JPH11187281A - High voltage adjusting circuit of monitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To promptly stabilize high voltage by varying the switching cycle of a pulse signal according to screen luminance voltage to be outputted from secondary side winding wire of a high voltage transformer and auxiliary voltage of an auxiliary winding wire. SOLUTION: A high voltage HV is stabilized by varying the switching cycle of a pulse signal by meons of a screen luminance signal to be outputted form the secondary side winding wire 220 of a high voltage transformer 200 and the auxiliary voltage of a auxiliary winding wire 230 by a high voltage regulator 300. In this high voltage regulator 300, DC voltage Vcc1 which is supplied from the outside is distributed according to an amount of outputted current of the secondary side winding wire 200 of the high voltage transformer 200 and outputted as the screen luminance voltage by a screen luminance signal processing part 310. The outputted voltage of the auxiliary winding wire 230 of the high voltage transformer 200 is rectified, the rectified voltage is amplified and the auxiliary voltage is outputted by an auxiliary voltage processing part 320. The screen luminance voltage and the auxiliary voltage are distributed, and the distributed voltage is fed back to a pulse width modulation part 120 by a feedback voltage output part 330.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a monitor, and more particularly, to a screen brightness signal (brightness) output from a high voltage transformer.
The present invention relates to a high voltage regulation circuit of a monitor for stabilizing a high voltage by a ness signal.

[0002]

2. Description of the Related Art Generally, the degree of acceleration of electrons emitted from the cathode of a cathode ray tube (hereinafter referred to as CRT) is determined in accordance with the magnitude of the voltage supplied to a grid terminal. Are deflected by the magnetic field generated by the vertical and horizontal deflection coils and collide with the phosphor screen to form a screen.

Such a CRT has a heater voltage of about 6.3 V, a focus grid voltage and a screen grid voltage supplied to a grid terminal for focusing emitted electrons, and a technique for accelerating the emitted electrons. A high voltage of about 25 KV is supplied to the anode terminal.

The luminance of the screen changes according to the magnitude of the high voltage supplied to the anode terminal of such a CRT. That is, if the amount of current flowing to the anode terminal of the CRT is small, the voltage is also reduced, but the screen size is thereby reduced. On the other hand, if the amount of current flowing to the anode terminal of the CRT increases, the voltage also increases, and the screen size increases.

FIG. 1 is a diagram showing a configuration of a high voltage generating circuit of a general monitor. As shown in FIG. 1, a high voltage generation circuit of a general monitor includes a voltage conversion unit 1 for converting an AC voltage AC supplied from the outside into a DC voltage, and a pulse width modulation of the DC voltage of the voltage conversion unit 1 by pulse width modulation. A pulse width modulation section 2 for converting the signal into a signal; a horizontal deflection voltage generation section 3 for outputting a horizontal deflection voltage B + externally supplied by being switched by the pulse signal of the pulse width modulation section 2;
And a high voltage transformer 4 for generating a high voltage HV and an auxiliary voltage according to the horizontal deflection voltage B +, and a high voltage regulator 5 for stabilizing the high voltage by adjusting the switching period of the pulse signal by the auxiliary voltage. I have.

Here, the high-voltage transformer 4 is supplied with the horizontal drive signal HD and the horizontal deflection voltage B +, and flows through the primary winding 41, and induces a high voltage according to the amount of current flowing through the primary winding. A secondary winding 42 and an auxiliary winding 43 for sensing the excitation voltage of the secondary winding and changing the amount of current flowing through the primary winding 41 to stabilize the excitation voltage of the secondary winding are provided.

Further, the configuration of the high-pressure regulator 5 will be described in more detail as follows.

A diode 5 for half-wave rectifying the auxiliary voltage is provided at the output of the resistor 51 for passing the auxiliary voltage of the auxiliary winding 43.
2 is connected to the anode side, and one side of a capacitor 53 for smoothing the output signal of the diode 52 is connected to the cathode side of the diode 52. The other side of the capacitor 53 is grounded.

The cathode of the diode 52 is connected to one side of a resistor 54 for passing the smoothed voltage of the capacitor 53, and the other side of the resistor 54 is connected to a resistor 55 for distributing the output voltage of the capacitor 53. One side is connected,
The other side of the resistor 55 is connected to one side of a variable resistor 56 that changes according to the frequency of the horizontal synchronization signal. Here, the other side of the variable resistor 56 is grounded.

The operation of the high-voltage adjusting circuit of the general monitor configured as described above will be described with reference to the accompanying drawings.

