JPH10224656A - Display monitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display monitor at a low cost, with ensured high voltage insulation, ease of handling and reducing surely an alternate electric field without the use of an externally mounted high voltage capacitor. SOLUTION: A high voltage rectifier diode 3 is connected in series with each of the devided high voltage secondary coils 6 of a flyback transformer 1 and a high voltage capacitor 2 is connected between a cathode of the high voltage rectifier diode 3d at the final stage amount the high voltage rectifier diodes 3 and ground. The flyback transformer 1 supplies a high voltage to a display device. Then a high voltage output wire 22 is wound on or passes through the core 23 other than a core 15 of the flyback transformer 1 to form a pulse induction transformer 31 that induces pulses in phase or opposite to the phase of a horizontal pulse for driving a deflection yoke, the pulses in phase or opposite to the phase of the horizontal pulse for driving the deflection yoke are superimposed on the pulses on a high voltage output wire 22 via the pulse induction transformer 31, and a control circuit 25 that adjusts at least any of a peak, a phase and a waveform of the output pulses is connected to a primary winding of the pulse induction transformer 31.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display monitor (CRT monitor) using a cathode ray tube, and more particularly to a technique for reducing an alternating electric field transmitted from a surface of the cathode ray tube.

[0002]

2. Description of the Related Art FIG. 16 shows a flyback transformer (hereinafter abbreviated as "FBT") which is a high-voltage generating transformer for a general display monitor. An example of a circuit for reducing an electric field is shown in U.S. Pat.
This is an example in which the invention described in US Pat. No. 5,218,270 is applied.

In FIG. 1, reference numeral 1 denotes an FBT, 2 denotes a built-in high-voltage capacitor, 3 (3a, 3b, 3c, 3d) denotes a high-voltage rectifier diode, 4 denotes a tertiary-side reverse pulse generating winding, and 5 denotes an external high voltage. A capacitor, 6 (6a, 6b, 6c, 6d) is a high voltage coil, 7 is a deflection yoke, 16 is a horizontal output transistor, 17 is a primary side low voltage coil, and 18 is a waveform comparison controller.

FIG. 17 shows an example of a conventional alternating electric field reducing system. In the figure, reference numeral 8 denotes an interior graphite film, 9 denotes the capacitance of a deflection yoke, 10 denotes a high-voltage / deflection circuit, and 11 denotes a cathode ray tube. In this system, the charge Q ₁ in the interior graphite film 8 is represented by the following equation.

[0005] _{Q 1 = k × C DY ×} V DY wherein the k: constant at about 0.5 C _DY: (capacitance of the deflection yoke) between the capacitance between the interior graphite film and the deflection yoke V _DY : horizontal pulse for driving the deflection yoke The pulse e _X of the coil to be superimposed to cancel the alternating electric field is selected so that the superimposed electric charge Q ₂ is equal to the electric charge Q ₁ in the interior graphite film 8.

This is determined by the capacity C ₁ of the built-in high-voltage capacitor, the capacity C _{2 of} the CRT, and the pulse peak value e _P. The number of turns of the reverse pulse generating coil is determined in consideration of the capacity C ₁ of the built-in high-voltage capacitor, and the reverse pulse e is applied to the interior graphite film 8.
By applying _X , the amplitude of the alternating electric field V _DY ′ is reduced.

FIG. 18 is a circuit diagram equivalently showing an example of the alternating electric field reduction system of FIG. In FIG.
2 is a panel transparent conductive film, 13 is a surface resistance of the panel transparent conductive film 12, and 14 is a capacitance of the panel transparent conductive film 12.

In this equivalent circuit, the alternating electric field is reduced by the following operation. The horizontal pulse V _DY (1000 V _PP ) for driving the deflection yoke 7 is applied to the capacitance 9 of the deflection yoke 7.
A pulse voltage V _DY ′ is generated in the interior graphite film 8 of the cathode ray tube 11 via (60 _PF ). Pulse voltage V _DY 'is the capacitance 14 and the surface resistance 13 of the panel transparent conductive film 12, the impedance divided V _P is generated in the panel transparent conductive film 12, a source of alternating electric field.

