KR20030071166A - CRT electron gun - Google Patents

Abstract

PURPOSE: An electron gun of a color CRT(Cathode Ray Tube) is provided to be capable of reducing the vibration generated at an AC(Alternating Current) focus electrode due to the supply of AC voltage and preventing the vibration from being transferred to an electron gun part and a net glass part by using a conductive damping part loaded at a DC(Direct Current) focus electrode. CONSTITUTION: An electron gun comprises an AC focus electrode and a DC focus electrode, an anode fixedly melted on a bead glass part, located at the front portion of the AC applied focus electrode for focusing and accelerating electron beam to a screen, a shield tap loaded at the DC focus electrode for preventing high voltage of the anode from flowing into a triode part, a stem pin connected with the focus electrode through a wire for being capable of applying AC voltage to the focus electrode. Preferably, a conductive damping part(31) is loaded at the DC focus electrode instead of the shield tap.

Description

Color cathode ray tube electron gun {CRT electron gun}

The present invention relates to a color cathode ray tube electron gun, and more particularly, an alternating current and direct current applying focus electrode, which is a component of an electron gun that collides with a fluorescent surface in a color cathode ray tube panel and forms an image by light emission of the fluorescent surface. The conductive damping member is mounted on the direct current applying electrode to which the voltage is applied, thereby reducing the vibration generated by the alternating current applying electrode according to the application of the alternating voltage, thereby preventing the vibration from being transmitted to the entire electron gun and the neck glass. The present invention relates to a color cathode ray tube tank gun which improves the sensitivity of the color cathode ray tube by preventing high frequency noise of resonance caused by matching with the natural frequency of the neck glass.

A cathode ray tube, generally called a TV cathode ray tube, converts an electric signal into an optical image such as an image, a figure, or a character by an electron beam. Same as

The color cathode ray tube (braungwan) is, as shown in Figure 1, the glass coated with three primary colors (red, green, blue) phosphor 3 to emit light upon collision of the scanned electron beam to convert into visual information Panel (1) of ash, and the internal shape is coated inside the entire shape forming a cone shape, and is fixed to the panel (1) of the glass material funnel (bulb) to form a vacuum container (2), an electron gun (3) inserted into the neck portion (5) of the funnel (2), which emits an electron beam in accordance with an electrical signal for displaying image information, and an outer neck (5) portion of the funnel (2) A deflection yoke 4 mounted on the rear surface and deflecting the electron beam emitted from the electron gun 3 up, down, left and right so that the panel 1 can be reproduced in two dimensions. Electrons mounted in the panel 1 and deflected by the deflection yoke 4 so as to be located at This consists of a plurality of color selection through the through-hole so that the injection into the phosphor screen 7 in the predetermined position of the shadow mask electrode (shadow mask) (6).

In addition, the detailed configuration of the electron gun 3, which is a component of the color cathode ray tube, will be described with reference to FIGS. 2A, 2B, and 3, which are cathodes that emit electrons according to the heat source of the inherent heater. 12), a control electrode 13 which is a first grid electrode for controlling the amount of electrons emitted from the cathode 12, and an agent for accelerating a controlled amount of electrons in a beam form through the control electrode 13; An acceleration electrode 14 that is a second grid electrode and an electron beam scanned through the acceleration electrode 14 are focused and accelerated first and second by the main lens (electrostatic lens) effect of the electron beam passing hole to be scanned on the fluorescent surface The first focusing / acceleration electrode 17, 18 and the second focusing / acceleration electrode 19 and the second focusing / acceleration electrode 19 are mounted to shield and weaken the leakage magnetic field of the deflection yoke 4. A shielding electrode (shield cup) 20 and fixed to both ends of the electrodes 12 to 19 so that the electrodes Bead glass 23 for fixing and holding at intervals, and BSC 28 for holding the electron gun 3 in the neck portion 5.

Reference numeral 15 is a third grid electrode, 16 is a fourth grid electrode, 24 is a shield tab, and 27 is a stem pin.

