JPS6016026Y2 - cathode ray tube cathode - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a cathode structure used in a small cathode ray tube.

The electron gun of a small cathode ray tube requires a small, low-power cathode, and a directly heated structure with excellent starting characteristics is generally used.

For this purpose, a cathode having the structure shown in FIGS. 1 and 2, for example, has been proposed.

In the figure, 1 is a cylindrical grid electrode with a bottom, 1a is an electron beam transmission hole drilled in the bottom of the grid electrode 1, and 2
The emitter material 3 is deposited at the center of a Dungesten heater wire to form a cathode wire.

4゜5 is a V-shaped notch for tensioning the heater wire (
V-shaped groove) A rectangular insulating plate with 4a and 5a, 6°7 is a metal support plate that supports the insulating plates 4 and 5 and also serves as a lead wire,
8. 10.11 is a spring piece made of stainless steel or the like, one end of which is welded to the support plates 6, 7. 12 is an insulator made of alumina or the like. 13 is a tenor for fixing the insulator 12 to the grid electrode.

In this structure, the rivets 8,
9 is fixed at the waist, and the roots 6a of the support plates 6, 7 are attached to the slots 12a, 12b of the router 12. The height h from the top surface of the insulator 12 to the upper edge of the insulating plate 4.5 can be increased by simply inserting the plate a and fixing it with an adhesive such as low-melting glass 14.14.
is determined, and the relative position of the V-shaped groove 4at5a to the center of the insulator 12 can be uniquely determined.

Then, by simply inserting this integrated body into the grid electrode 1, bringing the upper edges of the insulating plates 4 and 5 into contact with the bottom surface of the grid, and fixing it by welding to the first grid 1 using the retainer 13, the V-groove 4at5a is inserted. The distance GK between the emitter material 3 on the stretched heater wire 2 and the electron beam transmission hole 1a is set by the depth of the V-shaped groove.

That is, this structure allows it to be used in a conventional cathode (not shown).

There is no need for a spacer to maintain a constant distance between the insulator 12 and the first grid 1, and the size can be reduced by the space required for the arrangement.

Incidentally, in assembling such a cathode, the heater wire 2 was stretched in a conventional manner.

First, as shown in FIG. 3, the emitter material 3 is deposited on the tungsten wire 15, and metal pieces 16a, 16b, such as nickel, are fixed to both ends of the emitter material 3, so that the emitter material 3 is located in the center.

In this case, small pieces of metal such as nickel 16a and 16b are attached to both ends.
The tungsten wire 15 is made to protrude by a predetermined length 1.

This length 1 part is used as a grip part for tensioning the heater wire 2.

In addition, a small piece of metal such as nickel 1 is attached to the tungsten wire 15.
6a and 16b are fixed by welding, for example, by bending a nickel piece and inserting it in between.

As shown in FIG. 4, a small metal piece 16a such as a nickel piece on one side of the heater wire 2 formed in this manner is overlapped with the welding tongue piece 10a at the tip of one spring piece 10, and then a pair of welding electrodes 17. At step 17, clamp and fix by welding.

Next, hold the protruding length l of the heater wire 2, and as shown in FIG.
It is installed between the characters i4a and 5a.

Then, pull the protruding length 1 part so that the metal piece 16b, such as nickel, on the side that is not welded and fixed to the welding tongue piece 11a at the tip of the other spring piece 11 overlaps.

Then, with one spring piece 10 close to the insulating plate 4, the other small metal piece 16b of nickel or the like and the welding tongue piece 11a
to weld.

After this, if you release the welding electrode 17.17 and the protruding length 1 that was being pulled, the heater wire 2 will automatically move to a position where the spring pressures of the spring pieces 10.11 on both sides are balanced. do.

As shown in FIG. 1, the heater wire 2 is stretched with the emitter material 3 facing the electron beam transmission hole 1a.

However, in order to enable small power operation, this heater wire is made of, for example, a 15 μφ tungsten wire, which is very thin, and the welding tongue pieces 10a, 11 of the spring pieces 10.11.
In order to avoid heat radiation as much as possible, a is, for example, 0.4 mm wide and 0 mm long.
．． It has only a very narrow area of about 7mm.

For this reason, the workability of the heating wire tensioning process by welding was extremely poor.

Furthermore, the emitter material 3 and the electron beam transmission hole 1a are
The spacing βK and the installation in the direction of the heater wire require precision in position.

However, since the welding process is performed under the condition that the thin tungsten wire described above is fixed in a very narrow position, the accuracy of the welding position is limited.

Therefore, even though the grid cathode spacing GK is determined by the cut depths 4a and 5a of the insulating plates, positional deviations in the heater wire direction tend to occur, making it difficult to obtain stable characteristics.

Further, as shown in FIG. 3, the heater wire 2 prepared for this welding process is made of small pieces of metal such as nickel 16a, 1
A portion of length I protruding from 6b is required for positioning during welding, but it has to be removed in the end, so it is wasted.

