JPH11329285A - Electron gun for cathode-ray tube, and assembling method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance adjusting efficiency for bead assembling. SOLUTION: An electron beam passing hole 21 which is concentric to an electron passing hole 11 of the first electrode 1 formed in a side facing opposite to the first electrode 1 in the second electrode 2, and a guide hole 22 concentric to an electron beam passing hole 31 of the third electrode 3 formed in a side facing to the third electrode 3 and having a diameter same to the passing hole 31 are formed. Positioning is caried out in a small diameter part 51 and a large diameter part 52 of a bead mandrel 5 by the electron beam passing hole 21 and the guide hole 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electron gun for a cathode ray tube and a method for assembling the same.

[0002]

2. Description of the Related Art FIG. 7 shows a conventional electron gun for a cathode ray tube. In the figure, 1 is a first electrode for controlling an electron beam emitted from a cathode (not shown), 2 is a second electrode for extracting an electron beam from the first electrode 1, and 3 is a second electrode 2.
A third electrode for focusing the electron beam extracted from the first electrode, 1
1 is an electron beam passage hole of the first electrode 1, 21 is a second electrode 2
Reference numeral 31 denotes an electron beam passage hole of the third electrode 3.

The electron gun also has electrodes of a main lens system (not shown) arranged following the third electrode 3, each of which is supported on both sides by two bead glasses 4, concentrically and It is kept at a predetermined interval. The electron gun for a cathode ray tube forms an image of a crossover in which an electron beam is once narrowed very narrowly in the vicinity of a second electrode 2 of a triode system.
And an electrode group of the main lens system arranged at a position closer to the phosphor screen than this, so as to form an image on the phosphor screen.

Next, "bead assembly" of the electron gun for a cathode ray tube will be described. FIG. 8 is a vertical cross-sectional view showing a state where the bead of the electron gun is assembled. In the bead assembly of the electron gun, the electrode group of the triode system and the electrode group of the main lens system are arranged at a predetermined interval, and the bead glass 4 that has been heated and softened is sandwiched from both sides of each electrode to support the support of each electrode. Each electrode is embedded in the bead glass 4, cooled and hardened, and each electrode is supported by the bead glass 4.

In FIG. 8, reference numeral 5 denotes a bead mandrel used for assembling a bead, which has a small diameter portion 51 and a large diameter portion 52 concentric with the small diameter portion 51. Reference numeral 6 denotes an electrode spacer that regulates the distance between the first electrode 1 and the second electrode 2, and reference numeral 7 denotes an electrode spacer that regulates the distance between the second electrode 3 and the third electrode 3. Guide holes 61 and 71 are formed respectively. .

[0006] The bead assembling procedure using the bead mandrel 5 is as follows.
1, the guide hole 71 of the electrode spacer 7, the electron beam passage hole 21 of the second electrode 2 in the small diameter portion 51, and the guide hole 61 of the electrode spacer 6.
Then, each electrode is fixed with a bead glass 4 in a state where the positions and the intervals of the electrodes are determined by inserting the electron beam passage holes 11 of the first electrode 1. Thus, an electron gun in which the distance between the electrodes and the position of the electron beam passage hole are accurately positioned can be obtained.

[0007]

The triode system of the conventional electron gun for a cathode ray tube is assembled by using the above-described bead mandrel 5, so that the electron beam passage holes 11, 21,.
In order to make the central axes of the electrodes 31 coincide with each other with high precision, it is necessary to minimize the clearance between the hole diameters of the electron beam passage holes 11, 21, 31 of each electrode and the diameter of the bead mandrel 5.