Among the electrodes of the color cathode ray tube electron gun 3 configured as described above, a voltage of 250 to 1000 V is applied to the acceleration electrode 14, and a high voltage of 25 to 35 mA is applied to the second focusing / acceleration electrode 19. When a medium voltage corresponding to 20-30% of the second focusing / acceleration electrode 19 is applied to each of the first focusing / acceleration electrodes 17 and 18, the first focusing / acceleration electrodes 17 and 18 and Opening holes (not shown) of the first focusing / acceleration electrode (hereinafter, referred to as a direct current applying focusing electrode and an alternating applying focusing electrode) 17 and 18 due to the voltage difference with the second focusing / acceleration electrode 19. And an equipotential surface are formed in the opening hole (not shown) of the second focusing / acceleration electrode (hereinafter, referred to as an anode) 19 to serve as a main lens, so that the cathode 12 and the control electrode 13 ), The electron beam scanned through the acceleration electrode 14 is focused and accelerated at the main lens unit, and the electron beam accelerated as described above is transferred to the shadow mask 6. Passes through the beam passing holes hit the three primary colors (red, green, and blue) phosphor screen 7, the phosphor screen 7, the screen on the panel 1 is formed are to be formed.

In order to improve the image quality of the color cathode ray tube, when an AC voltage (dynamic voltage) is applied to one or two or more electrodes of the focusing electrodes 17 and 18 of the electron gun 3, FIGS. As shown in Fig. 4B, an alternating voltage induced at a predetermined point on the inner surface of the neck glass 22 is measured, and at this time, up to about 55 to 80% of the alternating voltage is induced in the neck glass 22. 4C illustrates a position where an AC voltage outside the neck glass is measured.

When the input voltage of Equation 1 is applied to the electrode, an electrostatic force such as Equation 2 is caused by the charge induced on the surface of the neck glass 22.

(Equation 1)

V = VDC + VAC cos ωt

Here, VDC: DC voltage applied to each electrode (heater, cathode, control electrode, acceleration electrode, etc.) of the electron gun.

VAC cosωt: AC voltage applied to the focusing electrode.

ω: Angular frequency of AC voltage

t: time

(Equation 2)

F (t) = (σb / 2ε ₀ ) C VDC + (1/2) (dC / dz) {VDC ² + (1/2) VAC ² }

+ (σb / 2ε ₀ ) C VAC cosωt + (dC / dz) VDCVAC cosωt

+ {(1/4) (dC / dz) VAC ² cos2ωt}

Where F (t) is the force interacting between the neck glass and the focusing electrode to which an AC voltage is applied.

σb: Surface charge density of neck glass.

ε ₀ : permittivity in vacuum.

C: Capacitance between the focusing electrode and the neck glass to which an AC voltage is applied.

At this time, the electrostatic force F (t) is greatly changed with time by the AC component, that is, the cosωt component. As shown in FIG. 5, the focusing electrode 18 to which the AC voltage is applied and the AC voltage are applied. Vibration is caused to the conductive wire 26 or the like.

More specifically, as shown in FIG. 5, the focusing electrode 18 and the conducting wire 26 to which the alternating voltage is applied are vibrated by a change in the amount of charge on the surface of the focusing electrode 18 to which the alternating voltage is applied. The vibration of the focusing electrode 18 and the conductive wire 26 is transmitted to the stem 25 to vibrate the neck glass 22 connected to the stem 25 or to be fused together with the bead glass 23. By vibrating the various electrodes 12 to 19 in (3), the entire electron gun 3 is vibrated, and the electrostatic force acting between the electrodes in the electron gun 3 is expressed by Equation (3).

(Equation 3)

F (t) = ε ₀ × S × (dV) ² / (2 × D ² )

Here, F (t): The force interacting between the electrode facing the AC voltage is applied.

ε ₀ : permittivity in vacuum.

S: opposed area between electrodes.

dV: potential difference between electrodes.

D: distance between electrodes.

Furthermore, when the vibrations generated at the focusing electrode 18 and the conductive wire 26 coincide with the resonance frequency of the neck glass 22, the vibrations cause resonance with each other and the focusing electrode 18 and the conductive wire 26 There is a problem that causes the emotional characteristics of the color cathode ray tube worsened, such as amplification greater than the first generated vibration in the high frequency noise.

The present invention has been made to solve the above problems, while reducing the vibration generated in the alternating current applying electrode according to the application of the alternating current voltage by the conductive damping member mounted on the direct current applying focusing electrode, the vibration is an electron gun The purpose of the present invention is to improve the image quality of the color cathode ray tube by blocking the transmission to the whole and the neck glass to prevent high frequency noise of resonance caused by matching with the neck glass natural frequency.

