JP2000106100A - Connection structure and manufacture of electron gun cathode heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce manufacturing manhours by forming a bent material into a generally U-shaped form, and by cutting out the joining part of the U-shaped form to form it into two parallel straight and the same length bars shape form after welding it to adjacent metal pins of a stem. SOLUTION: In a first process, terminating parts of a cathode heater are welded and fixed to a plate material 32 bent into a U-shaped form. This process allows the work to be carried out independently of assemblage of other electron gun components, and is used as a welding process for the two components, so that jigs and tools can be simplified. In a second process, the assembled part in the first process is welded and fixed to metal pins 30, 31 extending from a stem 1. In a third process, an unnecessary part 33 of the plate material 32 bent into the U-shaped form is cut out. Thereafter, other assembly processes of the electron gun are carried out and the assemblage of the electron gun and the stem is to be completed. For the metal pins of the stem, for example, pins separate from each other by two pin-intervals as well as immediately adjacent pins can be used as long as the U-shaped form permits.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cathode heater connection structure and a manufacturing method for an electron gun mounted on a cathode ray tube.

[0002]

2. Description of the Related Art A cathode ray tube generally comprises a funnel serving as an outer container, an electron gun for emitting electrons, and a face plate having a fluorescent film for emitting light by electron collision to draw an image. Here, the cathode serving as the electron emission source of the electron gun is:
Electron emission is promoted by being heated by a heater, also called a hot cathode. This heater is called a cathode heater and is usually constituted by a coil made of tungsten wire of several tens of microns.

FIGS. 1 and 2 are half sectional views of a conventional electron gun and a stem, and FIG. 3 is a perspective view of the stem. The stem 1 is composed of seven metal terminals (3 to 9) and glass 2, and each metal terminal (hereinafter referred to as a metal pin) is positioned and welded to the glass 2. The electron gun is the control electrode 1
0, an acceleration electrode 11, a focus electrode 12, and two bead glasses 13 and a cathode 15 for positioning and fixing each of them. FIG. 4 is a half cross-sectional view of the cathode 15. The cathode 15 includes a cathode heater 20, a holder 16, a cathode sleeve 17, and a plurality of straps 1.
8, the cathode material 19 and the like. The components of the electron gun and the metal pins of the stem are connected by leads or the like. The metal pins 7, 8 which have been bent in advance are welded to the terminals 21, 22 of the cathode heater, and the metal pins 3, 4 and the control electrode 10, the metal pin 5 and the acceleration electrode 11, the metal pin 6 and the focus electrode 12, the metal pin 9 and the holder 16 are connected by metal leads 23, 24, 25, 26 and 27, respectively, by welding or the like.

[0004] The assembly of the electron gun and the assembly of the electron gun and the stem will be described. The electron gun has a control electrode 10, an acceleration electrode 11,
It is composed of a focus electrode 12, two bead glasses 13 for positioning and fixing each, and a cathode 15. The control electrode 10, the acceleration electrode 11, the focus electrode 1
2 and two bead glasses 1 for positioning and fixing each
3 is positioned and fixed by a dedicated jig, and bead glass 1
3 are integrated. The cathode 15 is incorporated into the control electrode 10 together with other components without the cathode heater 20. The leads 23 and 24 connecting the metal pins 3 and 4 and the control electrode 10 play a role of positioning and fixing the electron gun and the stem 1, and are fixed first. Next, the cathode heater 20 is inserted into the cathode sleeve 17, and the terminal portions 21 and 22 of the cathode heater 20 are welded to the metal pins 7 and 8 that have been bent in advance. Finally, the metal pin 5 and the acceleration electrode 11, the metal pin 6 and the focus electrode 12, and the metal pin 9 and the holder 16 are connected by metal leads 25, 26 and 27, respectively, by welding or the like. FIG. 5 is a perspective view in which the metal pins 7, 8 and the cathode heater 20 are fixed, and other parts are omitted.

[0005]

However, the terminal portions 21 and 22 of the cathode heater 20 fixed to the metal pins 7 and 8 of the stem 1 are tungsten wires themselves and have a fine diameter of several tens of microns. Furthermore, the outer diameter of the metal pins 21 and 22 of the stem 1 is about 0.6 mm, and it is very difficult to mechanically press the terminal portions 21 and 22 of the cathode heater 20 and fix them by electric resistance welding or the like. In addition, the work under the microscope due to the enlargement requires a large number of man-hours, and the cost is high.

[0006]

According to the present invention, a cathode heater is welded to a previously bent plate, and then the plate is welded and fixed to a metal pin of a stem, and unnecessary portions of the plate are cut off.

According to the present invention, a bent plate is formed into a substantially U-shape, and after welding to a metal pin adjacent to a stem,
By cutting the connected portion of the U-shape to form a D-shape, the cathode heater is configured to be in an open state from a state in which both ends of the cathode heater are short-circuited.