The AC voltage AC supplied from the outside is supplied to the voltage converter 1, and the voltage converter 1 converts the AC voltage AC supplied from the outside into a DC voltage. The DC voltage is supplied to the pulse width modulation unit 2, and the pulse width modulation unit 2 converts the DC voltage into a pulse signal by performing pulse width modulation. The pulse signal is supplied to the horizontal deflection voltage generator 3, and the horizontal deflection voltage generator 3 is switched by the pulse signal and outputs a horizontal deflection voltage B + supplied from outside.

The horizontal deflection voltage B + and the horizontal drive signal HD are supplied to the primary winding 41 of the high-voltage transformer 4. That is, a current flows through the primary winding 41 by the horizontal drive signal HD and the horizontal deflection voltage B +, whereby the secondary winding 42 and the auxiliary winding 43 are excited, and the excitation voltage of the secondary winding 42 is C
It is supplied to the anode terminal of RT.

On the other hand, the auxiliary voltage of the auxiliary winding 43 is supplied to the diode 52 through the resistor 51 of the high voltage regulator 5, and the diode 52 rectifies the output voltage of the resistor 51.
The output voltage of the diode 52 is supplied to the capacitor 53, and the capacitor 53 smoothes the output voltage of the diode 52.

The output voltage of the resistor 53 is expressed by resistors 54, 55,
And the variable resistor 56 distributes the output voltage of the resistor 53. Further, the distribution voltage is supplied to the pulse width modulation unit 2.

That is, if the screen becomes bright and the amount of current flowing through the secondary winding increases, the high voltage of the secondary winding 42 of the high-voltage transformer 4 and the excitation voltage of the auxiliary winding 43 decrease. As described above, when the auxiliary voltage of the auxiliary winding decreases, the magnitude of the auxiliary voltage supplied to the pulse width modulation unit 2 decreases, thereby increasing the switching period of the pulse signal.

The pulse signal having a longer switching cycle is supplied to a horizontal deflection voltage generator 3 where a horizontal deflection voltage B +
And the high pressure HV rises as a result. When the frequency of the horizontal synchronizing signal is about 31 KHz and the screen brightness is white, the high voltage HV supplied to the anode terminal is about 2 kHz.
5KV, high pressure about 26.02K for black
V. That is, the high voltage difference is about 1000V.

However, the frequency of the horizontal synchronizing signal is about 68K.
High-frequency HV is about 26KV when the screen is white at Hz or higher.
When the screen is black, the high voltage HV is about 25.3K
V. Therefore, the high pressure difference is about 680 KV.

In such a high voltage adjustment circuit of a general monitor, the number of secondary windings of the high voltage transformer is larger than the number of auxiliary windings. Therefore, when the high voltage changes from 1000 V to 680 V, the response speed of the auxiliary voltage becomes slow. However, this often causes a problem that the screen size changes in accordance with the screen luminance and the image quality deteriorates.

[0019]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems.
A high-voltage adjustment circuit for a monitor that can quickly stabilize the high voltage by changing the switching period of the pulse signal according to the screen luminance voltage output from the secondary winding of the high-voltage transformer and the auxiliary voltage of the auxiliary winding. To provide.

[0020]

In order to achieve the above object, a high-voltage adjusting circuit for a monitor according to an embodiment of the present invention comprises:
A voltage conversion unit for converting an AC voltage supplied from the outside into a DC voltage, a pulse width modulation unit for generating a pulse signal by pulse width modulation of the DC voltage, and a horizontal deflection voltage switched by the pulse signal and supplied from the outside A horizontal deflection voltage generating unit for passing a horizontal deflection voltage to a primary winding in accordance with a horizontal drive signal to generate a screen brightness voltage from a secondary winding and an auxiliary winding A high-voltage transformer for generating an auxiliary voltage from the high-voltage transformer; and a high-voltage regulator for stabilizing the high voltage by changing the switching period of the pulse signal according to the screen luminance voltage and the auxiliary voltage of the high-voltage transformer.