In addition, a high voltage applied to the anode by the conductive damping member mounted on the direct current applying focusing electrode absorbs and blocks the flow into the negative electrode, the control electrode, and the acceleration electrode to protect the negative electrode of the triode. have.

1 is a cross-sectional view showing the main portion of a general color cathode ray tube.

2A and 2B are side cross-sectional views and bottom state cross-sectional views showing major portions of the electron gun mounted in FIG.

3 is a cross-sectional view of the electron gun fixed to the neck glass.

4A and 4B are diagrams showing distribution states of AC voltages applied to one or two or more electrodes.

4C is a measurement position diagram showing an AC voltage measuring portion of a cathode ray tube neck portion;

5 is a state diagram showing the principle of vibration generated in the focusing electrode which is a conventional electron gun component.

Figure 6 is a bottom state cross-sectional view showing the main portion of the cathode ray tube electron gun of the present invention.

7 is a perspective view of a conductive damping member applied to the electron gun of the present invention.

8 is a cross-sectional view of an electron gun equipped with a conductive damping member according to the present invention.

9 is a graph showing the relationship between the natural frequency ratio and the amplitude ratio according to the damping coefficient of the electron gun to which the conductive damping member is applied.

10 is a graph showing an amplitude change with time of an electron gun to which a conductive damping member is applied.

11 is a state diagram showing a damped state of vibration in a direct current applying focusing electrode mounted with a conductive damping member.

<Explanation of symbols for main parts of the drawings>

11. Heater 12. Cathode 13. Control electrode 14. Acceleration electrode

15. 3rd grid electrode 16. 4th grid electrode 17. Direct current applying focusing electrode

18. AC applied focusing electrode 19. Anode 20. Shield cup 22. Neck glass

23. Bead glass 24. Shield tab 25. Stem 26. Lead wire

27. Stem pin 28. BSC 31. Conductive damping member 32. Damping material

33. Conductive thin plate 34. Electrode folding part

Color cathode ray tube electron gun 100 of the present invention for achieving the above object, by mounting two or more focusing electrodes (17) (18) in order to improve the image quality of the color cathode ray tube to increase the focusing intensity according to the position of the screen In order to be different, an AC voltage is applied to one electrode, and a DC voltage is applied to the other electrode, respectively. The anodes 19 positioned to focus the electron beam toward the screen are fused and fixed to the bead glass 23, respectively, and the triodes 12, 13 and 14 from the anode 19 to the direct current applying focusing electrode 17. A shield tab 24 is installed to block a high voltage from flowing to the condenser, and the condenser electrode 18 and the stem pin 27 are connected to the conductive wire 26 so that an alternating voltage can be applied to the condenser electrode 18. In the electron gun for the color cathode ray tube connected is configured;

Instead of the shield tab mounted on the DC applying focusing electrode 17, the vibration generated by the AC applying focusing electrode 18 is attenuated by a change in the amount of charge generated on the electrode surface according to the application of the AC voltage. Conductive damping member 31 that can reduce the transmission of vibration to the entire electron gun 100 and the neck glass 22 is mounted.

In addition, the conductive damping member 31 is positioned at each upper end of the bead glass 23 and surrounds the bead glass 23 so as to be mounted on and fixed to the upper and lower surfaces of the direct current applying focusing electrode 17. However, the conductive thin plate 33 having an arc-shaped electrode folding part 34 formed at the center thereof is fixed to the upper end of the conductive thin plate 33 to attenuate the vibration of the alternating current applying focusing electrode 18 generated by applying an alternating voltage. It is composed of a damping material 32 to block the transfer to the entire electron gun 100 and the neck glass 22 through the direct current application focusing electrode 17.

Hereinafter, the color cathode ray tube electron gun of the present invention will be described in detail.

Figure 6 is a cross-sectional view showing the main portion of the cathode ray tube electron gun of the present invention in the bottom state, Figure 7 is a perspective view of a conductive damping member applied to the electron gun of the present invention, Figure 8 is a cross-sectional view of the electron gun fixed to the neck glass It is shown.

The color cathode ray tube electron gun 100 of the present invention attenuates vibration generated from the alternating current applying electrode 18 by applying alternating current voltage through a conductive damping member 31 mounted on the direct current applying focusing electrode 17. At the same time, the transmission of the electron gun 100 through the neck glass 22 through the direct current applying focusing electrode 17 is reduced.

