KR790000972B1 - Vertical convergence circuits - Google Patents

Abstract

A dynamic convergence circuit for a colored multibeam receiver, consisted of a first and second inputs connected to a vertical deflection circuit, a magnetic field inducing device, and two current paths. The first and second paths are coupled respectively to the series connections of the unilateral resistors. The circuit applies the excitation signal to the vertical deflecting yoke according to the vertical injection ratio.

Description

Formula Convergence Circuit

1 is a partial circuit diagram of a color television receiver comprising a vertical convergence circuit constructed in accordance with the principles of the present invention.

2 is a partial circuit diagram of the FIG.

3 is a series of current and voltage waveform diagrams for the circuit of FIG.

TECHNICAL FIELD The present invention relates to a dynamic convergence circuit of a multibeam color receiver, and more particularly, to a vertical or numbered convergence circuit.

In color television receivers using multi-beam receivers, shadow mask receivers and three electron guns are commonly used to correct errors caused by false convergence of beams.

This can be done by using an electromagnet device in response to signals of varying (horizontal) and field (vertical) injections in order to properly change the path of the beam. Types commonly used to change the path of a beam include electromagnets each associated with a corresponding magnetic pole piece inside the receiving tube, each of which is associated with one of the beams, each of which is vertical Each winding is included for use in scan water.

The present invention relates to a convergence circuit which is particularly suitable for temperature or controlling current in the vertical convergence winding of a convergent electromagnet. In the conventional convergence structure used in the Delabee water tube, the beam landings that occur when the electronics corresponding to the red and green beams are magnetized move diagonally (including the vertical horizontal movement) while blue The non-landing caused by the magnetization of the convergence winding is only vertical movement. Furthermore, the diagonal axes through which the red and green beams move intersect each other. Therefore, if the currents of the red and green convergences are equal to each other, the vertical moving directions of the red and green beams are the same and the horizontal moving directions are opposite to each other. When the currents of the red and green convergences are opposite to each other, the horizontal movement directions of the red and green beams are the same, and the vertical movement directions are opposite to each other.

In practice, dynamic convergence circuits require several variable controllers, which can be used to correct convergence errors by properly correcting false convergence errors due to errors in manufacturing of the receiver. There must be sufficient tolerance to control the current. Powering the red and green convergence windings mutually effectively controls the main amplitude and differential control of the convergence winding current so that the registration of the red and green non-landing points can be easily aligned in a horizontal and vertical line. Can be. Convergence trimming can then be done by appropriate adjustment of the blue convergence current to allow the rest of the horizontal trimming. For many wrong convergence patterns that need correction, the wrong convergence at the top of the screen does not match the wrong convergence at the bottom of the screen, so in the actual convergence adjustment the amplitude of the beginning (top) of the scan waveform is There must be a device for alternatingly changing the amplitude of the end (bottom) of the scanning waveform relative to. The difficulty with circuits according to the prior art is that these problems have to be solved by manipulating the control. For example, in proportion to the beginning of the scan amplitude, the end of the scan amplitude (as determined by other controls) tended to interfere with the beginning of the scan amplitude. So I had to repilot to another control.

Vertically controlling each effectively during the interval between syringes in U.S. Patent No. 3,491,261 to M. Michael W. hill and Lawrence E. Smith on January 20, 1970. Announced convergence circuit. The type of circuit modified to significantly reduce the mutual effects of the control devices published by Hill et al. Is described in US Patent Application No. 143,861 filed by Michael W. Hill on May 17, 1971, which application is 1970 It is based on British Patent Application Nos. 23,940 / 70 and 24,941 / 70, filed in the UK on 18 May.

The present invention uses ancillary devices to avoid interaction between the various controls. Furthermore, a feature of the present invention is that a signal source for driving the whole with the vertical convergence circuit can be drawn from the two terminals of the vertical deflection circuit without using any transformer.

The circuit of the present invention is in contrast to conventional circuits which require several different drive signal sources. The typical type of the conventional type is to supply several different drive waveforms by using several windings in a vertical output transformer or by using a combination of windings and a filter (circuit) connected to a main current path of a vertical output element (ie, a vacuum tube or a transistor). However, the convergent waveform supply power supply according to the present invention does not use a complicated and expensive transformer like the device described in the above patent application.

