JP2000156158A - Electron gun for cathode-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electron gun for a cathode-ray tube having satisfactory assembling efficiency by reducing the number of processes for assembling electrodes, and reducing the number of positional adjustments at fitting of a metal conductor. SOLUTION: A support member 5, formed of an insulator such as bead glass, supports a first electrode 1, a second electrode 2, a third electrode 3 and an anode 4. A metal conductor 6 for improving the withstand voltage is provided. A peripheral surface of the third electrode 3, to which the metal conductor 6 is to be fixed, is formed with a recessed part 3A having a prescribed length in the X-axis direction, so as to facilitate the direct welding of the metal conductor 6, and a bottom part of this recessed part 3A is formed into a welding flat surface for fixing the metal conductor 6.

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 which can improve production efficiency.

[0002]

2. Description of the Related Art When manufacturing a cathode ray tube, a metal conductor is arranged together with an electron gun in a neck of the cathode ray tube. The metal conductor prevents the electric field intensity in the neck from increasing when the electron gun is operated by applying a voltage to each electrode, thereby stabilizing the potential in the neck.

First, a conventional electron gun provided with such a metal conductor for improving withstand voltage will be described.

FIG. 7 is a side view showing the structure of a conventional electron gun for a cathode ray tube. In the figure, the left side is a cathode side emitting thermoelectrons, and the right side is a phosphor screen side on which an image of a cathode ray tube is displayed.

At the cathode (not shown), thermal electrons are emitted by heating the heater. Thermionic electrons have three electrodes
The electron beam is controlled by an anode 4 disposed at the final position of the electrode arrangement, and forms a predetermined electron beam to reach the phosphor screen to form an image.

The first electrode 1 controls the direction of the electron beam from the cathode, the second electrode 2 accelerates and extracts the electron beam from the first electrode 1, and the third electrode 3 accelerates the electron beam. Focus. Between the third electrode 3 and the anode 4,
An electron lens for focusing the electron beam is formed. The first, second, and third electrodes 1 to 3 and the anode 4 are all supported by a support member 5 made of an insulator such as bead glass from above and below in the figure, and are fixed to each other at a predetermined interval. . Among them, the third electrode 3 has flat conductors 7 fixed to the upper and lower outer peripheral surfaces thereof by welding, and a bar-shaped metal conductor bent over the upper and lower support members 5 with respect to these flat conductors 7. 6 are fixed at both ends by welding.

An optimum mounting position of the metal conductor 6 is selected for stabilizing the potential in the neck. Usually, it is arranged between the second electrode 2 on the low voltage side and the third electrode 3 on the high voltage side.

FIG. 8 is an enlarged view showing the metal conductor 6 attached to the third electrode 3. FIG. 2A shows the second electrode 2.
7 shows the positional relationship between the third electrode 3 and the support member 5 as viewed from the side, where the left half of the Y-axis shows an aa cross section of FIG. 7 and the upper half of the X-axis shows a metal conductor 6 attached. It shows the state where it was turned on. As shown in FIG.
The cathode ray tube has a predetermined width in the tube axis direction (Z-axis direction), and the length in the X-axis direction orthogonal to the tube axis is substantially equal to the width of the third electrode 3 in the X-axis direction.

The third electrode 3 has an oval cross section that is long in the X-axis direction, and three openings 31 to 33 are formed on the X-axis at equal intervals. The metal conductor 6 is bent along the outer surface of the support member 5, and both end portions thereof are fixed to the vicinity of an end in the X-axis direction of the plate conductor 7 fixed to the outer peripheral surface of the third electrode 3. At this time, the fixing position of the metal conductor 6 in the electron gun can be adjusted according to the width of the flat conductor 7 in the tube axis direction.

In such a conventional electron gun, the metal conductor 6
Is fixed to a predetermined position on the outer peripheral surface of the third electrode 3 by welding. First, the third electrode 3 and the flat plate conductor 7 are welded, and each of the electrodes 1 to 4 is After being fixed in position, the metal conductor 6 is welded to a predetermined position of the flat conductor 7. In these two weldings, different jigs and tools are used for positioning the flat conductor 7 with respect to the third electrode 3 and for positioning the metal conductor 6 with respect to the flat conductor 7.

FIG. 9 is a diagram showing an example of a welding jig for welding the third electrode 3 and the flat plate conductor 7. As shown in FIG. The lower welding electrode 9 is arranged in contact with the flat conductor 7, and the third electrode 3 forms the upper welding electrode. Reference numeral 10 denotes a resistance welder.

Next, the operation of such an electron gun for a cathode ray tube will be described.