In order to assemble a bead of the electron gun for a cathode ray tube with high accuracy, the speed of sandwiching the bead glass 4 from both sides, pressing force, right and left balance, suction holding of the bead glass 4 and softening of the baking table for heating and softening. It is necessary to adjust a number of conditions such as the center axis coincident with the center axis of the bead mandrel 5, and if these adjustments are insufficient, the electron beam passage holes 11, 21, 31 of each electrode will come into contact with the bead mandrel 5. As a result, an impact force is applied to the electron beam passage holes 11, 21, 31 to deform the electron beam passage holes 11, 21 and 31, so that the original focus performance of the electron gun cannot be obtained. Since the second electrode 2 is a thin flat plate component, it is particularly vulnerable to impact force, and has a problem that the electron beam passage hole 21 is easily deformed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an electron gun for a cathode ray tube which can perform adjustment at the time of assembling a bead without worrying about deformation of an electron beam passage hole of a second electrode. And an assembling method thereof.

[0010]

In the electron gun for a cathode ray tube according to the present invention, a guide hole which is positioned by being engaged with a bead mandrel is provided on a side of a second electrode constituting a three-electrode system opposed to a third electrode. It is provided.

Further, the planar shape of the guide hole of the second electrode is
Concentric with and larger than the electron beam passage hole formed in the second electrode, and having a diameter in the direction in which the second electrode is supported by the bead glass and having the same diameter as the electron beam passage hole of the third electrode. It was done.

Further, the electron beam passage hole formed in the second electrode has a diameter larger than that of the first electrode.

The second electrode comprises a first electrode member having an electron beam passage hole formed therein and a second electrode member having a guide hole formed therein.

Further, the second electrode is constituted by a single electrode member having an electron beam passage hole formed on the first electrode side and a guide hole formed on the third electrode side.

Further, in the method for assembling an electron gun for a cathode ray tube according to the present invention, the third electrode and the electrode spacer are inserted into a large diameter portion of a bead mandrel having a large diameter portion and a small diameter portion formed concentrically. A step of inserting an electron beam passage hole of the second electrode into a small diameter portion of the bead mandrel, and fitting a guide hole of the second electrode into a tip end of a large diameter portion of the bead mandrel; The method includes a step of inserting a beam passage hole into a small diameter portion of the bead mandrel, and a step of pressing and fixing bead glass to the first, second, and third electrodes from both sides, respectively.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be specifically described with reference to the drawings showing the embodiments. Embodiment 1 FIG. FIG. 1 is a view showing an electron gun for a cathode ray tube according to a first embodiment of the present invention. FIG. 1 (a) is an enlarged side view near a triode system, and FIG. 1 (b) is an arrow in FIG. 1 (a). FIG. 4 is an enlarged plan view of a second electrode viewed from a direction b. In the figure, reference numeral 1 denotes a cup-shaped first electrode for controlling an electron beam emitted from a cathode (not shown), and 2 denotes a plate-shaped second electrode for extracting an electron beam from the first electrode 1. A first electrode member 2A in which an electron beam passage hole 21 having the same diameter as the electron beam passage hole 11 is formed, and a guide hole 22 having the same diameter as the electron beam passage hole 31 of the third electrode 3 are formed. The second electrode member 2B. Before the bead assembly, the first electrode member 2A and the second electrode member 2B are assembled and welded so that the electron beam passage hole 21 and the guide hole 22 are concentric.

Next, the "bead assembling step" of the first embodiment will be described. FIG. 2 is a vertical cross-sectional view showing a state where the beads of the electron gun are assembled. In FIG. 2, reference numeral 5 denotes a bead mandrel used for assembling a bead.
And a large-diameter portion 52 coaxial therewith. 6 is the first
An electrode spacer for regulating the distance between the electrode 1 and the second electrode 2, 7
Is an electrode spacer that regulates the distance between the second electrode 2 and the third electrode 3, and has guide holes 61 and 71, respectively.

Next, a procedure for assembling a bead of the electron gun will be described. First, the electron beam passage hole 31 of the third electrode 3 is inserted through the large-diameter portion 52 of the bead mandrel 5, the guide hole 71 of the electrode spacer 7 is inserted, and then the electron beam passage hole 21 of the second electrode 2 is inserted. Guide hole 22 through the small diameter portion 51
Is inserted into the distal end of the large-diameter portion 52, then the guide hole 61 of the electrode spacer 6 is inserted into the small-diameter portion 51, and then the electron beam passage hole 11 of the first electrode 1 is inserted. Is determined, the bead glass 4 is pressed and fixed from both sides of each electrode.