According to a preferred embodiment of the present invention, an externally supplied AC voltage is supplied to a voltage converter and converted into a DC voltage, and the DC voltage is supplied to a pulse width modulator. The pulse width modulator outputs a pulse signal by pulse width modulating the DC voltage, the pulse signal is supplied to a horizontal deflection voltage generator, and the horizontal deflection voltage generator is switched in response to the pulse signal and is supplied from an external source. Outputs deflection voltage. The horizontal deflection voltage is supplied to the primary winding of the high-voltage transformer by a horizontal drive signal, thereby exciting the secondary winding and the auxiliary winding. The secondary winding outputs a screen luminance signal, and the auxiliary winding outputs an auxiliary voltage. The screen luminance signal and the auxiliary voltage are supplied to the high-voltage regulator, and the high-voltage regulator changes the switching period of the pulse signal according to the screen luminance signal and the auxiliary voltage. Therefore, the high voltage fluctuates quickly according to the screen luminance signal, and the high voltage can be quickly stabilized.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

FIG. 2 is a diagram showing a configuration of a high voltage generating circuit of a monitor according to an embodiment of the present invention. In FIG. 1, reference numeral 100 denotes an AC voltage AC supplied from the outside, which is converted into a DC voltage DC, the converted DC voltage DC is modulated into a pulse signal, and is switched by the modulated pulse signal to be supplied from the outside. And a voltage supply circuit for outputting the horizontal deflection voltage B +.

Reference numeral 200 denotes a horizontal drive signal HD.
Primary winding 21 that supplies horizontal deflection voltage B +
0, a current is supplied to the secondary winding 220 and the primary winding 210 which are excited when the horizontal deflection voltage B + is supplied to the primary winding 210 and generate the high voltage HV and the screen luminance signal ABL. A high-voltage transformer including an auxiliary winding 230 that is excited when a voltage is generated to generate an auxiliary voltage.
This is a high voltage regulator for stabilizing the high voltage HV by changing the switching cycle of the pulse signal.

Here, the voltage supply circuit 100 includes a voltage conversion unit 110 for converting an externally supplied AC voltage AC to a DC voltage DC, and a pulse width modulation for pulse width modulation of the DC voltage DC to generate a pulse signal. And a horizontal deflection voltage generator 130 that switches by a pulse signal to pass an externally supplied horizontal deflection voltage B +.

The high-voltage regulator 300 distributes a DC voltage Vcc1 supplied from the outside according to the output current of the secondary winding 220 of the high-voltage transformer 200, and outputs a screen luminance signal as a screen luminance signal. An auxiliary voltage processing unit 3 for rectifying the output voltage of the auxiliary winding 230 of the high-voltage transformer 200, amplifying the rectified voltage and outputting the auxiliary voltage
20 and a feedback voltage output unit 330 for distributing the screen luminance voltage and the auxiliary voltage and feeding back the distributed voltage to the pulse width modulation unit 120.

Here, the configuration of the high-pressure regulator 300 will be described more specifically. On the output side of the secondary winding 220 of the high-voltage transformer 200, one side of the resistor 311 of the screen luminance signal processing unit 310 for shaping the screen luminance signal ABL, which is the amount of current flowing through the secondary winding 220, and the capacitor 312 One side is connected, and the other side of the resistor 311 and the capacitor 312 are grounded.

The DC voltage Vcc1 supplied from the outside is distributed to the resistors 311 and 313, and one side of the resistor 311 is connected to one side of the resistor 313 for outputting a screen luminance voltage.

On the other hand, the auxiliary winding 23 of the high-voltage transformer 200
0 is connected to one side of a resistor 321 for passing the output signal of the auxiliary winding 230, and the other side of the resistor 321 is connected to the anode side of a diode 322 for half-wave rectifying the output signal of the resistor 321. Connected.

One side of a resistor 323 for smoothing the output signal of the diode 322 and one side of a capacitor 324 are connected to the cathode side of the diode 322.
The other side is connected to the base side of the transistor 325 that is switched by the output signal of the resistor 323. The input side of the externally supplied DC voltage Vcc2 is connected to the collector side of the transistor 325.
A resistor 326 is connected between the emitter side of P.5 and ground. The output current amount of the transistor 325 is determined by the resistor 326, and a voltage is generated at both ends of the resistor 326.
Here, this is called an auxiliary voltage.

The resistance 3 of the screen luminance signal processing unit 310
13, the other side of the resistor 326 of the auxiliary voltage processing unit 320 has a common point, and the common point is connected to one side of the resistor 331 of the feedback voltage output unit 330 that distributes the auxiliary voltage and the screen luminance voltage. The other side of the resistor 331 is connected to one side of a variable resistor 332 that changes according to the frequency of the horizontal synchronization signal. The other side of the variable resistor 332 is grounded.

The operation and effect of the high voltage regulator of the monitor according to the embodiment of the present invention will be described with reference to the accompanying drawings.

