KR19990016407A - Unnecessary radiation wave removing device of video display device - Google Patents

Abstract

The present invention relates to an apparatus for removing unnecessary radiation in an image display apparatus, which is capable of removing a unnecessary radiation field noise generated in a front face portion by applying a parabolic waveform and adjusting the gain and phase will be.

Conventionally, in order to remove unwanted radiated electric field noise by applying an unnecessary radiation wave generated in a front portion of a video display device to an open loop wire by using a flyback pulse, There is a problem that the viewer can not be provided with the means and harm the human body of the viewer.

The present invention relates to a vertical parallax wave generating apparatus, comprising: a waveform generating unit for generating a vertical and horizontal parabolic waveform; a signal combining unit for outputting the generated waveform as a combined waveform; an amplifying unit for amplifying a waveform coupled at the signal combining unit; A phase adjusting unit for adjusting the phase of a signal applied from the gain adjusting unit to apply a negative voltage to the open loop wire of the front face of the cathode ray tube, A negative voltage is applied to the unwanted radiation field noise generated from the front face of the screen from the open loop wire on the front face of the cathode ray tube to remove unnecessary radiation field noise, In addition, the pattern change of the unnecessary radiated electric field noise generated on the front surface of the cathode ray tube, Applied to the sense and the unit pulse level by adjusting the gain and phase adjustment to the detected value by the open-loop wire is to be removed by the unnecessary radiation noise electric field.

Description

Unnecessary radiation wave removing device of video display device

The present invention relates to an apparatus for removing unwanted radiation in an image display apparatus (monitor, TV, LCD, etc.), particularly a video display apparatus that removes unnecessary radiation noise generated on the entire screen and satisfies the radio wave standard (TCO95) will be.

As shown in FIG. 1, in the conventional apparatus for removing unnecessary radiation wave of a video display device,

A horizontal pulse generating unit 1 for applying a horizontal drive driving signal to switch the horizontal pulse to the high voltage generating unit 2 and a high voltage generating unit 2 for boosting the horizontal pulse generated by the horizontal pulse generating unit 1 to the secondary side, A high voltage generating portion (FBT) 2 for supplying an anode gap of the cathode ray tube 3 to the anode gap of the cathode ray tube 3; resistors R1 and R2 for dividing the deflection output waveform of reverse polarity induced in the high voltage generating portion 2 to level- A resistor R3 and a capacitor C2 for waveform-correcting the deflection output waveform of the opposite polarity so as to be level-regulated by the resistors R1 and R2 and the waveform correction by the resistor R3 and the capacitor C2, A resistor R4 and a capacitor C3 for eliminating the spike noise of the reverse polarity deflection output waveform and the capacitor R1 are wound around the CPT by one turn (1 turn) in a state of not being a closed circuit, Of the deflected output waveform of the opposite polarity from which the spike noise is removed by the constant voltage (C2) Was applied only to the CPT consists of a wire (L1) to remove the unnecessary radiation wave on the CPT.

The high voltage generating unit 2 includes the coils L2 to L9, the diodes D2 to D6, the resistors R5 to R6, and the resistors R5 to R6. , And a condenser (C _HV ) to generate a high pressure.

The operation of the unnecessary radiation canceling circuit in the conventional CPT configured as described above will now be described with reference to FIG.

First, when a horizontal driving pulse is applied to the horizontal pulse generating unit 1, the horizontal transistor Q1 of the horizontal pulse generating unit 1 is turned on and outputted, and the on / off switching operation of the transistor Q1 The deflection output waveform is generated in the deflection coil DY to which the diode D1 and the capacitor C4 are connected.

On the other hand, the deflection output waveform generated in the deflection coil DY is charged and discharged by the condenser C1, and then supplied to the primary side of the high-voltage generating portion (FBT) 2 in accordance with on / off switching operation of the transistor Q1 The high voltage generating portion 2 generates a high voltage by the resistors R5 and R6, the coils L3 to L9, the diodes D2 to D6 and the condenser C _{HV in the} coil L2 And is applied to the anode gap of the cathode ray tube 3.

The deflection output waveform V of the reverse polarity (negative pulse) induced in the secondary side of the high-voltage generating portion 2 is level-adjusted while being divided by the constant voltage B ⁺ and the resistors R1 and R2.

The deflection output waveform of the opposite polarity that is level-adjusted by the resistors R1 and R2 is waveform-corrected by the resistor R3 and the capacitor C2. At this time, the set value of the resistors R1 and R2 It is possible to adjust the pulse and amplitude of the deflection output waveform and the direct current (DC) level.

Therefore, the deflection output waveform of the opposite polarity corrected by the resistor R3 and the capacitor C2 passes through the resistor R4 and the capacitor C3. In the resistor R4 and the capacitor C3, The spike noise of the deflected output waveform of the corrected reverse polarity is removed.

