JPH09130635A - Deflector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To exactly perform linearity correction by providing 1st and 2nd sawtooth wave generating circuits, vertical drive output circuit, feedback means and integration circuit and modulating the amplitude of a horizontal output pulse corresponding to the output signal of the integration circuit. SOLUTION: A control circuit 11 detects the 1st sawtooth wave of a 1st sawtooth wave generating circuit 30 and control the amplitude of a 2nd sawtooth wave of a 2nd sawtooth wave generating circuit 31 corresponding to that detected value. The circuit 31 is provided as the dummy of the circuit 30, and the linear sawtooth wave is generated without performing any feedback to the circuit 31 and impressed to an integration circuit 32. The integration circuit 32 integrates the sawtooth wave and outputs a parabolic wave. This parabolic wave changes the power supply voltage of a horizontal output circuit 17. When the power supply voltage of the circuit 17 is changed, the amplitude of the horizontal output signal is changed corresponding to it and horizontal linearity correction is enabled. Namely, the circuit 33 is provided so that the amplitude of the saw-tooth wave from the circuit 30 can be equal with the amplitude of the sawtooth wave from the circuit 31.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a horizontal and vertical deflecting device used in a TV receiver or a computer display, and more particularly to a deflecting device for performing horizontal and horizontal screen correction (pin cushion correction).

[0002]

2. Description of the Related Art In a display device using a cathode ray tube such as a TV receiver or a computer display, the distance between the electron gun and the screen varies depending on the place (center and corner).
It is necessary to make corrections. This correction is done both horizontally and vertically. This correction has been performed even in the conventional TV receiver, but recently, due to the enlargement of the screen of the TV receiver and the use of the computer display, the overscan area is almost eliminated, and a better correction is required.

FIG. 2 shows a deflecting device which has made such a correction. A vertical trigger pulse from the input terminal (1) is formed into a pulse having a constant width by a monomulti (monomultivibrator) (2). Shaped sawtooth wave generation circuit (3)
Is applied to The sawtooth wave generation circuit (3) has a configuration as shown in FIG. 3, and switches (6) and (7) are opened and closed according to the pulse of the constant width applied to the terminals (4) and (5). To do.

In response to opening / closing of the switches (6) and (7), the capacitor (8) is charged by the variable current source (9) and discharged by the constant current source (10). As a result, a sawtooth signal as shown in FIG. 4A is generated at the output terminal of the sawtooth wave generation circuit (3). Then, the sawtooth signal is applied to a vertical drive output circuit (12) that generates a vertical deflection current in the vertical deflection coil (11). The vertical deflection current flows through the DC blocking capacitor (13) and the AC feedback resistor (14).

A parabola wave (for S-shaped correction) is generated at point A and a sawtooth wave shown in FIG. 4B is generated at point B, and a sawtooth wave generation circuit ( 3) and the vertical drive output circuit (12). As a result, a curved sawtooth signal is generated at the output end of the sawtooth wave generating circuit (3) to correct the linearity of the screen by various feedbacks as shown in FIG. 4 (a). The output signal of the sawtooth wave generation circuit (3) is integrated by the integration circuit (16) and applied to the horizontal output circuit (17) as a power supply voltage.

The horizontal trigger pulse from terminal (18) is
The horizontal oscillator (2) is applied to the horizontal AFC circuit (19).
0) Synchronize the oscillation. Synchronized horizontal oscillator (20)
The oscillation output of is applied to a horizontal deflection coil (not shown) via a horizontal output circuit (17). Here, the output voltage waveform of the integrating circuit (16) changes as shown by the dotted line in FIG. 4 (d), and the horizontal output power supply voltage is modulated by the parabolic waveform of this dotted line. The scanning amplitude becomes large, and the scanning amplitude becomes small in the horizontal scanning lines near the top and bottom of the screen.