The present invention is also particularly suitable for use in connection with low impedance (about 1-5 Ω) vertical deflection yokes. Such yokes are currently wound in a toroidal fashion and are suitable for use with semiconductor vertical output circuits without the use of transformers. Convergence circuits are also suitable for paralleling with low impedance yokes in series driven transistor output circuits. If the convergence circuit is connected in series with the low impedance yoke of such a circuit, the higher output should be supplied to its vertical output stage. In order to increase this power, conventional methods use agricultural devices. But such methods are bad from an economic point of view. Therefore, since the parallel connection convergence arrangement, which is a feature of the present invention, consumes relatively low power, there is no need to add a non-driving device using a transistor or the like.

According to an embodiment of the invention the convergence circuit is connected between the first and second input terminals of the vertical deflection circuit (i.e., both ends of the yoke). The current flows through at least one convergence winding during the half period of the vertical scanning period (voltage of the half period sawtooth of FIG. 3 or positive voltage) of each circuit conducting only in a single direction including the first variable resistor. It is connected between the two terminals of the jack. A unidirectional conducting circuit comprising a second variable resistor is connected between both terminals of the yoke such that current flows through the convergence winding for the remaining half period of each vertical scan period. During the later half cycle between the syringes the current does not flow through the first circuit, whereas during the first half cycle between the syringes the current does not flow through the second circuit. In single-directional conducting devices, the variable resistor is controlled to change the current so that it flows in only one path, separating it from passing through the other current path. Thus, independent upper and lower convergence controls are alternately powered.

According to another feature of the invention, the second convergence winding is connected at the first by two variable resistors and the rest differentially controls current through two (red and green) convergence windings.

Another suitable configuration of the unidirectional conducting element is connected to the second winding.

In an embodiment of the invention the convergence circuit is connected in parallel with the vertical deflection yoke.

The above and other advantages of the present invention will be described in detail with reference to the accompanying drawings.

)으로 분리되어 있으며 핀쿠숀(pincushion)교정 변압기 T₁은 요우크 Li에 두 부분 사이에서 연결되어 있다. 부성온도계수를 갖는 온도 보상 서미스터 NTC는 요우크 L₁과 직렬로 연결되어 있다. 비교적 큰 값의 S-교정 캐패시터 C₁과 전류 샘플링 저항R₁₁은 요우크 L₁의 전류를 귀환하도록 기준전위(즉 접지)에 연결하여 커환 통로를 형성한다. 변압기가 없는 수직 편향 회로들에 보통 사용되는 이와같이 각각 콘덴서 C₁과 전류샘플링 저항 R₁₁로 증폭기 10에 적절한 귀환(도시안됨)전압이 공급된다.Referring to the circuit of FIG. 1, the transformerless vertical deflection output amplifier 10 is connected to a relatively low impedance vertical deflection yoke L ₁ . Output amplifier 10 connects two transistors of opposite conductivity, and yoke L ₁ is connected to the collector common connection of the transistors. As is known, output amplifiers without various types of transformers can be used for vertical deflection. For example, in addition to the above, it may also be used as a quasi-complementary symmetric amplifier or complementary symmetric amplifier with an emitter output. The windings of the yoke L ₁ are the same two parts (

The pincushion calibration transformer T ₁ is connected between the two parts of the yoke Li. The temperature compensated thermistor NTC with negative temperature coefficient is connected in series with the yoke L ₁ . The relatively large value of the S-calibration capacitor C ₁ and the current sampling resistor R ₁₁ are connected to the reference potential (ie ground) to return the current in the yoke L ₁ to form a feedback path. As is commonly used in transformerless vertical deflection circuits, the capacitor C ₁ and current sampling resistor R ₁₁ are supplied with an appropriate return (not shown) voltage to amplifier 10, respectively.

Typically, the yoke L ₁ has an impedance of about 1-5Ω in the case of an annular winding. A typical value for a toroidal winding yoke available today is 1.5Ω. The yoke is shown in the sawtooth wave voltage yoke L _1, as shown on the side of the L ₁ when the first bias circuit is operating normally degrees. This sawtooth waveform is repeated as a vertical deflection (ie about 60 Hz in US standard). This sawtooth voltage is used to drive the vertical convergence circuit in parallel with the yoke L ₁ .

The vertical convergence circuit is configured as a red convergence winding L ₂ and a green convergence winding L ₃ . A diode having the same polarity as the vertical-nodal variable resistor R ₁ , the horizontal-nodal variable resistor R ₂ , the winding L _2, and the diode CR ₁ in a pair of linear connection diodes CR ₁ constituting the first single directional conduction current path. CR ₄ is connected in series and is connected in parallel with yoke L ₁ from input terminal P ₁ to input terminal P ₂ .

