KR200154414Y1 - Horizontal deflection accelerator - Google Patents

Abstract

The present invention relates to a horizontal deflection accelerator which increases the deflection force at the retrace period boundary of the horizontal deflection signal in a video display device such as a TV receiver.

In the conventional horizontal deflection circuit, there is a part where the deflection current variation is momentarily slowly changed at the boundary portion of the horizontal deflection signal (just before and immediately after the deflection current starts retrace), and such a gentle change in the deflection current Nonlinear deflection parallax may be caused to result in image overlap or screen drift at the left and right ends of the image when the image signal is displayed.

According to the present invention, as shown in FIG. 5, a signal obtained by differentiating the horizontal pulse 501 into the differentiator 502 is subjected to current compensation 503 and amplification process 504, and is non-linear to the return boundary of the horizontal deflection current. The present invention provides a horizontal deflection acceleration device which performs deflection acceleration to compensate for this in a deflection parallax generation section by forcibly flowing a deflection compensation current, and prevents image overlapping or moxibustion at the left and right sides of the screen.

Description

Horizontal deflection accelerator

The present invention relates to an accelerator of horizontal deflection in an image display device such as a TV receiver.

The conventional horizontal deflection circuit is shown in FIG.

A horizontal output transistor Q1 that is switched upon receiving a horizontal drive pulse H-Drive, a deflection coil DY through which a horizontal deflection current flows by switching of the horizontal output transistor Q1, and a return of the horizontal deflection current; The resonant capacitor C _T performing energy charging and discharging during the period, a damper diode D1 for flowing a damping current in the turn-off period of the horizontal output transistor Q1, and a + B power supply. It consists of a Fryback Transformer (FBT) for generating high voltage and supplying horizontal output power.

The deflection operation by the conventional horizontal deflection circuit configured as described above will be described with reference to the waveform diagram of FIG.

When the rectified power supply voltage + B is supplied to the horizontal deflection coil DY through the flyback transformer FBT, the current flowing in the horizontal deflection coil DY increases linearly.

At this time, the horizontal driving pulse H-DRIVE as shown in FIG. 2A is input to the base of the horizontal output transistor Q1 to switch the horizontal output transistor Q1 on and off.

When the horizontal output transistor Q1 is turned on, the current flowing to the collector of the horizontal output transistor Q1 increases linearly, and when it is turned off, the current is cut off so that a sawtooth current as shown in (b) of FIG. 2 is applied to the horizontal output transistor Q1. Flows into the collector.

Corresponding to this, the current flowing in the horizontal deflection coil DY also increases and decreases linearly so that the current flows in the horizontal deflection coil DY in a waveform as shown in FIG.

On the other hand, when the horizontal output transistor Q1 is turned off, the current as shown in FIG. 2D while charging the energy through the resonant capacitor C _T by the current energy flowing through the horizontal deflection coil DY during the on period. It flows and is subjected to the same voltage as (bar).

Charging of the resonant capacitor C _T takes place during Tr / 2, and discharges through loop A for the remaining Tr / 2.

At this time, even if the current charged in the resonant capacitor (C _T ) completes the discharge, the damper diode (D1) is turned on by the energy remaining in the horizontal deflection coil (DY), and the current flows through the loop B as shown in FIG. It continues to flow.

By repeating the above process periodically, the horizontal deflection current as shown in (C) of FIG. 2 flows to the horizontal deflection coil DY.

Observing the current flowing in the horizontal deflection coil DY as described above, as shown in FIG. 3, immediately before switching from the scanning section Ts to the retrace section Tr, and the return section Immediately after the transition from the scan interval to, i.e., just before and after the deflection current starts retrace, the section where the current change is getting slower is observed.

This is a phenomenon appearing just before the direction of current flow is completely changed in the opposite direction. This part causes the change in the slope of the deflection current to have a nonlinear smoothness, which causes a deficiency of the deflection force.

That is, when horizontal deflection is made with a deflection current such as (b) with respect to an image signal having an overscan area as shown in (a) of FIG. 4, the left and right edges of the screen (just before horizontal blanking) are shown as (c). Image overlay phenomenon on the screen).

Since the image superposition appears as a distortion of the image, the image quality deteriorates.

In addition, a screen drift phenomenon may occur in which a gap occurs between both ends of the screen and the image to be actually displayed.

The image distortion is caused by the above image overlap and the occurrence of moxibustion.

The present invention provides a conventional deflection force shortage phenomenon occurring in the return period of horizontal deflection, and a horizontal deflection acceleration device which can prevent the occurrence of image overlap and screen drift caused by this.