First, the AC voltage AC supplied from the outside is supplied to the voltage converter 110, and the voltage converter 110 converts the AC voltage AC supplied from the outside into a DC voltage. The DC voltage is supplied to the pulse width modulation unit 120, and the pulse width modulation unit 120 converts the DC voltage into a pulse signal by performing pulse width modulation. The pulse signal is supplied to the horizontal deflection voltage generator 130. The horizontal deflection voltage generator 130 is switched by the pulse signal, and a horizontal deflection voltage B supplied from the outside.
Outputs +.

The horizontal deflection voltage B + and the horizontal drive signal HD are supplied to the primary winding 210 of the high-voltage transformer 200. The high-voltage transformer 200 is switched by the horizontal drive signal HD, and the primary winding 210 is supplied with the horizontal deflection voltage B +. Supplied. Thereby, the secondary winding 220 and the auxiliary winding 230
Is excited. The high voltage HV of the secondary winding 220 is supplied through the anode terminal of the CRT.

The screen luminance signal ABL changes in accordance with the amount of current flowing through the secondary winding 220. The screen brightness signal ABL is supplied to the resistor 311 and the capacitor 312 of the screen brightness signal processing unit 310. The resistor 311 and the capacitor 312 smooth the screen brightness signal ABL, and the DC voltage Vcc1 and the smoothed voltage supplied from outside are equal to the resistance 311. This is supplied to the resistor 313. The resistance 311 and the resistance 313 are the DC voltage Vc.
The screen luminance voltage is output by distributing c1 and the smoothing voltage.

On the other hand, the auxiliary voltage of the auxiliary winding 230 passes through the resistor 321 of the auxiliary voltage processing unit 320 and the diode 322
, And the diode 322 rectifies the output voltage of the resistor 321. The output voltage of the diode 322 is supplied to the capacitor 324, and the capacitor 324 is connected to the diode 32.
2 is smoothed, and the smoothed voltage is
5 is supplied. The output voltage of the transistor 325 changes depending on the resistance value of the resistor 326 and the smoothed voltage.

The auxiliary voltage and the screen luminance voltage are superimposed, and the superimposed voltage is supplied to the resistor 331 and the variable resistor 332 of the feedback voltage output unit 330. The resistor 331 and the variable resistor 332 distribute the superimposed voltage and output the feedback voltage. I do. The feedback voltage is supplied to the pulse width modulator 120.

At this time, the auxiliary voltage and the screen luminance signal ABL
Adjusts the magnitude of the feedback voltage.

That is, the screen becomes brighter and the screen luminance signal becomes larger. As a result, the excitation voltage of the secondary winding 220 of the high-voltage transformer 200, the auxiliary voltage of the auxiliary winding 230, and the screen luminance voltage become lower.

As described above, when the auxiliary voltage of the auxiliary winding and the feedback voltage decrease, the feedback voltage supplied to the pulse width modulation unit 120 also decreases. Therefore, the switching cycle of the pulse signal becomes longer.

The pulse signal having the longer switching cycle is supplied to the horizontal deflection voltage generator 130, the horizontal deflection voltage B + increases, and the high voltage HV increases. Since the processing speed of the screen luminance voltage of the screen luminance signal processing unit is faster than the processing speed of the auxiliary voltage processing unit, the rising speed of the high voltage is faster.

That is, the frequency of the horizontal synchronizing signal is about 31 KH
When z, the magnitude of the high voltage is about 25.38 KV if the magnitude of the screen luminance signal is the maximum value, and the magnitude of the high voltage is about 26.01 if the magnitude of the screen luminance signal is the minimum value.
KV. That is, the high voltage difference is about 630V.

The frequency of the horizontal synchronizing signal is about 68 KH.
When z, the magnitude of the high voltage is about 25.58 KV if the magnitude of the screen luminance signal is the maximum value, and the magnitude of the high voltage is about 26.01 if the magnitude of the screen luminance signal is the minimum value.
KV. That is, the high voltage difference is about 430V.

FIG. 3 is a diagram showing a configuration of a high-voltage adjusting circuit of a monitor according to another embodiment of the present invention. In the figure, reference numeral 100 converts an externally supplied AC voltage AC to a DC voltage DC, modulates the converted DC voltage DC into a pulse signal, and switches by the modulated pulse signal to be externally supplied. And a voltage supply circuit for outputting the horizontal deflection voltage B +.

