JPH09129153A - Electron gun for cathode-ray tube and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the displacement of a cathode sleeve resulting from temperature rise at a cathode operation time by providing a specified means in an electron gun for a cathode-ray tube in which plural electrodes including at least first grid, a control electrode, are provided in front of a cathode emitting electrons. SOLUTION: An electron gun for a cathode-ray tube is equipped with an insulating electrode hold means which is for arranging a cathode and plural electrodes with predetermined spacings, sleeve hold means 41a, 41b which have point-symmetric shapes with respect to the cross section centers 50R2, 50G2, 50B2 of the cathode sleeves 50R, 50G, 50B of the cathode, and hold the peripheries of the cathode sleeves 50R, 50G, 50B, and cathode hold means 40a, 40b which are fixed to electrode hold means 8a, 8b, and fix sleeve hold means 41a, 41b so that the cathode and first grid are arranged with a predetermined spacing. It is desirable that the cathode hold means 40a, 40b have point- symmetric shapes with respect to the cross section center 50R2 of the cathode sleeve 50R of the cathode.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron gun for a cathode ray tube and a manufacturing method thereof, and more particularly to an electron gun for a cathode ray tube having a characteristic in a cathode sleeve holding portion and a manufacturing method thereof.

[0002]

2. Description of the Related Art An electron gun for a CRT has, for example, a structure in which a cathode sleeve, first to seventh grids, etc. are fixed to a bead glass so as to be located in order at predetermined intervals in the Z-axis direction. The cathode sleeve has, for example, a diameter of 1 to
2 mm, length 5 to 10 mm, thickness 10 to 30 μm, and a base metal obtained by adding a reducing agent such as magnesium (Mg), tungsten (W) or silicon (Si) to a cylindrical body of nickel with barium ( It is manufactured by coating powder of ternary carbonate of Ba), strontium (Sr) and calcium (Ca) by a spraying method or the like.
Here, the distance d ₀₁ between the cathode surface of the cathode sleeve and the inner surface of the first grid needs to be set with high accuracy in order to prevent the occurrence of back clusters and shutdown. Thus, in order to set the distance d ₀₁ with high accuracy, welding of the cathode sleeve is performed as follows.

That is, in the first method, the cathode holder, which is a component for fixing the cathode sleeve to the bead glass, is fusion-fixed in advance during beading. Then, while measuring the distance d ₀₁ , the cathode sleeve is inserted and fixed in the cathode holder. The second method is
An insulator such as ceramic or glass is fixed to the first grid that is previously fixed to the bead glass, and the cathode holder is fixed to this insulator. Then, while measuring the distance d ₀₁ , the cathode sleeve is inserted into the cathode holder and welded and fixed.

In the cathode, FIGS. 9 (A) and 9 (B) are shown.
As shown in FIG. 1, the cathode sleeves 7, 8 and 9 whose both ends are fixed to the bead glass 5 and 6 are connected to the cathode sleeve 2 and
3 and 4 are attached. The cathode holders 7 to 9 hold the cathode sleeves 2 to 4 by gripping about one half of the outer circumference of the cathode sleeves 2 to 4. That is, the shapes of the cathode holders 7 to 9 are not point-symmetric with respect to the centers 2a, 3a, 4a of the cathode sleeves 2 to 4.

[0005]

By the way, in recent electron guns, in order to obtain good spot characteristics, as shown in FIG. 10, the inner diameter of the holes 10a of the first grid 10 is set to 0.2.
Cathode sleeve 11 reduced to about 0.4 mmφ
Also, the distance d ₀₁ between the cathode surface and the inner surface of the first grid is 10
The thickness may be reduced to 0 μm or less to reduce the wall thickness in the vicinity 10b of the holes 10a of the first grid 10. However,
In the above-mentioned conventional electron gun for a cathode ray tube, the shape of the cathode holders 7 to 9 is the centers 2a and 3 of the cathode sleeves 2 to 4.
Since it is not point-symmetric with respect to a and 4a, the temperature of the cathode holders 7 to 9 shown in FIGS. When 7 to 9 thermally expand, FIG.
As shown in, each is displaced by about 10 to 20 μm in the direction of the arrow (direction orthogonal to the Z direction). When the cathode holders 7 to 9 are displaced in this way, the cathode sleeve 11
There is a problem that the first grid 10 may come into contact with the first grid 10.

