KR100337878B1 - Cathode assembly of the electron gun for cathode ray tube - Google Patents

Abstract

A cathode structure of an electron gun for a cathode ray tube is disclosed. The present invention provides a base member coated with an electron emission material, a sleeve supporting the base member, a heater installed inside the sleeve to generate heat, and installed to surround an outer circumferential surface of the sleeve. And at least two holder members installed to prevent heat generated from the heater from being transferred to portions other than the base member side.

Description

Cathode assembly of the electron gun for cathode ray tube

The present invention relates to a cathode structure, and more particularly, to a cathode structure of an electron gun for a cathode ray tube having an improved structure to minimize initial thermal deformation when power is applied to a heater of a cathode structure that is an electron emission source of an electron gun.

Typically, the cathode structure refers to a device for emitting hot electrons by thermal energy as an electron emission source of the electron gun. This can be classified into a direct heat type negative electrode structure which is a direct heating method and a heat dissipation type negative electrode structure which is an indirect heating method according to a heating method. The direct type negative electrode structure has a form in which the electron emitting portion is in direct contact with the filament, and the heat dissipation type negative structure has a form in which the filament and the electron emitting portion are separated from each other. In particular, the heat radiation type negative electrode structure is applicable to an electron gun requiring a large amount of hot electrons, and can be subdivided into an oxide negative electrode structure and a dispenser negative electrode structure according to its structural characteristics.

1 illustrates an example of a conventional heat dissipating cathode structure 10.

Referring to the drawings, the cathode structure 10 includes a base member 11 made of a metal material disposed adjacent to the G1 electrode 100, which is a control electrode of the electron gun, and a sleeve supporting the lower portion of the base member 11. And a holder 14 installed at a predetermined distance from the sleeve 12 to support the sleeve 12. One end of the ribbon 13 is welded to the sleeve 12 at its lower end, and the other end of the ribbon 13 is welded to the upper surface of the holder 14.

In addition, a small amount of electron emitting material 17 is applied to the upper surface of the base member 11. In addition, a heater 15 for heating the electron-emitting material 17 is wound in the sleeve 12 along the length direction of the sleeve 12.

The negative electrode structure 10 having such a structure is supported by the bead portion provided in the funnel neck portion of the cathode ray tube although not shown in the drawing in the state welded to the negative electrode support 16 at the lower end of the outer peripheral surface of the holder 14. Take it.

Looking at the action of the negative electrode structure 10 configured as described above are as follows.

When a predetermined power is applied to the terminal of the heater 15, the heater 15 generates heat. When the heater 15 generates heat, the sleeve 12 and the base member 11 are heated by this heat to heat the electron-emitting material 17.

When the electron emitting material 17 is heated, hot electrons are emitted therefrom. The emitted hot electrons are focused and accelerated by the electron lens formed on the electrodes of the electron gun including the G1 electrode 100 shown in the drawing, and selectively deflected by the deflection yoke to land on the fluorescent film of the panel to excite the phosphor. do. Thus, the image is reproducible.

However, the conventional negative electrode structure 10 has the following problems.

The cathode structure 10 is maintained at a high temperature while power is applied to the heater 15 to emit heat electrons from the electron emission material 17. That is, when the cathode structure 10 starts to be driven at room temperature, heat is transferred to the other part by the heater 15 in only a few seconds, and rapidly rises to about 700 to 900 ° C. This causes thermal deformation.

Referring to the process of thermal deformation during the initial driving as described above is as follows.

When a predetermined power is applied to the heater 15, the sleeve 12 in which the heater 15 is installed is heated, and the base member 11 supported by the sleeve 12 is heated. When the base member 11 is heated, hot electrons are emitted from the electron emission material 17 applied to the upper surface thereof, and the G1 electrode 100 provided adjacent to the base member 11 causes thermal deformation. 1 undergo thermal deformation process.

At the same time, the heat transferred from the heater 15 to the sleeve 12 is also conducted to the ribbon 13 which is welded to the lower end thereof and suspends the sleeve 12 from the holder 14, thereby allowing the holder 14 to be moved. Will be heated. This heated heat undergoes a second thermal deformation process for heating the cathode support 16 which is welded and supported at the lower end of the holder 14. In addition, the holder 14 is also heated by the radiant heat emitted from the sleeve 12, which in turn causes a third thermal deformation process to heat the cathode support 16.

As such, rapid thermal deformation occurs within a few seconds from the time when the power is applied to the heater 15, and then has a thermal stabilizer of a considerable time, for example, about 10 to 30 minutes.

As mentioned above, the cathode structure 10 conducts heat through the point A where the ribbon 13 is welded to the lower end of the sleeve 12 during the second and third thermal deformation processes. 13 and holder 14 are transmitted to holder 14 via a welded point B. Subsequently, the heat is transferred to the cathode support 16 through the point C welded to the lower end of the outer circumferential surface of the holder 14, resulting in deformation of the cathode support 16 and a predetermined time elapsed. Next, it can be said that the heat loss is large, resulting in the restoration of thermal stability.

The heat loss of such a cathode structure 10 requires a heater 15 having a larger heat capacity, thereby increasing the power consumption, especially when a high heating temperature is required, such as an impregnated cathode structure. Is difficult.