According to the first embodiment, the second electrode 2
Since the electron beam passage hole 21 is positioned at the small diameter portion 51 of the bead mandrel 5 and the guide hole 22 is further positioned at the large diameter portion 52 of the bead mandrel 5, the electron beam passage hole of the second electrode 2 can be assembled at the time of assembling the bead. The shock applied to 21 is greatly reduced. For this reason, since the deformation of the electron beam passage hole 21 of the second electrode 2 hardly occurs, the adjustment at the time of assembling the bead can be performed smoothly.

The guide hole 22 of the second electrode member 2B
If the clearance of the large-diameter portion 52 of the bead mandrel 5 is reduced, the above effect is further improved.

Embodiment 2 FIG. FIG. 3 is a view showing the vicinity of a triode of a cathode ray tube electron gun according to Embodiment 2 of the present invention.
FIG. 3A is an enlarged side view in the vicinity of the triode system, and FIG. 3B is an enlarged plan view of the second electrode viewed from the direction of arrow b in FIG. FIG. 4 is a longitudinal sectional view showing a state of assembling the bead of the electron gun according to the second embodiment. The same reference numerals as those in FIGS. 1 and 2 denote the same or corresponding parts.

In the second embodiment, the second electrode 2 is formed of a single member, and the second electrode 2 is concentric with the electron beam passage hole 11 of the first electrode 1 on the side facing the first electrode 1. Further, an electron beam passage hole 21 having the same diameter is formed, and a guide hole 23 having the same diameter as the electron beam passage hole 31 of the third electrode 3 is formed on the side facing the third electrode 3.

The procedure for assembling the bead of the electron gun according to the second embodiment is the same as that of the first embodiment, and a description thereof will be omitted.

It is apparent that the same effects as those of the first embodiment can be obtained in the second embodiment. Also,
Since the second electrode 2 has an integrated structure and has both the electron beam passage hole 21 and the guide hole 23, the two electrodes having the electron beam passage hole 21 and the guide hole 22 separately as in the first embodiment. There is no need to assemble the members 2A and 2B in advance, and one step can be omitted.

Embodiment 3 FIG. 5 is a view showing the vicinity of a triode of a cathode ray tube electron gun according to Embodiment 3 of the present invention.
FIG. 5A is an enlarged side view in the vicinity of the triode system, and FIG. 5B is an enlarged plan view of the second electrode viewed from the direction of arrow b in FIG. 5A. FIG. 6 is a longitudinal sectional view showing a state of assembling the bead of the electron gun according to the third embodiment. The same reference numerals as those in FIGS. 3 and 4 denote the same or corresponding parts.

The difference between the third embodiment and the second embodiment is that the electron beam passage hole 24 of the second electrode 2 is concentric with the electron beam passage hole 11 of the first electrode 1 and that the electron beam passage hole This is a point formed to have a diameter larger than 11.

The procedure for assembling the bead of the electron gun according to the third embodiment is the same as that of the second embodiment, and a description thereof will be omitted.

It is apparent that the same effects as in the first embodiment can be obtained in the third embodiment. Also,
Since the electron beam passage hole 24 of the second electrode 2 is formed to have a larger diameter than the small diameter portion 51 of the bead mandrel 5, the electron beam passage hole 24 of the second electrode 2 can be easily formed in the small diameter portion 51 of the bead mandrel 5 during assembling. The workability in assembling the bead is improved, and the small-diameter portion 51 of the bead mandrel 5 is inserted into the electron beam passage hole 24.
Are not in contact with each other, so that the electron beam passage hole 24 is not deformed.

Although the guide holes 22 and 23 are circular in the above embodiments, they may be elliptical or the like.

[0030]

Since the present invention is configured as described above, it has the following effects.