As an example of reducing the alternating electric field, as described above, the reverse pulse V _F ′ (−150 V _PP ) obtained by the reverse pulse generating winding 4 on the tertiary side of the FBT 1 is connected to the external high voltage of the FBT 1. By applying the voltage to the interior graphite film 8 via the capacitor 5 (capacitance: C _F = 200 _PF ), the pulse voltage V _DY ′ is canceled by the reverse pulse V _F ′ in the interior graphite film 8 and radiated from the CRT 11. The amplitude of the alternating electric field V _DY ′ is reduced.

This relationship can be expressed by the following equation. k × C _DY (60 _PF ) × V _DY (−1000 V _PP ) = − 3 × 10E-8 [C] = C _F (200 _PF ) × V _F ′ (−150 V _PP ) (where k ≒ 0.5 FIG. 19 is an external view of a conventional external high-voltage capacitor, and FIG. 20 is an internal circuit diagram of the high-voltage capacitor. In these figures, reference numeral 19 denotes an anode cap, 20 denotes a high-voltage connector, and 21 denotes a ground terminal.

[0011]

This external high-voltage capacitor 5 is provided with a high-voltage insulation as shown in FIG.
An outer case of about 40 mm × 40 mm × 65 mm and an insulating resin (epoxy resin or the like) to be injected therein are required. This not only increases the cost, but also limits the installation location in the display monitor, and poses a problem that handling is difficult due to its structure. In addition, since high-voltage connection is required, there is a disadvantage that it is difficult to ensure the reliability of the high-voltage connection portion (high-voltage connector 20).

An object of the present invention is to provide an inexpensive and high-voltage insulation without using a conventional external high-voltage capacitor.
Another object of the present invention is to provide a display monitor that is easy to handle and that can reliably reduce an alternating electric field.

[0013]

In order to achieve the above object, the present invention provides a high voltage rectifier diode connected in series to the output side of each divided high voltage coil on the secondary side.
A high voltage is supplied to the display by a flyback transformer in which a high voltage capacitor is connected to the cathode side of the final high voltage rectifier diode of the high voltage rectifier diode, and a high voltage is supplied to a core different from the flyback transformer core. An output wire is wound or passed therethrough, and a pulse induction transformer having a winding for inducing a pulse having the opposite phase or the same phase as the horizontal pulse for driving the deflection yoke by using the separate core is provided, and the deflection yoke is driven via the pulse induction transformer. A pulse having the opposite phase or the same phase as the horizontal pulse for use is superimposed on the high-voltage output wire, and for example, on the primary side of the pulse induction transformer, for example, an inductor for adjusting a peak value, and a differentiation circuit in which a capacitor and a resistor are connected in series. A phase and waveform adjustment circuit in which a parallel circuit of a rectifier diode and a resistor is connected in series at the previous stage. It is characterized in that it has connecting al constructed control circuit.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As described above, the present invention superimposes a pulse having a phase opposite to or the same as the horizontal pulse for driving the deflection yoke on a high voltage output wire wound or passed through another core via a pulse induction transformer. Thereby, the alternating electric field can be reduced. This eliminates the need for an external case and an expensive external high-voltage capacitor insulated with liquid injection resin.
It is inexpensive, easy to insulate at high voltage, and has good handleability.

Further, since a control circuit capable of adjusting at least one of the peak value, phase and waveform of the output pulse is connected to the primary side of the pulse induction transformer, the control circuit is connected to the high-voltage output line via the pulse induction transformer. It is possible to superimpose a pulse of opposite phase or in-phase having the same amplitude equivalent to the electric field, so that the effect of reducing the alternating electric field is reliably exhibited and a highly reliable display monitor can be provided.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a circuit diagram of the FBT according to the first embodiment. High-voltage coil 6a divided into multiple parts of FBT1
In addition to connecting the high-voltage rectifier diodes 3a to 3d to the output side (end of winding) of to 6d, a control circuit 25 and a pulse induction transformer 31 are provided. In this example, the pulse induction transformer 31 is built in the FBT1.

The control circuit 25 comprises a peak value adjusting inductor 32, a peak value and phase adjusting capacitor 33, a peak value and phase adjusting resistor 34, a waveform adjusting resistor 35, and a capacitor 36. As shown in the figure, a series circuit of a resistor 35 and a capacitor 36 is connected between the subsequent stage of the series differentiating circuit of the capacitor 33 and the resistor 34 and the ground, and the peak value and phase / waveform adjustment of the output pulse are adjusted. Do.