A pair of series-connected diodes CR, a vertical red-green upper potentiometer R ₄ , a horizontal red-green upper potentiometer R ₃ , a winding L _2, and a diode CR ₂ , forming a second single directional conduction current path of opposite polarity Directional diode CR ₃ is also connected in parallel to yoke L ₁ from input terminal P ₁ to input terminal P ₂ .

The control taps (upper and lower main amplitude voltage dividers) of the voltage dividers R ₄ and R ₁ are connected to the adjustment taps (upper and lower vehicle voltage dividers) of the voltage dividers R ₃ and R ₂ , respectively. The red convergence winding L ₂ is connected to one end between the voltage divider R ₂ and R ₃ and the green convergence winding L ₃ is connected to the other end between the variable resistors R ₂ and R ₃ so that L ₂ and L ₃ are separated from each other. have. The termination of the green winding L ₃ is reconnected to the lower end of the yoke L ₁ by diodes CR ₈ and CR _{7 which} are conducted simultaneously when diodes CR ₂ and CR ₂ conduct respectively. In addition, diodes CR ₅ and CR ₆ are connected in series with current limiting resistors R ₅ and R ₆ respectively, and are wound across windings L ₃ and L ₂ , respectively.

The blue convergence winding L ₄ also receives an energy waveform from the yoke L ₁ . Both ends of the blue capacitance winding L ₄ are again connected to the bottom of the yoke L ₁ by resistors R ₈ and R ₁₀ . The blue horizontal upper variable resistor R ₈ is connected in parallel across the blue winding L ₄ . The variable taps of the variable resistors R ₇ and R ₈ are connected to the top of the yoke L _{1 so that} the driving current is supplied via diodes CR ₉ and CR ₁₀ connected in opposite polarities, respectively.

The circuit operation of FIG. 1 will be described next with reference to the schematic diagram of FIG. 2 in which only the red convergence winding L ₂ is included. The resistor NTC and the pincushion transformer T ₁ are also omitted here. Symbol characters for various circuit elements of FIG. 2 are denoted by the same symbol characters for the same parts as those in FIG.

In FIG. 2 the yoke L ₁ is represented by a single winding.

Diodes CR ₁ and CR ₂ are also indicated as single junction elements.

In driving the circuit, the voltage across yoke L ₁ (first wave in FIG. 3) changes relatively rapidly from a positive maximum to a negative maximum during the vertical return period of the vertical deflection cycle. A gentle linear change from the positive maximum to the negative maximum occurs between its vertical syringes, i.e. during the trace interval. The voltage across yoke L ₁ during the first half period of this vertical scan is negative, during which the upper half of the television image is scanned. This polarity is suitable for forward biasing the current path including diodes CR ₂ , variable resistors R ₄ and R ₃ , red winding L ₂ and diodes CR ₃ . Therefore, the voltage at point B (B waveform in FIG. 3) is a half-cycle sawtooth waveform that is the negative polarity during the first half-cycle of the vertical scan. Diodes CR ₁ and CR ₄ are reverse biased during this period. The variable resistors R ₁ and R ₂ are bypassed due to the forward conduction state of the diode CR ₃ . Controlling the variable resistor R ₄ controls the magnitude of the voltage applied to point B, red-locking (as in the green-high degree of the circuit in Figure 1) to control the main amplitude of the top of the screen.

For example, during the first half-cycle between syringes through the red winding L ₂ (see Figure 3), current will flow from terminal A to terminal B, but due to the inductance of the winding L ₂ the applied sawtooth voltage is integrated as shown. This results in a reduced parabolic current (at current AB).

During the second half period of the vertical winding period, diodes CR ₂ and CR ₃ are reverse biased by their applied voltage waveform (current positive value). According to the polarity of the applied voltage waveform, the diodes CR ₁ and CR ₄ become conductive and a current which increases in a parabolic manner flows from the terminal A to the terminal B through the red winding L ₂ . The variable resistor R ₁ therefore acts as the lower main amplitude control for the vertical convergence circuit. During the positive voltage (i.e. voltage A) of this vertical scan, diode CR ₄ turns the variable resistors R ₃ and R ₄ to the side. Therefore, it can be obtained by adjusting the amplitude of the independent upper and correction waveforms respectively.

