KR100813827B1 - Electron gun and CRT utilizing the same - Google Patents

Abstract

According to the present invention, a cathode forming a three-pole portion, a control electrode and a screen electrode which is installed adjacent to the cathode and spaced apart by a coupling means, a plurality of focus electrodes sequentially installed from the screen electrode, and At least one of the focus electrodes is divided into a plurality of split electrodes and supports each split electrode together, and a final accelerating electrode disposed adjacent to the focus electrode at a final position from the cathode or surrounding the outer circumferential surface of the focus electrode. And bead glasses for fixing the electrodes.

Description

Electron gun and cathode ray tube using same {Electron gun and CRT utilizing the same}

1 is a cross-sectional view showing a typical cathode ray tube,

2 is a perspective view showing a conventional electron gun,

3 is a partial cross-sectional view of a cathode ray tube having an electron gun according to the present invention;

4 is a perspective view showing a support embedded in bead glass and a split electrode supported by the support;

5 is a perspective view showing another example of a support embedded in bead glass and a split electrode supported by the support;

Figure 6 is a perspective view showing another embodiment of the support.

<Description of the symbols for the main parts of the drawings>

40; Bulb

50; Electron gun.

55; Second focus electrode,

55a, 55b, 55c; Split electrode (forming the second focus electrode)

80; Support

The present invention relates to a cathode ray tube, and more particularly, to an electron gun mounted on a neck portion of a cathode ray tube to emit an electron beam for exciting a fluorescent film and a cathode ray tube using the same.

Generally, there are various types of cathode ray tubes according to functional characteristics such as a projector, an oscilloscope, a monitor, and a TV. FIG. 1 shows an example of such cathode ray tubes.

As illustrated, the panel 12 includes the fluorescent film 11 and the funnel 15 encapsulated with the panel, and the electron gun 20 is enclosed in the neck 13. A deflection yoke 16 for deflecting the electron beam emitted from the electron gun 20 is installed at the cone of the funnel 15. In addition, a velocity modulator (hereinafter, referred to as a VM coil) to which a differential value of an image signal is applied is installed on an outer circumferential surface of the neck 13 to control the deflection speed of the electron beam caused by the deflection yoke. Herein, the panel and the funnel may be formed integrally, and the inside of the panel may be equipped with a shadow mask frame assembly, but may be a monochromatic tube such as a cathode ray tube used in a projector, an oscilloscope, or the like. In this case it is not necessary.

The electron gun mounted on the neck portion may vary depending on the cathode ray tube forming the monochrome image or the color image, the arrangement state of the electrodes constituting the electron gun, and the state of the voltage applied to each electrode. Showed.

The electron gun as shown is disclosed in U.S. Patent No. 4,904,898. The cathode 21, the control electrode 22 and the screen electrode 23 for emitting hot electrons are sequentially installed adjacent to the screen electrode. An upper focusing electrode 24 and a lower focusing electrode 25 and a final accelerating electrode 26 surrounding the end of the upper focusing electrode 25 are provided. Each electrode constituting the electron gun has support portions formed at both sides thereof and is fixed by a pair of bead glass 27.

In the cathode ray tube equipped with the electron gun 20 configured as described above, the electron beam emitted from the cathode of the electron gun is focused and accelerated through an electron lens formed between each electrode constituting the electron gun. As described above, the focused and accelerated electron beam is selectively deflected by the deflection yoke according to the dice of the fluorescent film to excite the fluorescent film. In this process, in order to make the difference between the bright and dark areas of the image formed by the excitation of the fluorescent film more clear, a current proportional to the derivative value is applied to the VM coil according to the image signal, so that the bright and dark areas of the image The contrast of the image can be improved by adjusting the deflection speed by means of the deflection yoke. This method is to improve the contrast of the image by controlling the instantaneous scanning speed of the electron beam as a two-pole coil mounted in the same direction as the horizontal deflection magnetic field of the deflection yoke.

By the way, the focus electrode of the electron gun mounted at a position corresponding to the site where the VM coil is installed has a cylindrical shape, and the high frequency current generated by the VM coil generates a eddy current on the surface of the electrode. This eddy current generates a magnetic field generated by the nose in a reverse direction, which causes a decrease in the sensitivity of the electron beam to the current of the VM coil. As a result, the resolution of the image is reduced due to the decrease in the deflection force of the electron beam.

An electron gun for a cathode ray tube for solving such a problem is disclosed in Patent Application No. 99-35188. The disclosed electron gun is provided with eddy suppression means, and is formed by forming a plurality of slots in the longitudinal direction or the circumferential direction on the focus electrode. Such an electron gun has a problem that it is difficult to suppress the mandrel current generated on the surface of the focus electrode by the VM coil with only the slot formed in the focus electrode.

