JPH10125255A - Electron gun and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To integrate electrodes without applying excessive force to them, generate no distortion on a main electron lens in spite of having a small diameter, and obtain high resolution, by overlapping a fitting section protruded from the side wall of an insulating rod on the grid electrodes arranged on a straight line at prescribed intervals, and welding and fixing them with a laser beam. SOLUTION: Support members 24, 25, 26a, 26b, 27 are constituted of fixing sections A and fitting sections B, the fitting section B are protruded to both the right and left ends of insulating rods 19, and the fixing sections A are buried in the insulating rods 19 at the prescribed intervals in advance. The insulating rods 19 are arranged on both sides of guide electrode 1, 7, 8, 13 arranged and positioned at the prescribed intervals on a straight line, the fitting sections B are overlapped on the side walls of the grid electrodes 1, 7, 8, 13, a laser beams is irradiated to the portions X of the fitting sections B, and the fitting sections B and the grid electrodes 1, 7, 8, 13 are welded and fixed. The grid electrodes 1, 7, 8, 13 are not deformed, and a stable cutoff characteristic and a good focus characteristic can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron gun and a method of manufacturing the same, and more particularly, to an electron gun having good assembling accuracy and capable of obtaining a high resolution even with a small diameter.

[0002]

2. Description of the Related Art FIGS. 10 and 1 show an example of a cathode ray tube electron gun used for a display device such as a personal computer.
The description starts from 1. In the figure, 1 has a skirt portion 1b on the periphery of an oval flat portion 1a, and a flat support portion 1c protrudingly formed on the long side of the skirt portion 1b,
A first grid electrode in which three electron beam transmission holes (only a central transmission hole 1d is shown in the illustrated example) is formed on a straight line along the long axis of the plane portion 1a. An intermediate plate having substantially the same shape is formed by projecting a flat supporting portion 2a on the long side and forming a large-diameter through hole (only the center through hole 2b is shown in the illustrated example) at the position of the electron beam transmitting hole. I have. Numeral 3 denotes a cylindrical body having substantially the same shape as the flat portion 1a of the first grid electrode 1, and a support portion 4a of a support member 4 shown in FIG. 12 is fixed to a side wall along a long side. The supporting portion 4b adjacent to and bridging with the supporting portion 4a overlaps with the supporting portion 2a of the intermediate plate 2 superimposed on the supporting portion 1c of the first grid electrode 1, and welds and integrates three members to form the first grid electrode. 1 is provided with a support portion 4c extending outward from the support member 4. External lead leads are connected to the first grid electrode 1 but are not shown. Reference numeral 5 denotes a glass block into which a set of three sleeves 6 (only one is shown in the illustrated example) into which a cathode (not shown) is inserted is fitted and welded to the cylindrical body 3. Reference numeral 7 denotes a second grid electrode having substantially the same shape as the first grid electrode 1, having an electron beam transmitting hole 7a formed therein, and a support portion 7b formed on a long side.
A third grid electrode 8 has an oval cylindrical body 9 having a bottom 9a at one end and an electron beam transmitting hole 9b formed at the bottom 9a, and an oval cylindrical body 10 having both ends opened. In the cylindrical body 10, a correction electrode 11 having an electron beam transmitting hole is disposed, and the abutted oval cylindrical bodies 9, 10
Are welded and integrated. In the third grid electrode 8, a support member 12 is fixed in advance to the outer periphery of the cylindrical body 9 in addition to the support portions 9c and 10a. Reference numeral 13 denotes a fourth grid electrode in which a correction electrode 15 having an electron beam transmitting hole is disposed in an oval cylindrical body 14 having both ends opened, and is opposed to the third grid electrode 8. A support member 16 having a U-shaped side surface is fixed to the outer periphery of the cylindrical body 14 in advance. The first to fourth grid electrodes 1, 7, 8, and 13 are provided on both sides of support portions 1c, 2a, 4c, 7b, 9c, 10a, 12, 16 of the respective electrodes in an electrode arrangement jig (not shown). The electron beam transmitting holes are concentrically arranged while being inserted into the core rod toward the center and spaced apart by spacers. The electrode arrangement jig is connected to a cathode heater wire, and a support piece 17 for connecting the assembled electron gun to the stem pin is provided.
18 are also arranged. In this manner, in a state where the support portions and the support pieces are arranged on both sides on the electrode array jig, the heated and softened glass insulating rod 19 is pressed against the support portions from both sides, and the support portions and the support pieces are formed. Insulated tip 1
9 and press-fitted to obtain an intermediate structure of the electron gun. Further, a cathode sleeve 20 having an emitter material 21 adhered to an end face 20a is inserted into each sleeve 6, the lower end of the sleeve 6 is welded to the cathode sleeve 20, and both ends of the lead are connected to the metal tab 22, The metal tabs 22, 22 are connected to the support pieces 17, 17 by inserting the wound and insulated heater 23, and the other support pieces 18, 18 are not shown, but are supported by the stem airtightly penetrated by the stem. Then, the supporting pieces 17 and 17 are connected to the stem pin for the heater, the other lead for external drawing and the corresponding stem pin are sequentially connected, and a shield cup electrode is attached to the tip of the fourth grid electrode 13 (not shown). To complete the electron gun. In this electron gun, electrons emitted from the emitter material 21 (cathode electrode) are focused by a main electron lens portion formed by an electrostatic field between grid electrodes. However, in order to obtain high resolution, the magnification of the main electron lens portion is increased. The smaller the spherical aberration, the better.