At this time, the wire L1 wound on the CPT image (for example, the front surface portion or the rear surface portion) in one rotation (1 turn) in the state of not being a coil circuit is electrically disconnected from the current (For example, front or back) by applying only a certain voltage to the CPT image (for example, the front surface or the rear surface) without applying the components of the CPT.

There is a problem in that unnecessary radiation noise generated in the front face of the cathode ray tube is not completely blocked by blocking the unnecessary radiation field noise generated without the means for detecting the unnecessary radiation field noise generated on the front surface of the cathode ray tube.

The apparatus includes a parabolic waveform generator for generating a vertical and horizontal parabolic waveform, a vertical and horizontal waveform corrector for correcting levels of the generated vertical and horizontal periods of the parabolic waveform, A signal combining unit for adding a horizontal parabola waveform of a horizontal period to a parabola waveform of a vertical period of the corrected waveform; an amplifying unit for amplifying the combined signal; a gain adjusting unit for adjusting a gain of the amplified signal; A phase adjusting unit for adjusting the phase of the gain adjusted signal in the gain adjusting unit and applying the phase adjusted signal to the front open loop wire of the Braun tube; and an open loop wire for removing unnecessary radiation field noise generated on the screen by the signal applied from the phase adjusting unit. And detecting a change in the voltage of the unnecessary radiated electric field noise by the open loop wire, The unnecessary radiation field noise generated in the screen is removed and the unnecessary radiation field noise is adjusted and removed in accordance with the change of the unnecessary radiation field noise. As a result, in the video display device, So that the harmful part can be solved.

1 is a circuit diagram of an apparatus for removing unwanted radiation in a conventional video display device

2 is a block diagram of an unnecessary radiation wave removing apparatus of a video display device according to the present invention

FIG. 3 is a view for showing an electric field radiated from the front portion of the image display device of the present invention

4 is a waveform diagram of each part of the unwanted radiant wave removing apparatus of the image display apparatus according to the present invention.

2 and 3, the configuration of the apparatus for removing unwanted radiant electric field noise in the front part of a video display device according to the present invention includes a parabolic waveform generator for generating a horizontal and vertical parabola waveform (H-PARA) (V-PARA) (11) for correcting the level of the horizontal parabolic waveform, a horizontal waveform correction unit (12) for correcting the level of the horizontal parabolic waveform, a vertical waveform correction unit (13) for correcting the level of the vertical parabolic waveform, A gain adjusting unit (16) for adjusting a gain of the amplified signal; a gain adjusting unit (16) for adjusting a gain of the amplified signal; A phase adjustment unit 17 for adjusting the phase of the gain adjusted by the phase adjustment unit 17 and applying the adjusted phase to the front off loop wire 18 of the cathode ray tube 19, (19) in front of An open loop wire 18 for attenuating unwanted radiated electric field noise on the screen and a sensing unit 20 for sensing radiation noise waves generated around the cathode ray tube 19.

The horizontal waveform correction unit 12 includes a capacitor C11 and a resistor R11 for charging and discharging the input horizontal waveform and outputting a signal corrected to a predetermined level and a vertical waveform correction unit 13 comprises capacitors C13 and C14 and a resistor R13 for charging and discharging the input vertical waveform and outputting a signal corrected to a predetermined level and the waveform combining unit 14 comprises a vertical and horizontal parabola And a coupler OP1 that couples the waveform to the gain by the resistor R12 and the resistor R14.

The signal amplifying unit 15 includes a transistor Q11 for inverting and amplifying the inputted parabolic waveform and applying it to the base of the transistor Q12 and a parabola waveform inverted and amplified by the transistor Q11 as a cascade, Amplifying the amplified signal and applying the amplified signal to the base of the transistor Q14; and a flyback transformer (FBT) and a gain adjuster (Q12) via a voltage drop of the emitter resistor R22 16).

C15 and C16 are capacitors, D11-D14 are diodes, ZD11 and ZD12 are Zener diodes, SG1 is a spark gap, and B1 ⁺ and B2 ⁺ are supply voltages.

The apparatus for removing unwanted radiation noise in the front part of the image display apparatus according to the present invention will now be described with reference to FIGS. 2 to 4. FIG.

First, when the horizontal parabola waveform (H-PARA) of the horizontal period _H is generated at the predetermined level (V _H ) as shown in FIG. 4A in the waveform generator 11, the generated horizontal parabola waveform Is applied through the resistor R12 of the waveform combining unit 14 to the horizontal parabola waveform corrected and discharged at the capacitors C11 and C12 and the resistor R11 of the horizontal waveform correcting unit 12. [

When the vertical parabolic waveform V-PARA of the vertical period _V is generated at the predetermined level V _V as shown in FIG. 4B in the waveform generating unit 11, the generated vertical parabolic waveform Is applied to the negative terminal (-) of the combiner OP1 of the waveform combining unit 14 by the correction of the vertical parabolic waveforms charged and discharged in the capacitors C13 and C14 and the resistor R12 of the horizontal waveform correcting unit 12 do.