The present invention has been made to solve the above problems, to provide a negative electrode structure of the electron gun for the cathode ray tube, the structure is improved to reduce the time taken for the initial thermal stability when driving the negative electrode structure, and to reduce the power consumption There is a purpose.

1 is a cross-sectional view showing a conventional cathode structure,

2 is a cross-sectional view showing a state in which the electron gun is mounted on the neck portion of the cathode ray tube according to the present invention;

3 is an exploded perspective view illustrating a negative electrode structure according to the present invention;

4 is a cross-sectional view of the negative electrode structure of FIG.

<Brief description of symbols for the main parts of the drawings>

10,30 ... cathode structure 11,31 ... base member

12,32 ... sleeve 13,33 ... ribbon

14 ... holder 15,35 ... heater

16,36 ... cathode support 17 ... electron emitting material

34.Top holder 38 ... Bottom holder

In order to achieve the above object, a cathode structure of an electron gun for a cathode ray tube according to an aspect of the present invention,

A base member having an electron emission material applied thereon;

A sleeve supporting the base member from below;

A heater installed inside the sleeve to generate heat when a predetermined power is applied; And

And at least two holder members disposed adjacent to and supporting the outer circumferential surface of the sleeve and installed to prevent heat generated from the heater from being transferred to portions other than the base member side. It features.

In addition, the holder member is characterized in that it comprises an upper holder which is installed to receive the sleeve in a state spaced apart a predetermined interval, and a lower holder is installed on the lower surface of the upper holder and coupled to the upper holder spaced at a predetermined interval .

Further, the upper holder and the lower holder is characterized in that the welded by a plurality of welding points.

Hereinafter, a negative electrode structure according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 shows a state in which the cathode structure 21 of the present invention is installed on the neck portion 210 of the cathode ray tube.

Referring to the drawings, the electron gun 20 is provided with a cathode structure 21 for emitting hot electrons. The electrodes forming the electronic lens are sequentially disposed on the cathode structure 21 in the order of the first electrode 22a, the second electrode 22b, the third electrode 22c, and the fourth electrode 22d. do.

On both sides of the cathode structure 21 and the first to fourth electrodes 22a, 22b, 22c and 22d, a plurality of bead glasses 23 are provided in parallel to fix them. .

And the lower part 24 of the cathode structure 21 is supported by the stem 25 in order to apply a predetermined current to each electrode. The stem 25 is sealed when the electron gun 20 is assembled to the neck portion 210.

On the other hand, the shield cup 26 is provided in the upper surface of the 4th electrode 22d which is a final acceleration electrode, and the bulb space 27 is welded to the outer peripheral surface of the said shield cup 26. As shown in FIG. A getter container 28 which is in contact with the inner circumferential surface of the neck portion 210 is installed at one side of the outer circumferential surface of the shield cup 26.

Here, the negative electrode structure 21 is supported by the bead glass 23 by the negative electrode support 29 and the heater support part 200.

3 is an exploded perspective view illustrating an example of the negative electrode structure of FIG. 2, and FIG. 4 is a cross-sectional view of the negative electrode structure 30 of FIG. 3.

3 and 4, the cathode structure 30 is provided with a base member 31 made of a metal material adjacent to the electron beam through hole 22a 'of the G1 electrode 22a which is a control electrode of the electron gun. The upper surface of the base member 31 is coated with an electron emission material 37. The electron-emitting material 37 is composed of an alkaline earth metal oxide mainly composed of barium oxide, such as a ternary metal oxide including Ba, Sr, and Ca.

The lower portion of the base member 31 is provided with a sleeve 32 for supporting the base member 31. One end of the plurality of ribbons 33 is welded (welding point D) to the lower end of the outer circumferential surface of the sleeve 32 while maintaining a 120 degree interval.

Inside the sleeve 32, a heater 35, which is a heat source that supplies heat to heat the electron-emitting material 27 to emit thermal electrons, is installed so as not to come into contact with the sleeve 32. The heater 35 is wound in the longitudinal direction of the sleeve 32 in the form of a wire made of an alloy of tungsten and rhenium, and a surface thereof is coated with a coating layer such as alumina oxide for insulation purposes. . Each end 35a, 35b drawn out from the heater 35 is welded to the heater support 200.

The upper holder 34 is installed on the outer surface of the sleeve 32 to be spaced apart by a predetermined interval. The upper holder 34 surrounds the sleeve 32. In addition, the upper holder 34 has a flange portion 34a formed thereon, so that the other end of the ribbon 33 is welded (welding point E) while the other end portion of the ribbon 33 is in surface contact with the flange portion 34a. have. The sleeve 32 is suspended by the ribbon 33 on the upper holder 34.

In addition, a lower holder 38 having a diameter corresponding to the upper holder 34 is installed below the upper holder 34. The upper surface of the lower holder 38 is welded (welding point G) at one point in a state corresponding to the lower surface of the upper holder 34. At this time, the height of the upper holder 34 and the lower holder 38 in the combined state is approximately equal to the height of the conventional holder 14 (see FIG. 1). A negative electrode support 36 for supporting the negative electrode structure 30 is welded (welding point F) to the lower end of the outer circumferential surface of the lower holder 38.

