KR20030077267A - Improved structure of electron gun in cathode ray tube, and it's method of improvement - Google Patents

Abstract

PURPOSE: An enhancement structure and a method thereof are provided to lower the defective ratio of electron gun of cathode ray tube by preventing damages of cathode. CONSTITUTION: An electron gun(100'') comprises a cathode(110) and a first grid(120) covering one side of the cathode. A gap is formed between a terminal(112) of the cathode and the first grid. A spacer(180') is arranged around the gap and supports the first grid. The spacer has an extended portion(182) extended in a central direction from the inner of the spacer. A gap(d5) is formed between an end of the extended portion and a body(113) of the cathode.

Description

IMPROVED STRUCTURE OF ELECTRON GUN IN CATHODE RAY TUBE, AND IT'S METHOD OF IMPROVEMENT

The present invention relates to an electron gun in a cathode ray tube, and more particularly, to an improved structure and method of an electron gun in a cathode ray tube for protecting a cathode during high pressure treatment, which is carried out for the purpose of responding to stray emission in a cathode ray tube. will be.

In general, in a cathode ray tube, an electron gun emits and focuses electrons and collides an electron beam that accelerates them with a fluorescent surface to form a predetermined image on a display screen of a panel. The electron gun needs three electron beams to emit red, green, and blue fluorescent points separately, and three electron guns are provided in the cathode ray tube.

In addition, stray emission refers to the fact that a small leakage current exists to cause the phosphor to emit light although it does not reach discharge, and is classified into a G1 stray, a G2 stray, and a G3 stray.

G1 strays are caused by cathodic decomposition aging or other factors that cause the carbonate crystals to evaporate and adhere to the holes in the first grid, while the G2 strays evaporate carbonate crystals past the first grid and onto the second grid. It is caused by one case or by foreign matter. When G3 strays have micro projections, tips, and foreign materials on the third grid, the entire area becomes stronger than the surroundings, and field emission occurs. This severe phenomenon is called discharge or fluorescence.

1 is a schematic side view showing the structure of an electron gun in a cathode ray tube.

In the structure of the electron gun 100 in the cathode ray tube 1, the color CRT and the monochrome CRT are generally the same, but in the case of the CRT, the convergence electrode 160 is placed at the tip of the fourth grid 150. There is one more electrode that is not in the black and white CRT.

Heaters (111) embedded in each cathode (110) are interconnected in parallel and in series, the cathode (110), the first grid (control electrode; 120), the second grid (screen electrode; 130, the third grid (focus electrode) 140, and the fourth grid (anode applying electrode) 150 are applied with separate voltages to each. In addition, since the fourth grid 150 and the converging electrode 160 are connected to each other, the same voltage is applied to the whole.

Next, an operation relationship of each electrode illustrated in FIG. 1 with respect to one electron gun 100 will be described.

The cathode 110 heated by the heater 111 emits hot electrons E at the terminal portion 112 made of oxide, which is connected to the positive voltage of the second grid 130. As it is attracted, it is accelerated in the axial direction through the small hole 121 of the first grid 120, and the first grid 120 is applied with a negative voltage (-) than the cathode 110. The flow is controlled. Meanwhile, a high voltage of 20,000 to 25,000 V applied to the anode terminal 210 embedded in the funnel 200 is applied to the fourth grid 150 through an internal conductive film (not shown), and to the third grid 140. A voltage of 4,000 to 5,000 V corresponding to 1/5 to 1/6 of the voltage of the anode terminal 210 is applied.

The electron flow passing through the second grid 130 is accelerated toward the third and fourth grids 140 and 150, and after passing through the fourth grid 150, the fluorescent surface inside the panel 300 at a constant speed. It is rushing toward the 310, the electron flow is focused in the form of a beam by the action of the electrostatic lens consisting of the third grid 140 and the fourth grid 150 to reach the fluorescent surface 310. .

2 is an enlarged plan view of the structure of a conventional electron gun for the portion "A" of FIG. 1, and FIG.

Referring to the structure of the conventional electron gun 100 ′ as shown in FIG. 2, a bidirectional through retainer 170 is provided at one side of the first grid 120, and the heater 170 is provided inside the retainer 170. A cathode 110 having a built-in 111 is provided.