In order to solve such a problem, conventionally, a plurality of focus electrodes are divided into divided electrodes, and a single potential is applied to them.

However, such a configuration is difficult to align when the split electrodes are fixed to the bead glass, and the alignment state of the split electrodes fixed to the bead glass is disturbed by the pressing force when welding the metal connector for supplying voltage to each split electrode. have.

The present invention is to solve the above problems, it is possible to prevent the deflection sensitivity is lowered due to the eddy current due to the VM coil and improve the alignment state of the split electrodes located on the side corresponding to the VM coil. The purpose is to provide an electron gun and a cathode ray tube using the same.

Another object of the present invention is to provide an electron gun and a cathode ray tube using the same that do not require the installation of a connector for supplying voltage to each split electrode.

Electron gun for cathode ray tube of the present invention to achieve the above object                     

A cathode constituting a triode, a control electrode and a screen electrode which are installed adjacent to the cathode and are fixed to be spaced apart by a coupling means, a plurality of focus electrodes sequentially installed from the screen electrode, and at least one of the focus electrodes A focus electrode of which is divided into a plurality of split electrodes and supports the split electrodes together, a final accelerating electrode installed adjacent to the focus electrode at a final position from the cathode or surrounding an outer circumferential surface of the focus electrode; It is characterized by including bead glass for fixing the electrodes.

In the present invention, an opening is formed by cutting a portion corresponding to between the split electrodes.

In order to achieve the above object, the color cathode ray tube of the present invention,

A bulb including a screen surface having a fluorescent film formed thereon and a funnel portion having a neck portion at a side corresponding to the screen surface;

 A velocity modulator mounted on the neck portion of the bulb;

 It is installed in the neck portion, a cathode forming a tripolar portion, the control electrode and the screen electrode is installed adjacent to the cathode and spaced apart by the coupling means, and a plurality of focus sequentially installed from the screen electrode Electrodes, a focus electrode corresponding to the velocity modulator, is divided into a plurality of split electrodes and supports the split electrodes together, and is installed adjacent to the focus electrode at a final position from the cathode or An electron gun including a final acceleration electrode surrounding an outer circumferential surface and bead glasses for fixing the electrodes;

And a deflection yoke mounted on the bulb and deflecting the electron beam emitted from the electron gun.

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

One embodiment of the cathode ray tube according to the present invention is shown in Figs.

As shown in the drawing, the cathode ray tube is a panel portion (not shown) having a fluorescent film formed on an inner surface thereof, and is sealed to the panel portion, and includes a bulb including a neck portion 41 and a funnel portion 43 having a cone portion 42 ( 40). An electron gun 50 is enclosed in the neck part 41, and a deflection yoke 60 is provided on an outer circumferential surface of the cone part to deflect the electron beam emitted from the electron gun 50. On the outer circumferential surface of 41a), a VM coil 70 is provided for controlling the deflection speed of the electron beam emitted from the electron gun to clarify dark and bright portions of the image.

Here, the electron gun 50 is mounted on the neck portion 41 of the bulb 40, and the cathode assembly 51, the control electrode 52 and the screen electrode 53, which form a triode, and the screen electrode ( 53 and a plurality of first and second focus electrodes 54 and 55 installed adjacent to the second focus electrode 55 that is farthest from the cathode assembly 51 and are provided with an extension. The final acceleration electrode 56 is formed to surround the outer circumferential surface of the electrode 55 at a predetermined interval to form a main lens. Among the electrodes constituting the electron gun, an electrode corresponding to the VM coil 70, that is, the second focus electrode 55, has a second focus electrode 55 in order to suppress generation of a eddy current by the VM coil 70. Are separated into a plurality of split electrodes 55a, 55b, 55c.

On the other hand, each electrode constituting the electron gun is supported by a pair of bead glass 57, each electrode has an electrode support or integral support formed integrally with the electrode.

In FIG. 4, the split electrodes 55a, 55b, 55c constituting the second focus electrode 55 according to the present invention are fixed to the bead glass 57 by the support 80.

Referring to the drawings, the support body 80 supporting the split electrodes 55a, 55b and 55c of the second focus electrode 55 maintains a predetermined interval between the split electrodes 55a, 55b and 55c. And a fixed portion 81 fixed with a sieve, and a buried portion 82 extending from both edges of the fixed portion 81 and embedded in the bead glass 57. The buried protrusions 82b are formed in the buried portions 82 and 82 by forming a dove tail-shaped cutout portion 82a so as to be easily embedded in the softened bead glass 57. Here, the buried protrusion 82b is not limited to the above-described embodiment and may be any structure as long as the structure can fix the electrode to the bead glass 57.

