JP3260440B2 - Getter device for large electron tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a getter device used for a large electron tube.

[0002]

2. Description of the Related Art Recently, for example, in the field of consumer television, large-sized televisions of about 32 inches to 37 inches have become widespread.
Naturally, it becomes very large. When it comes to such a very large electron tube,
Since the number of parts in the pipe increases and the pipe volume increases,
After the evacuation, the pressure in the pipe increases, and accordingly, the oxidizing gas ratio tends to increase as compared with the conventional large pipe. If the electron tube is operated in such a state where the exhaust is insufficient, the characteristics are adversely affected. Therefore, it is necessary to sufficiently remove unnecessary gas using a getter device before the operation.

By the way, if a 200-mg flash type getter device used for a general large electron tube is used for a super-large electron tube of 30 inches or more, the getter capability is initially lost and a problem occurs in the life. For example, a getter device having a capacity of about 300 to 350 mg in terms of flash Ba is required. Therefore, a getter device in which the amount of the getter material to be filled is increased has been studied.

[0004] Such a getter device with an increased amount of getter material includes, for example, an outer diameter of 20 mm, an inner diameter of 10 mm, and an outer height of 4.0 m.
m, a getter material made of a mixed powder of Ba-Al alloy powder and Ni powder (for example, a weight ratio of 50:50) is placed in a getter container having an opening at one end made of stainless steel and having an inner peripheral height of 2.4 mm.
mg-filled ones. In this case, the getter material used is a mechanically mixed getter material. Such a getter device is manufactured by filling a metal container with 1200 to 1500 mg of a getter material at a time and pressurizing with a press or the like. The getter device thus manufactured is disposed at a predetermined position of the electron tube, and forms a barium film on the inner wall of the tube by external heating such as high-frequency induction heating.

However, in a getter device in which the amount of the getter material is increased in order to increase the surface area of the getter film of barium deposited on the electron tube, the barium film is formed on the inner wall of the electron tube by increasing the amount of the getter material. In such a case, there arises a problem that a phenomenon in which the getter material is lifted from the metal container easily occurs. When such a phenomenon of the getter material floating occurs, a predetermined amount of getter flush is not performed, and the purpose of increasing the surface area of the barium film cannot be achieved. That is, a gap is formed between the metal container and the getter material due to the lifting of the getter material, so that the getter material is not sufficiently heated, and barium does not scatter from the getter material in the raised portion. Therefore, the amount of barium scattered was also reduced, and the getter material was increased in order to increase the barium film surface area.
It has no effect. Further, the above-described phenomenon of lifting of the getter material may cause formation of a barium film in a portion of the electron tube where a barium film should not be originally formed, which may cause deterioration of withstand voltage characteristics and getter flash. Later, the getter residue falls into the tube and becomes a source of dust in the tube, causing a problem that the function of the electron tube is significantly impaired.

On the other hand, various proposals have been made as measures for preventing the floating phenomenon in a general getter device for an electron tube. For example, Japanese Utility Model Publication No. 48-12038 discloses that a V-groove is formed in a getter material filled in a container, and U.S. Pat. No. 3,428,168 discloses that an L-shaped part is provided in an annular metal container. It describes an attached one or an annular metal container provided with a protrusion inside the bottom surface. Further, U.S. Pat. No. 4,128,782 describes an annular metal container having an inner surface provided with irregularities.

[0007] In addition, the present inventors have proposed a getter device in which the oxidation resistance of the getter material is improved in order to prevent explosive barium scattering at the time of getter flash (Japanese Patent Application Laid-open No. Sho.
No. 62-73536). In this getter device, when the getter material is filled in a container in two layers, the upper layer contains nickel powder having a larger particle size than the lower layer, and the presence of this coarse nickel powder layer Prevents oxidation of getter material and suppresses abrupt reaction.

[0008]

However, the above-described various getter devices are effective when scattering about 200 mg of barium, but are large in size, requiring about 300 to 350 mg of barium as the amount of barium to be scattered. In the case of electron tubes, there is a problem that a sufficient amount of scattering cannot be obtained.

As described above, for example, in the case of recent televisions, large-sized televisions having a size of about 32 inches to 37 inches are becoming widespread. Development of a getter device that can cope with a large-sized electron tube has been an issue since the reflection of the screen is reduced and the life is reduced.

SUMMARY OF THE INVENTION The present invention has been made to address such a problem, and has provided a getter device for a large-sized electron tube capable of stably scattering a sufficient amount of getter material on a large-sized electron tube. It is intended to provide.

[0011]

A getter device for a large electron tube according to the present invention is a getter device for a large electron tube in which a getter material containing a Ba-Al alloy is filled in a metal getter container. It consists condyle <br/> granularity of a mixture of the Ba-Al alloy and Ni, wherein the granulate is characterized in that it is filled in the getter container.

The getter material used in the getter device of the present invention is, for example, 40 to 60% by weight of Ba-Al alloy powder and 60 to 4% by weight.
A mixed powder with 0% by weight of Ni powder is exemplified. In the present invention, such a getter material is used by granulating the mixed powder .

When granulating the mixed powder, first, Ba
-Mechanically mixing Al alloy powder and Ni powder in a desired ratio. Next, for example, a tablet is formed into a mass, which is crushed to an appropriate size, and then sieved to obtain a granular getter material having a desired particle size , that is, a mixture of a Ba-Al alloy and Ni.
To obtain a granular material .