According to the present invention, there is provided a method of manufacturing a stem having glass pins welded to a cathode pin of an electron gun for external conduction to a cathode heater of the electron gun, and a connection structure of two cathode heater terminals of the electron gun connected to the metal pin. Securing the two terminals of the cathode heater to a pre-bent integral plate, and connecting the plate to the stem of the stem.
A method for manufacturing a connection structure for an electron gun cathode heater, comprising the steps of: fixing to one metal pin; and separating unnecessary portions of the plate material.

[0009]

FIG. 6 is a perspective view of one embodiment of the present invention, which will be described below with reference to the drawing.

In the present invention, a plate material 32 previously bent into a U-shape is welded and fixed to the metal pins 30, 31 which are welded and fixed from the stem 1 which also serves as the base of the electron gun, and
The plate member 32 previously bent in a U-shape is formed as an auxiliary material for fixing the terminal portions 21 and 22 of the cathode heater 20 by welding and fixing a predetermined portion by welding. Unnecessary portions 33 of the plate 32 after welding and fixing (represented by dashed lines in the figure and sandwiched between them) are cut off. As a result, the terminal portions 21 and 22 of the cathode heater 20 are released from a state where they are electrically short-circuited. In driving the cathode ray tube (electron gun), a voltage is applied to the terminal portions 21 and 22, and the cathode heater 20 heats.

The manufacturing method in the above embodiment is, for example, in the following procedure. As a first step, the terminal portions 21 and 22 of the cathode heater 20 are welded and fixed to a plate 32 bent into a U-shape. In this step, it is possible to work independently of the assembly of other electron gun parts, and it becomes a welding step of the two parts, so that the jigs and the like can be simplified. As a second step, the articles assembled in the first step are fixed by welding to metal pins 30 and 31 extending from the stem 1 (as shown in FIG. 6). As a third step, an unnecessary portion 33 (cut portion) of the plate material 32 bent into a U-shape is cut. Thereafter, other assembly processes of the electron gun are advanced, and the assembly of the electron gun and the stem is completed. In addition, the metal pin of the stem is not limited to the immediately adjacent pin, but may be, for example, an adjacent pin beyond one pin as long as the U-shape allows, and many modifications may be made without departing from the spirit of the present invention. Can be implemented.

[0012]

According to the present invention, the terminal portion of the cathode heater of the electron gun is as fine as several tens of microns in the diameter of the tungsten wire, but the cathode material is bent into a U-shaped plate in advance. This welding operation can be facilitated by welding and fixing the terminal portion of the heater as a separate process from the assembly of the electron gun. In addition, when welding and fixing to the metal pin of the stem, the U-shaped part can be welded by hooking it on the metal pin, and it is cut into a two-shaped shape after welding, making work easier and reducing man-hours And a manufacturing method of the electron gun can be provided. The bending of the metal pin is not required, and for example, the electron gun is suitable for application to an electron gun of a small small cathode ray tube.

[Brief description of the drawings]

FIG. 1 is a half sectional view of an electron gun and a stem according to the prior art.

FIG. 2 is a half sectional view of a conventional electron gun and a stem.

FIG. 3 is a perspective view of a stem.

FIG. 4 is a half sectional view of a cathode.

FIG. 5 is a perspective view in which a metal pin and a cathode heater are fixed.

FIG. 6 is a perspective view of one embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 stem 2 glass 3 metal pin 4 metal pin 5 metal pin 6 metal pin 7 metal pin 8 metal pin 9 metal pin 10 control electrode 11 acceleration electrode 12 focus electrode 13 bead glass 15 cathode 16 holder 17 cathode sleeve 18 strap 19 cathode material 20 Cathode heater 21 Terminal 22 Terminal 23 Lead 24 Lead 25 Lead 26 Lead 27 Lead 30 Metal pin 31 Metal pin 32 Plate 33 Cut of plate

Claims (3)

[Claims] 1. A connection structure of a stem formed by welding a metal pin to a glass for externally connecting to a cathode heater of an electron gun and two cathode heater terminals of the electron gun connected to the metal pin. After fixing two cathode heaters to an integrated plate material that has been bent in advance,
The connection structure for an electron gun cathode heater, wherein the plate member is fixed to two metal pins of the stem, and unnecessary portions of the plate member are cut off. 2. The bent plate material is generally U-shaped, and after being welded to a metal pin adjacent to the stem,
2. The electron gun cathode heater connection according to claim 1, wherein the U-shape connected portion is cut to form a D-shape to open the cathode heater from a state where both ends of the cathode heater are short-circuited. Construction. 3. A method of connecting a cathode formed by welding glass pins to a cathode heater of an electron gun from the outside and connecting two cathode heater terminals of an electron gun to the metal pins. An electron gun comprising: a step of fixing two terminals of a heater to an integrated plate material that has been bent in advance; a step of fixing the plate material to two metal pins of a stem; and a step of separating unnecessary portions of the plate material. Manufacturing method of cathode heater connection structure.