KR20030088260A - The Cathode-Ray-Tube - Google Patents

Abstract

PURPOSE: A color cathode ray tube is provided to achieve improved sensitivity of cathode ray tube by improving the shape of the mount supporter and preventing vibrations of the electron gun. CONSTITUTION: An electron gun comprises a cathode for emitting electron beams toward a phosphor screen; a plurality of electrodes for focusing and accelerating the electron beams; and a bead glass(23) for supporting the electrodes. A mount supporter(29) for fixing the electron gun to a stem has a surface on which a stem pin(27) is welded, wherein the surface is not parallel to the in-line direction of the electron gun.

Description

Color Cathode Ray Tube {The Cathode-Ray-Tube}

The present invention relates to an electron gun for a cathode ray tube, and more particularly, to an electron gun for a cathode ray tube that improves the sensitivity of a cathode ray tube by changing the shape of a mount supporter for fixing the electron gun to a stem to prevent vibration of the electron gun when an alternating current is applied to the stem pin. .

As shown in FIG. 1, the conventional flat color cathode ray tube structure includes a front glass called panel 1 and a rear glass called funnel 2, and a fluorescent surface having a predetermined light emission therein, and the fluorescent surface. An electron gun 8 emitting an electron beam 11 emitting light, a shadow mask 3 serving as color screening, a frame 4 for welding and fixing the shadow mask, a stud pin 6 and a spring 5; It consists of. In addition, the inner shield 7 which serves to shield the cathode ray tube so as to be less affected by external geomagnetism during operation is fixed to the frame 4 and is sealed with high vacuum.

The general principle of cathode ray tube operation is as follows. In the electron gun 8 embedded in the neck of the funnel 2, the electron beam 11 strikes the fluorescent surface formed on the inner surface of the panel 1 by the anode voltage applied to the cathode ray tube, and the electron beam reaches the fluorescent surface. Before the deflection yoke (9) is deflected up, down, left and right to form a screen. And there is a magnet to correct the trajectory so that the electron beam hits the phosphor accurately, thereby preventing poor color purity. In addition, since the cathode ray tube is made of high vacuum, it may be easily deflated due to external impact. To prevent this, the reinforcing band 10 is mounted on the skirt portion of the panel to disperse the stress of the cathode ray tube in a high vacuum state, thereby improving impact resistance. Secure.

Referring to the configuration of the electron gun in detail with reference to the drawings, as shown in Figure 2, the cathode 12 for generating an electron beam, the first electrode 13 is spaced apart from the cathode by a predetermined distance, and a predetermined distance from the first electrode The second electrode 14, the third electrode 15, and the fourth electrode 16 arranged in this manner, the focusing electrodes 17, 18 and the anode 19 arranged to be separated by a predetermined distance from the fourth electrode; It is attached to the anode end is composed of a shield cup 20 for shielding the leakage magnetic field and the BSC 28 for supporting the electron gun. The electrodes are fixed by the bead glass 23 while maintaining a constant interval, the electron gun is inserted into the neck glass 26 constituting the neck portion of the funnel (2) and the neck glass from the outside to the voltage to the electron gun The stem pin 27 and the mount supporter 29 are connected to each other in the stem 25 to be applied to the cathode ray tube.

Referring to the operation of the electron gun, the heater 22 embedded in the cathode 12 receives the voltage applied to the stem pin 27 to emit electrons, and the emitted electrons are the first electrode 13 which is a control electrode. The electron beam is controlled by the second electrode 14, which is an acceleration electrode, and the UPF lens is formed between the third electrode 15, the fourth electrode 16, and the focusing electrode 17. The electron beam is partially focused, and the electron beam is mainly focused and accelerated by the focusing electrode 18 and the anode 19 to pass through the shadow mask 3 provided on the inner surface of the fluorescent surface and collide with the fluorescent surface to generate light. In addition, the electron beam 11 emitted from the electron gun is deflected to the entire screen by the deflection yoke 9 mounted to the outside of the electron gun, thereby realizing a screen.

In general, in order to improve the image quality of the color cathode ray tube, an AC voltage, for example, a dynamic voltage, is applied to one or two or more electrodes of the focusing electrodes 17 and 18 of the electron gun. Then, the AC voltage induced at each point outside the neck glass can be measured, and the voltage induced at the neck glass is induced at about 55 to 80% of the applied voltage. 3A illustrates an AC voltage induced at each point outside the neck glass, and FIG. 3B illustrates a position where the AC voltage of FIG. 3A is measured.

The total voltage V applied to the electron gun is as follows.

In the above formula, V _DC is a DC voltage applied to each electrode of the electron gun, that is, the first electrode, the second electrode, the cathode, the heater, and the like, and V _AC cos t is an AC voltage applied to the focusing electrode, Is the angular frequency of the AC voltage, and t is the time.

When the alternating current voltage is applied to the focusing electrode, the electrostatic force F (t) is applied between the neck glass and the focusing electrode to which the alternating voltage is applied by the charge induced on the surface of the neck glass.

In the above formula _b is the surface charge density of the neck glass, ₀ is the dielectric constant in vacuum, and C is the capacitance between the focusing electrode and the neck glass to which an alternating voltage is applied.

When such forces act, the forces of the third, fourth, and fifth terms of the equation are alternating current components, cos It can be greatly changed with time by the t component, causing vibration to the focusing electrode 18 to which an AC voltage is applied as shown in FIG. 4.

The force F (t) acting between the electrode facing the alternating voltage is applied as follows.

Where S is the opposite surface between the electrodes, dV is the potential difference between the electrodes, and D is the distance between the electrodes.