Therefore, the horizontal deflection signal, which has been subjected to the horizontal linearity correction, is obtained at the terminal (21). Therefore,
According to the circuit of FIG. 2, the linearity of the screen can be corrected in both the horizontal and vertical directions.

[0008]

However, in the circuit of FIG. 2, the correction of the horizontal deflection signal obtained by the correction of the linearity in the horizontal and horizontal directions obtained at the terminal (21) is not perfect. That is, in the circuit of FIG. 2, the output voltage waveform of the integrating circuit (16) is shown by the dotted line in FIG. 4 (d), but originally it is a parabolic wave shown by the solid line in FIG. 4 (d). Need to be

This is because the output signal of the sawtooth wave generation circuit (3) is not a simple sawtooth wave but has various curves due to feedback.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and a first sawtooth wave generating circuit for generating a first sawtooth wave in response to a vertical trigger pulse, and the first sawtooth wave. A vertical drive output circuit for generating a vertical deflection current according to a first sawtooth wave from the sawtooth wave generation circuit, a feedback means for returning the vertical deflection current to the first sawtooth wave generation circuit, and the vertical trigger pulse. A second sawtooth wave in response to the second
A sawtooth wave generation circuit, an integration circuit that integrates the second sawtooth wave from the second sawtooth wave generation circuit, and a modulation unit that modulates the amplitude of the horizontal output pulse according to the output signal of the integration circuit. It is characterized by being provided.

[0011]

FIG. 1 shows an embodiment of a deflecting device of the present invention, in which (30) is a first sawtooth wave generating circuit for generating a first sawtooth wave in response to a vertical trigger pulse. ,
(31) is a second sawtooth wave generating circuit that generates a second sawtooth wave in response to a vertical trigger pulse, and (32) integrates the second sawtooth wave from the second sawtooth wave generation circuit (31). An integrating circuit (33) detects the amplitude of the first sawtooth wave of the first sawtooth wave generation circuit (30), and according to the detected value, the second sawtooth wave of the second sawtooth wave generation circuit (31). It is a control circuit that controls the amplitude of the wave.

In FIG. 1, the same circuit blocks as those in FIG. 2 are designated by the same reference numerals and the description thereof will be omitted. FIG.
The first sawtooth wave generation circuit (30) of the feedback circuit (1
A sawtooth wave or the like is fed back via 5), and the operation is the same as that of the sawtooth wave generation circuit (3) in FIG. On the other hand, in the present invention, the second sawtooth wave generation circuit (31), which is a dummy of the first sawtooth wave generation circuit (30), is provided, and the second sawtooth wave generation circuit (31) has the above-mentioned configuration. A linear sawtooth wave was output without feedback. The second sawtooth wave generation circuit (31) generates a linear sawtooth wave shown in FIG. 4 (c) and applies it to the integration circuit (32).

Then, the integrator circuit (32) operates as shown in FIG.
The sawtooth wave is integrated to output the parabolic wave shown by the solid line in FIG. The parabolic wave changes the power supply voltage of the horizontal output circuit (17) as in the case of FIG. When the power supply voltage of the horizontal output circuit (17) changes, the amplitude of the horizontal output signal changes (modulates) accordingly, and the linearity correction in the horizontal direction becomes possible.

The solid line in FIG. 5 shows the horizontal output signal of the horizontal output circuit (17), and the alternate long and short dash line shows the change in the power supply voltage of the horizontal output circuit (17). In the central portion of FIG. 5, the amplitude of the horizontal output signal increases as the power supply voltage increases, and it decreases on both sides. This change makes it possible to correct the linearity in the horizontal direction. The circuit of FIG. 3 can also be used as the second sawtooth wave generation circuit (31).
The amplitude of the sawtooth wave of the first sawtooth wave generation circuit (30) is changed according to the screen size (50HZ / 60HZ). In that case, the amplitude of the sawtooth wave of the second sawtooth wave generation circuit (31) needs to be made to follow in the same manner.