[0003]

In the manufacturing process of this electron gun, support members 1c, 2a, 4c, 7b, 9c, 10
A, 12, and 16 are press-fitted into an insulating rod 19 to integrate a plurality of electrodes so as to keep a distance from their axes. However, even if the glass insulating rod 19 is heated and softened, the glass insulating rod 19 cannot be heated enough to be fluidized and deformed. At the time of press-fitting, the supporting portion of the electrode is pressed by an excessive force, and the electrode is deformed. In this case, there is a problem that an axial deviation of each electron beam transmitting hole occurs, an electron lens portion formed between the electrodes is distorted, a focal point of each electron beam is deviated, focus characteristics are deteriorated, and resolution is reduced. Also, there is a problem that the cutoff characteristics determined by the distance between the emitter material 21 (cathode electrode) and the first grid electrode 1 and the distance between the first and second grid electrodes 1 and 7 vary. On the other hand, when the size of the electron gun is reduced in order to cope with miniaturization and energy saving, the magnification of the main electron lens portion generally increases and the spherical aberration also increases. Deformation of the electrode has a significant effect on focus characteristics and cut-off characteristics even if the amount of deformation is slight, so it has been an important problem in a cathode ray tube requiring high resolution. To solve such a problem, for example, Japanese Patent Laid-Open No. 57-829
No. 44 (Prior Art 1) and JP-A-61-2229 (Prior Art 2) are known. Prior Art 1 discloses an electron gun in which a supporting member is implanted in advance on an insulating rod, the insulating rod is disposed along the positioned electrode group, and the electrode and the supporting member are welded and fixed by laser light. More specifically, it is disclosed that the shape of the support member is desirably formed in an L-shape or a T-shape in order to widen a portion that comes into contact with each electrode, and the drawing shows a fixing member embedded in an insulating rod. An electron gun is disclosed in which a mounting portion is provided at the end of the portion along the axis of the electrode, and a supporting member having an L-shaped or T-shaped side surface is connected to the electrode. Further, in the prior art 2, a support member is implanted in advance on an insulating rod, an electrode support is welded and fixed to the side wall of each electrode in advance, and the support member of the insulating rod is joined to the electrode support of the positioned electrode group. A method of manufacturing an electron gun in which the abutting portion is welded and fixed by laser light is disclosed. Since an excessive force is not applied to the grid electrode at the time of connection between the electrode and the support member, there is no deformation of the electrode, so that an electron gun which is characteristically stable can be expected. However, in either technique, it is necessary to abut the end surface of the support member with the electrode side wall or the electrode support fixed to the electrode, and irradiate the laser beam along a narrow joint surface exposed on the side of the abutment portion. There is
There is a problem that the focal position of the laser light must be controlled accurately. Further, when the electron gun is exposed to a high temperature in the manufacturing process of the cathode ray tube, stress due to thermal expansion may concentrate on the welded portion and the welded portion may be peeled off. It is necessary to weld the joint surface from both sides continuously or at a plurality of places, and to make it more reliable. There was a problem that it took time to work. In the former, the support member is directly welded to the electrode. However, in the case of an oval cylindrical grid electrode, the support member is welded to the middle of the grid electrode in the major axis direction, so that the laser light is applied to the grid. It must be irradiated along the peripheral wall of the electrode. However, considering the slight inclination of the electrode, it is necessary to irradiate the laser light with a slight inclination to the peripheral wall of the electrode. On the other hand, if the height of the support member protruding from the insulating rod is reduced to reduce the distance between the grid electrode and the insulating rod in order to reduce the size of the electron gun, the welded portion between the support member and the electrode is hidden by the insulating rod and −
Since the optimum irradiation angle of the light is limited, it is necessary to precisely set the positioning of the electrodes and the support members, the irradiation angle of the laser light, and the like in a small electron gun. Further, in the latter case, it is necessary to fix the electrode support to the electrode in advance, so that the number of work steps is increased and there is a problem that miniaturization is limited by the electrode support.