A cathode (not shown) and first and second electrodes 1 and 2
Constitutes a three-pole portion of an electron gun, the direction of an electron beam from a cathode is controlled by a first electrode 1, and an acceleration electric field is applied to a second electrode 2. In the vicinity of the second electrode 2 of the triode portion, a crossover image is formed in which the electron beam is once narrowed down very finely, and thereafter the third electrode 3 and other anodes 4 arranged near the phosphor screen are formed. The electron beam is focused on the phosphor screen by the main lens system configured as described above. After disposing such an electron gun at the neck, the metal conductor 6 welded to the third electrode 3 is heated by the high-frequency coil, and a metal deposition film is formed on the inner surface of the glass of the cathode ray tube. By forming a metal deposition film in this way,
During the operation of the electron gun, the potential in the neck can be kept stable without increasing the electric field intensity from the second electrode 2 to the vicinity of the cathode.

[0014]

In the conventional electron gun for a cathode ray tube, when the metal conductor 6 is fixed, the flat electrode 7 is welded to the third electrode 3 and the metal conductor 6 is further welded.
A jig for positioning is required for each welding process.
Therefore, when an electron gun having a different electrode structure is disposed in the neck of the cathode ray tube, the position of the third electrode 3 in the neck will be different. In order to weld at the position,
Adjustment of the welding position is required.

If the width of the flat conductor 7 is narrow, the metal conductor 6 cannot be arranged at a desired position in the neck unless the welding position with respect to the third electrode 3 is changed. This necessitates a reduction in the efficiency of electron gun production.

[0016] Further, as the number of times of welding increases, the chance of welding debris (splash) adhering to jigs and tools and electrodes increases, so that the burden of regular management of tools and the like also increases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and has as its object to reduce the number of steps for assembling electrodes and reduce the number of position adjustments when attaching a metal conductor. An object of the present invention is to provide a cathode ray tube electron gun with high assembling efficiency.

[0018]

An electron gun for a cathode ray tube according to the present invention has a plurality of electrodes, a support member made of an insulator for supporting each electrode, and a member extending in a direction orthogonal to a tube axis of the cathode ray tube. A metal conductor for improving withstand voltage, which is fixed to an outer peripheral portion of one of the electrodes so as to straddle the supporting member, and a welding plane for welding the metal conductor is formed on the outer peripheral portion of the electrode. Is what it is.

The metal conductor is welded to an electron beam focusing electrode among the plurality of electrodes.

The welding plane is the bottom of a concave portion formed on the outer peripheral surface of the electrode or the top of a convex portion.

The welding plane is an outer peripheral portion of the electrode, and is formed by being cut and raised in a vertical direction orthogonal to the tube axis direction of the cathode ray tube.

Further, the welding plane is an outer peripheral portion of the electrode, and is formed by being cut and raised in the left-right direction orthogonal to the tube axis direction of the cathode ray tube.

Further, the welding plane is formed such that the dimension in the tube axis direction of the cathode ray tube is 1 to 10 times the width of the metal conductor.

[0024]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
An embodiment of the present invention will be described.

Embodiment 1 FIG. 1 is a side view showing an electron gun for a cathode ray tube according to Embodiment 1 of the present invention. FIG. 2 is an enlarged front sectional view and a side view showing a third electrode to which a metal conductor is welded.

In the drawing, 1 is a first electrode, 2 is a second electrode, 3 is a third electrode, 4 is an anode, 5 is a supporting member such as bead glass, and 6 is a metal conductor. These members 1 to 6 are the same as those of the conventional electron gun (FIG. 7), and detailed description thereof will be omitted. The difference from the conventional configuration is the shape of the outer peripheral surface of the third electrode 3 to which the metal conductor 6 is fixed. In the first embodiment, a concave portion 3A having a predetermined length in the X-axis direction is formed so that the metal conductor 6 can be easily welded directly to the outer peripheral surface of the third electrode 3, and the bottom of the concave portion 3A is formed. It is a welding plane for fixing the metal conductor 6.

After assembling each of the electrodes 1 to 4 at a predetermined position by the support member 5, the metal conductor 6 is disposed so as to straddle the outer surfaces of the upper and lower support members 5 and to be positioned at the predetermined position. Is welded to the welding portion 3A of the third electrode 3. That is, unlike the conventional electron gun, the metal conductor 6 can be securely fixed without having to weld the flat plate conductor to the third electrode 3 in advance.

The concave portion 3A of the third electrode 3 is formed at the same coordinate position in the tube axis direction (Z-axis direction) of the cathode ray tube and has a width somewhat larger than the thickness (width) of the metal conductor 6. ing. Even when assembling an electron gun having a different distance from the cathode to the third electrode 3, if the concave portion 3A has a width, for example, ten times the thickness of the metal conductor 6, the metal conductor 6 in the neck can be formed. The relative position can always be set constant. In addition, the jigs and tools at the time of welding can be fixed without having to readjust.