The pulse induction transformer 31 includes a control circuit 25
(In the present embodiment, two types) of primary windings 24a and 2 in which a pulse having a phase opposite to or in phase with the horizontal pulse for driving the deflection yoke whose peak value and phase / waveform are adjusted by the above is induced.
4b, a core winding coil 30 for each high-voltage output electric wire serving as a secondary winding (high-voltage output electric wire 22), and another core 23 for pulse induction
a, 23b and 23c.

FIG. 2 is an external view showing a cross section of a part of the FBT provided with the reverse pulse induction transformer 31. As shown in FIG. As shown in the figure, a core 23a around which a primary winding 24a is wound and a core 23b around which a primary winding 24b is wound are housed side by side in a holding case 26b, and a core 23c which is not wound with a winding is used for holding. The cores 23a, 23b and the core 23c are housed in the case 26a,
Are arranged facing each other. This separate core 23 for pulse induction
a, 23b, and 23c are obtained by dividing a cylindrical core into two along the axial direction to form a toroidal shape, one of which is a core 2.
3c, and the remaining core is further shifted at an intermediate position in the axial direction by 2
The cores 23a and 23b are divided into two parts, so that the cores 23a and 23b and the core 23c are opposed to each other, so that the cores 23a and 23b become substantially the original cylindrical shape. And the cores 23a, 23
The reverse pulse induction transformer 31 is constructed by inserting the high voltage output electric wire 22 into the hollow portions of the b and 23c (through the cases 26a and 26b).

In this embodiment, a case 26c accommodating a printed circuit board 60 on which the control circuit 25 is mounted is provided.
Are attached integrally to the case 26b, and the primary windings 24a and 24b are connected to a printed wiring board 60.

FIGS. 3A and 3B are external views showing another example of another core for inverting pulse induction. A cylindrical winding is cut in half along the axial direction of the core, and the cut surface is used in abutting manner. A so-called two-piece toroidal core 23 has a primary winding 24 (primary winding) for reverse pulse induction. Winding 2
4a or primary winding 24b or both windings 24a, 24
b) is wound for a predetermined number of turns, and these are
6a, 26b.

FIG. 4 is a view showing a state in which this is mounted on the FBT 1. The high-voltage output electric wire 22 is inserted into the hollow portions of the two-part toroidal cores 23, 23 whose cut surfaces are abutted (cases 26a, 26b are connected to each other). (Through) a reverse pulse induction transformer 31. In this embodiment, the printed circuit board 60 on which the control circuit 25 is mounted is not built in the reverse pulse induction transformer 31, but is mounted at another position outside the FBT 1 (not shown), and 31 and the printed wiring board 60 are connected via lead wires.

FIG. 5 is a view showing various examples of the separate core 23 for guiding the reverse pulse and the primary winding 24. Although not shown, a high-voltage output electric wire 22 is inserted through the hollow portion of the combined toroidal core.

FIG. 1A has one primary side core 23a and one secondary side core 23c, and the primary side core 23a has one core.
An example in which a primary winding 24 of a kind is wound is shown.

FIG. 2B has one primary side core 23a and one secondary side core 23c, and the primary side core 23a has two cores.
An example is shown in which primary windings 24a and 24ab of various kinds are wound.

FIG. 2C shows two primary cores 23a,
23b and one secondary core 23c,
An example is shown in which a primary winding 24a is wound around 3a and a primary winding 24b is wound around a primary core 23b.

FIG. 4D shows two primary cores 23a,
23b and two secondary cores 23c-1 and 23c-2. The primary winding 24a is wound on the primary core 23a, and the primary winding 24b is wound on the primary core 23b. An example is shown.

FIG. 2E shows a primary core 23a,..., 23n divided into a number n and a secondary core 23c. Winding 24a
,..., 24n are wound.

FIG. 2F shows a primary core 23a,..., 23n, which is divided into a number n, and secondary cores 23c-1, 23c-n, which are divided into a number n. Secondary core 23
, 23n are wound with primary windings 24a,..., 24n, respectively.

