JPH0821309B2 - Impregnated type cathode - Google Patents

Impregnated type cathode

Info

Publication number
JPH0821309B2
JPH0821309B2 JP5914586A JP5914586A JPH0821309B2 JP H0821309 B2 JPH0821309 B2 JP H0821309B2 JP 5914586 A JP5914586 A JP 5914586A JP 5914586 A JP5914586 A JP 5914586A JP H0821309 B2 JPH0821309 B2 JP H0821309B2
Authority
JP
Japan
Prior art keywords
cathode
metal
impregnated
electron emission
electron
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
JP5914586A
Other languages
Japanese (ja)
Other versions
JPS62217525A (en
Inventor
克夫 湯原
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Ltd
Original Assignee
Hitachi Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hitachi Ltd filed Critical Hitachi Ltd
Priority to JP5914586A priority Critical patent/JPH0821309B2/en
Publication of JPS62217525A publication Critical patent/JPS62217525A/en
Publication of JPH0821309B2 publication Critical patent/JPH0821309B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、撮像管,ブラウン管などの電子管に用いて
好適な含浸形カソードに関するものである。
TECHNICAL FIELD The present invention relates to an impregnated cathode suitable for use in electron tubes such as image pickup tubes and cathode ray tubes.

〔従来の技術〕[Conventional technology]

電子管の高性能化に伴つて、高電流密度カソードが必
要になり、多孔質金属体と電子放出物質からなる含浸形
カソードの開発が盛んである。多孔質金属体としては、
所望の空孔率を有し、空孔の大きさ、その分布が均一で
しかも、空孔のすべてが連結孔となつていることが必要
である。このような、多孔質金属体を作るには、粉末を
焼結することによつて作る。カソード形状にするために
は、大きな焼結体から切削加工による方法と最初からカ
ソード形状のプレス治具を用いて、粉末をプレス成型,
焼結することによつて作ることができる。このようにカ
ソード形状にした多孔質金属体中に電子放出物質を還元
性あるいは非酸化性雰囲気中で加熱溶融するなどの方法
により含浸して、含浸形カソード基体が作製される。こ
のように作製したカソード基体は、第2図に示すように
一般に、カソード基体1の裏面(ヒータ側)に障壁層2
を設けて、スリーブ3に固定され、さらにタングステン
線に絶縁層を設けたヒータ4と組立てられ、電極と組み
合されて電子管を作る。
As the performance of electron tubes has improved, high current density cathodes have become necessary, and impregnated cathodes composed of a porous metal body and an electron emitting material have been actively developed. As a porous metal body,
It is necessary that the holes have a desired porosity, that the size and distribution of the holes are uniform, and that all of the holes are connecting holes. In order to make such a porous metal body, it is made by sintering powder. In order to form the cathode shape, the powder is press-molded using a method of cutting from a large sintered body and using a cathode-shaped press jig from the beginning.
It can be made by sintering. Thus, the impregnated cathode substrate is manufactured by impregnating the electron-emitting substance into the cathode-shaped porous metal body by a method such as heating and melting in a reducing or non-oxidizing atmosphere. The cathode substrate thus prepared generally has a barrier layer 2 on the back surface (heater side) of the cathode substrate 1 as shown in FIG.
Is fixed to the sleeve 3 and further assembled with the heater 4 having a tungsten wire provided with an insulating layer and combined with the electrode to form an electron tube.

カソード基体1と障壁層2、及びスリーブ3の固着
は、ロウ付,溶接等の方法で行うが、ロウ付の場合、カ
ソード基体の微細孔にロウが浸み込みカソード基体と障
壁層の間に空隙が生じ、また、多量のロウを使用すると
カソード基体の奥深くまでロウ材が浸入したり、あるい
はカソードの表面、即ち電子放出面にまでロウ材が流れ
たりする不都合があつた。
The cathode base 1 and the barrier layer 2 and the sleeve 3 are fixed to each other by a method such as brazing or welding. In the case of brazing, the brazing metal penetrates into the fine holes of the cathode base and the space between the cathode base and the barrier layer. Voids are generated, and when a large amount of brazing material is used, the brazing material penetrates deep into the cathode substrate, or the brazing material flows to the surface of the cathode, that is, the electron emission surface.

また、溶接で固着する場合、障壁層,スリーブなど小
型のカソードの部品は肉厚も薄く、溶接時に亀裂が生
じ、カソードが動作時の高温では電子放出物質が容易に
隙間から蒸発してヒータ側にまわり込むという不都合が
あつた。
In addition, when fixed by welding, the small cathode parts such as the barrier layer and sleeve have a small thickness and cracks occur during welding, and the electron emission material easily evaporates from the gap at the high temperature when the cathode is in operation and the heater side There was the inconvenience of getting around.