The present invention has been made in view of the above-mentioned prior art, and an object of the present invention is to provide an electron gun for a cathode ray tube capable of suppressing the displacement of the cathode sleeve during the operation of the cathode, and a manufacturing method thereof.

[0007]

In order to solve the above-mentioned problems of the prior art and to achieve the above-mentioned object, an electron gun for a cathode ray tube according to the present invention has at least a control unit at the front of a cathode that emits electrons. An electron gun for a cathode ray tube provided with a plurality of electrodes including a first grid which is an electrode, comprising: an insulating electrode holding means for arranging the cathode and the plurality of electrodes at a predetermined interval; It has a point-symmetrical shape with respect to the center of the cross section of the cathode sleeve,
A sleeve holder for holding the outer circumference of the cathode sleeve; and a cathode holding means fixed to the electrode holding means and fixing the sleeve holding means so that the cathode and the first grid have a predetermined distance. .

Further, in the electron gun for a cathode ray tube according to the present invention, preferably, the cathode holding means has a shape which is point-symmetric with respect to a center of a cross section of a cathode sleeve of the cathode.

In the electron gun for a cathode ray tube according to the present invention, preferably, the sleeve holding means has a V-shape or a U-shape.

Further, according to the method of manufacturing an electron gun for a cathode ray tube of the present invention, a plurality of electrodes including at least a first grid which is a control electrode is provided in front of a cathode which emits electrons, a cathode holding means and a plurality of electrodes. A method of manufacturing an electron gun for a cathode ray tube, wherein electrodes are fixed to an insulating electrode holding means at a predetermined interval, wherein the cathode sleeve has a shape symmetrical with respect to a center of a cross section of the cathode sleeve. The sleeve holding body holding the outer circumference is fixed to the cathode holding means while adjusting the cathode and the first grit to have a predetermined distance.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION An electron gun for a cathode ray tube and a method of manufacturing the same according to embodiments of the present invention will be described below. First Embodiment FIG. 1A is a side view near the cathode of an electron gun for a cathode ray tube according to this embodiment, and FIG. 1B is a front view near the cathode of the electron gun for a cathode ray tube shown in FIG. is there. FIG. 2 is a conceptual diagram of a cathode ray tube (CRT) according to this embodiment, and FIG.
3A and 3B are views for explaining an electron gun for a cathode ray tube according to the present embodiment, FIG. 1A is a perspective view, and FIG.

First, the overall structure of the cathode ray tube according to this embodiment will be described. As shown in FIG. 2, the cathode ray tube 2
No. 0 has a panel glass 22 and a funnel glass 24, which are fused by a frit glass 26 and the inside is maintained in a high vacuum. An electron gun 30 for a cathode ray tube is built in a neck portion 28 of the funnel glass 24. A fluorescent screen 32 is formed on the inner surface of the panel glass 22, and an aperture grill 34 is attached to the rear surface thereof. Also,
A deflection yoke 36 is attached to the outer periphery of the neck portion 28, and the three electron beams emitted, controlled, accelerated, and focused from the electron gun 30 are deflected by the deflection yoke 36, so that the fluorescent screen 32 is displayed. It is designed to scan the entire surface of.

As shown in FIG. 3, the electron gun 30 has a first grid G1, a second grid G2, a third grid G3, a fourth grid G4, a fifth grid G5, and a sixth grid G6 at the front of the cathode. The seventh grid G7 is fixed to the bead glass 8 in this order at predetermined intervals along the longitudinal direction.

