JPH08129965A - Electron gun, cathode-ray tube and manufacture of cathode-ray tube - Google Patents

Abstract

PURPOSE: To effectively avoid scattering of metallic particulates, enhance reliability, and simply enable assembling by forming an electrode of an electron gun by metal mold molding. CONSTITUTION: In an electrode of an electron gun, tabs 15 and 16 protrusively formed on a side surface of a cylindrical electrode main body 14 and the main body 14 are integrally formed by metallic powder injection molding or the like. Therefore, sticking of metallic particulates to the main body 14 or the like by being scattered is avoided better than a welding method by resistance heating, and the electrode is formed with high accuracy, and a barrel polishing and cleaning process is eliminated. Plural electrodes of an electron gun or the like of a color cathode-ray tube are simultaneously and integrally formed in the positional relationship of the electrode in an assembling process by this molding method using a large metal mold, and are held by a holding member of an insulator after a baking process. Therefore, the electron is more simply assembled with high accuracy. Further, it may be molded by a lost wax method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron gun, a cathode ray tube and a method for manufacturing a cathode ray tube, for example, for a cathode ray tube applied to a television receiver, in which the quality is improved and the assembling work is simplified. Is.

[0002]

2. Description of the Related Art Conventionally, in an electron gun of a cathode ray tube, a prescribed voltage is applied to substantially cylindrical electrodes which are sequentially arranged at predetermined intervals to form an electrostatic lens between the electrodes. Thermoelectrons emitted from a heater or a cathode by an electrostatic lens are emitted in the form of an electron beam.

That is, as shown in FIG. 3, in this type of electron gun, after a stainless steel pipe is cut into a prescribed length, the protrusions are removed by, for example, barrel polishing, and then the deposits on the surface are washed. Are removed, and the electrode body 1 is formed. Further, in the electron gun, the tabs 2 and 3 are formed after the stainless steel plate material is punched out by a press, and then similarly barrel barreled and washed.

The electron gun has 2 to 2
A voltage is applied between the electrode body 1 and the tabs 2 and 3 with the tabs 2 and 3 being pressed by a pressing force of 3 [kg / cm ² ] respectively, whereby the electrode body 1 and the tabs 2 and 3 are
By the large current flowing between the electrode body 1 and the tabs 2 and 3, resistance heat is generated (that is, by resistance heating), and the tabs 2 and 3 are welded to the electrode body 1.

In this manner, in the electron gun, when the tabs are welded to the electrode bodies forming the electron gun to form the electrodes 4, the tabs of the electrodes 4 are formed by the glass material processed into a rod shape in the subsequent step. 2 and 3 are held, whereby a good insulating material made of glass is used to hold each electrode body 1 in an insulated manner in a prescribed positional relationship.

Thus, in the electron gun, even if a high voltage is applied in a high vacuum state by being incorporated in the cathode ray tube body, an accident such as discharge in the tube can be effectively avoided, and an accurate electrostatic lens can be formed. It is made possible.

[0007]

However, in the electron gun according to the conventional process, the electrode body 1 is formed by the resistance heat as described above.
When the tabs 2 and 3 are welded to each other, there is a problem that fine metal particles, which are so-called splashes, scatter as dust and adhere to the electrode body 1 and the like.

The sticking to the electrode body 1 or the like forms a protrusion on the surface of the electrode body 1 or the like. As a result, in the electron gun, the protrusions are formed in the assembly process even though the protrusions are removed at the component stage through processes such as barrel polishing, which limits the applied voltage between the electrodes and the distance between the electrodes. In addition, the quality of the cathode ray tube will deteriorate.

If it is possible to effectively avoid the scattering of such metal fine particles, the reliability and quality of the cathode ray tube can be improved. At this time, it would be convenient if the entire electron gun could be easily assembled.

As one method for solving this problem, a method of forming the electron gun main body and the tab integrally by applying a rolling method such as so-called squeezing can be considered. However, in the case of this method, there is a drawback that distortion and variation cannot be avoided due to the fact that the electrode cannot be formed thick and the stress remains inside. For this reason, in particular, in a color cathode ray tube, there is a problem that the electron gun that shapes three electron beams by an electrostatic lens having a large diameter cannot be applied due to the influence of the distortion or the like.

The present invention has been made in consideration of the above points, and it is possible to effectively avoid the scattering of metal fine particles to improve the reliability and to easily assemble the electron gun, the cathode ray tube, and the It is intended to propose a method for manufacturing a cathode ray tube.

[0012]

In order to solve such a problem, in the present invention, in an electron gun for irradiating a prescribed target with thermoelectrons generated in a thermoelectron source, an electrode forming the electron gun is provided with a mold. It is formed by molding using.