In the circuit of FIG. 1, the green convergence winding L ₃ also includes diodes CR ₇ and CR ₈ together which function as the functions of diodes CR ₃ and CR ₄ as described above. The variable resistors R ₂ and R ₃ are manipulated to distribute the current between the red winding L ₂ and the green winding L ₃ . Therefore, if the value of the red-green lower main amplitude control variable resistor R ₁ changes, the currents supplied to the red and green windings L ₂ and L ₃ change during the next (positive voltage) half cycle (bottom of the screen) of the scan. However, if the value of the variable resistor R ₂ changes, the currents applied to the windings L ₂ and L ₃ cause opposite changes.

With this satisfactory control characteristic, the variable resistor R ₁ can be controlled to concentrate the vertical red-green wire at the bottom half of the screen, and the variable resistor R ₂ can be controlled to concentrate the horizontal red-green line at the bottom half of the screen. .

The variable resistors R ₃ and R ₄ can also make the same control over the lines at the top of the screen.

In practice, the use of two diodes, CR ₁ and CR ₂ , has proved to be an advantage. The arrangement of these elements produces satisfactory steep parabolic current waveforms from the beginning to the end of the scan.

The blue convergence consists of diodes R ₉ and (R ₁₀ variable resistors R ₇ and R ₈ , resistors R ₉ and R ₁₀ and blue winding L4.

Blue convergence is provided by placement of diodes CR ₉ and CR ₁₀ variable resistors R ₇ and R ₈ , resistors R ₉ and R ₁₀ and blue winding L ₄ .

Diodes CR ₁₀ and CR ₉ are alternately advanced during the first and second half periods of the vertical scan period, respectively. The blue coil L ₄ forms a bridge circuit with resistors R ₉ and R ₁₀ . Therefore, the convergence current flowing through the blue winding L ₄ is controlled by the variable resistors R ₇ and R ₈ so as to flow to any side of the stone during the vertical scanning period of half a cycle each.

In the above description, for convenience, it is assumed that the voltage across the yoke L ₁ is a normal sawtooth waveform having the same negative maximum. In practice, however, yoke L ₁ exhibits the series-coupling characteristics of resistance and inductance. Therefore, the voltage across yoke L ₁ contains a negative traveling pulse during the vertical winding period. The pulse amplitude ratio to the sawtooth amplitude is determined by the ratio of inductance to the resistance of yoke L ₁ . Since the annular resin yokes used in recent years have a low resistance to inductance ratio, the pulse amplitude is very small during retracement and can be ignored.

However, if a large pulse amplitude is required, for example a yoke with a high resistance to inductance ratio, diodes CR ₅ and CR ₆ must be used in addition to the windings L ₃ and L ₂ in parallel. To prevent transient currents through diodes CR ₅ and CR ₆ , resistors R ₅ and R ₅ are connected in series with diodes CR ₅ and CR ₆ . Diodes CR ₅ and CR ₆ can reduce the distortion of the convergence waveform as much as possible at the top of the screen by turning the windings L ₂ and L ₃ to the side during the higher frequencies, which are negative traveling retrace pulses.

Although the present invention has been described so far in accordance with embodiments, various modifications can be made within the scope of the present invention.

An example of device values that can be used as an embodiment of the present invention is shown in FIG. These indicated values can be used well with a yoke with an impedance of 1.5Ω. Convergence windings L ₂ , L ₃ and L ₄ are also suitable as inductances of 28 mH each. A suitable diode is IN 914 type. If resistors R ₅ and R ₆ are used, 33 Ω is appropriate respectively. Representative operating voltage and current levels are shown in FIG.

Claims (1)

First and second input terminals connected to the vertical deflection circuit, magnetic field generating means having at least a first convergence winding, and first and second current paths formed at both input terminals. And the two current paths each have a series connection of a first unidirectional conductor and a first variable resistor and a series connection of a second unidirectional conductor and a second variable resistor, respectively. The conducting device of circulates the current through the winding, but bypasses the second current path so that the effect of the change in the second resistor in the predetermined half period between each vertical syringe does not affect the first current path. The two conductive elements are connected to each other at the same polarity as the current flowing through the first variable resistor in the other half cycle between the syringes. The device and current are passed through the windings, but the first current flow is bypassed so that the effect of the first variable resistor change does not affect the second current path in the remaining half period between each vertical syringe. A vertical deflection circuit which is connected at the same polarity as the current blocking the current flowing through the second variable resistor in a predetermined half period between the syringes, and supplies a driving signal of vertical scan rate to the vertical deflection yoke. Convergence circuit of a color television receiver comprising a.

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