The waveform coupling section 14 has a gain (AV = 1) due to the ratio of the resistor R12 and the resistor R14, And the parabolic waveform of the horizontal period is loaded on the parabolic waveform of the vertical period applied to the negative terminal (-) of the combiner OP1. Thus, the parabolic waveform having the horizontal period combined with the vertical period as shown in FIG. 4 (C) (V _H × N, V _V × N) is generated, and the generated parabolic waveform is applied to the signal amplification section 15.

The signal amplifying unit 15 inverts and amplifies the parabolic waveform input by the transistor Q11 into a waveform (N times as large as the waveform of FIG. 4) as shown in FIG. 4D (V _HC × N, V _VC × N And the inverted amplified signal is clipped to a predetermined level in the zener diode ZD11 and the capacitor C16 and applied to the base of the transistor Q13.

The signal applied to the base of the transistor Q13 is inversely amplified by the cascade-connected transistors Q12 and Q13 to a waveform as shown in FIG. 4 (E) with a predetermined amplification factor.

The inverted amplified signal is supplied to the flyback transformer FBT and the gain adjusting unit 16 with a waveform as shown in FIG. 4 (F) while a voltage drop is applied to the resistor R22 connected to the emitter terminal of the transistor Q14 .

Here, the gain AV of the signal applied to the gain adjuster 16 is adjusted by the ratio of the resistor R15 and the resistors R18 and R19 of the signal amplifying unit 15. [ That is, the gain AV .

The gain adjusting unit 16 adjusts the applied signal to the front surface radiation ripple voltage level of the cathode ray tube, and the adjusted signal is applied to the phase adjusting unit 17 with the waveform shown in FIG. 4 (G).

Here, the waveform as shown in (G) of FIG. 4 AC-couples the voltage level of the cathode-ray tube frontal noise level by 1 / N times in the waveform (F) of FIG.

The phase adjuster 17 coincides with the ripple voltage of the vertical period and synchronizes the instantaneous peak pulse voltage with a capacitor to remove the instantaneous peak pulse voltage.

4, the ripple voltage generated at the front of the cathode ray tube 19 as shown in FIG. 3 is applied to the front ripple voltage as shown in FIG. 4 (I) and FIG. 4 (-) voltage of the same waveform is applied to the open loop wire 18 to have the ground (GND) terminal potential as shown in FIG. 4 (J), and unnecessary radiation field noise can be removed.

The sensing unit 20 connected to the open loop wire 18 senses a pattern change or a load change occurring in the screen and feeds back the signal to the gain adjusting unit 16 to adjust the voltage change level using the sensed level , The phase adjusting unit 17 applies a negative pulse level to the open loop wire 18 according to the voltage change level to remove unnecessary radiation field noise.

The present invention enables the elimination of a part of the image display apparatus which causes harm to the human body due to the radiation noise on the whole screen and satisfies the radio wave standard (TCO95), thereby reducing the cost compared to the current flyback pulse, So that unnecessary radiated electric field noise is completely eliminated through the gain and phase adjustment, thereby providing reliability to the user.

Claims (2)

A horizontal waveform correcting unit 12 for correcting the level of the horizontal parabolic waveform, a vertical waveform correcting unit 13 for correcting the level of the vertical parabolic waveform, A signal combining unit 14 for combining the corrected vertical parabola waveform and a horizontal parabola waveform of a horizontal period, a signal amplifying unit 15 for amplifying the combined parabolic waveform, A gain adjustment unit 16 for adjusting the gain of the amplified signal of the gain adjustment unit 16 and the gain of the signal detected from the offloop wire 18 at the sensing unit 20, A phase adjustment unit 17 for adjusting the phase of the signal to apply to the open loop wire 18 and an open loop for removing unwanted radiation field noise generated on the front surface of the cathode ray tube 19 by using a signal applied from the phase adjustment unit 17. [ wire (20) for detecting a change in voltage level from the open loop wire (18) and applying the voltage to the gain adjusting unit (16) The signal combiner according to claim 1, wherein the signal combiner comprises a combiner (OP1) for combining a horizontal parabola waveform of a horizontal period with a gain according to a ratio of a resistor (R12) and a resistor (R14) The signal amplifying unit 14 includes a transistor Q11 for inverting and amplifying the combined parabolic waveform, transistors Q12 and Q13 for cascode amplifying the inverted amplified signal of the transistor Q11, And a transistor Q14 for applying a code amplified signal through a voltage drop resistor R22 of the emitter.