これらの問題を解決するため特開昭60−74229号公報
に示されているように障壁層とスリーブとをロウ付し、
カソード基体を溶接により固着する方法が提案されてい
る。しかし、電子放出物質が含浸したカソード基体を溶
接すると、溶接時の高温で電子放出物質が溶融して吹き
出し電子放出特性に悪影響する問題がある。
To solve these problems, the barrier layer and the sleeve are brazed as shown in JP-A-60-74229,
A method of fixing the cathode substrate by welding has been proposed. However, when the cathode substrate impregnated with the electron emitting substance is welded, there is a problem that the electron emitting substance is melted at a high temperature at the time of welding and the blown electron emitting characteristics are adversely affected.

他方、電子管の高性能化に伴い、カソードには高電流
密度カソードが要求される一方、カソードに対向する電
極すなわち第1グリツドの穴径が、どんどん小さくなる
方向に進んでいる。したがつてカソードは小さくても済
むことになる。しかし、含浸形カソードは酸化物カソー
ドに比べて動作温度が300℃以上も高い。このように高
い動作温度を必要とする含浸形カソード用ヒータの設計
が難しくなつている。特に、信頼性を保証するために
は、ヒータのタングステン線を太くする必要があり、ま
た、その時作られたヒータの最小コイル外径は現在の技
術では1.5mm程度である。したがつて、第1グリツドの
穴径に合せて、含浸形カソードを小さくしても、適用で
きるヒータが存在しないという問題がある。したがつて
現在のヒータを使用する必要があり、第3図に示すよう
な改良含浸形カソード構造が考えられている。この改良
構造の含浸形カソードでは、カソード基体1の電子放出
側端面に凸状部1Aを設け、該凸状部1Aの天頂面を実際の
電子放出面とするようにしているが、電子放出面以外の
電子放出側端面面積が大きいので、不必要なBa蒸発が多
く、グリツド・エミツシヨンの原因になり易いという不
都合があつた。したがつて、現在のヒータを使用し、し
かも含浸形カソードは、電子放出面以外は必要最小限面
積を小さくしBa蒸発量を減らす必要がある。
On the other hand, as the performance of the electron tube is improved, a cathode having a high current density is required for the cathode, while the hole diameter of the electrode facing the cathode, that is, the first grid, is becoming smaller and smaller. Therefore, the cathode can be small. However, the impregnated cathode has an operating temperature higher than 300 ° C as compared with the oxide cathode. As described above, it is difficult to design a heater for an impregnated cathode that requires a high operating temperature. In particular, in order to guarantee reliability, it is necessary to thicken the tungsten wire of the heater, and the minimum coil outer diameter of the heater made at that time is about 1.5 mm in the current technology. Therefore, even if the impregnated cathode is made smaller according to the hole diameter of the first grid, there is a problem that there is no applicable heater. Therefore, it is necessary to use the current heater, and an improved impregnated cathode structure as shown in FIG. 3 is considered. In the impregnated cathode of this improved structure, a convex portion 1A is provided on the end surface of the cathode substrate 1 on the electron emission side, and the zenith surface of the convex portion 1A is used as the actual electron emission surface. Since the end surface area on the electron emission side other than the above is large, there is a disadvantage that unnecessary Ba vaporization is large, and it is likely to cause grid emission. Therefore, the current heater is used, and the impregnated cathode needs to have a minimum required area other than the electron emission surface to reduce the Ba evaporation amount.

〔発明が解決しようとする問題点〕[Problems to be solved by the invention]

以上述べたように、ブラウン管用などの小型の含浸形
カソードにおいて、カソード基体の障壁層やスリーブへ
の固着が電子放出特性に悪影響を及ぼし、又、電子放出
面、及びその周辺からの余分なBa蒸発により、グリツド
エミツシヨンが生じるなどという欠点があつた。
As described above, in a small impregnated cathode for a cathode ray tube or the like, the sticking of the cathode substrate to the barrier layer or sleeve adversely affects the electron emission characteristics, and the excess Ba from the electron emission surface and its periphery is also affected. There is a drawback that the grid emission occurs due to evaporation.

したがつて本発明の目的は、電子放出特性に悪影響を
及ぼさず、カソード基体,障壁層,スリーブを強固に固
着でき、しかも、電子放出面以外からのBa蒸発が少ない
構造の含浸形カソードを提供することにある。
Therefore, an object of the present invention is to provide an impregnated cathode having a structure that does not adversely affect the electron emission characteristics, can firmly fix the cathode substrate, the barrier layer, and the sleeve, and has little Ba evaporation from other than the electron emission surface. To do.