Reference numeral 200 denotes a horizontal drive signal HD.
, A primary winding 210 for supplying a horizontal deflection voltage B +,
Excited when a current is generated by the horizontal deflection voltage B + supplied to the primary winding 210, the high voltage HV and the screen luminance signal AB
Secondary winding 220 for generating L, and primary winding 21
0 is a high-voltage transformer including an auxiliary winding 230 which is excited when a current is supplied to generate an auxiliary voltage.
Reference numeral 00 denotes a high-voltage regulator for stabilizing a high voltage by changing a switching period of a pulse signal according to a screen luminance signal ABL of the high-voltage transformer 200 and an auxiliary voltage.

Here, the voltage supply circuit 100 includes a voltage conversion section 110 and a pulse width modulation section 120 as shown in FIG.
And a horizontal deflection voltage generator 130. As shown in FIG. 2, the high-voltage transformer 200 includes a primary winding 210, a secondary winding 220, and an auxiliary winding 230.

As shown in FIG. 3, the high voltage regulator 400 includes a DC voltage Vcc1 supplied from outside according to the output current of the secondary winding 220 of the high voltage transformer 200.
A screen luminance signal processing unit 410 for distributing the image luminance as a screen luminance voltage, a screen luminance voltage control unit 420 for controlling the magnitude of the screen luminance voltage according to the mode signal CS supplied from the outside, Auxiliary voltage processing unit 4 for rectifying the output voltage of auxiliary winding 230 and outputting an auxiliary voltage
30 and a feedback voltage output unit 440 that distributes the auxiliary voltage and the screen luminance voltage to generate a feedback voltage and supplies the feedback voltage to the pulse width modulation unit 120.

Here, the configuration of the high-pressure regulator 400 will be described more specifically.

The output side of the secondary winding 220 of the high-voltage transformer 200 has one side of a resistor 411 and a capacitor 412 of a screen luminance signal processing section 410 for smoothing the screen luminance signal ABL.
Are connected, and the other side of the resistor 411 and the capacitor 412 are grounded.

The input side of the externally supplied DC voltage Vcc1 is connected to one side of a resistor 413 for distributing the externally supplied DC voltage Vcc1, and the other side of the resistor 413 is connected to one side of the resistor 411. Connected.

A transistor 41 switched by a smoothed voltage is provided on one side of the resistor 411 and one side of the capacitor 412.
4 is connected to the base side of the transistor 414, the collector side of the transistor 414 is connected to the input side of the DC voltage Vcc2 supplied from outside, and the emitter side of the transistor 414 determines the output current of the transistor 414 and outputs the screen luminance voltage. One side of the resistor 415 is connected.

Further, one side of the resistor 421 of the screen luminance voltage control unit 420 for distributing the mode signal CS is connected to the input side of the mode signal CS which changes according to the frequency of the horizontal synchronizing signal. The side is connected to one side of the resistor 422, and the other side of the resistor 422 is grounded.

The other side of the resistor 421 is connected to the resistors 421 and 422.
423 that switches by the divided voltage of
Are connected to each other, and the emitter side of the transistor 423 is grounded.

On the other hand, the externally supplied DC voltage Vcc
2 is connected to one side of a capacitor 424 that charges the DC voltage Vcc2, and the other side of the capacitor 424 is connected to the base side of a transistor 425 that switches according to the switching state of the transistor 423.

The collector of the transistor 425 has a resistor 4
15, the output side of the transistor 425 is connected to the emitter side of the transistor 425 to determine the amount of output current of the transistor 425.
15 is connected to one side of a resistor 426 for controlling the amount of current flowing through the resistor 15 to control the magnitude of the screen luminance voltage. Resistance 4
The other side of 26 is connected to the other side of the resistor 415.

The auxiliary winding 23 of the high-voltage transformer 200
One side of the resistor 431 of the auxiliary voltage processing unit 430 for passing the output signal of the auxiliary winding 230 is connected to the output side of the resistor 431, and the other side of the resistor 431 is used for half-wave rectification of the output signal of the resistor 431. Of the diode 432 is connected. One side of a resistor 433 and one side of a capacitor 434 for smoothing an output signal of the diode 432 are connected to the cathode side of the diode 432.

Further, in order to distribute the screen luminance voltage of the screen luminance signal processing section 410 and the auxiliary voltage of the auxiliary voltage processing section 430, the other side of the resistor 415 and the other side of the resistor 433 have a common point. Is connected to one side of a resistor 441 for distributing a superimposed voltage of the screen luminance voltage and the auxiliary voltage.
On the other side of 41, a variable resistor 44 adjusted according to the frequency of the horizontal synchronizing signal and for changing the magnitude of the feedback voltage.
2 are connected.