First grid G1 and second grid G2
Are a control electrode and an acceleration electrode, respectively, for example, voltages of 0 V and 300 V are applied, respectively. Third grid G
The third, fourth grid G4, and fifth grid G5 are focusing electrodes, and the third grid G3 and fifth grid G
A voltage of about 27 KV is applied to 5 and a variable voltage of about 8 to 9 KV is applied to the fourth grid G4. The sixth grid G6 and the seventh grid G7 are flat plate-shaped convergence electrodes that configure the deflection plate, and
A voltage of 24 to 25 KV is applied to 6, and a voltage of 27 KV is applied to the seventh grid G7.

A potential difference is applied to the sixth and seventh grids G6 and G7 for convergence, which constitutes a deflection plate provided at the tip of the electron gun 30, and each RBG electron beam is converted into a cathode ray by an electric field created thereby. The fluorescent surface of the tube is used for convergence. This plate-shaped sixth
Of the grid G6 and the seventh grid G7, the voltage on the relatively low side applied to the sixth grid G6 is the electron gun 3
The internal division resistor 8 attached to 0 is composed of, for example, IBR in which ceramic is glass-coated.

As shown in FIGS. 1A and 1B, the cathode assembly is arranged at a predetermined position in the longitudinal direction of the insulating bead glasses 8a and 8b. The cathode assembly has three cathode sleeves 50R, 50G, 50B. The cathode sleeve 50R has, for example, a diameter of 1 to
2 mm, length 5 to 10 mm, thickness 10 to 30 μm, and a base metal obtained by adding a reducing agent such as magnesium (Mg), tungsten (W) or silicon (Si) to a cylindrical body of nickel with barium ( Ba), strontium (Sr), and calcium (Ca) ternary carbonate powder is coated by a spraying method or the like, and when heated, thermoelectrons are emitted from the tip portion 50R1.

The cathode sleeve 50R includes cathode holders 40a and 40b and sleeve holders 41a and 41b.
Are fixed to the bead glasses 8a and 8b, respectively. The cathode holders 40a and 40b are formed by using, for example, thin plate-shaped multi-form glass for beading, and one end sides thereof are fixed to the bead glasses 8a and 8b by heat fusion. Cathode holder 40a, 4
On the other end side of 0b.
1b is fixed by welding or the like. Here, FIG.
As shown in (B), the sleeve holder 41a is fixed to the upper left end of the cathode holder 40a, and
1b is fixed to the lower right end of the cathode holder 40b.

In order to reduce the escape of heat, the sleeve holders 41a and 41b are preferably V-shaped or U-shaped, for example, a ground member having a wire diameter.
At this time, it is necessary to determine the wire diameter in consideration of the mechanical strength of the sleeve holders 41a and 41b. As a material for the sleeve holders 41a and 41b, for example, Hasteroid B or nichrome material having low thermal conductivity is used.

That is, the cathode holders 40a, 40b
The sleeve holders 41a and 41b are, as shown in FIG. 1B, a cross-section center 50R of the cathode sleeve 50R.
They are arranged symmetrically with respect to 2.

The cathode sleeves 50G and 50B are provided at the same positions as the cathode sleeve 50R in the longitudinal direction of the bead glasses 8a and 8b.
It has a structure similar to that of R and is fixed to the bead glasses 8a and 8b.

As described above, in the cathode ray tube electron gun according to the present embodiment, the cathode sleeves 50R, 50
The cathode holders 40a and 40b holding the G and 50B and the sleeve holders 41a and 41b are respectively the cross-section centers 50R2 of the cathode sleeves 50R, 50G and 50B.
They are arranged point-symmetrically with respect to 50G2 and 50B2.
Therefore, during operation of the cathode, the cathode holder 40
a, 40b and the temperature of the sleeve holders 41a, 41b rise to 300 to 400 ° C.
When 40b and the sleeve holders 41a, 41b are thermally expanded, the cathode sleeves 50R, 50G, 50B
Is the cathode holder 40a and the sleeve holder 41a.
1B, the force pushed in the horizontal (arrow) direction in FIG. 1B cancels the force pushed in the horizontal direction in FIG. 1B by the thermal expansion of the cathode holder 40b and the sleeve holder 41b. The cathode sleeves 50R, 5
0G and 50B do not move horizontally in FIG. 1 (B). As a result, contact between the cathode sleeves 50R, 50G, 50B and the first grid 1 is effectively avoided.