〔問題点を解決するための手段〕[Means for solving problems]

本発明によれば、上記の目的は、カソード基体の電子
放出面側に凸部を設け、凸部の天頂面を電子放出面と
し、この電子放出面以外をカバーする高融点金属からな
る金属蓋体と金属支持板とによりカソード基体を挾みこ
み、金属蓋体と金属支持板とを溶接又はロウ付した構造
とすることにより達成される。
According to the present invention, the above object is to provide a convex portion on the electron emission surface side of the cathode substrate, use the zenith surface of the convex portion as an electron emission surface, and cover the portion other than the electron emission surface with a metal lid made of a refractory metal. This is achieved by sandwiching the cathode substrate with the body and the metal supporting plate and by welding or brazing the metal lid and the metal supporting plate.

〔作用〕[Action]

本発明による含浸形カソードは、金属支持板と金属蓋
体を固着することにより、カソード基体を固定している
ため、カソード基体の電子放出面側への溶接,ロウ付等
の影響が全くなく、また、電子放出面以外の周辺部は金
属蓋体でカバーされているためBa蒸発が少ない高い信頼
性を持つた小型の含浸形カソードが得られる。
In the impregnated cathode according to the present invention, since the cathode base is fixed by fixing the metal supporting plate and the metal lid, there is no influence such as welding or brazing on the electron emitting surface side of the cathode base. In addition, since the periphery other than the electron emission surface is covered with a metal lid, a small impregnated cathode with high reliability with little Ba evaporation can be obtained.

〔実施例〕〔Example〕

第1図は、本発明の一実施例になる含浸形カソードの
断面構造を示す。直径1.45mm,高さ0.45mmのカソード基
体1の電子放出側端面に直径0.5mm,高さ0.1mmの凸部を
形成し、同時に厚さ0.1mm,直径1.65mm,高さ0.55mmで、
中心に直径0.5mmの円孔を有したモリブデン製の金属蓋
体6及び直径1.65mm,厚さ0.1mmのモリブデン製の金属支
持板5を用意した。この金属蓋体6と金属支持板5の接
合面にMo−41.6Ru共晶微粉末にバインダーとしてブチル
カルビトールアセテートを加えペースト状としたロウ材
を塗つた後、カソード基体1を金属蓋体6中に押し込ん
でから金属支持板5を組合せ、さらに内径1.65mm,外径
1.71mm,長さ5.3mmのスリーブ3の上部内周面にペースト
状のロウ材を塗り、真空中で約1950℃×1〜2秒間タン
グステンコイルヒータによつて加熱し、カソード基体1,
金属蓋体6,金属支持板5並びにスリーブ3を一体化し、
さらにタングステン線表面にアルミナを絶縁被覆してな
る外径1.48mmのヒータ4をスリーブ3内に挿入して、本
発明の含浸形カソードを作製した。
FIG. 1 shows a sectional structure of an impregnated cathode according to an embodiment of the present invention. A convex portion having a diameter of 0.5 mm and a height of 0.1 mm is formed on the end surface of the cathode substrate 1 having a diameter of 1.45 mm and a height of 0.45 mm, and a thickness of 0.1 mm, a diameter of 1.65 mm, and a height of 0.55 mm.
A metal cover 6 made of molybdenum having a circular hole with a diameter of 0.5 mm and a metal support plate 5 made of molybdenum with a diameter of 1.65 mm and a thickness of 0.1 mm were prepared. Mo-41.6Ru eutectic fine powder and butyl carbitol acetate as a binder were added to the joining surface of the metal lid 6 and the metal supporting plate 5 and a paste-like brazing material was applied thereto, and then the cathode substrate 1 was attached to the metal lid 6 After pushing it in, combine the metal support plates 5, and then the inner diameter 1.65mm, the outer diameter
A brazing material in the form of paste is applied to the upper inner peripheral surface of the sleeve 3 having a length of 1.71 mm and a length of 5.3 mm, and it is heated in a vacuum for about 1950 ° C. for 1 to 2 seconds by a tungsten coil heater.
Integrating the metal lid 6, the metal support plate 5, and the sleeve 3,
Further, a heater 4 having an outer diameter of 1.48 mm, which is obtained by insulatingly coating alumina on the surface of the tungsten wire, was inserted into the sleeve 3 to produce the impregnated cathode of the present invention.

金属蓋体6を用いて、カソード基体1の凸部1aの天頂
面以外を覆うことによつて、Ba蒸発量は直径1.45mmの従
来の含浸形カソードに比べて1桁近く減少し、グリツド
エミツシヨンの心配は解消できた。また、ロウ材・溶接
によるカソード基体への悪影響もなくなり、長時間安定
に動作し、含浸形カソードの信頼性も大幅に向上するこ
とができた。
By covering other than the zenith surface of the convex portion 1a of the cathode substrate 1 with the metal lid 6, the evaporation amount of Ba is reduced by almost an order of magnitude as compared with the conventional impregnated cathode having a diameter of 1.45 mm. I was able to eliminate the concern about the emission. Further, the adverse effect of the brazing material / welding on the cathode substrate was eliminated, stable operation was performed for a long time, and the reliability of the impregnated cathode could be greatly improved.