Further, after a plurality of electrodes forming this electron gun are simultaneously and integrally formed by this molding,
The electrodes are held by a holding member made of an insulator so that each electrode is insulated.

Further, in these cases, the molding is performed by metal powder injection molding or molding by the lost wax method.

In order to solve such a problem, according to the present invention, in a cathode ray tube for irradiating a prescribed target with an electron beam emitted from an electron gun, an electrode forming the electron gun is formed by molding using a mold. To do.

Further, after a plurality of electrodes forming this electron gun are simultaneously and integrally formed by this molding,
The electrodes are held by a holding member made of an insulator so that each electrode is insulated.

Further, in these cases, the molding is performed by metal powder injection molding or molding by the lost wax method.

In order to solve such a problem, in the present invention, in a method of manufacturing a cathode ray tube for irradiating a prescribed target with an electron beam emitted from an electron gun, a mold is used as an electrode forming the electron gun. It is formed by molding.

Further, the plurality of electrodes forming the electron gun are held in a prescribed positional relationship through the prescribed holding portion by this molding, and simultaneously with the previous holding portion,
In addition, after being integrally formed, it is formed by removing the previous holding portion after being held by the holding member formed of an insulator.

Further, in these cases, this molding is performed by metal powder injection molding or molding by the lost wax method.

[0021]

In the electron gun for radiating thermionic electrons generated by the thermoelectron source to the specified target, the electrodes forming the electron gun are not limited to the cathode ray tube electron gun as long as they are formed by molding using a mold. The electron gun can be formed in various electron beam sources without using welding using resistance heat.

At this time, a plurality of electrodes forming this electron gun are formed simultaneously and integrally by this molding, and then held by a holding member formed of an insulator, so that each electrode is formed insulated. By doing so, a plurality of electrodes can be integrated and assembled together.

Specifically, in these cases, metal powder injection molding or molding by the lost wax method can be applied as this molding.

Further, in a cathode ray tube for irradiating a prescribed target with an electron beam emitted from an electron gun, if the electrodes forming this electron gun are formed by molding using a mold, resistance heat is utilized in the cathode ray tube. The electron gun can be formed without the use of welding.

Also, after a plurality of electrodes forming this electron gun are simultaneously and integrally formed by this molding,
If a plurality of electrodes are held by a holding member made of an insulating material so that each electrode is insulated, a plurality of electrodes can be integrated and assembled.

Also in this case, specifically, metal powder injection molding or the lost wax method can be applied as this molding.

In the method of manufacturing a cathode ray tube for irradiating a prescribed target with an electron beam emitted from an electron gun, if the electrodes forming this electron gun are formed by molding using a mold, in the manufacturing process of the cathode ray tube. It is possible to form an electron gun without using welding using resistance heat.

Further, the plurality of electrodes forming the electron gun are held in a prescribed positional relationship via the prescribed holding portion by this molding, and simultaneously with the previous holding portion,
In addition, if it is formed by removing the previous holding part after it is held by the holding member made of an insulator after being integrally formed, it is possible to assemble multiple electrodes as a unit with a specified positional relationship. You can

Also in this case, specifically, metal powder injection molding or the lost wax method can be applied as this molding.

[0030]

Embodiments of the present invention will be described in detail below with reference to the drawings.

(1) First Embodiment FIG. 2 is a perspective view showing an electron gun according to an embodiment of the present invention. Here, this electron gun is an electron gun applied to a color cathode ray tube, and three electron beams are shaped and emitted integrally by a large-diameter electrostatic lens. Therefore, the electron gun 10 includes the first grid G1, the second grid G2, the third grid G3, the fourth grid G4, and the fifth grid G5.
Are fastened by the rod-shaped glass materials 11 and 12 and held in a prescribed positional relationship.

The electrodes composed of these first to fifth grids G1 to G5 are formed as shown in FIG. Figure 1
[Fig. 3] is a perspective view showing each electrode G1 to G5. The electrodes G1 to G5 are formed on the side surface of the cylindrical electrode body 14 so that the tabs 15 and 16 project, and the electrode body 14 and the tabs 15 and 16 are formed by metal powder injection molding (MetalI).
njection Molding).

Here, in the metal powder injection molding, a molding material formed by mixing fine metal powder with a binder is molded into a prescribed shape with a mold by an injection molding process similar to the plastic molding process. This is a molding method in which the binder is scattered through a firing step. Thereby, in the metal powder injection molding, a complicated metal material can be formed with high accuracy using a mold.

Accordingly, in this embodiment, the electrode body 14 and the tabs 15 and 16 are applied to each electrode forming the first to fifth grids G1 to G5 by applying the metal powder injection molding method.
And are integrally formed. Therefore, according to this process, the electrodes G1 to G1 are not required to undergo a welding process using resistance heat.
By forming G5, it is possible to effectively avoid the scattering of the metal fine particles and form the electrode with high accuracy.

