KR100651860B1 - Deflecting circuit and method for operating the same - Google Patents

Abstract

A deflecting circuit and a method for driving the same are provided to prevent the flowing of over-current, by setting a sufficient turn-on time for all capacitors including a main adjustment capacitor and subsidiary adjustment capacitors which is assigned to each screen area. A main capacitor(2a) and a plurality of subsidiary adjustment capacitors are configured to compensate for the distortion of a screen, on which an image is displayed according to application of an electric power. A plurality of switches are respectively connected to the subsidiary adjustment capacitors. A switch controller controls the switching of the switches. A regulator(7) transforms a first constant voltage of a first level into a second constant voltage of a second level and supplies the second constant voltage to the switch controller, when the electric power is applied. A delay circuit unit(9) delays the output of the regulator(7) for a predetermined time such that the regulator(7) outputs the second constant voltage, after the subsidiary adjustment capacitors are charged.

Description

Deflection circuit and its driving method {DEFLECTING CIRCUIT AND METHOD FOR OPERATING THE SAME}

1 is a block diagram illustrating a configuration of a general video device

2 is a view for explaining a horizontal deflection portion and an internal correction circuit according to the prior art;

3 is a view for explaining the current flow of the horizontal deflection portion and the internal correction circuit according to the prior art

4 is a view for explaining the state of the screen when the EW damage of the internal correction circuit of the imaging apparatus according to the prior art

5 is a view for explaining the current flow of the horizontal deflection portion and the internal correction circuit according to the present invention;

6 is a view for explaining a delay circuit according to the present invention;

7 is a view for explaining the operation of the regulator by the delay circuit according to the present invention;

Explanation of symbols on the main parts of the drawings

1: deflection control unit 2: horizontal deflection unit

3: inner correction circuit part 4: deflection yoke

5: CRT 6: linearity coil

7 regulator 8 switch control unit

9: delay circuit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deflection circuit, and more particularly, to a deflection circuit and a driving method thereof capable of protecting an internal switching element while minimizing screen distortion.

The cathode ray tube (CRT) of the display device focuses and accelerates the electrons emitted from the R / G / B electron gun and then collides with the R / G / B fluorescent surface through a shadow mask to form pixels. An electric current flows through the deflection coil to form a two-dimensional screen.

However, screen distortion occurs due to a deviation between the distance from the electron gun to the center portion of the CRT screen and the distance from the electron gun to the corner portion of the CRT screen.

For example, because the distance from the electron gun to the corner of the screen is relatively long, the width of the cross-hatch on the screen is not constant and the sharpness at the corners of the screen is greater than that of the center of the screen. Falls.

In addition, pin distortion occurs at the corners of the screen due to the above-described distance deviation. The narrower the gap between the electron gun and the CRT screen, the more severe the picture distortions described above.

Therefore, the disadvantage of such a CRT is to limit the distance between the electron gun and the CRT screen and to make the CRT display device ultra slim.

Hereinafter, a deflection circuit according to the prior art will be described with reference to the accompanying drawings.

1 is a block diagram illustrating a configuration of a general video device.

The imaging apparatus of FIG. 1 includes a deflection control unit 1 that provides an EW correction waveform, a horizontal deflection unit 2 that performs horizontal deflection according to the EW (East West) correction waveform, and a screen that passes through the deflection unit 2. It consists of an inner correction circuit section 3 for correcting distortion, a deflection yoke (hereinafter referred to as DY) 4 and a cathode ray tube (hereinafter referred to as CRT) 5.

2 is a view for explaining a horizontal deflection portion and the internal correction circuit according to the prior art, Figure 3 is a view for explaining the current flow of the horizontal deflection portion and the internal correction circuit according to the prior art, Figure 4 is a prior art A diagram for describing a state of a screen when an EW breakage of an internal correction circuit of an imaging device is performed.

The horizontal deflection unit 2 according to the prior art includes a main correction capacitor CS 2a and a horizontal output field effect transistor TR, and the internal correction circuit unit 3 includes first to fourth auxiliary correction capacitors. Size Capacity (CS1 to CS4) 3a and first to fourth switches SW1 to SW4 3b.

In the case of the conventional flat TV model, only the main correction capacitor CS (Size Capacitor) (2a) and the linearity coil (Linearity Coil) (6) is used to adjust the equal spacing, or linearity, of the screen. In the case of the slim model, as the CRT 5 length becomes shorter, linearity cannot be corrected with one CS, and an internal correction circuit 3 is employed.

The first to fourth auxiliary correction capacitors 3a are used to prevent area-specific distortion of the screen. For example, the first auxiliary correction capacitor CS1 corrects distortion in the center left and right areas of the screen together with the main correction capacitor 2a, and the second auxiliary correction capacitor CS2 is next to the center area. Corrects the distortion in the left and right regions, the third auxiliary correction capacitor CS3 corrects the distortion in the next left and right regions of the center region, and the fourth auxiliary correction capacitor CS4 is applied in the left and right edge regions of the screen. To correct the distortion.