〔発明の効果〕〔The invention's effect〕

本発明によれば、従来のヒータやスリーブの仕様を変
更することなく、電子放出面以外からのBa蒸発量を減少
できる特徴を有し、グリツドエミツシヨン対策上非常に
有利である。また、カソード基体は、金属蓋体および金
属支持板の固着により両者間に挟みこまれて固定される
ので,カソード基体を金属蓋体や金属支持板に溶接,ロ
ウづけなどにより固着する必要がないので、カソード基
体へのロウ材あるいは溶接による悪影響を解消すること
ができ、含浸形カソードの信頼性向上にきわめて有利で
ある。
According to the present invention, the amount of Ba vaporized from other than the electron emission surface can be reduced without changing the specifications of the conventional heater and sleeve, which is very advantageous as a countermeasure against grid emission. Further, since the cathode substrate is fixed by being sandwiched between the metal lid body and the metal supporting plate by being fixed, it is not necessary to fix the cathode substrate to the metal lid body or the metal supporting plate by welding or brazing. Therefore, the adverse effect of the brazing material or welding on the cathode substrate can be eliminated, which is extremely advantageous for improving the reliability of the impregnated cathode.

【図面の簡単な説明】 第1図は本発明の一実施例になる含浸形カソードの断面
模型図、第2図および第3図は従来の含浸形カソードの
それぞれ一構成例を示す断面模型図である。 1……カソード基体、1B……カソード基体の凸部、3…
…スリーブ、4……ヒータ、5……高融点金属からなる
金属支持板、6……高融点金属からなる金属蓋体。
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic sectional view of an impregnated cathode according to an embodiment of the present invention, and FIGS. 2 and 3 are schematic sectional views showing respective constitutional examples of a conventional impregnated cathode. Is. 1 ... Cathode substrate, 1B ... Convex portion of cathode substrate, 3 ...
... Sleeve, 4 ... Heater, 5 ... Metal support plate made of refractory metal, 6 ... Metal lid made of refractory metal.

Claims (1)

【特許請求の範囲】[Claims] 【請求項1】電子放出物質が含浸された高融点金属から
なるカソード基体と、このカソード基体が上部内周面に
挿入,固着された高融点金属からなるカソード・スリー
ブとを少なくとも具備する含浸形カソードにおいて、上
記カソード基体の電子放出面側に凸部を設け、該凸部の
天頂面を電子放出面とし、該電子放出面以外をカバーす
る高融点金属からなる金属蓋体と障壁層である金属支持
板とにより上記カソード基体を挾みこみ、上記金属蓋体
と金属支持板との接合面を溶接又はロウ付により固着し
てなることを特徴とする含浸形カソード。
1. An impregnated type comprising at least a cathode base made of a refractory metal impregnated with an electron emitting substance, and a cathode sleeve made of a refractory metal inserted and fixed to an inner peripheral surface of the upper part of the cathode base. In the cathode, a convex portion is provided on the electron emission surface side of the cathode substrate, and the zenith surface of the convex portion serves as an electron emission surface, and is a metal lid body and a barrier layer made of a refractory metal that covers other than the electron emission surface. An impregnated cathode characterized in that the cathode substrate is sandwiched by a metal supporting plate, and the joint surface between the metal lid and the metal supporting plate is fixed by welding or brazing.
JP5914586A 1986-03-19 1986-03-19 Impregnated type cathode Expired - Fee Related JPH0821309B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP5914586A JPH0821309B2 (en) 1986-03-19 1986-03-19 Impregnated type cathode

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP5914586A JPH0821309B2 (en) 1986-03-19 1986-03-19 Impregnated type cathode

Publications (2)

Publication Number Publication Date
JPS62217525A JPS62217525A (en) 1987-09-25
JPH0821309B2 true JPH0821309B2 (en) 1996-03-04

Family

ID=13104872

Family Applications (1)

Application Number Title Priority Date Filing Date
JP5914586A Expired - Fee Related JPH0821309B2 (en) 1986-03-19 1986-03-19 Impregnated type cathode

Country Status (1)

Country Link
JP (1) JPH0821309B2 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0511290U (en) * 1991-07-30 1993-02-12 関西日本電気株式会社 Impregnated cathode structure
CN102632312B (en) * 2012-03-30 2015-04-22 安徽华东光电技术研究所 Method for rapidly filling impregnated cathode alloy solder

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5745642U (en) * 1980-08-28 1982-03-13
JPS58111236A (en) * 1981-12-25 1983-07-02 Toshiba Corp Electron gun structure

Also Published As

Publication number Publication date
JPS62217525A (en) 1987-09-25

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