JP3575147B2 - Cathode ray tube electron gun - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electron gun for a cathode ray tube, and more particularly to an electron gun for a cathode ray tube capable of improving withstand voltage characteristics.
[0002]
[Prior art]
FIG. 4 is a diagram showing a configuration of an electron gun by breaking a neck portion of a conventional cathode ray tube, and FIG. 5 is a longitudinal sectional view showing a main part of the electron gun of the conventional cathode ray tube. In the drawing, reference numeral 1 denotes a neck portion, 2 denotes an electron gun, and a cathode 3, first, second, and third grid electrodes 4, 5, 6 and an anode 7 are held at predetermined intervals by bead glass 8. , The main part of the electron gun 2. Further, a cup 10 is welded to the anode 7, and the cup 10 is connected to an internal conductive film 12 via a spacer 11.
In operation, the cathode ray tube provided with the electron gun 2 configured as described above has an anode 7 of about 30 kv, a third grid electrode 6 of about 7 kv, a second grid electrode 5 of about 700 v, A voltage of about 0 V is applied to each of the lattice electrodes 4.
[0003]
In such an operation state, cold electrons are emitted from the low voltage portions of the first grid electrode 4 and the second grid electrode 5 by being pulled by the high voltage of the anode 7. The emitted cold electrons collide with the inner wall of the neck portion 1 to form a positively charged portion, and the charged portion moves to the vicinity of the cathode 3, and the low voltage of the cathode 3, the first grid electrode 4, etc. A creeping discharge is generated between the parts and the semiconductor parts constituting the driving circuit of the cathode 3 and the cathode ray tube are destroyed.
[0004]
In order to prevent the occurrence of such creeping discharge, for example, in a conventional cathode ray tube disclosed in Japanese Utility Model Publication No. 5-9807, both ends are welded to a third grid electrode 6 as shown in FIG. A conductive lead 9 is provided around the outer surface of the glass 8 so as to be interposed between the outer surface of the glass 8 and the inner wall surface of the neck portion 1. Heating is performed by a coil (not shown), and the conductive lead 9 made of a stainless steel wire is heated and evaporated to form a vapor-deposited film 13 on the inner wall surface of the opposing neck portion 1. Is prevented by the deposited film 13.
[0005]
[Problems to be solved by the invention]
In the conventional device configured as described above, when the conductive lead 9 is close to the inner wall surface of the neck portion 1, the conductive lead 9 expands when heated by a high-frequency heating coil to form the neck portion 1, in order to form the deposited film 13. There is a problem in that the neck portion 1 may be distorted and cracked depending on the temperature when the inner wall surface is touched.
[0006]
The present invention has been made in order to solve the above-described problems, and a cathode ray tube having a low possibility of contacting the inner wall surface of a neck portion even when the conductive lead is expanded by being heated by a high-frequency heating coil. The aim is to get an electron gun.
[0007]
[Means for Solving the Problems]
In the electron gun of the cathode ray tube according to the present invention, the both ends are fixed to the grid electrodes of the electron gun housed in the neck portion, and the outer surfaces of a pair of bead glasses holding the respective electrodes of the electron gun are surrounded by A conductive lead disposed so as to be interposed between the inner wall surface of the neck portion and the inner wall surface of the neck portion facing the conductive lead by heating and depositing the conductive lead; In the electron gun of a cathode ray tube, which is formed by depositing a vapor-deposited film, at least one end of the conductive lead is connected to the grid through a metal piece which pulls the conductive lead expanded by heating in the longitudinal direction. It is fixed to the electrode.
[0008]
The other end The metal strip is bimetallic, with this bimetal upright substantially parallel to the line connecting the pair of bead glasses, and approximately perpendicular to the extending direction of the conductive leads, one end of which is fixed to the grid electrode Is fixed to one end of a conductive lead.
[0009]
Further, the metal piece is a metal piece having elasticity, and the metal piece stands upright substantially in parallel with a line connecting the pair of bead glasses, and is substantially orthogonal to the extending direction of the conductive lead , and one end is connected to the grid electrode. It is fixed and one end of a conductive lead is fixed to the other end.
