JPS6051766B2 - Method for manufacturing directly heated cathode structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a directly heated cathode assembly.

A directly heated cathode assembly commonly used in cathode ray tube electron guns.
In particular, a multi-element cathode assembly, such as the electron gun of a color picture tube, has an extremely important function for emitting electron beams.

In particular, the amount of electron beam radiation from each power sword, the distance from each cathode surface to the first grid electrode, and the distance between each cathode must be set accurately. In addition, a directly heated cathode has better interlocking properties than an indirectly heated cathode, so it is advantageous to use it in an interlocking color picture tube. A multi-element directly heated cathode assembly used in an electron gun of a color picture tube is shown in FIG.

In the figure, reference numeral 1 denotes an elliptical substrate made of an insulating material such as a ceramic material or a glass material. This board 1 has three sets of heater support terminals (hereinafter simply referred to as support terminals) 2, 3 arranged opposite to each other so as to be lined up in the longitudinal direction of the board.
is planted, and one support terminal 3 has a spring 4.
is attached so that it protrudes outward. Reference numeral 5 denotes a filament, and the filament 5 has a cathode 10 made of a base metal 6 and an electron emitting substance 7 deposited thereon at its center.

Further, the filament 5 is stretched over the substrate 1 by a plurality of terminals such as the support terminals 2 and 3 and the spring 4, and is arranged in a straight line with the cathode along the longitudinal axis of the substrate 1. Arranged. Further, a through hole 21 is formed on the solid axis in the longitudinal direction of the substrate 1 so as to face a beam through hole (not shown) of the first grid electrode. This cathode assembly was later integrated into the electron gun assembly with a first
As a distance adjustment means for making the distance between the grid electrode and the cathode accurate, one of the support terminals 2 and 3 is made into a rectangular cylinder, and the filament 5 is pushed up from below into the cylinder to form the cathode structure ±■. It has an adjustment terminal 8 that can vary the position of. After adjusting the distance (hereinafter simply referred to as GIK distance) and position between the first grid electrode (not shown) and the cathode ±u, this adjustment terminal 8
It is fixed to the rectangular cylindrical support terminal 3, and is slidably disposed until then. The adjustment terminal 8 is pushed upward to adjust the GIK interval, and the rectangular cylindrical support terminal 3 is shorter in length than the other support terminal 2 disposed opposite to it. In such a directly heated cathode assembly, the filament is stretched obliquely to the substrate surface, and the GIK spacing is adjusted from this state. However, such a structure is extremely inconvenient when assembling the cathode assembly. It's bad. That is, since the support terminal 3 on the side having the adjustment terminal 8 is shorter than the other support terminal 2, the filament 5 stretched between the support terminals is inclined. Therefore, when welding the base metal 6 to the filament 5,
The filament 5 must be welded and fixed in an inclined state, and the base. The same applies when applying the electron radioactive substance 7 onto the metal 6, and in this case, a jig is used, making the work particularly troublesome. Therefore, an object of the present invention is to provide a method for easily manufacturing a directly heated cathode assembly with high precision. Ru.

In such a directly heated cathode structure, the important thing in the process of implanting and fixing the filament support terminal and welding the filament to the substrate with the adjustment terminal is to maintain the exact spacing between the three filaments and to keep the distance between the substrate and metal. These include ensuring that the welding position is accurate and that the filament is not bent.

The present invention was made to ensure these points, and three filaments are fixed to a frame separately from the cathode intermediate structure in which the filament support terminal and adjustment terminal including the spring are assembled on the substrate. After the integration, the cathode structure is formed in a flat state, and then,
The present invention relates to a method of manufacturing a directly heated cathode assembly, in which the intermediate assembly and the cathode assembly with a frame are assembled by overlapping each other.

Embodiments of the present invention will be described below with reference to the drawings. Note that the same parts as in FIG. 1 are indicated by the same numbers. First, as shown in FIG. 2, a plurality of filaments 5 are fixed at equal intervals by welding or adhesive to a rectangular frame 11 having holes 16 provided at both ends of the short side for positioning. do.