On the side of the electron gun facing the third electrode of the second electrode, there is provided a guide hole which is engaged with the bead mandrel, and is positioned by the guide hole when assembling the bead of the electron gun. Because it was configured to
The impact applied to the electron beam passage hole of the second electrode at the time of assembling the bead is reduced. For this reason, adjustment at the time of bead assembly can be performed without worrying about deformation of the electron beam passage hole of the second electrode.

Further, a third electrode and an electrode spacer are inserted through a large diameter portion of a bead mandrel having a large diameter portion and a small diameter portion formed concentrically. The guide hole of the second electrode is inserted into the tip of the large diameter portion of the bead mandrel, and the electron beam passage hole of the first electrode is inserted into the small diameter portion of the bead mandrel. Then, since this is an assembling method including a step of pressing and fixing bead glass from both sides to each electrode, adjustment at the time of assembling the bead without worrying about deformation of the electron beam passage hole of the second electrode. Can be.

[Brief description of the drawings]

FIG. 1 is a view showing an electron gun for a cathode ray tube according to Embodiment 1 of the present invention.

FIG. 2 is a longitudinal sectional view showing a state of the electron gun according to the first embodiment at the time of assembling the beads.

FIG. 3 is a view showing an electron gun for a cathode ray tube according to a second embodiment of the present invention.

FIG. 4 is a longitudinal sectional view showing a state of assembling a bead of an electron gun according to a second embodiment.

FIG. 5 is a view showing an electron gun for a cathode ray tube according to Embodiment 3 of the present invention.

FIG. 6 is a longitudinal sectional view showing a state of assembling a bead of the electron gun according to the third embodiment.

FIG. 7 is a view showing a conventional electron gun for a cathode ray tube.

FIG. 8 is a longitudinal sectional view showing a state when a bead of a conventional electron gun for a cathode ray tube is assembled.

[Explanation of symbols]

1 first electrode, 2 second electrode, 2A first electrode member,
2B 2nd electrode member, 3rd electrode, 4 bead glass, 5 bead mandrel, 6, 7 electrode spacer, 1
1,21,24,31 Electron beam passage holes, 22,23
Guide hole, 51 Small diameter part of bead mandrel, 52
Large diameter part of bead mandrel, 61, 71 Guide holes.

Claims (6)

[Claims] 1. A cathode, a first electrode for controlling electrons emitted from the cathode, a second electrode for extracting electrons from the first electrode, and a third electrode for focusing the electrons extracted from the second electrode. An electron gun for a cathode ray tube, comprising at least an electrode and a guide hole positioned on the side of the second electrode facing the third electrode so as to be engaged with a bead mandrel. 2. The planar shape of the guide hole of the second electrode is concentric with and larger than the electron beam passage hole formed in the second electrode, and the direction in which the second electrode is supported by the bead glass. 2. The electron gun for a cathode ray tube according to claim 1, wherein a diameter of the electron gun is formed to be the same as an electron beam passage hole of the third electrode. 3. The electron beam passage hole formed in the second electrode has a diameter larger than that of the electron beam passage hole in the first electrode.
3. The electron gun for a cathode ray tube according to claim 1. 4. The second electrode according to claim 1, wherein the second electrode comprises a first electrode member having an electron beam passage hole formed therein, and a second electrode member having a guide hole formed therein. The electron gun for a cathode ray tube according to any one of claims 1 to 3. 5. The second electrode comprises a single electrode member having an electron beam passage hole formed on the first electrode side and a guide hole formed on the third electrode side. The electron gun for a cathode ray tube according to any one of claims 1 to 3. 6. A step of inserting a third electrode and an electrode spacer into a large-diameter portion of a bead mandrel having a large-diameter portion and a small-diameter portion formed concentrically. Inserting the guide hole of the second electrode into the tip of the large-diameter portion of the bead mandrel, and inserting the electron beam passage hole of the first electrode into the small-diameter portion of the bead mandrel. A method for assembling an electron gun for a cathode ray tube, comprising the steps of: pressing and fixing bead glass to both the first, second, and third electrodes from both sides.