At this time, the conductive damping member 31 is fixed to the upper and lower surfaces of the direct current applying focusing electrode 17, as shown in FIG. 7, and has a high voltage from the anode 19 to the triodes 12, 13 and 14, respectively. It consists of a conductive thin plate 33 to block the flow, and a damping material 32 is fixed to the top of the conductive thin plate 33 to attenuate the vibration generated from the alternating applied focusing electrode 18, the double conductive thin plate ( 33 is positioned at each upper end of the bead glass 23 which is fixed at regular intervals by fusing each of the electrodes 12 to 19 constituting the electron gun 100 to surround the bead glass 23 and apply a direct current applying electrode. It is formed in a rectangular flat plate of a predetermined size so that it can be fixed to the mounting (17), and fixed to the upper and lower surfaces of the direct-current applying focusing electrode 17 by the arch-shaped electrode folding portion 34 formed in the center of both ends of the plate It is formed to be.

In addition, the damping material 32 is fixed to the upper end of the conductive thin plate 33, the damping coefficient of the damping material 32 to attenuate the vibration of the alternating current applying electrode 18 generated by the alternating voltage application Is formed of a material larger than the attenuation coefficient of the electrodes, or is formed in a shape that can cause attenuation mechanically. Particularly, the vibration generated from the alternating current applying electrode 18 causes the direct current applying focusing electrode 17 to Through the electron gun 100 and the neck glass 22 is formed to block the transmission.

The conductive damping member 31 configured as described above is mounted to be positioned between the bead glass 23 and the neck glass 22. A structure in which the conductive damping member 31 is installed will be described in detail with reference to FIG. As shown in the figure, the conductive thin plates 33 are positioned on the upper ends of each of the bead glasses 23 holding the direct current applying focusing electrode 17 to which the DC voltage is applied, so as to surround the bead glass 23. 33) The arc-shaped electrode folding part 34 formed at the centers of both ends is fixed to the upper and lower surfaces of the direct current applying focusing electrode 17, and the alternating current applying focus generated by applying an alternating voltage to the upper end of the conductive sheet 33. Since the damping material 32 that damps the vibration of the electrode 18 is fixed, the entire conductive damping member 31 is fixed to be positioned between the neck glass 22 and the bead glass 23.

9 is a natural frequency ratio according to the damping coefficient (a ratio of the frequency to the natural frequency ratio of the electron gun to vibrate according to the change in the charge amount of the alternating current or the applied electrode applied the alternating voltage) and the amplitude ratio (generated at DC voltage It is shown that the displacement caused by the force generated when the AC voltage is applied to the displacement caused by the force). This means that the displacement of the damping coefficient is significantly increased in the case of a structure having a small instantaneous damping coefficient having a natural frequency ratio of 1. That is, when an input signal of a frequency similar to the natural frequency of a structure is input, the structure is amplified by vibration and the vibration is reduced as the attenuation coefficient increases.

Recognizing the relationship between the natural frequency ratio and the amplitude ratio according to the damping coefficient and looking at the damping member 31 applied to the present invention, the vibration of the alternating current application focusing electrode 18 generated by the alternating voltage applied to the material having a high damping coefficient When the damping material is reduced by the damping material 32 formed and the natural frequency ratio approaches 1, the generation displacement of the damping coefficient becomes extremely small, so that the influence of the entire electron gun 100 or the neck glass 22 is not large. Reduced vibration is transmitted to the whole electron gun 100 or the neck glass 22, and the vibration width (X1 / X2) generated by the damping member 31 at the alternating current applying electrode 18 elapses over time. 10 illustrates a state of decreasing exponentially (see Equation 4).

(Equation 4)

Where ζ << 1

For this reason, it can be seen from the graph shown in FIG. 10 that the electromagnetic gun 100 of the present invention to which the conductive damping member 31 is applied has less occurrence of high frequency noise than the electron gun 3 to which the conventional shield tab 24 is applied. have.

Hereinafter, the effect | action of the color cathode ray tube electron gun which is this invention is demonstrated.

11 illustrates a state in which vibration is attenuated in the focusing electrode to which the conductive damping member is applied.

The operation of the present invention describes only the operation of the conductive damping member 31 fixed to the direct current applying focusing electrode 17.