Then, a base metal 6 is welded to the center of each filament 5. This welding of the filament 5 and the base metal 6 is performed in the third
By using a jig 30 as shown in the figure, it can be easily and accurately fixed. This jig 30 has a plurality of grooves 31 for accommodating the filament 5 and a recess 32 for fixing the position of the base metal 6.
They also serve as welding electrodes when welding the frame bodies 11 to respective predetermined positions. Positioning pins 33 that fit into the holes 16 bored in the frame 11 are provided at both short side ends of the jig 30 . The frame body 11 is firmly fixed in a predetermined position by the positioning pin 33, and the filament and base metal are inserted into the groove 31 and the recess 32.
They can be fitted and fixed respectively. The filament and base metal fixed to the frame 11 in this way are washed and hydrogenated as necessary, and then Basr, c
An electron radioactive substance such as acO3 is coated on the base metal by a spray method or the like. All of the above-mentioned processing is performed with the frame still in place, and all can be performed in a flat state, which makes the processing operations easy and does not cause problems as in the conventional case. Below, frame 1 like this
1 to which a filament 5 having a base metal 6 is fixed will be referred to as a frame-attached cathode structure ±J. on the other hand,
Substrate 1 of the cathode structure formed in an elliptical shape using ceramic or the like
As shown in FIG. 4, filament support terminals 2 and 3, one of which is cylindrical and the other of which is a rectangular tube, are erected facing each other.

A spring 4 whose tip protrudes outward is welded and fixed to the support terminal 3 on the rectangular cylindrical side. This will be welded and fixed to the filament in a later process to become a filament support terminal. The structure in which the support terminals 2 and 3 are fixed to the substrate 1 and the spring 4 is attached to one of the rectangular cylindrical support terminals 3 is referred to as a cathode intermediate assembly structure or simply an intermediate structure. Next, in the previous process, the cathode and filament (
A cathode structure with a frame, in which a cathode structure (hereinafter also referred to as a cathode structure) is fixed to a frame, and a cathode intermediate structure, in which the support terminals are attached to a substrate, are superimposed and assembled. This will be explained in detail using . During this assembly, a jig J that also serves as a welding electrode as shown in FIG. 5b is used. This jig μu is. The intermediate structure 1U
Positioning pins 47 and 48 are provided for overlapping the framed cathode structures ±J in a predetermined positional relationship. A positioning pin 47 near the center of the jig U supports the intermediate structure, that is, the substrate 1, and is fitted into a positioning hole 21 provided in the substrate 1. Jig (U
A positioning pin 48 near the end of the frame supports the framed cathode structure ±J, and is fitted into a hole 16 provided in the frame 11 for positioning. In such a jig μ■, the intermediate structure u and the cathode structure with frame ±
J are overlapped so as to correspond to predetermined positioning pins 47 and 48, respectively. Filament 5 of the intermediate structure 1U
The abutting portions are slanted because the heights of the cylindrical support terminals 2 and the rectangular cylindrical support terminals 3 from the surface of the substrate 1 are different, but this does not pose a problem during assembly. This is because the framed cathode structure ±J is configured so that its inclination can be changed freely to some extent on the positioning pin 48. That is, the inclination can be changed by making the portion of the positioning pin 48 in contact with the lower surface of the frame body 11 flat and slightly rounded. After overlapping in this manner, the filament 5 is welded to the spring 4 attached to the cylindrical support terminal 2 and the rectangular support terminal 3. After that, the filament 5 is separated from the frame 11. After completing the assembly of the cathode assembly and assembling it into the electron gun assembly, the adjustment terminal 8 is inserted and the position of the filament 5 is knotted while measuring the GIK interval, and the rectangular cylindrical support terminal 3
Fixed to. FIG. 6 is an improved version of the frame described in FIG. 2, in which the filament is supported and fixed in a different manner from that described above.

That is, a long groove 52 is provided along the long side 51 in the longitudinal direction, and a groove 53 for fixing the filament is provided perpendicularly to the long groove 52.
a frame body 50 provided with a convex portion 61 that matches the long groove 52;
The filament is sandwiched between the elongated plate body 60 and the filament. It is then clamped and fixed with an elastic U-shaped spring clip 62. Although not shown, the filament may be clamped and fixed by using the frame 50 and plate 60 as described above and screwing them together. Therefore, when fixing the filament, there is an advantage that it can be fixed with screws or springs without using welding or adhesive, and the frame can be used repeatedly. Further, instead of one temporary assembly structure, a continuous temporary assembly structure may be used.