The operation of the high voltage adjusting circuit for a monitor according to another embodiment of the present invention will be described in detail with reference to the accompanying drawings.

First, an externally supplied AC voltage AC is supplied to the voltage converter 110, and the voltage converter 110 converts the externally supplied AC voltage AC into a DC voltage. The DC voltage is supplied to the pulse width modulation unit 120, and the pulse width modulation unit 120 converts the DC voltage into a pulse signal by performing pulse width modulation. The pulse signal is supplied to the horizontal deflection voltage generator 130. The horizontal deflection voltage generator 130 is switched by the pulse signal and is supplied with an externally supplied horizontal deflection voltage B +.
Is output.

The horizontal deflection voltage B + and the horizontal drive signal HD are
It is supplied to the primary winding 210 of the high-voltage transformer 200.
That is, switching is performed by the horizontal drive signal HD, and 1
The horizontal winding voltage B + is supplied to the secondary winding 210, the secondary winding 220 and the auxiliary winding 230 are excited, and the high voltage HV of the secondary winding 220 is supplied to the anode terminal of the CRT.

The screen brightness signal ABL changes according to the amount of current flowing through the secondary winding 220. The screen brightness signal ABL is supplied to the resistor 411 and the capacitor 412 of the screen brightness signal processing unit 410, and the resistor 411 and the capacitor 412 smooth the screen brightness signal ABL.

The DC voltage Vcc 1 supplied from the outside is supplied to one side of the resistor 413, and the DC voltage Vcc 1 passing through the resistor 413 is superimposed on the smoothed voltage of the capacitor 412. The superimposed voltage is supplied to the transistor 414, and the output voltage of the transistor 414 changes depending on the magnitude of the superimposed voltage.

On the other hand, when the frequency of the horizontal synchronizing signal is low (about 31 KHz), the mode signal CS in the low potential state is input, and the mode signal CS in the low potential state is connected to the resistor 4.
21 and 422, the resistors 421 and 422 distribute the low potential mode signal CS.

The output voltages of the resistors 421 and 422 are supplied to the transistor 423, and the transistor 423 is turned on by the low potential mode signal CS. As a result, the externally supplied DC voltage Vcc2 is supplied to the capacitor 424, and the capacitor 424 charges the externally supplied DC voltage Vcc2.

The charging voltage of the capacitor 424 is supplied to the transistor 425, and the transistor 425 is turned on.

Accordingly, the output current of the transistor 414 and the output current of the transistor 425 are supplied to the resistor 441 and the variable resistor 442 through the resistor 415.

Here, the output current amount of the transistor 414 is determined by the resistance value of the resistor 415,
The output current amount of the resistor 25 is determined by the resistance value of the resistor 426.

On the other hand, the auxiliary voltage of the auxiliary winding 230 is supplied to the diode 432 through the resistor 431 of the auxiliary voltage processing unit 430.
The diode 432 rectifies the output voltage of the resistor 431. The output voltage of the diode 432 is supplied to the capacitor 434.
2 is smoothed, and the smoothed voltage is supplied to a resistor 433, which outputs an auxiliary voltage. Such an auxiliary voltage and the screen luminance voltage are superimposed, and the superimposed voltage is the resistance 44
1 and the variable resistor 442, the resistor 441 and the variable resistor 442 distribute the superimposed voltage to output a feedback voltage, and the feedback voltage is supplied to the pulse width modulator 120.

That is, the screen becomes brighter and the magnitude of the screen luminance signal increases.
Since the high voltage of the secondary winding 220 decreases, the auxiliary winding 230
, The auxiliary voltage and the screen luminance voltage decrease. When the auxiliary voltage of the auxiliary winding and the screen luminance voltage decrease, the feedback voltage supplied to the pulse width modulation unit 120 decreases. Therefore,
The switching cycle of the pulse signal becomes longer.

The pulse signal having the longer switching cycle is supplied to the horizontal deflection voltage generator 130 to increase the horizontal deflection voltage B +, thereby increasing the high voltage HV.

When the frequency of the horizontal synchronizing signal is about 31 KHz, if the magnitude of the screen luminance signal is the maximum value, the magnitude of the high voltage is about 25.56 KV, and if the magnitude of the screen luminance signal is the minimum value. The magnitude of the high pressure is about 26.01 KV. Therefore, the high voltage difference is about 450V.

That is, when the magnitude of the screen luminance signal varies from the minimum to the maximum, the changing speed of the high voltage is rapidly performed by the screen luminance voltage. The difference becomes smaller.