Next, a method of manufacturing the electron gun for a cathode ray tube shown in FIG. 1 will be described. The cathode holders 40a and 40b shown in FIG. 1 and the first grid G1 shown in FIG. 3 are provided on the bead glasses 8a and 8b shown in FIGS.
Second grid G2, third grid G3, fourth grid G
The fourth, fifth grid G5, sixth grid G6 and seventh grid G7 are fixed. Also, the cathode sleeve 50
The sleeve holders 41a and 41b are welded to R so as to be point-symmetric with respect to the center 50R2. Similarly, for the cathode sleeves 50G and 50B, the center 50
The sleeve holders 41a and 41b are welded so as to be point-symmetric with respect to G2 and 50B2. Then, while adjusting the distance d ₀₁ between the tip portion 50R2 of the cathode sleeve 50R and the first grit G1 to a predetermined value, the sleeve holders 41a and 41b are replaced with the cathode holders 40a and 40b shown in FIG. Weld and fix.

Second Embodiment FIG. 5A is a side view of the electron gun for a cathode ray tube according to this embodiment, and FIG. 5B is a front view of the electron gun for a cathode ray tube shown in FIG. 5A. The cathode ray tube electron gun according to the present embodiment basically has a structure substantially the same as that of the cathode ray tube electron gun shown in FIG. 1 described above, but as shown in FIGS. As the body, thin plate-shaped sleeve holders 51a and 51b are used.

The sleeve holders 51a and 51b are shown in FIG.
As shown in FIG. 5B, it has a thin plate shape for holding the cathode sleeves 50R, 50G, and 50B in a direction orthogonal to the longitudinal direction of the bead glasses 8a and 8b, that is, in the vertical direction of FIG. 5B.

The cathode ray tube electron gun according to the present embodiment also includes
Cathode holders 40a and 40b holding the cathode sleeves 50R, 50G and 50B and a sleeve holder 51.
a and 51b are cathode sleeves 50R and 50, respectively.
Since they are arranged point-symmetrically with respect to the cross-sectional centers 50R2, 50G2, and 50B2 of G and 50B, the same effect as that of the electron gun for a cathode ray tube according to the first embodiment described above can be obtained during the cathode operation.

Third Embodiment FIG. 6A is a front view of a cathode holder 60 and a sleeve holder 61 of an electron gun for a cathode ray tube according to the present embodiment.
FIG. 6B is a side view taken along the line BB in FIG. 6A. FIG. 7 is a side view of the electron gun for a cathode ray tube according to the present embodiment before inserting the cathode sleeve. FIG. 8 is a side view of the electron gun for a cathode ray tube according to the present embodiment after the cathode sleeve is inserted and attached.

The electron gun for a cathode ray tube according to this embodiment is
Basically, it is a cathode ray tube electron gun for a projector, which has substantially the same structure as the cathode ray tube electron gun shown in FIG. 1 described above, but has one cathode sleeve, and as shown in FIGS. Body 60 and sleeve holder 6
The shape of 1 is different from that of the first embodiment.

The sleeve holder 61 is shown in FIG.
As shown in (B), it is a substantially rectangular parallelepiped member having a through hole 61a for inserting the cathode sleeve. As shown in FIG. 8, the cathode sleeve 50 is inserted into the through hole 61 a of the sleeve holder 61.

The cathode holder 60 is composed of thin plate-like plates 60a and 60b, one end of which is shown in FIG.
As shown in (B), it holds the outer circumference of the sleeve holder 61, and the other ends are fixed to bead glasses 8a and 8b, respectively, as shown in FIG.

The electron gun for a cathode ray tube according to this embodiment also includes
Cathode holder 60 holding the cathode sleeve 50
Since the a and 60b and the sleeve holder 61 are respectively arranged point-symmetrically with respect to the cross-sectional center 61a1 of the cathode sleeve 50, the above-mentioned first portion
The same effects as those of the electron gun for a cathode ray tube according to the embodiment can be obtained.