When an alternating current voltage is applied to the alternating current applying electrode 18, the focusing electrode 18 vibrates with a constant amplitude while the electrostatic force generated by the change of the amount of charge charged on the alternating application focusing electrode 18 is applied. The vibration generated as described above is transmitted to the direct current applying focusing electrode 17 through the bead glass 23 which is fixed at regular intervals by fusion bonding the electrodes 12 to 19.

The conductive damping member 31 composed of the conductive thin plate 33 and the damping material 32 is fixed to the direct current applying focusing electrode 17 to which the vibration is transmitted as described above, so that the damping coefficient of the damping member 31 is large. While the vibration transmitted to the direct current applying focusing electrode 17 is attenuated by the damping material 32 formed of a material or formed into a shape capable of mechanically attenuating, the entire electron gun 100 or the neck glass ( Reduced vibrations that do not significantly affect 22 are transmitted to the entire electron gun 100 or the neck glass 22.

Further, the bead glass 23 is fixed to the bottom surface of the damping material 32 to fuse each of the electrodes to be fixed at regular intervals so that the bead glass 23 is wrapped in an arc-shaped electrode folding part on the upper and lower ends of the DC applying focusing electrode 17. The high voltage applied to the positive electrode 19 by the conductive thin plate 33 to which the 34 is fixed is prevented from flowing into the negative electrode 12, the control electrode 13, and the accelerating electrode 14, which are three-pole portions, thereby blocking the three-pole. To protect the parts 12, 13 and 14.

As described above, the color cathode ray tube electron gun 100 according to the present invention effectively attenuates the vibration generated by the alternating current applying electrode 18 by the conductive damping member 31 mounted and fixed to the direct current applying focusing electrode 17, Accordingly, it is an excellent invention that can effectively remove the high frequency noise generated when driving the conventional color cathode ray tube to improve the image quality of the color cathode ray tube.

As described above, in the electron gun for color cathode ray tube of the present invention, a conductive damping member is attached to a direct current applying focusing electrode to which a direct current voltage is applied, and the alternating current applying focus according to the application of an alternating voltage by the conductive damping member. Along with the effect of reducing the vibration generated in the electrode, the vibration is prevented from being transmitted to the entire electron gun and the neck glass to prevent high frequency noise of resonance caused by matching with the natural frequency of the neck glass, There is an excellent effect that the image quality is improved.

In addition, the high voltage applied to the anode by the conductive damping member mounted on the direct current applying focusing electrode blocks and prevents the high voltage applied to the cathode from flowing into the cathode, the control electrode, and the acceleration electrode, thereby protecting the cathode of the cathode.

Claims (4)

In order to improve the image quality of the color cathode ray tube, two or more focusing electrodes are mounted so that the focusing intensity can be changed according to the position of the screen. The direct current applying focusing electrode and the anode positioned in front of the alternating application focusing electrode and focused on the bead glass are fused and fixed to the bead glass, respectively, and the high voltage flows from the anode to the direct current applying focusing electrode to the tripolar portion. In the electron gun for the color cathode ray tube equipped with a shielding tab for blocking, the focusing electrode and the stem pin is connected by a conductor so that an alternating voltage is applied to the focusing electrode; Instead of the shield tab mounted on the DC applying focusing electrode, the vibration generated by the AC applying focusing electrode is attenuated by a change in the amount of charge generated on the electrode surface according to the application of alternating voltage, and the vibration is generated by the entire electron gun and the neck. Color cathode ray tube electron gun, characterized in that the conductive damping member is configured to reduce the transmission to the glass. The electrode of claim 1, wherein the conductive damping member is positioned at each upper end of the bead glass and is surrounded by the bead glass so as to be fixed to the upper and lower surfaces of the direct current applying focusing electrode. A ground plate fixing is formed on the conductive plate and the top of the conductive sheet is fixed to attenuate the vibration of the alternating current applying electrode generated by the alternating voltage application, while blocking the transmission to the electron gun and the neck glass through the direct current applying the focusing electrode Color cathode ray tube electron gun, characterized in that composed of a damping material. The color cathode ray tube electron gun according to claim 1, wherein the damping coefficient of the damping material, which is a component of the conductive damping member, is formed of a material larger than the damping coefficient of the electrodes. The color cathode ray tube electron gun according to any one of claims 1 to 2, wherein the conductive damping member is formed in a shape capable of mechanically damping vibration.