FIG. 6 shows an example in which the high voltage output electric wire 22 is wound around the secondary core 23c. FIG. 2A has one primary side core 23a and one secondary side core 23c.
In this example, the primary winding 24 is wound around the secondary core 23a, and the high-voltage output electric wire 22 is wound around the secondary core 23c.

FIG. 3B shows two primary cores 23a,
23b and two secondary cores 23c-1 and 23c-2, a primary winding 24a is wound around the primary core 23a, and a primary winding 24b is wound around the primary core 23b. An example is shown in which the high-voltage output electric wires 22 are wound around the secondary cores 23c-1 and 23c-2.

The conduction transformer 31 is constituted.

FIG. 7A is a diagram showing a negative-phase pulse induction system, and FIG. 7B is an equivalent circuit diagram of a negative-phase pulse induction transformer. As shown in FIG. 7A, the control circuit 25 adjusts the peak value, phase and waveform of the reverse pulse e ₂ generated by the tertiary reverse pulse generating coil 4 of the FBT 1.

The control circuit 25 includes the phase adjusting capacitor 3
3. It has a resistor 34 for phase adjustment, a resistor 35 for waveform adjustment and a capacitor 36 (see FIG. 1).
(A) As shown in FIG.
3 and the waveform v ₂ adjusted by the peak value and phase adjustment resistor 34, as shown in FIG.
And the capacitor 36 is adjusted to the waveform v ₂ ′.
The inverted pulse e ₃ whose peak value, phase and waveform have been adjusted in this manner is transmitted to the primary winding 2 of the inverted-phase pulse induction transformer 31.
4 (see FIG. 7A).

This control circuit may be a control circuit 37 having the configuration shown in FIG. 9, and this circuit can also adjust the pulse peak value, phase, and waveform. In the figure, 38 is a peak value adjusting inductor, 39 is a peak value and phase adjusting capacitor, 40 is a peak value and phase adjusting resistor, 41 is a waveform adjusting resistor, and 42 is an inductor. As shown in the figure, a parallel circuit of a resistor 41 and an inductor 42 is connected to a stage subsequent to the series differentiating circuit of the capacitor 39 and the resistor 40, and adjusts the peak value, phase and waveform of the output pulse.

In this example, the pulse generated from the tertiary side of the FBT 1 has been described as a negative pulse. However, even if the pulse generated from the tertiary side is a positive pulse, if the winding direction of the reverse pulse induction coil 24 is reversed, Similarly, a pulse opposite to the horizontal pulse for driving the deflection yoke can be superimposed on the high voltage output electric wire 22.

In FIG. 7B, the self-inductance of the reverse pulse induction coil 24 is L ₁ , the self-inductance of the core winding coil 30 for each high-voltage output electric wire is L ₂ ,
Assuming that the currents of the circuits in which the respective circuits (X) and (Y) are coupled by the mutual inductance M are I ₁ and I ₂ , respectively, the following relationships are established in the circuits (X) and (Y).

(R ₁ + jωL ₁ ) I ₁ + jωMI ₂ = e
₃ jωMI ₁ + (R ₂ + jωL ₂ ) I ₂ = 0 In the equation, ω: angular frequency ω = 2πf When the current I ₂ of the circuit (Y) is obtained from this equation, it is expressed as the following equation.

I ₂ = −jωMe ₃ / [(R ₁ + jω
L ₁ ) (R ₂ + jωL ₂ ) + ω ² M ² ] where Me _{3 is a} mutual inductance. Therefore, the reverse pulse e ₄ generated in the core-wound coil for each high-voltage output electric wire is represented by the following expression.

E ₄ = −jωMe ₃ R ₂ / [(R ₁ + jωL
₁ ) (R ₂ + jωL ₂ ) + ω ² M ² ] Negative-phase pulse e ₄ induced by the inverse-pulse induction transformer 31
Is superimposed on the high-voltage output electric wire 22, the induced horizontal pulse of the deflection yoke is canceled in the interior graphite film 8 of the cathode ray tube 11, and the amplitude of the alternating electric field is reduced.

The deflection yoke driving horizontal pulse according to this embodiment is described as a positive pulse. However, even when the deflection yoke 7 is driven by a horizontal negative pulse, a high voltage is applied through the reverse pulse induction transformer 31 in the same manner. By superimposing the positive pulse on the output wire 22, the horizontal pulse is canceled and the amplitude of the alternating electric field V _DY 'is reduced.