The first to fourth switches 3b are controlled by the switch controller 8, and the switch controllers 8 sequentially operate the first to fourth switches 3b by 5v constant voltage applied through the regulator 7. Operate with

The inner correction circuit unit 3 divides the screen into four parts, and each of the first to fourth switches SW1 to SW4 and 3b is a turn on switch of the main correction capacitor. (CS1 to CS4) are independently controlled to correct linearity.

In this case, when the power is turned on after the power supply to the slim TV, that is, when the initial screen is turned on, only the first switch SW1 that supplies a 5 V constant voltage to the first auxiliary correction capacitor CS1 for correcting distortion in the center left and right areas of the TV screen is turned on. When turned on, only the first switch SW1 is turned on when the first to fourth auxiliary compensation capacitors CS1, CS2, CS3, and CS4 have insufficient impedance. The current to be divided into the first to fourth auxiliary correction capacitors CS1, CS2, CS3, and CS4 is instantaneously provided to the first auxiliary correction capacitor CS1 and the horizontal output field effect transistor TR as shown in FIG. 3. Excessive current flows.

In the case of the horizontal output field effect transistor TR, the internal voltage is high to withstand the amount of current, but the EW transistor EW TR is applied to the current transmitted only through the first auxiliary correction capacitor CS1 and the first switch SW1. Could not withstand internal pressure and could be broken.

That is, when the initial power-on is turned on, the overcurrent flows in a state where the amount of impedance of the first to fourth auxiliary correction capacitors is not sufficient. At this time, the overcurrent may seriously damage not only the peripheral IC, especially the horizontal output field effect transistor TR, but also the EW transistor EW TR shown in FIG. 3, which may cause no screen or display distortion as shown in FIG. there was.

Therefore, the deflection circuit according to the prior art has a problem that the screen of the TV can be distorted.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems of the prior art, and an object of the present invention is to provide a deflection circuit and a driving method thereof capable of protecting an internal switching element while minimizing screen distortion.

In order to achieve the above object, the present invention provides a main capacitor and a plurality of auxiliary correction capacitors for compensating for distortion of a screen displaying an image as power is applied, and a plurality of auxiliary correction capacitors connected to each of the plurality of auxiliary correction capacitors. Switches, a switch controller for controlling switching of the plurality of switches, a regulator configured to receive a constant voltage of a first level when the power is applied, and to convert and supply a constant voltage of a second level to the switch controller; And a delay circuit unit configured to delay the output of the regulator for a predetermined time so that the regulator outputs the constant voltage of the second level after the auxiliary correction capacitor is charged by the power supply.

Here, the delay circuit unit is preferably composed of a resistor and a capacitor.

In addition, the auxiliary correction capacitor is preferably charged by the current applied from the linearity coil.

In order to achieve the above object, the present invention provides a method of driving a deflection circuit including a main capacitor and a plurality of auxiliary correction capacitors to compensate for distortion of a screen displaying an image as power is applied. Charging the auxiliary correction capacitor by a current applied through a linearity coil, and supplying a constant voltage set to a switch controller that controls a plurality of switches for turning on the auxiliary correction capacitor while the auxiliary correction capacitor is being charged. Delaying the generation of the set constant voltage to a regulator for a predetermined time through a delay circuit, charging the auxiliary correction capacitors, and outputting the constant voltage to the switch controller when the set time has elapsed, the switch controller From above Through a number of said plurality of switches connected to the auxiliary capacitor compensation turns the plurality of auxiliary compensation capacitor to sequentially provide a deflection circuit comprising the steps of: on.

Accordingly, the present invention can provide an ultra-slim CRT display device while minimizing screen distortion.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The same components as in the prior art are given the same names and the same reference numerals for convenience of description, and detailed description thereof will be omitted.

5 is a view for explaining the current flow of the horizontal deflection portion and the internal correction circuit according to the present invention.

The horizontal deflection unit 2 according to the present invention includes a main correction capacitor CS 2a and a horizontal output field effect transistor TR, and the internal correction circuit unit 3 includes first to fourth auxiliary correction capacitors. Size Capacity (CS1 to CS4) 3a and first to fourth switches SW1 to SW4 3b.

Here, the inner correction circuit unit 3 divides the screen into four parts as described above, and sets the first to fourth switches SW1 to SW4 to the turn-on switch of the first to fourth auxiliary correction capacitors 3a. Turn On SW to independently control the first to fourth auxiliary correction capacitors CS1 to CS4 3a to correct linearity.