Particularly, in the metal powder injection molding method, the influence of deformation and the like due to residual stress can be effectively avoided, so that the three electron beams are integrated by an electrostatic lens having a large diameter as in this embodiment. Apply to shaping electron gun,
A highly accurate electron gun can be created.

Further, each of the electrodes is formed through a firing process so that the electrodes can be formed cleanly by omitting the steps of barrel polishing and washing as in the case of forming electrodes by processing a conventional stainless steel material. In addition to this, since the electrode body 14 and the tabs 15 and 16 can be integrally formed, the entire assembling process can be simplified accordingly.

In the above structure, the electron gun 10 has tabs 15 and 16 and an electrode body 14 in each of the electrodes G1 to G5.
And are integrally formed by metal powder injection molding, and then the tabs 15 and 16 of the electrodes G1 to G5 are made of glass materials 11 and 1, respectively.
It is formed by being fastened by 2. By integrally forming the tabs 15 and 16 and the electrode body 14 by this metal powder injection molding, an electrode can be formed without using welding using resistance heat, thereby effectively avoiding scattering of metal fine particles. be able to. Also, by integrally forming the tabs 15 and 16 and the electrode body 14 by metal powder injection molding, it is possible to easily assemble them.

According to the above construction, the tabs 15 and 16 and the electrode body 14 are integrally formed by metal powder injection molding to form the respective electrodes G1 to G5, so that welding utilizing resistance heat is applied. It is possible to form the electrode without doing so, and thereby scattering of the metal fine particles can be effectively avoided, and the assembly process can be simplified.

(2) Second Embodiment In this embodiment, the process of assembling the electron gun according to the first embodiment described above is further simplified. In this embodiment, an electron gun which is almost the same as that of the first embodiment described above is formed and will be described using the reference numerals used in FIGS. 1 and 2 described above.

Here, in this embodiment, in the process of assembling the electron gun, the electrodes forming the above-mentioned first to fifth grids G1 to G5 are simultaneously and integrally formed by metal powder injection molding. At this time, in this assembly process, a metal mold is used for metal powder injection molding by using a large mold so that the first to fifth grids G1 to G5 are formed according to the positional relationship of the electrodes actually assembled in the electron gun. The electrodes G1 to G5 are formed.

Further, in this embodiment, the electrodes G1 to G5 are integrated with the runner so that the electrodes G1 to G5 are held by the runner so that the positional relationship between the electrodes G1 to G5 is maintained even after firing. Are formed. That is, this runner includes a coupling portion main body that extends above and below the electrodes G1 to G5 in FIG. 2 in the axial direction of the electron gun along the electrodes G1 to G5, and from the coupling portion main body to the side surfaces of the electrodes G1 to G5. It is formed by extending the branch portion of the connecting portion, so that when the electrodes G1 to G5 and the runner are viewed as a whole, the electrodes G1 to G5 are held in a substantially ladder shape.

As a result, the electrodes G1 to G according to this embodiment are
After the firing step, the tabs 15 and 16 are fastened by the glass materials 11 and 12 and fastened by the glass materials 11 and 12 in a state where the runners are kept in a prescribed positional relationship. Further subsequently, the runners of the electrodes G1 to G5 are cut, whereby the electrodes G1 to G5 are insulated and held by the glass materials 11 and 12 at a predetermined interval and in a positional relationship.

In this way, in this metal powder injection molding die, even if the runner is finally cut in this manner, the characteristics of the electrostatic lens are not disturbed by the remains of the runner remaining on the electrodes G1 to G5 side. In addition, the formation position of the runner is selected with respect to the electrodes G1 to G5. In addition, in the connecting portion between the runner and the electrodes G1 to G5, for example, a concave portion is formed on the electrodes G1 to G5 side so that local electric field concentration does not occur due to the remains of the runner remaining on the electrodes G1 to G5 side. The runner is formed to extend from the bottom of the recess. In the runner cutting step, the runner is cut so that the debris left on the electrodes G1 to G5 side becomes small.

In practice, the electrodes G1 ...
If molding is performed integrally and simultaneously so that the positional relationship between G5 becomes the final positional relationship in the electron gun,
Each of the electrodes G1 to G5 can be positioned with high accuracy that is higher than the accuracy during assembly. Therefore, if the electrodes G1 to G5 are fastened with the glass materials 11 and 12 and processed into the final form while maintaining this positional relationship by the runner,
The electron gun can be formed with the high assembly precision obtained at the time of molding.

Therefore, not only can the electrodes be simultaneously formed to simplify the assembly process, but also the positioning work required for the assembly of the electron gun can be omitted, and the assembly process of the electron gun can be made easier than ever before. It can be remarkably simplified and highly accurate.