The present invention provides a horizontal deflection accelerator having means for further flowing a compensation current for deflection force compensation of the horizontal deflection current from a predetermined signal corresponding to the scanning of the horizontal deflection and the retrace timing.

The present invention has a means for differentiating a horizontal pulse into a nonlinear compensation current, and a means for amplifying the nonlinear compensation current and adding a horizontal deflection current immediately before and immediately after the return period of the horizontal deflection current, thereby providing a horizontal deflection force. A horizontal deflection accelerator is provided to compensate for the above and to prevent the conventional image superimposition or screen drift from the above.

1 is a conventional horizontal deflection circuit diagram

2 is a waveform diagram of current and voltage flowing through each portion of a conventional horizontal deflection circuit.

3 is a view for explaining the deflection force of the conventional horizontal deflection current.

4 is a view for explaining the problems caused by the lack of conventional deflection force.

5 is an exemplary circuit diagram of a horizontal deflection accelerator according to the present invention.

6 is a waveform diagram of a horizontal deflection current of the present invention.

7 is a view showing a deflection current and the screen improved by the present invention

As shown in FIG. 5, the horizontal deflection accelerator according to the present invention has a horizontal output transistor Q1 that is switched by receiving a horizontal drive pulse (H-Drive) and horizontally by switching the horizontal output transistor Q1. A deflection coil DY through which a deflection current flows, a resonant capacitor C _T for performing energy charging and discharging in the return period of the horizontal deflection current, and a damping current in a turn-off period of the horizontal output transistor Q1. A horizontal deflection circuit comprising a damper diode D1 for supplying a high voltage by a + B power supply and supplying a horizontal output power;

Differentiation means 502 for differentiating and receiving the horizontal pulse (H-PULSE) 501, and converts the non-linear compensation current in order to flow the compensation current of the horizontal retrace section from the horizontal pulse differentiated from the differential means 502 Non-linear current compensation means 503, amplification means 504 for amplifying the compensation current output from the non-linear current compensation means 503, and the compensation current amplified by the amplification means 504 flows immediately before the return section. It comprises an auxiliary deflection coil (DY ') that reinforces the horizontal deflection force immediately after.

The deflection operation by the horizontal deflection circuit according to the present invention configured as described above will be described with reference to the waveform diagram of FIG. 6, and the same components as in FIG.

As shown in (a) of FIG. 6, a horizontal pulse (H-PULSE) 501 is input to the differential means 502 as an information signal representing a scanning section Ts and a retrace section Tr of the horizontal deflection current. The differential signal is output as shown in (b) of FIG.

This differential signal passes through the nonlinear current compensating means 503 and is converted into a nonlinear compensating current waveform as shown in FIG.

The nonlinear compensation current waveform is amplified by the amplifying means 504 and flows to the auxiliary deflection coil DY '.

Therefore, the nonlinear compensation current of (C) is equivalently compensated for the deflection current by the horizontal deflection coil DY as shown in FIG. 6 (D), so that the horizontal deflection current of the current waveform of FIG. Will flow.

In other words, the smooth current changes appearing immediately before and after the return period are compensated in a linear form to the portion where the image signal for accurate sawtooth current shape-overscan is compensated by nonlinear compensation current.

In this way, the horizontal deflection force is reinforced by the compensated horizontal deflection current such as (b) at the image signal timing as shown in (a) of FIG. Undistorted image is displayed.

The compensation of the horizontal deflection sufficiently utilized the overscan area of the video signal.

Although the auxiliary deflection coil DY 'is used in FIG. 5, even when the output of the current amplifying means 504 is superimposed on the deflection coil DY without using the auxiliary deflection coil DY', the same applies. Embodiment configurations in which effects can be secured are also possible.

The horizontal deflection accelerator according to the present invention can prevent the lack of horizontal deflection force due to the gradual change of current appearing immediately before and after the return period during horizontal deflection, and thus the image overlapping and screen drift.

Therefore, it is possible to prevent the image from being displayed with some overlap or space between both edges of the screen, thus preventing image distortion and deterioration in image quality.

Claims (3)

And a means for flowing a compensation current for the deflection force compensation of the horizontal deflection current to the horizontal deflection coil from a predetermined signal corresponding to the scan and retrace timing during the horizontal deflection. And means for differentially converting the horizontal pulses into nonlinear compensation currents, and means for amplifying the nonlinear compensation currents and adding the horizontal deflection currents immediately before and after the return period of the horizontal deflection currents. 3. The horizontal deflection acceleration of claim 2, wherein the deflection current for the compensation further includes an auxiliary deflection coil connected in parallel to the horizontal deflection coil, and equally compensates the horizontal deflection current by flowing a compensation current thereto. Device.