On the other hand, when the frequency of the horizontal synchronizing signal is high (about 68 KHz), the mode signal CS in the high potential state is input, and the mode signal CS in the high potential state is
21 and 422, the resistors 421 and 422 distribute the high potential mode signal CS.

The output voltages of the resistors 421 and 422 are supplied to the transistor 423, and the transistor 423 is turned on by the high potential mode signal CS. Accordingly, the externally supplied DC voltage Vcc2 charged in the capacitor 424 is applied to the transistor 4
25, which switches transistor 425 into a turned-off state.

Therefore, the screen luminance voltage is determined by the resistance value of the resistor 415.

On the other hand, the auxiliary voltage of the auxiliary winding 230 is
The output voltage of the resistor 431 is rectified by the diode 432. The output voltage of the diode 432 is supplied to the capacitor 434. The capacitor 434 smoothes the output voltage of the diode 432. The smoothed voltage is supplied to the resistor 433, and the resistor 433 outputs an auxiliary voltage. The auxiliary voltage and the screen luminance voltage are superimposed, and the superimposed voltage is supplied to the resistor 441 and the variable resistor 442. The resistor 441 and the variable resistor 442 generate a feedback voltage, and supply the feedback voltage to the pulse width modulator 120.

That is, since the screen becomes bright and the magnitude of the screen luminance signal increases, the excitation voltage of the secondary winding 220 of the high-voltage transformer 200 decreases, and the auxiliary voltage of the auxiliary winding 230 and the screen luminance voltage are reduced. Becomes lower. When the auxiliary voltage of the auxiliary winding and the screen luminance voltage decrease, the magnitude of the feedback voltage supplied to the pulse width modulation unit 120 decreases, and the switching period of the pulse signal increases.

The pulse signal having the longer switching cycle is supplied to the horizontal deflection voltage generator 130, and the horizontal deflection voltage B + increases, thereby increasing the high voltage HV.

When the frequency of the horizontal synchronizing signal is about 68 KHz, the magnitude of the high voltage is about 25.58 KV if the magnitude of the screen luminance signal is the maximum value, and if the magnitude of the screen luminance signal is the minimum value. The magnitude of the high pressure is about 26.01 KV. The high voltage difference is about 430V.

[0080]

As described above, according to the high voltage adjusting circuit of the monitor of the embodiment of the present invention, the high voltage fluctuates due to the screen luminance voltage and the auxiliary voltage output from the secondary winding of the high voltage transformer. When the magnitude of the screen luminance voltage changes from the minimum value to the maximum value, the high voltage is quickly increased by the screen luminance voltage, and the high voltage can be quickly stabilized. As a result, the screen size is kept constant, and the image quality is improved.

Although the present invention has been described based on specific embodiments, the present invention is not limited to these embodiments.
Obviously, modifications and improvements can be made without departing from the ordinary knowledge of those skilled in the art.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a high voltage generating circuit of a general monitor.

FIG. 2 is a diagram showing a configuration of a high-voltage generation circuit of the monitor according to the embodiment of the present invention.

FIG. 3 is a diagram showing a configuration of a high-voltage generation circuit of a monitor according to another embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 voltage supply circuit 110 voltage converter 120 pulse width modulator 130 horizontal deflection voltage generator 200 high-voltage transformer 210 primary winding 220 secondary winding 230 auxiliary winding 300, 400 high-voltage regulator 310, 410 screen brightness signal processing Unit 320, 430 Auxiliary voltage processing unit 330, 440 Feedback voltage output unit 420 Screen luminance voltage control unit

Claims (8)