The peak value of the negative-phase pulse e ₄ superimposed on the interior graphite film 8 of the cathode ray tube 11 is determined by the number of turns of the primary low-voltage coil 17 of the FBT 1, the number of turns of the primary-side reverse pulse generating coil 4,
Although adjustable number of turns of Oyohi inversion pulse induction coil 24, the optimum conditions of the reverse phase pulse e ₄ by the control circuit 25, to the fine adjustment of the peak value and the phase-waveform of the reverse phase pulse e ₄ Thus, the same pulse signal as the alternating electric field can be set, which is effective for canceling the alternating electric field.

In FIG. 7A, the negative phase pulse e ₄ at both ends of the core winding coil 30 for each high voltage output electric wire is shared by the built-in high voltage capacitor C ₁ and the cathode ray tube capacitance C ₂ . However, the negative-phase pulse e ₄ at both ends of the coil 30
Varies depending on the winding position of the coil 30, the surrounding wiring, and the like.

The CRT 11 has a capacity of structural limit, internal high-voltage capacitor 2 is provided in the interior of FBT1 to correct CRT capacitance C ₂ (see Figure 1).
The capacity (capacitance of the built-in high-voltage capacitor C ₁ + capacitance of the CRT C ₂ ) is used to stabilize the high voltage. If the high-voltage capacity is small, it causes a phenomenon such as a bend on the screen of the CRT 11.

By changing the capacity of the built-in high-voltage capacitor 2, the peak value of the negative-phase pulse e ₄ applied to the high-voltage output wire 22 can be adjusted. When the capacity is increased, the peak value increases, and when the capacitance is decreased, the peak value decreases.

In the present invention, both the capacity function of applying a reverse pulse to the anode electrode of the cathode ray tube 11 and the capacity function of the cathode ray tube 11 for stabilizing the high voltage can be used.

FIG. 10 is a circuit diagram of an FBT according to a second embodiment of the present invention, FIG. 11A is a waveform diagram of a pulse induced in a high pressure deflection system separated type interior graphite film, and FIG.
FIG. 9 is a waveform diagram of a pulse induced by the reverse pulse induction transformer according to the second embodiment.

When the size of the cathode ray tube 11 is increased, the display monitor uses a transistor 16 to improve the image quality.
-Driven deflection system and field-effect transistor (FET)
It may be driven separately from the high-pressure system driven by 27. When the driving is performed in this manner, the transistor 1
Since the switching time of the FET 27 is shorter than that of the FET 6, the pulse induced in the interior graphite film 8 of the cathode ray tube 11 has a phase shift between the high-voltage system component and the deflection system component, as shown in FIG.

The high-voltage pulse component is generated due to a large internal impedance of the built-in high-voltage capacitor 2 and a large amount of high-voltage fluctuation of the FBT 1. Graphite film 8
Are combined with each other to form a pulse waveform as shown in FIG.

Therefore, as shown in FIG. 10, the horizontal centering transformer 28 is provided with a deflection system reverse pulse generating coil 29.
The inverted pulse whose peak value and phase have been adjusted by the control circuit 25 is transmitted through the inverted pulse induction transformer 31 to FIG.
By using a configuration in which the reverse pulse is superimposed on the high-voltage output electric wire 22 as shown in FIG. 11B, the pulse voltage [FIG. 11A] combined in the interior graphite film 8 of the cathode ray tube 11 is changed to the reverse pulse voltage [FIG. (B)], the amplitude of the alternating electric field can be reduced.

FIG. 12 shows an FBT according to the third embodiment.
FIG. In this embodiment, the control circuit 50
Are a peak value adjusting inductor 51, a peak value and phase adjusting capacitor 52, a peak value and phase adjusting resistor 53,
It is composed of a rectifier diode 54 for phase and waveform adjustment, and a resistor 55 for phase and waveform adjustment. As shown in the figure, a circuit in which a rectifying diode 54 and a resistor 55 are connected in parallel is connected in series at the preceding stage of a series differentiating circuit of a capacitor 52 and a resistor 53. Further, an inductor 51 is connected in parallel to these circuits.

When the inductance of the peak value adjusting inductor 51 is increased, the peak value is reduced, and when the phase adjusting capacitor 52 and the resistor 53 are reduced, the phase is advanced and the peak value is increased.

