KR940003038Y1 - Circuit for compensating horizontal side pincushion - Google Patents

Abstract

No content.

Description

Horizontal side pincushion correction circuit

1 is a block diagram of a conventional horizontal side pincushion correction circuit.

2 is an explanatory view of the operation according to FIG.

3 is a composite waveform diagram according to FIG.

4 is a block diagram of a horizontal side pincushion correction circuit of the present invention.

5 is a detailed circuit diagram according to FIG.

6 is an explanatory view of the operation according to FIG.

7 is a composite waveform diagram according to FIG.

* Explanation of symbols for main parts of the drawings

1: convergence correction signal generation IC 2: OPAMP

3: convergence output IC 4: horizontal convergence correction junk

5 horizontal sawtooth wave and vertical parabolic wave synthesis circuit 51 constant current source circuit

52: constant voltage circuit 53: first differential amplifier

54: second differential amplifier 55: buffer

C ₁ -C ₃ : Capacitor I: Current

Q ₁ -Q ₁₀ : Transistor R ₁ -R ₂₂ : Resistance

V _CC : Power VR ₁ : Variable resistor

The present invention relates to a side pincushion correction signal generating circuit of a convergence correction circuit for a projection TV, and more particularly, to a horizontal side pincushion correction circuit suitable for minimizing heat generation of the convergence correction output IC. will be.

In the conventional horizontal side pincushion correction circuit, as shown in FIG. 1, the convergence correction signal generation IC 1 into which the horizontal and vertical pulses are inputted through the capacitor C ₁ and the variable resistor VR ₁ . The non-inverting terminal (+) of the convergence output IC 3 is connected to the non-inverting (+) terminal of the amplifier 2 and the output of the op amp 2 is connected through the capacitor C ₂ . The inverting terminal (-) is connected to the ground terminal (R ₁ ) through a resistor (R ₂ ), and to the output terminal of the convergence output IC (3) through the horizontal convergence correction yoke (4). It is connected structure.

In the conventional horizontal side pincushion correction circuit configured as described above, the horizontal side pincushion correction signal obtained by synthesizing the horizontal sawtooth wave signal and the vertical parabolic wave signal input from the convergence correction signal generation IC 1 is shown in FIG. ₁ ) the amplitude is adjusted by the variable resistor VR ₁ and applied to the op amp 2, and the signal amplified by the op amp 2 is transferred to the convergence output IC 3 through the condenser C ₁ . The applied and amplified signal drove the horizontal convergence correction yoke 4 to correct the horizontal side pin arrangement as shown in FIG.

However, such a conventional horizontal side pincushion correction circuit should be corrected by the difference between a and b as shown in FIG. 2, wherein the larger the difference between a and b, the larger the amplitude V _PP as shown in FIG. As it increases, the current flowing through the convergence output IC 3 also increases, causing a lot of heat.

The present invention devised a horizontal side pincushion correction circuit to synthesize a horizontal sawtooth signal and a resin parabolic signal using a differential amplifier in view of the above problems. same.

4 is a block diagram of the horizontal side pincushion correction circuit of the present invention, and outputs the output signal of the convergence correction signal generating IC 1 which inputs horizontal and vertical pulses to the horizontal sawtooth wave and the vertical parabolic wave synthesis circuit 5. Is applied to the inverting (-) and non-inverting (+) terminals of the op amp 2 through the capacitor C ₁ and the variable resistor VR ₁ , and the output of the op amp 2 is connected to the capacitor C ₁ . To the non-inverting terminal (+) of the convergence output IC (3), and the inverting terminal (-) is connected to the grounding resistor (R ₁ ) through the resistor (R ₂ ) and the horizontal convergence correction is performed. It is configured by connecting to the output terminal of the convergence output IC 3 via the yoke 4.

5 is a detailed circuit diagram of the horizontal sawtooth wave and the vertical parabolic wave synthesis circuit 5, and as shown therein, the constant current source circuit 51 and the transistor Q which are current mirror circuits using the transistors Q ₁ and Q ₂ . ₉ ) a second circuit comprising a constant voltage circuit 52 for keeping the base voltages of the transistors Q ₅ -Q ₈ constant, and a transistor Q ₃ and Q ₄ receiving a vertical parabolic signal as a base. A second differential amplifier composed of a first differential amplifier 53 and a transistor (Q ₅ ), (Q ₈ ) and transistors (Q ₆ ), (Q ₇ ) receiving a horizontal sawtooth wave signal as a base, respectively operated by a differential amplifier; And a buffer unit 55 for outputting the waveform synthesized by the unit 54 and the first and second differential amplifiers 53 and 54.