The present invention is not limited to the above embodiment. That is, the present invention is not limited to the above-described form as long as the cathode holder that holds the cathode sleeve and the sleeve holder are arranged point-symmetrically with respect to the cross-sectional center of the cathode sleeve.

[0032]

As described above, according to the electron gun for a cathode ray tube of the present invention, even if the temperature rises during the operation of the cathode, the displacement of the cathode in a plane perpendicular to the tube axis of the electron gun. Can be prevented and contact between the first grid and the cathode can be avoided.

[Brief description of the drawings]

FIG. 1A is a side view of an electron gun for a cathode ray tube according to a first embodiment of the present invention, and FIG. 1B is a front view of the electron gun for a cathode ray tube shown in FIG.

FIG. 2 is a cathode ray tube (CR according to the first embodiment of the present invention.
It is a conceptual diagram of T).

3A and 3B are views for explaining an electron gun for a cathode ray tube according to the first embodiment of the present invention, in which FIG. 3A is a perspective view and FIG.
Is a side view.

FIG. 4 is a diagram for explaining a manufacturing method of the electron gun for a cathode ray tube shown in FIG.

FIG. 5 is a side view of the electron gun for a cathode ray tube according to the second embodiment of the present invention, and FIG. 5B is a front view of the electron gun for a cathode ray tube shown in FIG.

6A is a front view of a cathode holder and a sleeve holder of an electron gun for a cathode ray tube according to a third embodiment of the present invention, and FIG. 6B is a side view taken along a sectional line BB in FIG. is there.

7 is a side view of the electron gun for a cathode ray tube shown in FIG. 6 before inserting a cathode sleeve.

8 is a side view of the electron gun for a cathode ray tube shown in FIG. 6 after the cathode sleeve is inserted and attached.

FIG. 9 is a diagram for explaining a conventional electron gun for a cathode ray tube.

FIG. 10 is a diagram for explaining a conventional electron gun for a cathode ray tube.

[Explanation of symbols]

1 ... 1st grid 8a, 8b ... Bead glass 40a, 40b, 60a, 60b ... Cathode holding body 41a, 41b, 51a, 51b, 61 ... Sleeve holding body 50, 50R, 50G, 50B ... Cathode sleeve

Claims (5)

[Claims] 1. An electron gun for a cathode ray tube, wherein a plurality of electrodes including at least a first grid, which is a control electrode, is provided in front of a cathode that emits electrons. Insulating electrode holding means for arranging at intervals, a sleeve holder that is point-symmetric with respect to the cross-sectional center of the cathode sleeve of the cathode, and holds the outer circumference of the cathode sleeve, and the electrode holder Fixed to the means, said cathode and said first
An electron gun for a cathode ray tube, comprising: cathode holding means for fixing the sleeve holding means so that the grid and the grid have a predetermined distance. 2. The electron gun for a cathode ray tube according to claim 1, wherein the cathode holding means has a shape that is point-symmetric with respect to the center of the cross section of the cathode sleeve of the cathode. 3. The electron gun for a cathode ray tube according to claim 1, wherein the sleeve holding means is V-shaped or U-shaped. 4. The electron gun for a cathode ray tube according to claim 2, wherein the sleeve holding means has a V shape or a U shape. 5. A plurality of electrodes including at least a first grid, which is a control electrode, is provided in front of a cathode that emits electrons, and the cathode holding means and the plurality of electrodes are insulating electrode holding means at predetermined intervals. A method for manufacturing an electron gun for a cathode ray tube fixed to a cathode holding tube, the sleeve holding body having a shape symmetrical with respect to a cross-sectional center of the cathode sleeve of the cathode and holding the outer circumference of the cathode sleeve, A method of manufacturing an electron gun for a cathode ray tube, which is fixed to the cathode holding means while adjusting the first grit to have a predetermined distance.