FIG. 13A is an input waveform diagram of the control circuit 50, and FIG. 13B is an output waveform diagram of the control circuit 50.
(A) of FIG.
And a steep pulse input of the control circuit input waveform v ₂ in advance the phase, as shown in FIG. (B), the pulse rises by a resistor 55 can be pulled back a short time to zero level.

FIG. 14 is a circuit diagram of the FBT according to the fourth embodiment. The FBT according to the third embodiment is shown in FIG.
This is an example in which a horizontal centering transformer 28 is connected as in the case of the second embodiment shown in FIG. Therefore, the waveform of the pulse induced by the reverse pulse induction transformer is the same as that in FIG.

The reverse pulse induction transformer 31 is an FBT.
It is also possible to attach it to an external position separately from the device 1 and install it at an arbitrary position.

FIG. 15 is a waveform chart for explaining the operation and effect of the display monitor according to the embodiment of the present invention. If an attempt is made to apply a reverse pulse as shown in FIG. 2B to the cathode-ray tube surface waveform as shown in FIG. 2A, the self-inductance component of the coil and the initial magnetic permeability of the core will cause the same. As shown in c), the output waveform has a phase delay α and a waveform distortion β with respect to the input waveform. When the pulse waveform induced by the pulse induction transformer is superimposed on the high-voltage output electric wire, and the tube surface waveform of the CRT is observed, the result is as shown in FIG. Even with this, the electric field intensity is reduced, but it is difficult to reliably reduce the electric field intensity to 1 V / m or less. Therefore, a completely inverted pulse waveform is adjusted by the control circuit with respect to the combined waveform of FIG. As shown in (e), the alternating magnetic field can be substantially eliminated.

[0057]

As described above, according to the present invention, the alternating electric field is reduced by superimposing a pulse in the opposite phase or the same phase as the horizontal pulse for driving the deflection yoke on the high voltage output wire of another core via the pulse induction transformer. be able to. for that reason,
This eliminates the need for an external case and an expensive external high-voltage capacitor insulated with a liquid injection resin, and is inexpensive, facilitates high-voltage insulation, and improves handling.

Further, since a control circuit capable of adjusting at least one of the peak value, phase, and waveform of the output pulse is connected to the primary side of the pulse induction transformer, the control circuit is connected to the high-voltage output line via the pulse induction transformer. It is possible to superimpose a pulse of opposite phase or in-phase having the same amplitude equivalent to the electric field, so that the effect of reducing the alternating electric field is reliably exhibited and a highly reliable display monitor can be provided.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of an FBT according to a first embodiment of the present invention.

FIG. 2 is an external view showing a part of the FBT as a cross section.

FIGS. 3A and 3B are external views showing another example of the reverse pulse induction transformer. FIGS.

FIG. 4 is an external view in which a part of a flyback transformer provided with the reverse pulse induction transformer is cut.

FIGS. 5A to 5F are diagrams showing various examples of a core and a primary winding in an inverse pulse induction transformer.

FIGS. 6A and 6B are diagrams showing examples of a reverse pulse induction transformer in which a high-voltage output wire is wound around a core.

FIG. 7 (a) is a diagram showing a reversed-phase pulse induction system,
(B) is an equivalent circuit diagram of the negative-phase pulse induction transformer.

8 (a) is a peak value and a phase adjustment capacitor and peak value and the waveform diagram of waveforms v ₂ which is adjusted by the phase adjusting resistor of the control circuit, (b) is followed by the waveform adjusting resistor FIG. 7 is a waveform diagram of a waveform v ₂ ′ adjusted by a capacitor.

FIG. 9 is a circuit diagram showing a modification of the control circuit.

FIG. 10 is a circuit diagram of an FBT according to a second embodiment of the present invention.

FIG. 11 (a) is a waveform diagram of a pulse induced in a high pressure deflection system separated type interior graphite film, and FIG. 11 (b) is a waveform diagram of a pulse induced in a reverse pulse induction transformer according to the second embodiment. is there.

FIG. 12 is a circuit diagram of an FBT according to a third embodiment of the present invention.

13A is an input waveform diagram of the control circuit according to the embodiment, and FIG. 13B is an output waveform diagram of the control circuit.