FIG. 7 shows that after welding the base metal 6 to the filament 5,
The assembly structure is manufactured by applying an electron radioactive material, and fixing it to a frame (not shown) while pulling it out. This method is useful for automating the assembly of the cathode structure, and after welding a plurality of base metals 6 to the filament 5 wound around the substantially flat electrode 70, an electron emitting substance is applied. Then, the filament 5 is fixed to the frame while being sequentially unwound. As explained above, the present invention provides a plurality of sets of heater support terminals 2 on a generally elliptical insulating substrate 1 having a plurality of positioning holes 21.
and a step of assembling the intermediate structure 2 by implanting the cylindrical support terminals 3 to which the springs 4 of lower height are welded, and forming another frame 11, 50 having a positioning hole 16.
A plurality of filaments 5 and a base metal 6 are fixed in parallel to each other at predetermined positions, and an electron radioactive substance 7 is placed on the base metal.
a step of assembling a cathode structure with a frame ±J by covering the
The intermediate structure 1U is connected to one of the positioning pins 47 of the jig μ■, which is equipped with two sets of positioning pins 47 and 48 and also serves as a welding electrode, through a positioning hole 21 formed in its insulating substrate.
and the other positioning pin 48 is fitted into the positioning hole 16 of the cathode structure with frame ±J, and the filament 5 is connected to the heater support terminal 2 and the cylindrical support terminal 3. A step of supporting the filaments diagonally so that they are in contact with each other, and a step of welding and fixing each filament 5 to the heater terminal 2 and spring 4 of the intermediate structure 1, using the jig 1 as one welding electrode in this state, and then Frame 1
1 and 50, and then adjusting the height of the base metal 6 by adjusting the adjustment terminal 8 inserted inside the cylindrical support terminal 3 of the intermediate structure su, and fixing it. A method for manufacturing a directly heated cathode assembly, comprising:

Therefore, it is possible to assemble a plurality of cathodes easily and with high positioning accuracy.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a directly heated cathode assembly, FIG. 2 is a top view of the frame and cathode assembly used in the method of manufacturing a directly heated cathode assembly according to the present invention, and FIG. 3 is a directly heated cathode assembly according to the present invention. 4 and 5 are explanatory diagrams for assembling the directly heated cathode structure. FIGS. 6 and 7 show a method for fixing the frame and the cathode structure. It is a figure explaining a modification. 1... Board, 2, 3... Support terminal, 5
...Filament, 6...Base metal,
11... Frame body, 30, 40... Jig.

Claims (1)

[Claims] 1 A cylindrical support terminal 3 in which a plurality of sets of heater support terminals 2 and springs 4 each having a lower height than the heater support terminals 2 are welded to a generally elliptical insulating substrate 1 having a plurality of positioning holes 21.
and fixing a plurality of filaments 5 and base metal 6 in parallel to each other in predetermined positions of frames 11 and 50 having positioning holes 16, and fixing electrons on this base metal. A step of assembling a cathode structure with a frame body for 17 yen by covering it with radioactive material 7, and a jig for 40 yen that is equipped with two sets of positioning pins 47 and 48 and also serving as a welding electrode. Structure ￥20￥
is fitted into the positioning hole 21 formed in the insulating substrate and supported, and the positioning hole 16 of the cathode structure with frame is fitted into the other positioning pin 48, and the filament 5 is A process of diagonally supporting the heater support terminal 2 and the cylindrical support terminal 3 so as to contact them, and in this state, each filament 5 is attached to the heater terminal 2 of the intermediate structure by using the jig ¥40 as one welding electrode. and a step of welding and fixing each filament to the spring 4, and then a step of separating each filament 5 from the frame bodies 11 and 50, and then a step of moving the adjustment terminal 8 inserted inside the cylindrical support terminal 3 of the intermediate structure ¥20 back and forth. A method for manufacturing a directly heated cathode assembly, comprising the steps of adjusting and fixing the height of the base metal 6.