Referring to the operation and effect of the invention made in this way with reference to Figures 4 to 7 as follows.

First, the transistors Q ₁ and Q ₂ of the constant current source circuit 51 operate as a current mirror circuit as a constant current source, and the transistor Q ₉ of the constant voltage circuit 52 is connected to the second differential amplifier 54. The base bias of the transistors Q ₅ -Q ₈ is made constant, and the horizontal sawtooth signal is applied to the bases of the transistors Q ₅ and Q ₈ of the second differential amplifier 54 and the vertical parabolic signal is It is applied to the base of the transistor Q ₃ of the primary amplifier 53. Looking at the detailed operation, since the transistor Q ₁ operates as a constant current source, the current flowing through the transistor Q ₁ is I _CQ1 = I _CQ3 + I _CQ4. The relationship of = I _CQ5 + I _CQ6 + I _CQ7 + I _CQ8 is established and the base current of each transistor is ignored.

The transistors Q ₃ and Q _{4 of} the first differential amplifier 53 operate in differential pairs, and the transistors Q ₅ and Q ₆ and Q _{7 of} the second differential amplifier 54 are operated as differential pairs. Since Q ₈ ) operates in each differential pair, currents I _CQ3 and I _CQ4 have a phase difference of 180 ° and a current proportional to the magnitude of the vertical parabolic signal applied to the base of transistor Q ₃ . And the current I _CQ3 becomes the current source of the transistors Q ₅ and Q ₆ , and the current current I _CQ4 becomes the current source of the transistors Q ₇ and Q ₈ , so that the base of the transistors Q ₅ and Q ₈ even if the horizontal sawtooth signal input I _CQ3 = I _CQ5 + I by _CQ6 and flow the vertical parabola wave current I _CQ4 = I _CQ7 + by I _CQ8 and also flows to the vertical parabola wave current, the second differential amplifier (54 ) of the transistors (Q _5, Q ₈₎ when applied to the horizontal sawtooth signal to the base transistor (Q ₅₎ and the transistor (Q ₆₎ of the And a transistor (Q ₇₎ transistors (Q ₈₎ in which a current flows in becomes an operation in each differential pair transistors (Q ₃₎ a current (I _CQ3) and a transistor (Q _5, Q ₅₎ flowing in the overlap with each other, the composite waveform is output in the form of, wherein the output transistor (Q ₆₎ and the transistor (Q ₈₎ withdrawn from the collector, and a value corresponding to a difference between a current (I _CQ6) and the current current (I _CQ8) appears and the buffer section 55 of the A waveform as shown in FIG. 7 is applied to the operational amplifier 2 through the transistor Q ₁₀ .

As described in detail above, the present invention needs to increase the amplitude of the correction signal when the pincation ratio is severe when the pin correction is performed by using the correction signal in a TV with severe horizontal side pincushion distortion. The amplification dynamic range needs to be increased, and accordingly the power voltage is increased so that the overall power loss of the output circuit is increased and the characteristics of the output amplifier are also reduced. It can reduce the cost and increase the reliability.

Claims (2)

The horizontal side pincushion correction signal generated by the convergence correction IC (1) is amplitude-adjusted and amplified, and the horizontal convergence correction yoke (4) is driven through the convergence output IC (3). In a horizontal side pincushion correction circuit configured to correct a cushion, a horizontal sawtooth wave and a vertical parabola which synthesize a signal with a horizontal sawtooth wave and a vertical parabola generated by the convergence correction IC 1 to generate a horizontal side pincushion correction signal. Horizontal side pincushion correction circuit, characterized in that it comprises a combining circuit (5). The horizontal sawtooth wave and vertical parabolic wave synthesis circuit (5) according to claim 1, wherein the constant current source circuit (51) which is a current mirror circuit using transistors (Q ₁ ) and (Q ₂ ), and a transistor (Q ₉ ) are used. A first differential amplifier comprising a constant voltage circuit 52 which makes the base voltages of the transistors Q ₅ -Q ₈ constant, and a transistor Q ₃ and Q _{4 that} receive a vertical parabolic signal as a base. A second differential amplifier 54 which is composed of transistors Q ₅ , Q ₈ and Q ₆ , Q ₇ receiving the horizontal sawtooth signal as a base, respectively; And a buffer unit (55) for outputting the waveform synthesized by the first and second differential amplifiers (53, 54).