9 show the structure of the main part thereof. These FIGS.
In FIG. 6, parts corresponding to those in FIG.

In FIG. 7, reference numeral 30 is an alternating signal forming circuit, which comprises a frequency dividing circuit 31 and an inversion control circuit 32.
The horizontal synchronizing signal Hsy is supplied to the frequency dividing circuit 31, and 1 /
Divided by two. The vertical synchronizing signal Vsy is supplied to the inversion control circuit 32.
Is supplied. The inversion control circuit 32 controls the polarity of the output S31 of the frequency dividing circuit 31 based on the vertical synchronizing signal Vsy. The frequency divider circuit 31 and the control circuit 32 have, for example, the configuration shown in FIG.
As shown in, both JK flip-flops (hereinafter J
K-FF) is used.

Reference numeral 40 denotes a drive current forming circuit, which comprises a variable attenuator 41, an operational amplifier 42, and a drive amplifier 43. Then, the output S31 of the frequency dividing circuit 31 of the alternating signal forming circuit 30 is supplied to the non-inverting input terminal of the operational amplifier 42 through the variable attenuator 41, and the output S42 of the operational amplifier 42.
Are supplied to the drive amplifier 43.

As will be described later, the drive amplifier 43 is of a so-called single-ended push-pull (SEPP) type, and the output current i43 of this amplifier 43 is supplied to the control coil 44 for electron beam shift. The resistors Rf1 and Rf2 are connected in series between the other end of the control coil 44 and the reference potential (earth), and the connection midpoint of the resistors Rf1 and Rf2 and the inverting input terminal of the operational amplifier 42 are connected. , A negative feedback loop is formed.

As shown in FIG. 9, the control coil 44 for shifting the electron beam is divided into upper and lower coils 44a and 44b, which are divided into upper and lower portions of the neck portion 19n of the picture tube 19 (in the vertical direction of the screen). ) Is attached to. The control coil 44 is configured by connecting the upper and lower coils 44a and 44b in series with a predetermined polarity.

As shown in FIG. 8, the alternating signal forming circuit 30.
In the two JK-FFs 31 and 32, the non-inverting output terminal Q and the K input terminal are both directly connected, and the inverting output terminal Q ** ("**" in this specification represents inversion). , And the J input terminal are directly connected. Also,
The set input terminal and the reset input terminal of the JK-FF 32 are grounded.

The non-inverting output terminal Q and the inverting output terminal Q ** of the JK-FF 32 are connected to the set input terminal and the reset input terminal of the JK-FF 31 via differentiating circuits 33 and 34, respectively. Time constant τ of differentiating circuits 33 and 34
33 and τ34 are set to τ33 = τ34 = 1 μs, for example.

On the other hand, in the drive current forming circuit 40,
The alternating signal S31 from the JK-FF (frequency divider circuit) 31 of the signal forming circuit 30 is amplified to an appropriate level by the variable attenuator 41 and the operational amplifier 42. This operational amplifier 42
Is connected to two power sources of + Vcc and -Vcc, and a variable resistor 42r is provided at a pair of terminals for adjusting the offset of the input stage.
Are connected to each other, and the slider is connected to the negative power source -Vcc. The voltage of both power supplies supplied from the power supply circuit (not shown) of the receiver is, for example, + Vcc = 5V, −Vcc =
Each is set to -5V.

The drive amplifier 43 is an npn transistor 4
3a and the pnp transistor 43b are configured by SEPP connection. That is, the collectors of the transistors 43a and 43b are connected to the positive and negative power supplies + Vcc and -Vcc, respectively, and the emitters of the transistors 43a and 43b are connected to each other via the resistors Rea and Reb. In addition, power supply + Vcc,-
Four resistors Rb1, Rb2, Rb3, and Rb4 are connected in series between Vcc to form a voltage divider for bias, and the base of the transistor 43a is connected to the connection midpoint of the resistors Rb1 and Rb2. The base of the transistor 43b is connected to the connection midpoint of the resistors Rb3 and Rb4.

The connection midpoint of the voltage dividing resistors Rb2 and Rb3 is connected to the output terminal of the operational amplifier 42, and the control coil 44 is connected to the midpoint of the connection between the emitter resistors Rea and Reb via the resistor Rec. One end of is connected. This control coil 44
As described above, the resistor Rf is connected between the other end of the resistor and the ground.
A voltage divider for negative feedback composed of 1 and Rf2 is connected. Incidentally, protective diodes Da and Db are connected between one end of the control coil 44 and the power sources + Vcc and -Vcc, respectively.

Next, the operation of the above proposed example will be described with reference to FIG. In the alternating signal forming circuit 30, the horizontal synchronizing signal Hsy as shown in FIG. 10A is supplied to the clock terminal of one JK-FF 31, and the vertical synchronizing signal Vsy as shown in FIG.
It is supplied to the clock terminal of the K-FF 32.