[0004]

SUMMARY OF THE INVENTION The present invention has been proposed to solve the above-mentioned problems, and has a fixing portion embedded in an insulating rod and a connecting portion extending along the insulating rod connected to the fixing portion. A plurality of support members having mounting portions protruding from the side walls are arranged and implanted at predetermined intervals in advance, and the insulating rods are arranged along a plurality of grid electrodes arranged in a straight line at predetermined intervals. The present invention also provides an electron gun and a method for manufacturing the electron gun, wherein a mounting portion projecting from a side wall of an insulating rod and overlapping with a grid electrode is welded and fixed by laser light.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In an electron gun and a method of manufacturing the same according to the present invention, a mounting portion projecting from a side wall of an insulating rod is overlapped with a plurality of grid electrodes arranged in a straight line at a predetermined interval. Since the laser beam is used for welding and fixing, the electrodes can be integrated without applying undesired force to the electrodes, and even with a small-diameter electron gun, there is no distortion of the main electron lens, and an electron gun with good cut-off characteristics and good focus characteristics. Obtainable. The support member is not only L-shaped in cross section but also T-shaped.
Characters and π-shapes are available.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to FIGS. In the figure, the same components as those in FIGS. 10 and 11 are denoted by the same reference numerals, and duplicate description will be omitted. The difference between the figures is that the grid electrodes 1, 7, 8, 13
Specifically, a fixing portion A embedded in the insulating rod 19 and connected to the fixing portion A and extending to both sides along the insulating rod 19, and an outer end of the connecting portion A Support members 24, 25, 26a, 26b, and 27 having a mounting portion B protruding from the side wall are implanted in advance in the insulating rod 19, and the insulating rods 19 are arranged and positioned at predetermined intervals on a straight line. Are arranged on both sides of the plurality of grid electrodes 1, 7, 8, and 13, and the mounting portion B is overlapped on the side wall of each grid electrode.
The structure shown in FIG. 9 is integrally formed by irradiating a laser beam to a portion x shown in the figure protruding from the side wall of the substrate 9. Support members 24, 25, 26
As shown in FIGS. 3 to 5, a, 26b, and 27 have a structure in which a fixing portion A embedded in an insulating rod 19 is suspended at one end of a flat mounting portion B attached to an electrode, or both ends. Are attached to the electrodes, and fixed portions A, A embedded in the insulating rod 19 are suspended in the middle of the plate-shaped attachment portions B, B, and the middle of the plate-shaped attachment portion B is cut and raised toward both sides to be fixed. An L-shaped cross section, a T-shaped cross section, a π-shaped cross section, or the like, such as those in which the portion A is formed, are preferable. The width W of the mounting portion B is set according to the shape and size of the grid electrode to which the mounting portion B is connected. In this electron gun, the mounting portion B of the support member is configured such that the insulating rod 1
9 and overlaps with the grid electrode at a position exposed from the substrate 9, the laser light irradiation area is large, the laser light irradiation angle is less limited, and the control of the laser light focal position is easy. is there. Further, since the grid electrode and the mounting portion of the support member are in surface contact with each other, welding can be performed at a plurality of locations even within a small area on the mounting portion, and the connection can be reliably performed. In addition, since there is little restriction on the irradiation angle of the laser beam for welding, the height of the support member projecting from the insulating rod can be reduced to reduce the distance between the grid electrode and the insulating rod. As a result, the diameter of the electron gun can be reduced, the size can be reduced, and there is no deformation of the grid electrode, and there is no displacement of the axis or the gap of the electrode. Can be realized. Next, a method for manufacturing an electron gun according to the present invention will be described with reference to FIGS. In the figure, the same components as those in FIGS. 1 and 2 are denoted by the same reference numerals, and redundant description will be omitted. First, as shown in FIGS. 6 and 7, the support members 24, 25, 26 a, 26 b, and 27 are placed on the support member arrangement jig 29. The support member arrangement jig 29 is provided with positioning holes 29a, 29b, 29c, 29d, 29 for accommodating and positioning the support members 24-27 with the fixing portions A facing upward.
e, the first arrangement jig 29 having the perforations e, and the support pieces 17, 18
And a second arrangement jig 30 for holding the first and second arrangement jigs.
The alignment jigs 29 and 30 are provided with a mating hole 29f and an engagement pin 30a.