As described above, the electron gun of the first embodiment can omit one step of welding, which conventionally required two steps, and can simplify the assembling step. Further, only one kind of jigs and tools required for each welding process need to be prepared. Therefore, the chance of splash to be attached to the welding jig decreases, and the jig management becomes easy. Moreover, in the first embodiment, since the metal conductor is directly welded to the concave surface 3A of the third electrode 3, the manufacturing process of the electron gun is simplified as compared with the conventional electron gun, such that only one positioning operation is required. Is done.

Embodiment 2 FIG. 3 is an enlarged front sectional view and a side view showing a third electrode to which a metal conductor is welded, of a cathode ray tube electron gun according to Embodiment 2 of the present invention.

The electron gun of the second embodiment has a metal conductor 6 on the outer peripheral surface of the third electrode 3 as compared with the electron gun of the first embodiment.
Is different in that the top portion of the convex portion 3B having a predetermined length in the X-axis direction is a welding plane in order to directly weld the welding surface.
The other configuration is the same as that of the first embodiment, and therefore, the corresponding portions are denoted by the same reference characters and detailed description thereof will not be repeated.

In the electron gun according to the second embodiment, the first embodiment is also used.
As in the case of the first embodiment, the number of welding steps is one, and the assembling step can be simplified. Also, only one type of welding jig needs to be prepared, and the splash accompanying the welding operation is reduced. That is, in the second embodiment, it is only necessary to weld once to the convex surface portion 3B of the third electrode 3, and the positioning only needs to be performed once.
The manufacturing process of the electron gun is simplified.

Embodiment 3 FIG. 4 is an enlarged front sectional view and a side view showing a third electrode to which a metal conductor is welded, of a cathode ray tube electron gun according to Embodiment 3 of the present invention.

The electron gun according to the third embodiment is different from the electron gun according to the first embodiment in that a welded portion 3C formed on the third electrode 3 is formed.
The outer peripheral portion is cut and raised outward in the vertical direction (Y-axis direction) orthogonal to the tube axis direction of the cathode ray tube, and is different in that both end portions of the metal conductor 6 are welded to the plane portion. . Other configurations are the same as those of the first embodiment,
Here, corresponding parts are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the electron gun of the third embodiment, the electron gun of the first embodiment is also used.
Similarly, one welding step can be omitted, and the assembling step can be simplified. Also, only one type of welding jig needs to be prepared, and the splash accompanying the welding operation is reduced. That is, in the third embodiment, it is only necessary to perform welding once to the welded portion 3C of the third electrode 3, and only one positioning is required.
The manufacturing process of the electron gun is simplified.

Embodiment 4 FIG. FIG. 5 is an enlarged front sectional view and a side view showing a third electrode to which a metal conductor is welded, of a cathode ray tube electron gun according to Embodiment 4 of the present invention.

The electron gun according to the fourth embodiment is different from the electron gun according to the third embodiment in that a welded portion 3D formed on the third electrode 3 is formed.
The outer peripheral portion is cut and raised outward in the left-right direction (X-axis direction) perpendicular to the tube axis direction of the cathode ray tube, and both ends of the metal conductor 6 are welded to the plane portion. . Other configurations are the same as those of the first embodiment,
Here, corresponding parts are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the electron gun of the fourth embodiment, the first embodiment is also used.
Similarly, one welding process can be omitted, and the process can be simplified. Also, only one type of welding jig needs to be prepared, and the splash accompanying the welding operation is reduced. That is, in the fourth embodiment, only one welding is required to the welding portion 3D of the third electrode 3, and only one positioning is required, so that the manufacturing process of the electron gun is simplified as compared with the conventional electron gun. Will be.

FIG. 6 is a front sectional view and a side view showing a modification of the fourth embodiment. Like the welded portion 3E shown in this figure, the width in the tube axis direction (Z-axis direction) of the flat portion cut and raised on the outer peripheral portion of the third electrode is up to ten times the thickness of the metal conductor 6. By widening, even in an electron gun having a different distance from the cathode to the third electrode 3, it becomes easy to always fix the metal conductor 6 in the neck at a fixed position.

In the first to fourth embodiments, the case where the metal conductor 6 is welded to the outer peripheral surface of the third electrode 3 which is a focusing electrode has been described. However, the electron gun of the present invention can be similarly applied to a case where a metal conductor is welded to another electrode, and has the above-described effects.