Therefore, in the present invention, the amplitude of the first sawtooth wave of the first sawtooth wave generation circuit (30) is detected, and the second sawtooth wave generation circuit (31) of the second sawtooth wave generation circuit (31) is detected in accordance with the detected value. A control circuit (33) for controlling the amplitude of the sawtooth wave is provided to detect the amplitude of the sawtooth wave of the first sawtooth wave generation circuit (30) and the sawtooth wave of the second sawtooth wave generation circuit (31). The amplitude is made equal.

Specifically, the first sawtooth wave generation circuit (3
The amplitude of the first sawtooth wave 0) is detected, and the current value of the variable current source (9) in FIG. 3 is adjusted according to the detected value. When the current value of the variable current source (9) changes, the charging speed of the capacitor (8) changes and the amplitude of the sawtooth wave changes. Therefore, according to the apparatus of FIG. 1, a symmetrical parabolic waveform is obtained from the integrator circuit (32), and the amplitude of the horizontal output signal can be modulated in accordance with the parabolic waveform. It is possible to correct the sex.

[0017]

As described above, according to the present invention, since the second sawtooth wave generating circuit dedicated to the sawtooth wave is provided, the parabolic waveform symmetrical to the left and right can be obtained, and the parabolic waveform can be obtained according to the parabolic waveform.
Since the amplitude of the horizontal output signal can be modulated, accurate linearity correction in the horizontal direction of the screen becomes possible.

Further, according to the present invention, the amplitude of the first sawtooth wave of the first sawtooth wave generation circuit is detected, and the second sawtooth wave of the second sawtooth wave generation circuit is detected according to the detected value. A control circuit for controlling the amplitude is provided to equalize the amplitude of the sawtooth wave of the first sawtooth wave generation circuit and the amplitude of the sawtooth wave of the second sawtooth wave generation circuit. Even if there is a change, it is possible to always correct the horizontal straightness of the screen accurately.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a deflecting device of the present invention.

FIG. 2 is a block diagram showing a conventional deflection device.

FIG. 3 is a circuit diagram showing a specific circuit example of a sawtooth wave generation circuit.

FIG. 4 is a waveform diagram for use in the description of FIGS. 1 and 2.

FIG. 5 is a waveform chart for explaining FIG. 1;

[Explanation of symbols]

 (12) Vertical drive output circuit (15) Feedback circuit (17) Horizontal output circuit (30) First sawtooth wave generation circuit (31) Second sawtooth wave generation circuit (32) Integration circuit (33) Control circuit

Claims (2)

[Claims] 1. A first sawtooth wave generation circuit for generating a first sawtooth wave in response to a vertical trigger pulse, and a vertical deflection current in response to the first sawtooth wave from the first sawtooth wave generation circuit. A vertical drive output circuit for generating; a feedback means for feeding back the vertical deflection current to the first sawtooth wave generating circuit; and a second sawtooth wave generating circuit for generating a second sawtooth wave in response to the vertical trigger pulse. And an integrator circuit for integrating the second sawtooth wave from the second sawtooth wave generation circuit, and a modulator for modulating the amplitude of the horizontal output pulse according to the output signal of the integrator circuit. And a deflection device. 2. A first sawtooth wave generation circuit for generating a first sawtooth wave in response to a vertical trigger pulse, and a vertical deflection current in response to the first sawtooth wave from the first sawtooth wave generation circuit. A vertical drive output circuit for generating; a feedback means for feeding back the vertical deflection current to the first sawtooth wave generating circuit; and a second sawtooth wave generating circuit for generating a second sawtooth wave in response to the vertical trigger pulse. And a control means for detecting the amplitude of the first sawtooth wave of the first sawtooth wave generation circuit and controlling the amplitude of the second sawtooth wave of the second sawtooth wave generation circuit according to the detected value. An integration circuit for integrating the second sawtooth wave from the second sawtooth wave generation circuit, and a modulation means for modulating the amplitude of the horizontal output pulse according to the output signal of the integration circuit. Deflection device.