Are engaged and integrated. The support piece 17 is sandwiched between the first and second arrangement jigs 29 and 30, and the support piece 18 is held.
Is held by a leaf spring 31. Although not shown, the support member accommodated in the positioning hole is provided with a vacuum suction hole at the bottom of the hole and is vacuum-sucked. The pieces are prevented from falling. FIG. 8 shows a heat resistant support 32 for supporting the insulating rod 19 substantially horizontally.
And a gas burner 33 that is disposed so as to be vertically movable and heats and softens the insulating rod 19. This heat resistant support 32
The arrangement jig 2 is placed on the insulating rod 19 heated and softened above.
The fixing members 9 and 30 are horizontally moved and moved up and down with the fixing portions of the support member and the support piece facing downward to be polymerized, and each fixing portion is pressed into the insulating rod 19 by applying pressure. At this time, if the fixing portions of the support member and the support piece are preheated, the weldability with the insulating rod 19 is improved, and a minute displacement due to a difference in the coefficient of thermal expansion between the insulating rod 19 and the support member can be reduced. Even when the thickness of the fixed portion A is large or the embedded depth of the fixed portion A is deep, welding can be reliably performed without cracking the insulating rod 19. As a result, the insulating rod 19 is disposed on the arraying jigs 29 and 30 as shown by a dashed line in FIG. 6, and the mounting portions B are protruded from the side walls thereof so that the supporting members 24 to 27 and the supporting pieces 17 and 18 are connected. Adhere and integrate. The mounting portions A of the support members 24 to 27 implanted in the insulating rod 19 in this manner are brought into close contact with the bottoms of the positioning holes 29 a to 29 e of the array jig 29, so that the pressing force when welding to the insulating rod 19 is performed. Also, there is no deformation or displacement, and the components are integrated while maintaining the mutual distance accurately. Next, as shown in FIG. 9, the grid electrode 1 in which the intermediate plate 2 and the cylindrical body 3 are integrated in advance and the other grid electrodes 7, 8, and 13 are formed by using an electrode arrangement jig 34 with a core rod (FIG. (Not shown), the electron beam transmitting holes are arranged in a straight line, and spacers 35, 36, 37 are provided between the electrodes.
Is inserted to set the interval between the electrodes, and a plurality of electrodes are arranged at a predetermined interval on a straight line. The electrode arrangement jig 34 in which the electrodes are aligned in this manner is arranged so that the axis of each electrode is horizontal, and the insulating rod 19 to which the support members 24 to 27 are fixed in advance is arranged on each electrode. The insulating rod 19 is held down by a holding member that is not used. Next, a laser beam is sequentially applied to the mounting portion A protruding from the side wall of the insulating rod 19 when viewed in plan, and the support member and the grid electrode are welded. During this welding operation, there is no need to apply an excessive force to the electrodes, so there is no risk of the electrodes being deformed. Thus, one of the insulating rods 1
After connecting the supporting members of No. 9 to the grid electrode, the electrode arrangement jig 34 is turned upside down, and the supporting members of the remaining insulating rods 19 are connected to the grid electrodes to complete the intermediate structure of the electron gun. According to the above manufacturing method, it is easy to mutually position the plurality of electrodes arranged at a predetermined interval in a straight line in the electrode arrangement jig and the support member implanted in advance on the insulating rod, and to attach the support member. The area of the laser light irradiable area of the overlapping portion of the part and the electrode is large, the laser light irradiation angle is less limited,
Control of the focal position of the laser light is easy. Therefore, it is possible to manufacture an electron gun having excellent cut-off characteristics and focus characteristics without deformation or axial displacement of the electrodes. The present invention is not limited to the above embodiment. For example, the depth of the positioning holes of the array jig 29 for positioning the support member is appropriately changed, and the height of the fixing portion of the support member is correspondingly changed. By setting the height, the height position of the mounting portion can be set, and it is possible to correspond to grid electrodes having different diameters. Further, the present invention is not limited to the electron gun having the structure shown in the above embodiment, but can be applied to a unipotential electron gun, a bipotential electron gun, and other types of electron guns. The arrangement order of each grid electrode can also be appropriately changed. Needless to say, the present invention can be applied not only to an electron gun for a three-electron beam color cathode ray tube but also to an electron gun for a one-electron beam monochrome cathode ray tube or a color cathode ray tube.