In the configuration of the second embodiment, the electron gun 10
The electrodes G1 to G5 for forming the are formed by metal powder injection molding so as to have a final positional relationship in the electron gun and to maintain this positional relationship, together with the runner,
It is molded integrally and simultaneously. Further electrodes G1 to G5
Is maintained in this positional relationship by the runner,
After being fastened by the glass materials 11 and 12, the runner is cut and assembled into the final electron gun form.

According to the configuration of the second embodiment, the electron gun 10
After forming the electrodes G1 to G5 that form the electrodes integrally and simultaneously by metal powder injection molding so as to have a final positional relationship in the electron gun and to maintain this positional relationship, a glass material is formed. By assembling in the form of the final electron gun by fastening with 11 and 12, the electron gun can be assembled more easily and with higher accuracy in addition to the effect of the first embodiment.

(3) Other Embodiments In the second embodiment described above, the case where the runner holds the electrodes in a ladder shape and the electrodes are fastened by the glass material has been described, but the present invention is not limited to this. Instead, the point is that after holding each electrode in the final positional relationship and molding each electrode, the electrode should be held by the insulator again while maintaining this positional relationship.
For example, instead of fastening with a glass material, or in this fastening step, an insert molding method may be applied.

Further, in the above-described second embodiment, the case where the side surface of the electrode is held in a ladder shape by the runner has been described, but the present invention is not limited to this, and the point is that the electrode is held in the final positional relationship even after molding. Each electrode can be maintained, and each electrode may be held so as not to be harmful when it is finally assembled into an electron gun. For example, the place where the runner is formed can be freely selected as necessary. .

Further, in the above-mentioned embodiments, the case where the molding method using the metal powder injection molding is applied has been described, but the present invention is not limited to this, and for example, the so-called lost wax method is used. It is also possible to apply a molding method using.

In the above embodiments, the case where each electrode forming the electron gun is formed by metal powder injection molding has been described. However, the present invention is not limited to this, and a part of a plurality of electrodes may be formed if necessary. Alternatively, it may be formed by metal powder injection molding.

Further, in the above-mentioned embodiment, the case where the present invention is applied to the electron gun of the cathode ray tube for color has been described, but the present invention is not limited to this, and it is applicable to the electron gun of the cathode ray tube such as an oscilloscope. And mass spectrometer etc.
It can be widely applied to electron guns of various electron beam sources.

[0053]

As described above, according to the present invention, the electrode forming the electron gun is formed by molding using a mold, so that the electrode can be formed without applying welding using resistance heat. Therefore, it is possible to effectively avoid the scattering of the metal fine particles, improve the reliability, and easily assemble.

[Brief description of drawings]

FIG. 1 is a perspective view showing an electrode of an electron gun according to an embodiment of the present invention.

FIG. 2 is a perspective view showing the overall configuration of the electron gun of FIG.

FIG. 3 is a schematic perspective view for explaining a conventional electrode forming method.

[Explanation of symbols]

 1, 14 Electrode body 2, 3, 15, 16 Tab 4, G1 to G5 electrodes 10 Electron gun 11, 12 Glass material

Claims (9)

[Claims] 1. An electron gun for irradiating a prescribed target with thermoelectrons generated by a thermoelectron source, wherein electrodes forming the electron gun are formed by molding using a mold. 2. A plurality of electrodes forming the electron gun are formed simultaneously and integrally by the molding, and then held by a holding member formed of an insulator, and each electrode is formed to be insulated. The electron gun according to claim 1, wherein: 3. The electron gun according to claim 1, wherein the molding is metal powder injection molding or molding by a lost wax method. 4. A cathode ray tube for irradiating a prescribed target with an electron beam emitted from an electron gun, wherein the electrodes forming the electron gun are formed by molding using a mold. 5. A plurality of electrodes forming the electron gun are formed simultaneously and integrally by the molding, and then held by a holding member formed of an insulator so that the electrodes are insulated from each other. The cathode ray tube according to claim 4, wherein 6. The cathode ray tube according to claim 4, wherein the molding is metal powder injection molding or molding by the lost wax method. 7. A cathode ray tube manufacturing method for irradiating a prescribed target with an electron beam emitted from an electron gun, characterized in that the electrodes forming the electron gun are formed by molding using a mold. Pipe manufacturing method. 8. The plurality of electrodes forming the electron gun are held in a prescribed positional relationship via a prescribed holding portion by the molding, and are simultaneously and integrally formed with the holding portion. The method of manufacturing a cathode ray tube according to claim 7, wherein the holding member is formed by being held by a holding member made of an insulating material, and then the holding portion is removed. 9. The method of manufacturing a cathode ray tube according to claim 7, wherein the molding is metal powder injection molding or molding by a lost wax method.