[0014] The particle size of the condyles <br/> granularity of a mixture of such Ba-Al alloy and Ni is preferably in a range of 100 to 250 [mu] m. In the case of granules having a particle size of more than 250 μm, there is no difference from the state where the initial powder is mixed without granulation, and the packing state is high density filling in the upper and lower parts, but the coarse state is in the middle and getter material It is difficult to sufficiently suppress the phenomenon of floating. Therefore, the reactivity cannot be sufficiently improved. If the particle size is less than 100 μm, the fluidity is poor, and the filling state is generally a coarse density state, so that the reactivity is reduced. In addition, granules having a particle size exceeding 250 μm
Ba-Al alloy ratio tends to increase and particle size is 100μm
If it is less, the ratio of Ni tends to increase. From these facts, it is preferable to use granules having a particle size of 100 to 250 μm also in maintaining the initial mixing ratio of the Ba—Al alloy and Ni. In order to surely obtain 300 to 350 mg of Ba scattering required for a getter device for a large electron tube, the particle size of the granules is more preferably in the range of 140 to 200 μm.

[0015]

The getter device for large electron tube of the present invention, a granulate of a mixture of Ba-Al alloy and Ni as described above was filled in a metal getter container, obtained by pressurizing a press device or the like . The present invention, for example, the amount of Ba scattering 300
It is suitable for a getter device for a large-sized electron tube such as 350 mg and a getter material filling amount of 120012001500 mg.

[0017]

In the getter device for a large electron tube according to the present invention,
Getter material (Ba-Al alloy and Ni
Mixture) is used after granulation. For this reason, the filling property of the getter material into the getter container is improved, and the whole can be densely filled even when a large amount is filled. by this,
The floating phenomenon of the getter material can be prevented, and for example, a Ba scattering amount of 300 mg or more can be realized.

[0018]

Next, an embodiment of a getter device for a large electron tube according to the present invention will be described.

Example 1 First, 50.0% by weight of a Ba-Al alloy powder having a particle size of 40 to 100 μm
The mixture was mechanically mixed with 50% by weight of Ni powder having a particle size of 5 to 7 μm. The mixed powder was pressed with a 20-ton tableting machine, and then crushed by rubbing with a 10-mesh sieve. Thereafter, a getter material comprising a granular mixture having a particle size of 140 to 200 μm was prepared by sieving.

Next, the outer diameter is 20 mm, the inner diameter is 10 mm, and the outer peripheral height is 4.0
mm, 1400mg of the above granular getter material is filled in a stainless getter container with one end of 3.5mm inner height opened.
Pressing was performed by a press device to obtain a target getter device.

The getter device thus obtained was mounted in a color picture tube for a 37-inch television, and heated externally by a high frequency generator to perform getter flash. At this time, the total heating time was set to a constant value of 30 seconds, and the amount of Ba scattered was measured.
The amount of Ba scattered in mg was realized.

Observation of the state of filling of the getter material in the getter device shows that the getter container 1 is entirely and uniformly filled with the getter material 2 as shown in FIG. confirmed.

[0023]

[0024]

Comparative Example 1 A getter device was manufactured in the same manner as in Example 1 except that the mixed powder of the Ba-Al alloy powder and the Ni powder in Example 1 was used as a getter material as it was. This getter device
Example 1 Mounted inside a color picture tube for 37-inch TV
When the getter flash was performed under the same conditions as above, a rising phenomenon was observed at a flash start time of 9 seconds. When the flash start time was set to 11 seconds to prevent the floating phenomenon, the amount of Ba scattered was reduced to 220 mg.

Further, when the state of the getter material filled in the getter device was observed, as shown in FIG.
It was confirmed that the top layer 2a and the bottom layer 2b of the getter material 2 in the inside were densely filled, but the intermediate layer 2c was not sufficiently filled and was in a coarse density state.

[0027] This RaMinoru Example 1 and is clear from the evaluation results of Comparative Example 1, with the getter device of the present invention, the getter
Since the material is granulated and used, the fillability of the getter material into the getter container is improved, and a stable and uniform reaction can be obtained even when the filling amount is large. Therefore, a sufficient amount of Ba can be scattered, and a sufficient degree of vacuum can be realized even in a large electron tube.

[0028]

As described above, according to the getter device for a large electron tube of the present invention, the reaction can be stably and uniformly performed even when the amount of the getter material filled in the getter container is large. Therefore, a sufficient amount of getter material can be scattered in the large electron tube. Therefore, the getter device for a large electron tube according to the present invention exhibits a particularly excellent effect on a larger electron tube, and greatly contributes to the improvement of the quality and reliability of the large electron tube.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing a getter material filling state in a getter device according to one embodiment of the present invention.

FIG. 2 is a cross-sectional view schematically showing a getter material filling state in a conventional getter device.

[Explanation of symbols]

 1 ... getter container 2 ... getter material

────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Masaaki Suzuki 7-1 Nisshin-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Toshiba Electronic Engineering Co., Ltd. (56) References JP-A-62-73536 (JP, A) 57-189434 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01J 29/94 H01J 7/18

Claims (3)

(57) [Claims] 1. A getter device for large electron tube formed by filling a getter material containing Ba-Al alloy in a metal getter container, wherein the getter material is granular mixture of the Ba-Al alloy and Ni
A getter device for a large electron tube, wherein the getter container is filled with the granular material . 2. A getter device for large electron tube according to claim 1, wherein the granulate constituting the getter material is a getter device for large electron tube characterized by having a particle size in the range of 100 to 250 [mu] m. 3. The getter device for a large electron tube according to claim 1, wherein the getter material has a Ba scattering amount of 300 to 350 mg.
-A getter device for a large electron tube characterized by containing an Al alloy.