One end of the cathode 110 is drawn out from the inside of the retainer 170 so that the terminal portion 112 formed at the end of the end is located close to the first grid 120, and the first grid 120 is located. A cap-shaped spacer 180 is provided between the retainer 170 and the retainer 170 so that the first grid 120 and the retainer 170 are spaced apart from each other.

The spacer 180 has a through hole 181 formed at the center thereof so that the terminal 112 of the cathode 110 and one surface of the first grid 120 face each other, and the through hole 181 is the terminal part. Located around circumference 112, the inner end 181a of the through hole 181 is bent and extended toward the retainer 170.

The outside of the first grid 120 is surrounded by a bead glass 190 formed in the axial direction of the electron gun 100 ', and the first grid 120 is supported by a support member 191. It is fixed inside the bead glass 190.

The conventional electron gun 100 ′ having such a structure is the third grid 140, the second grid 130 from the fourth grid 150 by the high-pressure discharge during the high-pressure treatment for stray emission as shown in FIG. 3. At each gap portion d ₄ , d ₃ , d ₂ leading to the first grid 120, an electric spark of high pressure is generated, and then the first grid 120 and the cathode 110 are formed. The high voltage electric spark also occurs in the gaps d ₁ between).

Meanwhile, in the conventional electron gun 100 ', the first to fourth grids 150, 140, 130, and 120 are formed with a rounded structure so that the first to fourth grids 150, 140, 130, and 120 maintain a predetermined strength during the high pressure treatment. Although it is intended to be safe for, the case of the cathode 110 causes severe damage to the terminal portion 112 due to the high-voltage electrical spark generated in the gap (d ₁ ), which eventually leads to product defects there was.

It is an object of the present invention to provide an improved structure and method of an electron gun in a cathode ray tube, which prevents damage to the cathode during high pressure treatment performed for the purpose of counteracting a stray emission in the cathode ray tube, thereby lowering a defect rate of the product.

1 is a schematic diagram showing the structure of an electron gun in a cathode ray tube;

FIG. 2 is an enlarged plan view of the structure of a conventional electron gun for the portion "A" of FIG.

3 is a circuit diagram schematically showing an energized state during a high-pressure process for a conventional electron gun

4 is an enlarged detailed view showing the structure of the electron gun of the present invention for part "A" of FIG.

Figure 5 is a simplified diagram showing a circuit state during the high pressure treatment for the present invention gun

* Description of the symbols for the main parts of the drawings *

1: cathode ray tube 100,100 ', 100 ": electron gun

110: cathode 111: heater

112: terminal portion 113: body portion

120: first grid 130: second grid

140: third grid 150: fourth grid

160: Convergence electrode 170: Retainer

180: spacer 181: through hole

190: Bead glass 191,191a: Support member

200: funnel 210: anode wood terminal

300: panel 310: fluorescent surface

d ₁ , d ₂ , d ₃ , d ₄ , d ₅ : gap portion E: hot electron

The present invention for achieving the above object is configured to include a cathode and a first grid provided to surround one side of the cathode, spaced apart from each other so as to conduct electricity between the terminal portion of the cathode and the first grid In a cathode ray tube electron gun having a gap portion formed therein, and a spacer for supporting the first grid around the gap portion, the spacer forms an extension portion extending in the center direction at an inner end thereof, An improvement structure of an electron gun in a cathode ray tube is provided, wherein a predetermined gap portion is formed between the body portions of the cathode so as to be energized with each other.

The present invention includes a cathode and a first grid surrounding one side of the cathode, the gap being formed between the terminal portion of the cathode and the first grid so as to be electrically spaced apart from each other, wherein the gap portion A method for improving the structure of an electron gun in a cathode ray tube provided with a spacer for supporting the first grid at its periphery, the inner end of the spacer having an extension extending in the center direction thereof, the end of the extension and the A predetermined gap portion is formed between the body portions of the cathode so as to be electrically energized so that the cathode and the first grid are electrically connected in parallel, and the cathode is electrically connected in parallel to the stray emission. It provides a method of improving the structure of the electron gun in the cathode ray tube, characterized in that the damage can be prevented The.