[Claims] A voltage converter for converting an AC voltage supplied from the outside into a DC voltage; a pulse width modulator for generating a pulse signal by pulse width modulating the DC voltage; Voltage supply means including a horizontal deflection voltage generator for passing the supplied horizontal deflection voltage; a primary winding for supplying the horizontal deflection voltage in accordance with a horizontal drive signal generated by the frequency of the horizontal synchronization signal; A high-voltage transformer including a secondary winding that is excited when a current flows through the secondary winding and generates a high voltage and a screen luminance signal, and an auxiliary winding that is excited when a current is supplied to the primary winding and generates an auxiliary voltage. And a high voltage regulator for stabilizing the high voltage by changing a switching period of the pulse signal according to a screen luminance signal and an auxiliary voltage of the high voltage transformer. High-voltage adjustment circuit for monitor. 2. A high-voltage regulator, comprising: a screen luminance signal processing unit that distributes a first DC voltage supplied from outside according to an output current amount of a secondary winding of the high-voltage transformer and outputs the first DC voltage as a screen luminance voltage; An auxiliary voltage processing unit that rectifies the output voltage of the auxiliary winding of the high-voltage transformer, amplifies the rectified voltage and outputs the amplified voltage as an auxiliary voltage; and superimposes the screen luminance voltage and the auxiliary voltage and distributes the superimposed voltage. 2. The high-voltage adjusting circuit for a monitor according to claim 1, further comprising: a feedback voltage output unit that outputs a feedback voltage. 3. The high-voltage regulator distributes a first DC voltage supplied from outside according to an output current of a secondary winding of the high-voltage transformer, and outputs the distributed voltage as a screen luminance voltage. A screen luminance signal processing unit; a screen luminance voltage control unit that controls the magnitude of the screen luminance voltage according to a mode signal determined by the frequency of the horizontal synchronization signal; and rectifies an output voltage of an auxiliary winding of the high-voltage transformer. An auxiliary voltage processing unit that outputs the rectified voltage as an auxiliary voltage; and a feedback voltage output unit that superimposes the screen luminance voltage and the auxiliary voltage, distributes the superimposed voltage, and outputs the superimposed voltage as a feedback voltage. The high-voltage adjusting circuit for a monitor according to claim 1. 4. The screen luminance signal processing unit is connected in parallel to an output side of the secondary winding, and shapes a screen luminance signal generated according to an amount of current flowing through the secondary winding. 1
A resistor and a first capacitor; and a first DC voltage supplied from the outside and an output voltage of the first resistor are input, the first DC voltage supplied from the outside is distributed, and the distributed voltage is used as the screen brightness. A second resistor for outputting as a voltage;
The high-voltage adjusting circuit for a monitor according to claim 2, comprising: 5. An auxiliary voltage processing unit, comprising: a third resistor for passing an amount of current flowing through an auxiliary winding of the high-voltage transformer as an output signal of the auxiliary winding; an output signal of the third resistor being input; A first diode for half-wave rectifying the output signal of the third resistor; a second capacitor for receiving the rectified signal of the first diode and smoothing the rectified signal of the first diode; A fifth resistor for passing an output voltage of the two capacitors; an output voltage of the fifth resistor being input and being switched by the output voltage of the fifth resistor, for passing a second DC voltage supplied from the outside; A first transistor; and determining an output current amount of the first transistor; generating the auxiliary voltage according to the determined output current amount; Pressure adjusting circuit monitor according to claim 2, characterized in that it consists; sixth resistor supplies the modulation unit. 6. The screen brightness signal processing section is connected in parallel to the output side of the secondary winding, and smoothes a screen brightness signal which is an output current amount of the secondary winding. A resistor and a second capacitor; an eighth resistor for receiving the smoothed voltage of the seventh resistor and the first DC voltage, superimposing the first DC voltage and the smoothed voltage and outputting as the screen luminance voltage; An NPN-type second transistor that is switched by an output voltage of an eighth resistor; and an output current amount of the second transistor is determined based on a switching state of the second transistor, and the screen brightness voltage is determined based on the determined output current amount. 4. The high-voltage adjusting circuit for a monitor according to claim 3, comprising a ninth resistor for adjusting the size. 7. The screen brightness voltage control section is connected in series to an input side of a mode signal that changes according to the frequency of a horizontal synchronization signal supplied from the outside, receives the mode signal, and receives the input mode signal. And an eleventh resistor for distributing the voltage and outputting as a distribution voltage; a third transistor switched by the distribution voltage of the tenth and eleventh resistors; a third transistor for charging a second DC voltage supplied from the outside. A capacitor; a charging voltage of the third capacitor is supplied according to a switching state of the third transistor; a fourth transistor switched by the supplied charging voltage; and an output voltage of the fourth transistor is input, and the output voltage is input. To determine the amount of output current of the fourth transistor, and determine the screen luminance signal based on the determined amount of output current. Pressure adjusting circuit monitor as defined in claim 3, characterized in that it consists; 12th resistor to control the size of the screen brightness voltage processor. 8. The auxiliary voltage processing unit includes: a thirteenth resistor for passing an output signal of an auxiliary winding of the high-voltage transformer; a second diode for half-wave rectifying an output signal of the thirteenth resistor; A fourth capacitor for smoothing the output voltage of the second diode;
4. The high voltage adjusting circuit for a monitor according to claim 3, comprising: a fourteenth resistor for passing an output voltage of the capacitor.