Each time this vertical synchronizing signal Vsy arrives at JK-FF32, a set pulse S33 as shown in FIG. 10C and a reset pulse S34 as shown in FIG. It is supplied to the set input terminal and the reset input terminal of the FF31 respectively, and
From the non-inverting output terminal Q of the -FF31, as shown in FIG. 10E, the polarity (level) is inverted line by line and the polarity (phase) is also line by field at a cycle twice that of the horizontal synchronizing signal Hsy. An inverted alternating signal (pulse train) S31 is output.

As described above, since the alternating signal S31 is synchronized by the vertical synchronizing signal Vsy so that the polarity is inverted every field, it is not necessary to discriminate the field and control the shift direction, and one field is used. Even if the transition direction is deviated due to noise or the like in the middle of the, it will be correct at the beginning of the next field.

In the drive current forming circuit 40, the alternating signal S31 as described above is supplied to the variable attenuator 41 and the operational amplifier 4.
2, the signal is amplified to an appropriate amplitude and supplied to the SEPP-connected amplifier 43. From this amplifier 43,
The drive current i having the same waveform as the alternating signal S31 shown in FIG. 10E.
43 is output.

When this current i43 flows through the control coil 44, as shown by the broken line in FIG. 9, an alternating magnetic field in the vertical direction in which the polarity is inverted line by line is generated. This allows
The electron beams of the three primary colors R, G, and B are deviated from each other line by line, such as left on a certain line and right on the next line, so that the slit type color selecting mechanism is slightly shifted. And moire are reduced, and deterioration of image quality is prevented.

Since the proposed moire canceling device as described above is composed of a circuit system different from the deflection system of the receiver 10, even if the moire canceling device fails, the function of the receiver is impaired. It is rarely done.

The amount of deviation of the electron beam for reducing the moire is small as described above. Therefore, the required ampere turn (driving current i43 and the number of turns N44 of the coil 44).
I43 · N44 is significantly smaller than that of horizontal deflection, and the power consumption of the drive current forming circuit 40 is also significantly smaller than that of the horizontal deflection circuit 18, and the power consumption of the receiver increases. It stays within the margin of the power capacity of the circuit (not shown).

Further, various electronic circuits of the frequency dividing circuit 31 to the drive amplifier 43 can be combined in a relatively small space.

As shown in FIG. 11, the control coil 44 is attached to the neck portion 19n of the picture tube by inclining, for example, 45 ° from the vertical mounting direction as shown in FIG. 9, and alternating in the horizontal and vertical directions. By generating a magnetic field component, R, G,
Each electron beam of B is appropriately shifted line by line in the horizontal and vertical directions, and can correspond to a color picture tube provided with a round-hole type shadow mask having a spatial frequency component also in the vertical direction. .

Further, as shown in FIG. 12, in order to generate an alternating magnetic field that vertically shifts the electron beam, the coil 5 is provided on the left and right portions of the neck portion 19n of the picture tube.
4a and 54b are mounted, and the coils 54a and 54b are connected in series to form the control coil 54, and as shown by the broken line in FIG. 7, a drive current forming circuit 50 having the same configuration as the drive current forming circuit 40. This current forming circuit 5 is provided with
By supplying the alternating signal S31 as described above to 0,
It can also be applied to a color picture tube equipped with a round-hole type shadow mask.

By the way, in the above-mentioned proposed device, a control coil for moiré cancellation is additionally mounted on the neck portion of the picture tube on which the horizontal and vertical deflection coils and other parts are mounted. However, there is a problem that it is difficult to secure a space for this control coil.

In the proposed device, the horizontal and vertical synchronizing signals Hsy and Vsy necessary for the moire reduction and the power supply + Vcc and -Vcc of the alternating signal type circuit 30 and the drive current forming circuit 40 are used.
However, both are supplied from the receiver circuit, so when installing on an existing receiver, it is necessary to change the connection of the circuit of the receiver, and it is difficult to install on the existing receiver. There was a problem.

In view of the above points, the present invention is composed of a circuit system different from the deflection system of the image receiver, and it is not necessary to change the connection of the circuit of the image receiver. An object of the present invention is to provide a moire canceling device that can be easily mounted.

[0036]

In order to solve the above-mentioned problems, the moire canceling apparatus according to the present invention, in correspondence with the reference numerals of the embodiments described later, synchronizes with the horizontal synchronizing signal Hsy and outputs the level for each line. Alternating-current signal type circuit 30C that forms an alternating signal that changes, a drive current forming circuit 40 that forms a drive current i43 corresponding to the alternating signal, and an electromagnetic control coil 44 that is mounted at a predetermined position of the color picture tube.
F is a moire canceling device for supplying the drive current to the electromagnetic control coil to slightly shift the electron beam of the color picture tube in opposite directions line by line. It is characterized in that the electromagnetic control coil 44F is formed to be flexible and thin.