[0007]

As described above, according to the present invention, it is possible to obtain an electron gun which is easy to assemble and has excellent cut-off characteristics and focus characteristics.

[Brief description of the drawings]

FIG. 1 is a partially cutaway side view of an electron gun according to the present invention.

FIG. 2 is a plan view of the electron gun shown in FIG.

FIG. 3 is a perspective view showing an example of a support member.

FIG. 4 is a perspective view showing an example of a support member.

FIG. 5 is a perspective view showing an example of a support member.

FIG. 6 is a plan view showing a jig for arranging support members.

FIG. 7 is a sectional side view of a main part of the jig shown in FIG. 6;

FIG. 8 is a front view illustrating a step of integrating the support member with the insulating rod.

FIG. 9 is a side view illustrating a step of connecting a support member integrated with an insulating rod to an electrode.

FIG. 10 is a cross-sectional front view of a main part illustrating the structure of a conventional electron gun.

11 is a side view of the electron gun shown in FIG.

FIG. 12 is a perspective view showing a support piece that integrates a first grid electrode, an intermediate plate, and a tubular body.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st grid electrode 7 2nd grid electrode 8 3rd grid electrode 13 4th grid electrode 19 Insulating rod 24 Support member 25 Support member 26a Support member 26b Support member 27 Support member A Fixing part B Mounting part

Claims (2)

[Claims] A plurality of support members each having a fixed portion embedded in the insulating rod and a mounting portion connected to the fixed portion and extending along the insulating rod and projecting from a side wall of the insulating rod, are provided at predetermined intervals. The insulating rods are arranged along a plurality of grid electrodes arranged in a straight line at a predetermined interval, and the mounting portion projecting from the side wall of the insulating rod and overlapping with the grid electrode is applied to the laser beam. An electron gun characterized by being fixed by welding. 2. A plurality of supporting members having a fixing portion embedded in the insulating rod and a mounting portion orthogonally connected to the fixing portion and having an end protruding from a side wall of the insulating rod, are provided on the insulating rod in a predetermined axial direction. A step of arranging and implanting at an interval, a step of arranging a plurality of grid electrodes having electron beam transmission holes on a straight line at a predetermined interval, and arranging and supporting an insulating rod along the positioned grid electrode. Producing an electron gun, comprising: a step of superposing a mounting portion of a member on a peripheral wall of a grid electrode; and a step of irradiating a laser beam to a mounting portion superposed on the grid electrode and projecting from a side wall of an insulating rod and welding. Method.