[0010]
The metal piece is a metal piece having a higher linear expansion coefficient than the conductive lead, and the metal piece is arranged so that its extending direction is substantially parallel to the extending direction of the conductive lead, and the central part is fixed to the grid electrode. In addition, both ends of the conductive lead are fixed to both ends, respectively.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be specifically described with reference to the drawings showing the embodiments. In the drawings, the same reference numerals indicate the same or equivalent components as those of the related art.
[0012]
Embodiment 1 FIG.
FIG. 1 is a longitudinal sectional view showing a main part of an electron gun of a cathode ray tube according to Embodiment 1 of the present invention. In the figure, reference numeral 1 denotes a neck portion, 2 denotes an electron gun, and a cathode 3, first, second, and third grid electrodes 4, 5, 6 and an anode 7 shown in FIG. The main part of the electron gun 2 is thus held. Reference numeral 14 denotes a bimetal that stands upright substantially in parallel with a line connecting the pair of bead glasses 8, that is, a bimetal that stands upright on one side of the bead glass 8 substantially perpendicular to the direction in which the conductive leads 9 extend. And one end of the conductive lead 9 is welded to the other end. The conductive lead 9 surrounds the outer surface of the bead glass 8 and is provided so as to be interposed between the bead glass 8 and the inner wall surface of the neck portion 1, and the other end is welded to the third grid electrode 6. The bimetal 14 is configured such that the side closer to the neck 1 has a lower coefficient of thermal expansion.
[0013]
According to the electron gun 2 configured as described above, the bimetal 14 is heated together with the conductive leads 9 when high-frequency heating is performed to form the vapor-deposited film 13 during the manufacturing process of the cathode ray tube. Then, due to the relationship between the properties of the bimetal 14 and the mounting direction, the connection end of the bimetal 14 with the conductive lead 9 bends away from the bead glass 8. Due to this action, the conductive lead 9 is pulled in its longitudinal direction and does not extend toward the inner wall surface of the neck portion 1 even when expanded by heating, so that it does not contact the inner wall surface of the neck portion 1.
Note that not only one end of the conductive lead 9 but also both ends may be fixed to the third grid electrode 6 via the bimetal 14.
[0014]
Embodiment 2 FIG.
FIG. 2 is a longitudinal sectional view showing a main part of an electron gun of a cathode ray tube according to Embodiment 2 of the present invention. In the figure, reference numeral 1 denotes a neck portion, 2 denotes an electron gun, and a cathode 3, first, second, and third grid electrodes 4, 5, 6 and an anode 7 shown in FIG. The main part of the electron gun 2 is thus held. Reference numeral 15 denotes an elastic metal piece that stands upright on substantially one side of the bead glass 8 in a direction substantially parallel to a line connecting the pair of bead glasses 8, that is, perpendicular to the extending direction of the conductive leads 9. One end of the conductive lead 9 is welded to the grid electrode 6 and the other end is welded, and the connection end side with the conductive lead 9 is slightly bent to the bead glass 8 side. The conductive lead 9 surrounds the outer surface of the bead glass 8 and is provided so as to be interposed between the bead glass 8 and the inner wall surface of the neck portion 1, and the other end is welded to the third grid electrode 6. Further, the metal piece 15 is formed of, for example, Inconel (nickel, chromium, iron alloy), and the connection end side with the conductive lead 9 is urged away from the bead glass 8 to move the conductive lead 9 in the longitudinal direction. It is configured to be constantly pulled.
[0015]
According to the electron gun 2 configured as described above, even if the conductive leads 9 expand due to high-frequency heating for forming the vapor-deposited film 13 during the manufacturing process of the cathode ray tube, the tension of the metal pieces 15 causes Since the conductive lead 9 is pulled in the longitudinal direction, the conductive lead 9 is prevented from extending toward the inner wall surface of the neck portion 1, so that it does not contact the inner wall surface of the neck portion 1.
Note that not only one end of the conductive lead 9 but also both ends may be fixed to the third grid electrode 6 via the metal piece 15.
[0016]
Embodiment 3 FIG.