The moire canceling apparatus according to the second aspect of the present invention is made to correspond to the reference numerals of the embodiments described later,
Further, according to the present invention, the lead wire Lw18 of the horizontal deflection coil 18 is arranged along with the metal electrode piece to dispose the capacitor 3
6 is formed and the horizontal synchronizing signal Hsy is taken out from this capacitor to form the alternating signal S31.

Further, in the moire canceling apparatus according to the present invention, the transformer 61 is inserted in the lead wire Lw18 of the horizontal deflection coil 18, and the output of this transformer is rectified.
It is characterized in that required power supply voltages + Vcc and -Vcc of the alternating signal forming circuit 30C and the drive current forming circuit 40 are obtained.

[0039]

According to this structure, the drive current i43 whose level (or polarity) is inverted line by line,
The electron beam of the color picture tube is displaced in a predetermined direction so that the moire is canceled by the alternating magnetic field generated from the electromagnetic control coil which can be easily mounted, and the required synchronizing signal Hsy and the power supply + Vcc, -Vcc are supplied. The circuit of the receiver for obtaining the signal is completely galvanically separated from the moire canceling device.

[0040]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the moire canceling device according to the present invention will be described below with reference to FIGS. FIG. 1 shows the overall construction of an embodiment of the present invention, and FIGS. 2 to 5 show the construction of the essential parts thereof. In this FIG.
The parts corresponding to those in FIGS. 6 and 7 described above are denoted by the same reference numerals, and redundant description will be omitted.

In FIG. 1, 30C is an alternating signal forming circuit, and 44F (44Fa, 44Fb) is a control coil for moiré cancellation. In this embodiment, the control coil 44F has a flexible substrate Fbs as shown in FIG.
The coil-shaped pattern Pc that forms the coil portion 44Fa (or 44Fb) is formed on the top of the coil portion. As a result, the control coil 44F is made thin and has flexibility. In this case, the coil pattern formed on the flexible substrate Fbs may have any shape.

As shown in FIG. 3, the control coil 44F is closely attached to the neck portion 19 of the picture tube so that the coil portion 44Fa is on the upper side and the coil portion 44Fb is on the lower side. To be done. And the control coil 4
4F is a coil portion 4 provided on the flexible substrate Fbs.
It is connected to the drive amplifier 43 via a connection terminal portion 44cn connecting to 4Fa and 44Fb.

In this case, since the control coil 44F has the coil type pattern formed on the flexible substrate Fbs as described above, it is also attached to the lower portion of the deflection yoke or the neck assembly of other picture tubes. It is possible and can be installed anywhere.

The control coil 54F for shifting the electron beam in the vertical direction is also constructed similarly to the control coil 44F.

Further, in the case of this example, the power supply and signals (horizontal synchronizing signal and vertical synchronizing signal) necessary for the operation of the drive circuit of the control coil for moire cancellation are supplied from the deflection yoke.

That is, in FIG. 4, Lw15 is a vertical deflection lead wire of the deflection yoke, Lw18 is a horizontal deflection lead wire of the deflection yoke, and these lead wires Lw15 and Lw18 are electrostatically coupled to each other, so that the lead wire Lw15 is provided. , Lw18 are covered with the tubular metal electrode pieces 35p, 36p to form the coupling capacitors 35, 36. The metal electrode pieces 35p and 36p may be formed by inserting a tubular metal tube into the lead wires Lw15 and Lw18 in advance, or the metal pieces may be wound around the lead wires later.

Then, as shown in FIGS. 1 and 4, the horizontal synchronizing signal Hsy extracted through the capacitor 36 is directly supplied to the frequency dividing circuit 31. Also, the capacitor 35
As shown in FIG. 5A, since the vertical synchronizing signal Vsy taken out via the
It is supplied to the shaping circuit 37 and removed as a level component equal to or lower than a predetermined threshold value Vref. Then, the vertical synchronizing signal Vsy as shown in FIG. 5B from the shaping circuit 37 is supplied to the inversion control circuit 32.

Reference numeral 60 denotes a power supply circuit dedicated to canceling moire, which is composed of a transformer 61 and a rectifying circuit 62.

In this embodiment, as shown in FIG. 6, the transformer 61 includes a lead wire Lw18 of the horizontal deflection coil 18 and an annular ferrite core 6 into which the lead wire Lw18 is inserted.
1c and the secondary side lead wire 6 wound around the core 61c
It is formed with 1s. In this secondary side lead wire 61s,
A pulse having a horizontal cycle similar to a so-called flyback pulse is induced, and this induced pulse is supplied to the rectifier circuit 62.