The material of the metal conductor 6 must be a non-magnetic material so as not to affect the emission of an electron beam, but must have a low melting point in order to easily sputter a metal deposition film. Is preferred.

[0042]

Since the electron gun for a cathode ray tube according to the present invention is constructed as described above, it has the following effects.

According to the first aspect of the present invention, since a flat surface for welding the metal conductor is formed on the outer peripheral portion of the electrode to which the metal conductor is fixed, the conventional flat conductor welding step is eliminated, and the number of parts is reduced. The production efficiency of the electron gun can be improved by reducing the welding process together with the reduction in the number of welding processes.

According to the second aspect of the invention, since the plurality of electrodes are welded to the electron beam focusing electrode, the potential in the neck of the electron gun can be stabilized.

According to the third aspect of the present invention, since a flat surface is formed as a concave portion or a convex portion on the outer peripheral surface of the electrode to which the metal conductor is fixed, the conventional flat conductor welding step is eliminated, and the number of parts can be reduced. Along with the reduction, it is possible to improve the production efficiency of the electron gun by reducing the welding process.

According to the fourth aspect of the present invention, the outer peripheral portion of the electrode is formed as a portion which is cut and raised in a vertical direction orthogonal to the tube axis direction of the cathode ray tube. Instead, the number of parts can be reduced, and the production efficiency of the electron gun can be improved by reducing the number of welding processes.

According to the fifth aspect of the present invention, since the outer peripheral portion of the electrode is formed as a portion cut and raised in the left-right direction perpendicular to the tube axis direction of the cathode ray tube, the conventional flat conductor welding process is performed. Instead, the number of parts can be reduced, and the production efficiency of the electron gun can be improved by reducing the number of welding processes.

According to the sixth aspect of the present invention, even if there is a change in the position where the electrode to be welded to the metal conductor is fixed by the electron gun, the position set by the jig when welding the metal conductor is kept the same. Can be maintained and adjustment work can be easily performed.

[Brief description of the drawings]

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

FIG. 2 is an enlarged front sectional view and a side view showing a third electrode to which a metal conductor is welded.

FIG. 3 is an enlarged front sectional view and a side view showing a third electrode to which a metal conductor is welded, of a cathode ray tube electron gun according to Embodiment 2 of the present invention;

FIG. 4 is an enlarged front sectional view and a side view showing a third electrode to which a metal conductor is welded, of an electron gun for a cathode ray tube according to a third embodiment of the present invention.

FIG. 5 is an enlarged front sectional view and a side view showing a third electrode to which a metal conductor is welded, of an electron gun for a cathode ray tube according to a fourth embodiment of the present invention.

FIG. 6 is a front sectional view and a side view showing a modification of the electron gun for a cathode ray tube according to the fourth embodiment of the present invention.

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

FIG. 8 is an enlarged view showing a metal conductor attached to a third electrode.

FIG. 9 is a diagram showing an example of a welding jig for welding a third electrode and a flat conductor.

[Explanation of symbols]

1 1st electrode, 2 2nd electrode, 3 3rd electrode, 3A
Concave part, 3B Convex part, 3C, 3D, 3E weld, 4
Anode, 5 support member, 6 metal conductor, 7 plate conductor, 9 lower welding electrode, 10 resistance welder.

Claims (6)

[Claims] A plurality of electrodes; a support member made of an insulator for supporting the electrodes; and one of the electrodes extending in a direction orthogonal to a tube axis of the cathode ray tube and straddling the support member. A metal conductor fixed to an outer peripheral portion of the electrode for improving withstand voltage, and a welding plane for welding the metal conductor is formed on an outer peripheral portion of the electrode, for a cathode ray tube. Electron gun. 2. The electron gun for a cathode ray tube according to claim 1, wherein the metal conductor is welded to an electron beam focusing electrode among the plurality of electrodes. 3. The electron gun for a cathode ray tube according to claim 2, wherein the welding plane is a bottom portion of a concave portion formed on an outer peripheral surface of the electrode or a top portion of a convex portion. 4. The cathode ray according to claim 2, wherein the welding plane is formed by being cut and raised in a vertical direction orthogonal to a tube axis direction of the cathode ray tube at an outer peripheral portion of the electrode. Tube electron gun. 5. The cathode ray according to claim 2, wherein the welding plane is formed by being cut and raised in an outer peripheral portion of the electrode and in a lateral direction orthogonal to a tube axis direction of the cathode ray tube. Tube electron gun. 6. The welding plane according to claim 3, wherein a dimension of the cathode ray tube in a tube axis direction is 1 to 10 times a width of the metal conductor. Electron gun for cathode ray tube.