In this case, the first to fourth auxiliary correction capacitors CS1, CS2, and the second auxiliary correction capacitor CS1, CS2, which are caused when the power is turned on after the power supply to the slim TV, that is, only the first switch SW1 is turned on, are turned on. It is divided into CS3 and CS4 so as to prevent excessive current flow to the first auxiliary correction capacitor CS1 and the EW transistor EW TR by the first switch SW1. To this end, in the present invention, the 5v constant voltage output from the regulator 7 is delayed for a predetermined time through the delay circuit unit 9 and then applied to the first to fourth switches 3b through the switch control unit 8. Therefore, in this case, the auxiliary correction capacitors CS1, CS2, CS3, and CS4 of each of the first to fourth auxiliary correction capacitors 3a are sufficiently turned on to ensure sufficient impedance, so that the overcurrent causes the EW transistor EW TR. Can be prevented from flowing.

As the delay circuit unit 9, an RC delay circuit as shown in FIG. 6 may be used.

FIG. 6 is a diagram illustrating a delay circuit according to the present invention. An RC delay circuit unit 9 is provided for a regulator 7 for converting a 9V constant voltage, which is a first constant voltage, into a 5V constant voltage, which is a second constant voltage when the TV is initially powered on. Output by delaying for a set time (for example, 20 ms) through the first to fourth auxiliary correction capacitors (CS1 to CS4) (3a) by the current supplied from the linearity coil (6) The state is On.

After 5 ms, the 5V constant voltage is supplied from the regulator 7 so that the EW transistor EW TR is generated from the overcurrent generated at the initial power-on even when the first to fourth switches SW1 to SW4 and 3b are sequentially turned on by each timing pulse. Will be able to protect. To this end, the regulator 7 of the present invention outputs a 5v constant voltage when a high pulse enters the pin set from the delay circuit unit 9.

FIG. 7 is a view for explaining the regulator operation by the switching element protection circuit according to the present invention. When the voltage of pin 1 of the regulator 7 as shown in FIG. ), And it takes 20ms (sec) until input waveform more than 1V is reached on pin 4 due to delay of capacitor (C). That is, after a certain time, the 5V regulator 7 will give a constant voltage output.

That is, when power is applied to a deflection circuit including a main capacitor 2a and a plurality of auxiliary correction capacitors 3a to compensate for distortion of the screen, the auxiliary correction capacitors 3a are applied through the linearity coil 6. It is charged by the current which becomes.

At this time, the generation of the set constant voltage 5v is delayed in the regulator 7 for supplying the set constant voltage to the switch control unit 8 for controlling the plurality of switches 3b for turning on the auxiliary correction capacitors 3a. There is a delay for the time set by the circuit section 9.

Subsequently, the auxiliary correction capacitors 3a are charged, and when the set time has elapsed, the regulator 7 outputs a constant voltage to the switch control unit 8, and the switch control unit 8 includes the plurality of The plurality of auxiliary correction capacitors 3a are sequentially turned on through the plurality of switches 3b connected to the auxiliary correction capacitors 3a.

At this time, since the first to fourth auxiliary correction capacitors (CS1 to CS4) (3a) are all on (On) by the current supplied from the linearity coil 6 side (first) to the first to fourth switches (SW1 to Even if SW4) 3b is sequentially turned on, the EW transistor EW TR can be protected from overcurrent generated during initial power-on.

As described above, the present invention provides a sufficient on-time for all capacitors in controlling the main correction capacitor and the auxiliary correction capacitor allocated to each screen area by using a plurality of switches having different turn-on times. Flow can be prevented to prevent linearity distortion. Therefore, the CRT display device can be made ultra slim.

 Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention.

Therefore, the technical scope of the present invention should not be limited to the contents described in the embodiments, but should be defined by the claims.

Claims (4)

A main capacitor and a plurality of auxiliary correction capacitors for compensating for distortion of a screen displaying an image as power is applied; A plurality of switches connected to each of said plurality of auxiliary correction capacitors; A switch controller for controlling switching of the plurality of switches; A regulator configured to receive a constant voltage of a first level when the power is applied, convert the voltage into a constant voltage of a second level, and supply the voltage to the switch controller; And a delay circuit unit configured to delay the output of the regulator for a predetermined time so that the regulator outputs the constant voltage of the second level after the plurality of auxiliary correction capacitors are charged by the power supply. The method of claim 1, The delay circuit is a deflection circuit, characterized in that consisting of a resistor and a capacitor. The method of claim 1, And the auxiliary correction capacitor is charged by a current applied from the linearity coil. A method of driving a deflection circuit having a main capacitor and a plurality of auxiliary correction capacitors for compensating for distortion of a screen displaying an image as power is applied, When the power is applied, the auxiliary correction capacitor is charged by a current applied through the linearity coil; Delaying generation of the set constant voltage for a predetermined time through a delay circuit to a regulator for supplying a set voltage to a switch controller for controlling a plurality of switches for turning on the auxiliary correction capacitor while the auxiliary correction capacitor is being charged. ; Outputting the constant voltage from the regulator to the switch controller when the auxiliary correction capacitors are charged and the set time elapses; And sequentially turning on the plurality of auxiliary correction capacitors through the plurality of switches connected to the plurality of auxiliary correction capacitors in the switch control unit.

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