The present invention as described above is formed by extending the through-hole end of the spacer supporting the first grid in the inner center direction to distribute the generation point of the electrical spark during the high-pressure treatment carried out to cope with the stray emission, from the cathode It is possible to reduce the failure rate of the electron gun in the cathode ray tube by preventing the damage.

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

In the configuration of the present invention, the same reference numerals are given to the same components as in the prior art, and the new reference numerals are given only to the new components, and detailed description of the same components is omitted.

4 is an enlarged detailed view showing the structure of the electron gun of the present invention with reference to the portion "A" of FIG. 1, and FIG.

As shown, the electron gun 100 ″ of the present invention provides a structure in which the first grid 120 and the cathode 110 provided at one side thereof are connected in parallel from the conventional structure of FIG. 2.

More specifically, the inner end of the through hole 181 formed in the center of the spacer 180 ′ has an extension portion that is bent and extended toward its center direction, that is, the body 113 of the cathode 110. 182). In addition, the first grid 120, the extension 182 of the spacer 180 ′, and the terminal 112 and the body 113 of the cathode 110 are electrically connected to each other. It is structured.

On the other hand, there is there formed a predetermined gap portion (d ₅₎ between the inner extension portion 182 and the body portion 113 of the cathode 110 of the spacer (180 '), a clearance portion (d ₅₎ is Since the shorter the distance, the easier the electrical spark is generated, it is preferable to position the front end of the extension portion 182 closer to the body portion 113.

In addition, the spacer 180 ′ is preferably made of a conductive material having a predetermined strength so as to be able to conduct electricity with the cathode 110.

As shown in FIG. 5, the electron gun 100 ″ of the present invention having such a structure has only a gap d ₁ between the first grid 120 and the terminal portion 112 of the cathode 110 during the high pressure treatment. Unlike the structure of the conventional electron gun 100 ′ in which the electric spark was generated, the spacer 180 ′ is formed from the gap d ₁ between the first grid 120 and the terminal portion 112 of the cathode 110. The gap (d ₅ ) between the inner extension portion 182 and the body portion 113 of the cathode 110 can distribute the electrical spark generation point, the cathode generated in the high pressure treatment step of the electron gun manufacturing process The damage of the terminal portion 112 of the 110 will be much reduced.

From this, in the electron gun 110 ″ of the present invention, the cathode is able to withstand even higher voltages than the conventional electron gun, preferably at a high voltage of 60 to 70 KV.

In the above embodiment, the present invention is not limited to the form shown in the drawings, and the gap between the first grid and the retainer can be narrowed to form additional gaps. In addition, although not shown in the drawings, the gap may be formed in any form in the sleeve and the retainer of the cathode, and thus, the occurrence of electrical sparks may be dispersed therefrom to prevent damage to the cathode.

As described above, the present invention is formed by extending the through-hole end of the spacer supporting the first grid in the inner center direction to distribute the generation point of the electric spark during the high-pressure treatment performed to cope with the stray emission, from which the cathode It is possible to reduce the failure rate of the electron gun in the cathode ray tube by preventing the damage.

Claims (2)

And a first grid provided around the side of the cathode and having a cathode, and a gap between the terminal and the first grid of the cathode is formed so as to be energized with each other. In the cathode ray tube electron gun provided with a spacer for supporting the first grid, The spacer has an extension portion extending in the center direction at an inner end thereof, and a predetermined gap portion is formed between the end portion of the extension portion and the body portion of the cathode so as to be able to conduct electricity with each other. . And a first grid provided around the side of the cathode and having a cathode, and a gap between the terminal and the first grid of the cathode is formed so as to be energized with each other. A method for improving the structure of an electron gun in a cathode ray tube provided with a spacer for supporting a first grid, An extension portion extending in the center direction thereof is formed at an inner end portion of the spacer, and a predetermined gap portion is formed between the end portion of the spacer portion and the body portion of the cathode to electrically connect the cathode and the first grid. And a parallel connection, from which the damage to the cathode can be prevented during the high pressure treatment performed for the purpose of counteracting the stray emission.