FIG. 14 is a circuit diagram of an FBT according to a fourth embodiment of the present invention.

FIG. 15 is a waveform chart illustrating the operation and effect of the display monitor according to the embodiment of the present invention.

FIG. 16 is a circuit diagram of a conventional FBT.

FIG. 17 is a diagram showing a conventional alternating electric field reduction system.

FIG. 18 is an equivalent circuit diagram of the alternating electric field reduction system.

FIG. 19 is an external view of a conventional external high-voltage capacitor of an FBT.

FIG. 20 is an internal circuit diagram of the external high-voltage capacitor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 FBT 2 Built-in high voltage capacitor 3 High voltage rectifier diode 6 High voltage coil 7 Deflection yoke 8 Interior graphite film 11 CRT 22 High voltage output wire 23 Core 24 Primary winding 25,37,50 Control circuit 28 Horizontal centering transistor 30 High voltage output wire core Wound coil 31 Pulse induction transformer 32, 38, 42, 51 Inductor 33, 36, 39, 52 Capacitor 34, 35, 40, 41, 53, 55 Resistor 54 Rectifier diode 60 Printed wiring board

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kiyohiko Gokon 1 Kitano, Majo, Mizusawa-shi, Iwate Prefecture Hitachi Media Electronics Co., Ltd.

Claims (9)

[Claims] 1. A high voltage rectifier diode is connected in series to the output side of each of the divided secondary high voltage coils,
A high voltage is supplied to the display by a flyback transformer in which a high voltage capacitor is connected to the cathode side of the final high voltage rectifier diode of the high voltage rectifier diode, and a high voltage is supplied to a core different from the flyback transformer core. An output electric wire is wound or passed therethrough, and a pulse induction transformer having a winding for inducing a pulse having a phase opposite to or in phase with the horizontal pulse for driving the deflection yoke by using the separate core is provided, and the deflection yoke is driven via the pulse induction transformer. A control circuit capable of adjusting at least one of a peak value, a phase and a waveform of an output pulse is connected to a primary side of the pulse induction transformer by superimposing a pulse having a phase opposite to or the same as the horizontal pulse for use on the high-voltage output wire. A display monitor characterized by the following. 2. The display monitor according to claim 1, wherein the control circuit is configured to adjust three values of a peak value, a phase, and a waveform of the output pulse. 3. The control circuit according to claim 1, wherein the control circuit comprises a circuit in which a parallel circuit of a rectifier diode and a resistor is connected in series at a stage preceding a differentiation circuit in which a capacitor and a resistor are connected in series. A display monitor, characterized in that: 4. The control circuit according to claim 1, wherein the control circuit includes a parallel circuit of a rectifying diode and a resistor in series before a differentiating circuit in which a peak value adjusting inductor and a capacitor and a resistor are connected in series. A display monitor comprising a connected phase and waveform adjusting circuit. 5. The control circuit according to claim 1, wherein the control circuit comprises a circuit in which a series circuit of a resistor and a capacitor is connected in series between a subsequent stage of a differentiating circuit having a capacitor and a resistor in series and a ground. A display monitor, wherein a winding of the pulse induction transformer is connected to a connection between the differentiating circuit and the series circuit. 6. The control circuit according to claim 1, wherein the control circuit includes a series circuit of a resistor and a capacitor between a ground and a subsequent stage of a differential circuit in which a peak value adjusting inductor, a capacitor and a resistor are connected in series. A display monitor comprising a phase and waveform adjustment circuit connected in series, wherein a winding of the pulse induction transformer is connected to a connection between the differentiating circuit and the series circuit. 7. The method according to claim 1, wherein
A pulse having a phase opposite to or the same as that of the horizontal pulse for driving the deflection yoke is generated by the flyback transformer or the horizontal centering transformer and supplied to the cathode ray tube via the pulse induction transformer. Display monitor. 8. The display monitor according to claim 1, wherein the core of the pulse induction transformer is a toroidal core divided into two or more. 9. The method according to claim 8, wherein a primary side core of the toroidal core is divided into at least two, and at least one of the divided cores is used for adjusting a peak value of the control circuit. A pulse induction coil connected to a circuit is wound, and a pulse induction coil connected to a phase and waveform adjustment circuit of the control circuit is wound around another at least one of the divided cores. A display monitor.