As such, the negative electrode structure 30 of the present invention is separated into an upper holder 34 and a lower holder 38, and the upper and lower holders 34 and 38 are coupled to each other by a welding point G. In addition, the lower holder 38 is coupled to each other by the cathode support 36 and the welding point (F).

Looking at the operation of the negative electrode structure 30 according to the present invention as described above are as follows.

First, predetermined power is applied to both terminal portions 35a and 35b of the heater 35. As a result, the heater 35 made of an alloy material of tungsten and lenniche generates heat. When the heater 35 generates heat, heat is transferred to the sleeve 32 which is installed to be spaced apart from the heater 35 at a predetermined interval and accommodates the heater 35. At this time, the surface of the heater 35 is coated with an insulator such as alumina oxide so that the heater 35 can be insulated from the inner circumferential wall of the sleeve 32.

The heat transferred to the sleeve 32 heats the base member 31 supported by the sleeve 32. As a result, the electron emission material 37 applied to the upper surface of the base member 31 is heated, and thermal electrons are emitted therefrom. The emitted hot electrons are focused and accelerated by an electron lens formed between the electrodes of the electron gun including the control electrode G1 electrode 22a, and selectively deflected by the deflection yoke.

Subsequently, the electron beam is landed on the fluorescent film formed on the inner surface of the panel to excite the phosphor, thereby enabling the image to be reproduced.

Here, the process of thermal deformation during the initial driving of the cathode structure 30 according to the present invention will be described.

During the release of hot electrons from the electron-emitting material 37 from the time when the power is applied to the heater 35, the temperature rises rapidly to about 700 to 900 ° C. in a few seconds at room temperature. Accordingly, thermal deformation occurs in the negative electrode structure 30.

That is, when a predetermined amount of power is applied to the heater 35, the sleeve 32 in which the heater 35 is installed is heated, and the base member 31 supported by the sleeve 32 is heated. Heated. When the base member 31 is heated, hot electrons are emitted from the electron emission material 37 applied to the upper surface as described above, and at the same time, the G1 electrode 22a provided adjacent to the base member 31 is thermally heated. As a result, a first thermal deformation process occurs that causes deformation.

At the same time, the heat transfer from the heater 35 to the sleeve 32 is transferred to the cathode structure 30 and the ribbon 33 suspending the sleeve 32 from the upper holder 33 through the welding point D. And heat is transferred to the upper holder 34 coupled through the welding point E, resulting in a second thermal deformation process. In addition, a third thermal deformation process in which the upper holder 34 is heated by radiant heat emitted from the sleeve 32 also occurs.

Here, the upper holder 34 is coupled to the lower holder 38 by the welding point G, the lower holder 38 is fixed to the negative electrode support 36 by the welding point F. That is, the heat transferred to the upper holder 34 by the ribbon 33 minimizes the heat released to the negative electrode support 36 to reduce the time that the negative electrode structure 30 is deformed and thermally stabilized again. Given.

Although heat is transferred from the upper holder 34 to the lower holder 38, heat conduction occurs only through the welding point G, and a predetermined distance is provided between the upper and lower holders 33 and 38. This is because it is possible to control the amount of heat released.

In addition, the radiant heat emitted from the sleeve 32 also affects the thermal deformation of the upper holder 34. In this thermal deformation process, heat is transferred to the cathode support 36 to minimize thermal stability. This can reduce the time that elapses from recovery.

As such, the upper holder 34 and the lower holder 38 are separated from each other and bonded to each other by the welding point G so that the heat generated from the heater 35 during the initial driving of the negative electrode structure 30 causes the electrospinning material 37 to absorb. It can be said that it is possible to minimize the heat conducted other than the place where it is released.

As described above, the negative electrode structure of the electron gun for the cathode ray tube of the present invention may obtain the following effects by separating the holder for supporting the sleeve into an upper holder and a lower holder.

First, the heat generated from the heater can be minimized to be conducted to another part, so that the temperature of the cathode structure can be improved even when the heater having the same heat capacity is used. Accordingly, the power consumption of the heater can be reduced, so that it is possible to apply a heater of low power.

Second, even when a high heating temperature such as an impregnated cathode structure or a metal cathode structure is required, it is possible to minimize the phenomenon that the negative electrode support is thermally deformed due to heat conduction or radiant heat of the sleeve.

Third, it is possible to reduce the time taken to secure the electrical characteristics due to rapid thermal deformation at the beginning of driving, thereby improving the thermal efficiency of the cathode structure.

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 (3)

A base member having an electron-emitting material applied thereon; A sleeve for supporting the base member from below; A heater installed inside the sleeve to generate heat when power is applied; And Wraps around the outer circumferential surface of the sleeve to prevent heat generated from the heater from being transferred to a portion other than the base member side, And a holder member having an upper holder installed to accommodate the sleeve while being suspended by a ribbon formed on an outer circumference thereof, and a lower holder installed below the upper holder and welded to the upper holder. Cathode structure of electron gun for cathode ray tube. delete delete