The vibration generated from the focusing electrode 18 to which an alternating voltage is applied by the force as described above vibrates the electron gun as a whole, and the vibration is transmitted to the stem 25 through the mount supporter 29 and the stem pin 27, The neck glass 26 connected to the stem is vibrated. At this time, when the vibration generated from the electron gun coincides with the resonance frequency of the neck glass, the vibration is further amplified to generate a much larger vibration than the first vibration generated by the focusing electrode, thereby amplifying high frequency noise.

Meanwhile, FIGS. 5A to 5B illustrate a shape in which the conventional mount supporter 29 is inserted into the bead glass 23. As illustrated, the conventional mount supporter 29 has a transverse direction, that is, an X axis direction of the electron gun. The pin pin 23 is inserted into the bead glass 23 in parallel, and the stem pin 27 is welded on the inserted mount supporter 29.

5C is a sectional view of the electron gun when the cathode ray tube is viewed from the rear, and the arrow shows the direction of vibration generation. That is, the conventional welding of the mount supporter 29 and the stem pin 27 is made in the transverse direction, so it is vulnerable to the vibration in the vertical direction.

Accordingly, the present invention to solve the above problems, by changing the shape of the mount supporter for fixing the electron gun to the stem to prevent the vibration of the electron gun when applying an alternating voltage to provide an electron gun for cathode ray tube to improve the sensitivity characteristics of the cathode ray tube For the purpose of

1 is a structural diagram of a typical color cathode ray tube

2 is a structural diagram of a typical cathode ray tube electron gun

3A to 3B are diagrams showing the distribution of AC voltage in the conventional cathode ray tube neck portion.

4 is a view showing the operation principle of the prior art

Figure 5a is a view showing the welding shape of the conventional mount supporter and the stem pin

FIG. 5B is an enlarged view of portion A of FIG. 5A

Fig. 5C is a cross sectional view of a welded portion of the mount supporter and the stem pin as seen from behind the cathode ray tube;

6a to 6b is a view showing the welding shape of the mount supporter and the stem pin

Figure 7a is a view showing the vibration shape of the conventional mount supporter

Figure 7b is a view showing the vibration shape of the mount supporter according to the present invention

*** Explanation of symbols for the main parts of the drawing ***

23: Bead glass 25: Stem

27: stem pin 29: mount supporter

The technical means of the present invention for achieving this object is a cathode ray tube electron gun comprising a cathode for emitting an electron beam toward the phosphor screen, a plurality of electrodes for focusing and accelerating the electron beam, and a bead glass for supporting the electrodes The stem pin welding surface of the mount supporter for fixing the electron gun to the stem is not parallel to the in-line direction of the electron gun.

In addition, the stem pin welding surface of the mount supporter is characterized in that the angle of the in-line direction of the electron gun is 0 ~ 45 degrees.

Preferably, three or four mount supporters in the electron gun are mounted.

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

FIG. 6A illustrates the configuration of the present invention. As shown in FIG. 6A, the welding surface of the stem pin 27 of the mount supporter 29 is formed to have an angle equal to the horizontal direction of the electron gun, that is, the x axis direction and θ.

6B is a cross-sectional view of the electron gun equipped with the mount supporter 29 of the present invention configured as described above seen from the cathode ray tube. The dotted line is a diagram of the vibration direction, and it can be seen that the vibration in the vertical direction is reduced compared to the prior art of FIG. 5C.

Hereinafter, the vibration reduction effect according to the present invention will be described in detail. In the related art, since the surface of the mount supporter 29 to which the stem pin 27 is welded is parallel to the inline direction of the electron gun as shown in FIG. 7A, the mount supporter 29 is well deformed against the vibration in the vertical direction (y-axis direction). . That is, three to four mount supporters 29 supporting the electron gun are directed in the transverse direction of the electron gun, that is, in the x-axis direction. When the stem pin 27 is welded to the mount supporter 29, the entire electron gun 3 is supported. Is vulnerable to vibration in the vertical direction, and vibration in the vertical direction occurs.

However, when the mount supporter 29 according to the present invention is applied, vibration is generated in a direction perpendicular to the welding surface forming an angle by the x-axis and θ as shown in FIG. 7B, wherein the vibration in the vertical direction is a cos θ component. Only a small vibration is generated. When the mount supporter is composed of three to four as shown in FIG. 6B, the vibration in the lateral direction, that is, the x-axis direction, is canceled and the vibration in the vertical, ie, y-axis direction, is relatively small. It will be reduced than before.

As described above, in order to improve the image quality of the cathode ray tube, the electrostatic force generated by the alternating amount of charge charged on the surface of the electrode by the alternating voltage applied to a part of the focusing electrode is opposite to the neck glass and the anode. When the vibration occurs when the vibration coincides with the natural frequency of the neck glass, a resonance occurs in the neck glass to amplify the noise, thereby fixing the electron gun to the stem 25 to prevent the sensitivity of the cathode ray tube from deteriorating. By changing the shape of the mount supporter 11, which serves to suppress the vibration of the bead glass and reduce the vibration transmitted to the neck glass to effectively remove the high frequency noise generated when driving the cathode ray tube to improve the sensitivity characteristics of the cathode ray tube. You can.

Claims (3)

An electron gun for a cathode ray tube comprising a cathode for emitting an electron beam toward a phosphor screen, a plurality of electrodes for focusing and accelerating the electron beam, and a bead glass for supporting the electrodes, Electron gun for cathode ray tube, characterized in that the stem pin welding surface of the mount supporter for fixing the electron gun to the stem is not parallel to the in-line direction of the electron gun. The method of claim 1, Electron gun for the cathode ray tube, characterized in that the angle of the stem pin welding surface of the mount supporter and the in-line direction of the electron gun is 0 ~ 45 degrees. The method of claim 1, Electron gun for the cathode ray tube, characterized in that three or four mount supporters in the electron gun is mounted.