Therefore, this invention improves the above conventional drawbacks by forming a slit 19 for locking the heater wire in the spring piece 18 for locking the heater wire as shown in FIG. As shown in the figure, a small piece of metal such as nickel 16a,
The heater wire 2 is formed without a protruding part from 16b.
0 metal pieces 16a and 16b of nickel etc. are attached to the spring piece 18
The heater wire 20 is stretched by being hooked onto the locking slit 19 of the heater wire.

That is, this invention prepares the cathode support shown in FIG. 8 assembled using the spring piece 18 shown in FIG. 6, and inserts one end of the heater wire 20 through the opening 19a of the slit 19 of the spring piece 18a. and pull the heater wire 20 to the other side while moving it to the inner part 19b.

Then, since the small metal piece 16a made of nickel or the like is larger than the spacing between the sulins 119, it is caught and locked by the tip of the spring piece.

Then, the heater wire 20 is fitted into each of the V-shaped grooves 4a and 5a of the pair of insulating plates 4 and 5, and pulled further to bring one spring piece 18a closer to the insulating plate 4 as shown in FIG. Then, pass it through the slit 19 of the other spring piece 18b in the same manner as above.

When the metal piece 16b made of nickel or the like is separated, the heater wire 20 is connected to the pair of spring pieces 18a, 1 as shown in FIG.
The emitter material 3 is moved to a position where the elastic force of the emitter material 8b is balanced, and the emitter material 3 is held at a position facing the electron beam transmission hole 1a.

By the way, when the spring piece 18 is processed into the shape shown in FIG. 6, the strength of the portion where the slit 19 is formed may be reduced depending on the material of the spring piece 18.

Therefore, as a countermeasure to this problem, the spring piece of this invention can be formed as shown in FIG. 11.

The tip of this spring piece 21 is bent into a hook shape, and a slit 19 is formed in the bent part. Even when this spring piece 21 is used, the tensioning work of the heater wire 20 is performed in the same manner as described above. This can be easily done by hooking and locking a small metal piece 16a such as nickel in the slit 19 as shown in FIG.

In addition, these flat spring pieces 18 or hook-shaped spring pieces 21
When using small metal pieces 16a, 16b of nickel etc.
The spring pieces 18 and 21 are fixed by using the slit 19 described above.
Hooking can be done by using welding and fixing together with the locking.

This is the slit 1 as shown in FIG. 13 or 14.
Small pieces of metal such as nickel 16a, 16 fixed to 9
b and the spring piece 18.21 are welded by sandwiching them between a pair of welding electrodes 17.17. At this time, the position of the heater wire 20 has already been regulated, so this welding work is performed as shown in Figures 4 and 5. The workability is much better than the conventional welding process shown in .

Therefore, even with this tensioning method that combines slit locking and welding, workability can be significantly improved compared to the conventional fixing method that only uses welding.

When this welding process is used in combination, the heater wire can be securely fixed and highly reliable.

Note that the small metal pieces 16a and 16b made of nickel or the like were used as the metal pieces for locking at both ends of the heater wire in the above embodiment.
The invention is not limited thereto, and may be formed of other metal pieces.

For example, as shown in FIG. 15, the end of the tungsten wire itself may be heated and softened to form a spherical lump 15'.

As explained above, according to this invention, it is possible to greatly improve the workability of fixing the heater wire to a pair of spring pieces that stretch the heater wire between a pair of insulating plates, and to facilitate the installation accuracy. can be raised to

Further, since there is no need to provide a protruding portion from a small piece of metal such as nickel at both ends of the heater wire, costs can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view showing an example of the cathode structure that is the premise of the present invention, Fig. 2 is a sectional view taken along line A-A in Fig. 5 and 5 are side cross-sectional views showing the conventional heating wire tensioning process, FIG. 6 is a front view of a spring piece showing an embodiment of this invention, and FIG. 7 is a view of the heating wire used in this invention. 8 to 10 are side sectional views showing the cathode assembly process according to this invention, FIG. 11 is a perspective view showing a spring piece according to another embodiment of this invention, and FIG. 12 is a diagram showing how to use the spring piece. Fig. 13 and Fig. 14 show an example in which the heater wire is further welded after being locked as shown in Fig. 10 and Fig. 12, respectively. The side sectional view and FIG. 15 are top views showing another embodiment of the heater wire used in this invention. 3...Emitter material, 4, 5...Insulating plate, 4a, 5a,...Notch, 16a, 16b
・・・・・・Small metal pieces such as nickel, 18, 18a, 1
8b, 21... Spring piece, 19... Slit, 20... Heater wire.

Claims (1)

[Scope of utility model registration request] Insulating plates having notches at their upper edges are placed opposite each other, a spring piece is provided on the outside of the insulating plate so that its tip is separated from the insulating plate, and a cathode wire partially coated with an emitter substance is inserted into the insulating plate. In the case where the tip of the spring piece is stretched across the notch, a small metal piece is fixed to both ends of the cathode wire, and the small metal piece is inserted and locked into a slit formed at the tip of the spring piece. A cathode ray tube cathode characterized by a welded tip.