As shown in FIG. 5, the support 80 corresponds to between the split electrodes 55a, 55b and 55c in the fixing part 81 where the split electrodes 55a, 55b and 55c are fixed. The site is excised to form the opening 81a. Preferably, the opening 81a extends to the buried portion 82.

The buried portion is not limited to the above-described embodiment, and may be any structure that can support the split electrodes as a support having a single body. for example. 6, the buried portion may be formed only at the edge of one side of the fixing portion.

A connector is connected to each of the electrodes constituting the electron gun to apply a voltage for driving the electron gun. The split electrodes constituting the second focus electrode have a single connector (not shown) on the support 80. Is connected to apply a voltage.

Referring to the operation of the electron gun and the cathode ray tube having the same as described above are as follows.

In the cathode ray tube, the electron beam emitted from the electron gun is deflected by the deflection yoke and landed on the fluorescent film to form an image. In this process, a voltage is applied to the VM coil to clarify the difference between the dark and bright areas of the image. A voltage is applied to delay the deflection of the electron beam. The application of this voltage creates an alternating polarity or magnetic field by the VM coil. Accordingly, since the second focus electrode 55 of the electron gun, which is a metal corresponding thereto, is composed of a plurality of split electrodes 55a, 55b, 55c, and spaced apart from each other at predetermined intervals, the occurrence of eddy current is suppressed. do. That is, since the split electrodes 55a, 55b, and 55c are spaced apart from each other, and openings are formed in the support 80 supporting the split electrodes 55a, 55b, and 55c, the eddy current is blocked without forming a closed curve. Accordingly, heat generation and current loss due to the generation of the eddy current of the second focus electrode 55 may be reduced, and the sensitivity of the VM coil may be increased.

In particular, the split electrodes 55a, 55b and 55c constituting the second focus electrode 55 may be supported by a single support to increase their alignment degree, and the deformation according to the maintenance of the spacing between the split electrodes may be improved. It can prevent and improve the quality of electron gun.

As described above, the electron gun of the present invention and the cathode ray tube using the same can support the split electrodes by using a single support, thereby reducing productivity of work due to alignment, thereby improving productivity, and in particular, connecting the connector to the support. As a result, voltages can be supplied to the three divided electrodes at the same time, thereby preventing the change and the position change of the divided electrodes due to the welding of the connector to each of the divided electrodes as in the related art.

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

Claims (9)

A cathode constituting a triode, a control electrode and a screen electrode which are installed adjacent to the cathode and are fixed to be spaced apart by a coupling means, a plurality of focus electrodes sequentially installed from the screen electrode, and at least one of the focus electrodes A focus electrode of which is divided into a plurality of split electrodes and supports the split electrodes together, a final accelerating electrode installed adjacent to the focus electrode at a final position from the cathode or surrounding an outer circumferential surface of the focus electrode; Electron gun for cathode ray tube, characterized in that it comprises a bead glass for fixing the electrodes. The method of claim 1, The support is a cathode ray tube electron gun, characterized in that it comprises a fixing portion for fixing each of the split electrodes, and a buried portion extending from at least one side of the edge of the fixing portion. The method of claim 2, An electron gun for a cathode ray tube, characterized in that an opening is formed in a portion corresponding to between the split electrodes. The method of claim 3, The opening is an electron gun for a cathode ray tube, characterized in that extending from the fixed portion to the buried portion. The method of claim 1, An electron gun for a cathode ray tube, characterized in that a connector for supplying voltage to each of the divided electrodes is connected to the support or at least one divided electrode. A bulb including a screen surface having a fluorescent film formed thereon and a funnel portion having a neck portion at a side corresponding to the screen surface; A velocity modulator mounted on the neck portion of the bulb; It is installed in the neck portion, a cathode forming a tripolar portion, the control electrode and the screen electrode is installed adjacent to the cathode and spaced apart by the coupling means, and a plurality of focus sequentially installed from the screen electrode Electrodes, a focus electrode corresponding to the velocity modulator, is divided into a plurality of split electrodes and supports the split electrodes together, and is installed adjacent to the focus electrode at a final position from the cathode or An electron gun including a final acceleration electrode surrounding an outer circumferential surface and bead glasses for fixing the electrodes; And a deflection yoke mounted on the bulb and deflecting the electron beam emitted from the electron gun. The method of claim 6, The support is a cathode ray tube, characterized in that it comprises a fixing portion for fixing each of the divided electrodes, and a buried portion extending from at least one side of the edge of the fixing portion. The method of claim 7, wherein Cathode ray tube, characterized in that the fixing portion has an opening formed in a portion corresponding to between the split electrodes. The method of claim 6, And a connector for supplying voltage to each of the divided electrodes to the support or at least one divided electrode.

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