FIG. 3 is a longitudinal sectional view showing a main part of an electron gun of a cathode ray tube according to Embodiment 3 of the present invention. In the figure, reference numeral 1 denotes a neck portion, 2 denotes an electron gun, and a cathode 3, first, second, and third grid electrodes 4, 5, 6 and an anode 7 shown in FIG. The main part of the electron gun 2 is thus held. Numeral 16 is disposed inside the bead glass 8 substantially in parallel with the extending direction of the conductive leads 9, and the center thereof is welded to the third grid electrode 6, and is made of, for example, aluminum having a higher linear expansion coefficient than the conductive leads 9. It is a configured metal piece. The conductive leads 9 are disposed so as to surround the outer surface of the bead glass 8 and be interposed between the conductive leads 9 and the inner wall surface of the neck portion 1, and both ends thereof are welded to both ends of the metal piece 16.
[0017]
According to the electron gun 2 configured as described above, during the manufacturing process of the cathode ray tube, when the high frequency heating is performed to form the vapor deposition film 13, the metal piece 16 is also heated together with the conductive leads 9. Then, the conductive lead 9 expands and expands. However, since the metal piece 16 extends more than the expansion of the conductive lead 9, the conductive lead 9 is pulled in its longitudinal direction, and the conductive lead 9 is formed inside the neck portion 1. Since it does not extend toward the wall surface, it does not contact the inner wall surface of the neck portion 1.
[0018]
In each of the above-described embodiments, the example in which the conductive lead 9 is fixed to the third grid electrode 6 has been described. However, needless to say, the case where the conductive lead 9 is fixed to the second grid electrode 5 can be similarly performed.
[0019]
【The invention's effect】
As described above, according to the present invention, at least one end of the conductive lead is fixed to the grid electrode via the metal piece that pulls the conductive lead expanded by heating in the longitudinal direction. Even if is heated and expanded, it does not come into contact with the inner wall surface of the neck portion, so that it is possible to prevent the neck portion from being distorted or cracked.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a main part of an electron gun of a cathode ray tube according to Embodiment 1 of the present invention.
FIG. 2 is a longitudinal sectional view showing a main part of an electron gun of a cathode ray tube according to a second embodiment of the present invention.
FIG. 3 is a longitudinal sectional view showing a main part of an electron gun of a cathode ray tube according to Embodiment 3 of the present invention.
FIG. 4 is a diagram showing a configuration of an electron gun by breaking a neck portion of a conventional electron gun.
FIG. 5 is a longitudinal sectional view showing a main part of an electron gun of a conventional cathode ray tube.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Neck part 2 Electron gun 6 Third lattice electrode 8 Bead glass 9 Conductive lead 13 Evaporated film 14 Bimetal 15 Metal piece 16 Metal piece

Claims (4)

Both ends are fixed to the grid electrode of the electron gun accommodated in the neck portion, and are interposed between the outer surfaces of the pair of bead glasses holding the electrodes of the electron gun and the inner wall surface of the neck portion. Having a conductive lead disposed as described above, and heating and evaporating the conductive lead so that a deposition film is formed on the inner wall surface of the neck portion facing the conductive lead. A cathode ray tube, wherein at least one end of the conductive lead is fixed to the grid electrode via a metal piece that pulls the conductive lead expanded by heating in the longitudinal direction. Electron gun. A metal piece bimetal conductive bimetal is upright in parallel lines and substantially connecting the pair of bead glasses, and approximately perpendicular to the extending direction of the conductive leads, the other one end is fixed to the grid electrode 2. An electron gun for a cathode ray tube according to claim 1, wherein one end of the conductive lead is fixed. The metal piece is a metal piece having elasticity, and the metal piece stands upright substantially in parallel with a line connecting the pair of bead glasses, and is substantially perpendicular to the extending direction of the conductive lead , and one end is fixed to the grid electrode. 2. An electron gun for a cathode ray tube according to claim 1, wherein one end of a conductive lead is fixed to the other end. The metal piece is a metal piece having a higher linear expansion coefficient than the conductive lead, and the metal piece is arranged so that its extending direction is substantially parallel to the extending direction of the conductive lead, and the central part is fixed to the grid electrode. 2. The electron gun for a cathode ray tube according to claim 1, wherein both ends of the conductive lead are fixed to both ends.

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