In this rectifier circuit 62, for example, two sets of half-wave voltage doubler rectifier circuits 62A and 62B generate required power supply voltages + Vcc and -Vcc, and the alternating signal forming circuit 30.
C and the drive current forming circuits 40 and 50, respectively.

The remaining structure is similar to that shown in FIG.

With the configuration as described above, the moire canceling device according to this embodiment also has the same moire canceling effect as the previously proposed example.

Furthermore, in this embodiment, since the flexible and thin flexible substrate forming coils 44F and 54F as shown in FIG. 2 are used as the moire canceling control coil, horizontal and vertical deflection coils and It can be mounted under (inside) other components, and can be mounted anywhere on the neck of the picture tube.

Further, in this embodiment, the synchronizing signals Hsy and Vsy required for moire cancellation and the power supplies + Vcc and -Vcc of the frequency divider 31 to the drive amplifier 43 are coupled capacitors 35 and 36 as shown in FIG. And the transformer 61 as shown in FIG. 6, the horizontal deflection circuit 18 of the receiver 10 supplies the moiré canceling device and the receiver circuit. There is no need to change the circuit connection.

Therefore, the moire canceling device of this embodiment can be easily mounted on the existing image receiver.

[0056]

As described above, according to the present invention, since a flexible and thin flexible substrate coil is used as the moire canceling control coil, the deflection yoke and the deflection yoke are provided in the neck portion of the picture tube. It can be attached under any other neck assembly and can be attached anywhere.

Further, in this embodiment, the synchronization signal necessary for moire cancellation and the power supply of the drive circuit for the control coil are
Since the pulse derived by induction from the lead wire of the horizontal deflection coil is rectified and taken out, the moire cancellation device and the circuit of the receiver are completely separated in terms of direct current, and it is necessary to change the connection of the circuit of the receiver. There is no.

Therefore, the moire canceling device of this embodiment can be easily mounted on an existing image receiver.

Further, since the power source of the drive circuit is supplied from the pulse voltage generated by the induction from the deflection yoke,
The energy leaked in vain can be efficiently used, and the power consumption of the moiré canceling device itself is small, so that the power consumption as a whole hardly increases.

[Brief description of drawings]

FIG. 1 is a block diagram showing the overall configuration of an embodiment of a moire canceling device according to the present invention.

FIG. 2 is a perspective view showing a configuration of a main part of an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a configuration of a main part of an embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of a main part of an embodiment of the present invention.

FIG. 5 is a waveform diagram for explaining a main part of one embodiment of the present invention.

FIG. 6 is a connection diagram showing the configuration of still another essential part of an embodiment of the present invention.

FIG. 7 is a block diagram showing a configuration example of a conventional moire cancellation device.

FIG. 8 is a block diagram showing a configuration example of a proposed moire canceling device.

FIG. 9 is a connection diagram showing a configuration example of a main part of the already proposed device.

FIG. 10 is a conceptual diagram for explaining the operation of the proposed device.

FIG. 11 is a time chart for explaining the operation of the already proposed device.

FIG. 12 is a conceptual diagram for explaining the operation of the proposed device.

FIG. 13 is a conceptual diagram for explaining the operation of the proposed device.

[Explanation of symbols]

 10 receiver 15 vertical deflection coil 18 horizontal deflection coil 19 color picture tube 30C alternating signal forming circuit 31 JK flip-flop 35, 36 coupling capacitor 40 driving current forming circuit 43 driving amplifier 44F flexible electromagnetic control coil 60 power supply circuit 61 transformer 62 Rectifier circuit Hsy Horizontal sync signal Vsy Vertical sync signal

Claims (3)

[Claims] 1. An alternating signal type circuit which forms an alternating signal whose level changes line by line in synchronization with a horizontal synchronizing signal, a drive current forming circuit which forms a drive current corresponding to the alternating signal, and a color. An electromagnetic control coil attached to a predetermined position of the picture tube is provided, and the drive current is supplied to the electromagnetic control coil to slightly shift the electron beam of the color picture tube in opposite directions line by line. A moiré canceling device configured as described above, wherein the electromagnetic control coil is formed to be flexible and thin. 2. An electrode piece for capacitor coupling is provided to a lead wire of a horizontal deflection coil, and the horizontal synchronizing signal is taken out from the coupling capacitor to form the alternating signal. Moire cancel device. 3. A pulse generated by induction is taken out from a lead wire of the horizontal deflection coil, and the pulse is rectified to obtain a required power supply voltage for the alternating signal forming circuit and the drive current forming circuit. The moire canceling device according to 1.